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Sample records for 5-hydroxymethyl furfural hmf

  1. A validated fast difference spectrophotometric method for 5-hydroxymethyl-2-furfural (HMF) determination in corn syrups.

    PubMed

    de Andrade, Jucimara Kulek; de Andrade, Camila Kulek; Komatsu, Emy; Perreault, Hélène; Torres, Yohandra Reyes; da Rosa, Marcos Roberto; Felsner, Maria Lurdes

    2017-08-01

    Corn syrups, important ingredients used in food and beverage industries, often contain high levels of 5-hydroxymethyl-2-furfural (HMF), a toxic contaminant. In this work, an in house validation of a difference spectrophotometric method for HMF analysis in corn syrups was developed using sophisticated statistical tools by the first time. The methodology showed excellent analytical performance with good selectivity, linearity (R(2)=99.9%, r>0.99), accuracy and low limits (LOD=0.10mgL(-1) and LOQ=0.34mgL(-1)). An excellent precision was confirmed by repeatability (RSD (%)=0.30) and intermediate precision (RSD (%)=0.36) estimates and by Horrat value (0.07). A detailed study of method precision using a nested design demonstrated that variation sources such as instruments, operators and time did not interfere in the variability of results within laboratory and consequently in its intermediate precision. The developed method is environmentally friendly, fast, cheap and easy to implement resulting in an attractive alternative for corn syrups quality control in industries and official laboratories.

  2. Ameliorative effects of 5-hydroxymethyl-2-furfural (5-HMF) from Schisandra chinensis on alcoholic liver oxidative injury in mice.

    PubMed

    Li, Wei; Qu, Xin-Nan; Han, Ye; Zheng, Si-Wen; Wang, Jia; Wang, Ying-Ping

    2015-01-22

    The aim of this paper is to evaluate the protective effect of 5-hydroxymethyl-2-furfural (5-HMF) on acute alcohol-induced liver oxidative injury in mice. 5-HMF, a maillard reaction product, was isolated from the fruits of Schisandra chinensis for animal experiments. Experimental ICR mice were pretreated with different doses of 5-HMF (7.5, 15, and 30 mg/kg) for seven days by gavage feeding. Biochemical markers and enzymatic antioxidants from serum and liver tissue were examined. Our results showed that the activities of ALT (alanine aminotransferase), AST (aspartate transaminase), TC (total cholesterol), TG (triglyceride), L-DLC (low density lipoprotein) in serum and the levels of MDA (malondialdehyde) in liver tissue, decreased significantly (p < 0.05) in the 5-HMF-treated group compared with the alcohol group. On the contrary, enzymatic antioxidants CAT (catalase), GSH-Px (glutathione peroxidase), and GSH SOD (superoxide dismutase) were markedly elevated in liver tissue treated with 5-HMF (p < 0.05). Furthermore, the hepatic levels of pro-inflammatory response marker tumor necrosis factor-alpha (TNF-α) and interleukin-1β (IL-1β) were significantly suppressed (p < 0.05). Histopathological examination revealed that 5-HMF (30 mg/kg) pretreatment noticeably prevented alcohol-induced hepatocyte apoptosis and fatty degeneration. It is suggested that the hepatoprotective effects exhibited by 5-HMF on alcohol-induced liver oxidative injury may be due to its potent antioxidant properties.

  3. Ameliorative Effects of 5-Hydroxymethyl-2-furfural (5-HMF) from Schisandra chinensis on Alcoholic Liver Oxidative Injury in Mice

    PubMed Central

    Li, Wei; Qu, Xin-Nan; Han, Ye; Zheng, Si-Wen; Wang, Jia; Wang, Ying-Ping

    2015-01-01

    The aim of this paper is to evaluate the protective effect of 5-hydroxymethyl-2-furfural (5-HMF) on acute alcohol-induced liver oxidative injury in mice. 5-HMF, a maillard reaction product, was isolated from the fruits of Schisandra chinensis for animal experiments. Experimental ICR mice were pretreated with different doses of 5-HMF (7.5, 15, and 30 mg/kg) for seven days by gavage feeding. Biochemical markers and enzymatic antioxidants from serum and liver tissue were examined. Our results showed that the activities of ALT (alanine aminotransferase), AST (aspartate transaminase), TC (total cholesterol), TG (triglyceride), L-DLC (low density lipoprotein) in serum and the levels of MDA (malondialdehyde) in liver tissue, decreased significantly (p < 0.05) in the 5-HMF-treated group compared with the alcohol group. On the contrary, enzymatic antioxidants CAT (catalase), GSH-Px (glutathione peroxidase), and GSH SOD (superoxide dismutase) were markedly elevated in liver tissue treated with 5-HMF (p < 0.05). Furthermore, the hepatic levels of pro-inflammatory response marker tumor necrosis factor-alpha (TNF-α) and interleukin-1β (IL-1β) were significantly suppressed (p < 0.05). Histopathological examination revealed that 5-HMF (30 mg/kg) pretreatment noticeably prevented alcohol-induced hepatocyte apoptosis and fatty degeneration. It is suggested that the hepatoprotective effects exhibited by 5-HMF on alcohol-induced liver oxidative injury may be due to its potent antioxidant properties. PMID:25622257

  4. A 5-hydroxymethyl furfural reducing enzyme encoded by the Saccharomyces cerevisiae ADH6 gene conveys HMF tolerance.

    PubMed

    Petersson, Anneli; Almeida, João R M; Modig, Tobias; Karhumaa, Kaisa; Hahn-Hägerdal, Bärbel; Gorwa-Grauslund, Marie F; Lidén, Gunnar

    2006-04-30

    The fermentation of lignocellulose hydrolysates by Saccharomyces cerevisiae for fuel ethanol production is inhibited by 5-hydroxymethyl furfural (HMF), a furan derivative which is formed during the hydrolysis of lignocellulosic materials. The inhibition can be avoided if the yeast strain used in the fermentation has the ability to reduce HMF to 5-hydroxymethylfurfuryl alcohol. To enable the identification of enzyme(s) responsible for HMF conversion in S. cerevisiae, microarray analyses of two strains with different abilities to convert HMF were performed. Based on the expression data, a subset of 15 reductase genes was chosen to be further examined using an overexpression strain collection. Three candidate genes were cloned from two different strains, TMB3000 and the laboratory strain CEN.PK 113-5D, and overexpressed using a strong promoter in the strain CEN.PK 113-5D. Strains overexpressing ADH6 had increased HMF conversion activity in cell-free crude extracts with both NADPH and NADH as co-factors. In vitro activities were recorded of 8 mU/mg with NADH as co-factor and as high as 1200 mU/mg for the NADPH-coupled reduction. Yeast strains overexpressing ADH6 also had a substantially higher in vivo conversion rate of HMF in both aerobic and anaerobic cultures, showing that the overexpression indeed conveyed the desired increased reduction capacity.

  5. Method to convert biomass to 5-(hydroxymethyl)-furfural (HMF) and furfural using lactones, furans, and pyrans as solvents

    DOEpatents

    Dumesic, James A.; Ribeiro Gallo, Jean Marcel; Alonso, David

    2014-07-08

    Described is a process to produce hydroxymethyl furfural (HMF) from biomass-derived sugars. The process includes the steps of reacting a C5 and/or C6 sugar-containing reactant derived from biomass in a monophasic or biphasic reaction solution comprising water and a co-solvent. The co-solvent can be beta-, gamma-, and/or delta-lactones derived from biomass, tetrahydrofuran (THF) derived from biomass, and/or methyltetrahydrofuran (MTHF) derived from biomass. The reaction takes place in the presence of an acid catalyst and a dehydration catalyst for a time and under conditions such that at least a portion of glucose or fructose present in the reactant is converted to HMF.

  6. In house validation from direct determination of 5-hydroxymethyl-2-furfural (HMF) in Brazilian corn and cane syrups samples by HPLC-UV.

    PubMed

    de Andrade, Jucimara K; Komatsu, Emy; Perreault, Hélène; Torres, Yohandra R; da Rosa, Marcos R; Felsner, Maria L

    2016-01-01

    In this work the development and in house validation of the HMF direct determination in corn and cane syrups by HPLC-UV was carried out for the first time. The separation was done with isocratic elution of a mobile phase comprising water (with 0.5% formic acid) and acetonitrile (90:10, v/v) on Phenomenex C18 column (5.0 μm, 4.6 × 150 mm), at 30 °C, flow rate of 0.8 mL min(-1) and detection at 285 nm. The validated method showed excellent performance with low limits (LOD and LOQ of 0.09 and 0.26 mg L(-1), respectively), good accuracy (recovery rates between 100% and 104%) and precision (RSD's for repeatability and intermediate precision between 0.57% and 6.43%). Good selectivity and linearity were also observed. HMF contents in both foods were very high (406.6-2121.3 mg kg(-1) for corn syrup and 109.2-893.1 mg kg(-1) for cane syrup), which arouses concern about food safety of these products.

  7. Isolation, structural elucidation, and biological evaluation of a 5-hydroxymethyl-2-furfural derivative, asfural, from enzyme-treated asparagus extract.

    PubMed

    Ito, Tomohiro; Sato, Atsuya; Ono, Tomoko; Goto, Kazunori; Maeda, Takahiro; Takanari, Jun; Nishioka, Hiroshi; Komatsu, Kenichi; Matsuura, Hideyuki

    2013-09-25

    A novel 5-hydroxymethyl-2-furfural (HMF; 1) derivative, which is named asfural (compound 2), was isolated from enzyme-treated asparagus extract (ETAS) along with HMF (1) as a heat shock protein 70 (HSP70) inducible compound. The structure of compound 2 was elucidated on the basis of its spectroscopic data from HREIMS and NMR, whereas the absolute configuration was determined using chiral HPLC analysis, compared to two synthesized compounds, (S)- and (R)-asfural. As a result, compound 2 derived from ETAS was assigned as (S)-(2-formylfuran-5-yl)methyl 5-oxopyrrolidine-2-carboxylate. When compound 2, synthesized (S)- and (R)-asfural, and HMF (1) were evaluated in terms of HSP70 mRNA expression-enhancing activity in HL-60 cells, compound 2 and (S)-asfural significantly increased the expression level in a concentration-dependent manner. HMF (1) also showed significant activity at 0.25 mg/mL.

  8. Metal-free dehydration of glucose to 5-(hydroxymethyl)furfural in ionic liquids with boric acid as a promoter.

    PubMed

    Ståhlberg, Tim; Rodriguez-Rodriguez, Sergio; Fristrup, Peter; Riisager, Anders

    2011-02-01

    The dehydration of glucose and other hexose carbohydrates to 5-(hydroxymethyl)furfural (HMF) was investigated in imidazolium-based ionic liquids with boric acid as a promoter. A yield of up to 42% from glucose and as much as 66% from sucrose was obtained. The yield of HMF decreased as the concentration of boric acid exceeded one equivalent, most likely as a consequence of stronger fructose-borate chelate complexes being formed. Computational modeling with DFT calculations confirmed that the formation of 1:1 glucose-borate complexes facilitated the conversion pathway from glucose to fructose. Deuterium-labeling studies elucidated that the isomerization proceeded via an ene-diol mechanism, which is different to that of the enzyme-catalyzed isomerization of glucose to fructose. The introduced non-metal system containing boric acid provides a new direction in the search for catalyst systems allowing efficient HMF formation from biorenewable sources.

  9. Developing an effective means to reduce 5-hydroxymethyl-2-furfural from caramel colour.

    PubMed

    Guan, Yongguang; Chen, Mingshun; Yu, Shujuan; Tang, Qiang; Yan, He

    2014-01-15

    Supercritical carbon dioxide fluid extraction was used to extract 5-hydroxymethyl-2-furfural from caramel colour (solid content was about 75%). The procedure was carried out by response surface methodology using a quadratic polynomial model. Extraction pressure, time, temperature and ethanol content were selected as the independent variables. Conditions to obtain the highest extraction ratio of 5-hydroxymethyl-2-furfural were determined to be an extraction pressure of 21.65MPa, time of 46.7min, temperature of 35°C and 70% ethanol content of caramel colour. The predicted 5-hydroxymethyl-2-furfural extraction ratio was 87.42%. Under the conditions stated above, the experimental value of 5-hydroxymethyl-2-furfural extraction ratio was 86.98%, which was similar to the predicted value by the model. This study indicated that supercritical carbon dioxide fluid extraction can effectively reduce 5-hydroxymethyl-2-furfural from caramel colour, which can help food industry to improve the safety of the food material, as well as provide more healthy caramel colour for human beings.

  10. Bis-sulfonic acid ionic liquids for the conversion of fructose to 5-hydroxymethyl-2-furfural.

    PubMed

    Sim, Sang Eun; Kwon, Sunjeong; Koo, Sangho

    2012-10-31

    Homogenous bis-sulfonic acid ionic liquids (1 mol equiv.) in DMSO (10 mol equiv.) at 100 °C efficiently mediated the conversion of D-fructose into 5-hydroxymethyl-2-furfural in 75% isolated yield, which was roughly a 10% increment compared to the case of the mono-sulfonic acid ionic liquids.

  11. Protein Engineering of GRE2 from Saccharomyces cerevisiae for Enhanced Detoxification of 5-Hydroxymethyl Furfural

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Furfural and 5-hydroxymethylfurfural (HMF) are representative inhibitors generated by lignocellulosic biomass pretreatment such as dilute acid hydrolysis that inhibit microbial growth and subsequent fermentation. It is possible to in situ detoxify these inhibitory compounds using tolerant Saccharomy...

  12. Organocatalytic Upgrading of Furfural and 5-Hydroxymethyl Furfural to C10 and C12 Furoins with Quantitative Yield and Atom-Efficiency

    PubMed Central

    Zang, Hongjun; Chen, Eugene Y. X.

    2015-01-01

    There is increasing interest in the upgrading of C5 furfural (FF) and C6 5-hydroxymethyl furfural (HMF) into C10 and C12 furoins as higher energy-density intermediates for renewable chemicals, materials, and biofuels. This work utilizes the organocatalytic approach, using the in situ generated N,S-heterocyclic carbene catalyst derived from thiazolium ionic liquids (ILs), to achieve highly efficient self-coupling reactions of FF and HMF. Specifically, variations of the thiazolium IL structure have led to the most active and efficient catalyst system of the current series, which is derived from a new thiazolium IL carrying the electron-donating acetate group at the 5-ring position. For FF coupling by this IL (0.1 mol %, 60 °C, 1 h), when combined with Et3N, furoin was obtained in >99% yield. A 97% yield of the C12 furoin was also achieved from the HMF coupling by this catalyst system (10 mol % loading, 120 °C, 3 h). On the other hand, the thiazolium IL bearing the electron-withdrawing group at the 5-ring position is the least active and efficient catalyst. The mechanistic aspects of the coupling reaction by the thiazolium catalyst system have also been examined and a mechanism has been proposed. PMID:25830482

  13. Quantitative determination of caffeine, formic acid, trigonelline and 5-(hydroxymethyl)furfural in soluble coffees by 1H NMR spectrometry.

    PubMed

    del Campo, Gloria; Berregi, Iñaki; Caracena, Raúl; Zuriarrain, Juan

    2010-04-15

    A quantitative method for the determination of caffeine, formic acid, trigonelline and 5-(hydroxymethyl)furfural (5-HMF) in soluble coffees by applying the proton nuclear magnetic resonance technique ((1)H NMR) is proposed. Each of these compounds records a singlet signal at the 7.6-9.5 ppm interval of the spectrum, and its area is used to determine the concentration. 3-(Trimethylsilyl)-2,2,3,3-tetradeuteropropionic acid is added in an exact known concentration as a reference for delta=0.00 ppm and as an internal standard. The method is applied to commercial soluble coffees and satisfactorily compared with results obtained by standard methods. The limits of detection and the coefficients of variation (N=10) are, respectively, 1.32 mg/g of solid product and 4.2% for caffeine, 0.45 mg/g and 2.6% for formic acid, 0.58 mg/g and 2.4% for trigonelline, and 0.30 mg/g and 7.3% for 5-HMF. The described method is direct and no previous derivatization is needed.

  14. Effects of 5-hydroxymethyl-2-furfural on the volume and membrane permeability of red blood cells from patients with sickle cell disease.

    PubMed

    Hannemann, Anke; Cytlak, Urszula M; Rees, David C; Tewari, Sanjay; Gibson, John S

    2014-09-15

    The heterocyclic aldehyde 5-hydroxymethyl-2-furfural (5HMF) interacts allosterically with the abnormal form of haemoglobin (Hb), HbS, in red blood cells (RBCs) from patients with sickle cell disease (SCD), thereby increasing oxygen affinity and decreasing HbS polymerization and RBC sickling during hypoxia. We hypothesized that should 5HMF also inhibit the main cation pathways implicated in the dehydration of RBCs from SCD patients - the deoxygenation-induced cation pathway (Psickle), the Ca(2+)-activated K(+) channel (the Gardos channel) and the K(+)-Cl(-) cotransporter (KCC) - it would have a synergistic effect in protection against sickling, directly through interacting with HbS, and indirectly through maintaining hydration and reducing [HbS]. This study was therefore designed to investigate the effects of 5HMF on RBC volume and K(+) permeability in vitro. 5HMF markedly reduced the deoxygenation-induced dehydration of RBCs whether in response to maintained deoxygenation or to cyclical deoxygenation/re-oxygenation. 5HMF was found to inhibit Psickle, an effect which correlated with its effects on sickling. Deoxygenation-induced activation of the Gardos channel and exposure of phosphatidylserine were also inhibited, probably indirectly via reduced entry of Ca(2+) through the Psickle pathway. Effects of 5HMF on KCC were more modest with a slight inhibition in N-ethylmaleimide (NEM, 1 mm)-treated RBCs and stimulation in RBCs untreated with NEM. These findings support the hypothesis that 5HMF may also be beneficial through effects on RBC ion and water homeostasis.

  15. Impact of flavour solvent (propylene glycol or triacetin) on vanillin, 5-(hydroxymethyl)furfural, 2,4-decadienal, 2,4-heptadienal, structural parameters and sensory perception of shortcake biscuits over accelerated shelf life testing.

    PubMed

    Yang, Ni; Hort, Joanne; Linforth, Robert; Brown, Keith; Walsh, Stuart; Fisk, Ian D

    2013-11-15

    The influence of choice of flavour solvent, propylene glycol (PG) or triacetin (TA), was investigated during accelerated shelf life (ASL) testing of shortcake biscuits. Specifically, the differential effect on the stability of added vanillin, the natural baked marker compound 5-(hydroxymethyl)furfural (HMF), specific markers of oxidative rancidity (2,4-decadienal, 2,4-heptadienal), and the structural parameters of hardness and fracturability. Significantly more HMF was formed during baking of biscuits prepared with TA; these biscuits were also more stable to oxidative degradation and loss of vanillin during ageing than biscuits prepared with PG. Fresh TA biscuits were significantly more brittle than fresh PG biscuits. There was no impact of solvent choice on hardness. Sensory evaluation of hardness, vanilla flavour and oily off-note was tested during ASL testing. There was no significant impact of storage on sensory ratings for either the PG or TA biscuits.

  16. A continuous flow strategy for the coupled transfer hydrogenation and etherification of 5-(hydroxymethyl)furfural using Lewis acid zeolites.

    PubMed

    Lewis, Jennifer D; Van de Vyver, Stijn; Crisci, Anthony J; Gunther, William R; Michaelis, Vladimir K; Griffin, Robert G; Román-Leshkov, Yuriy

    2014-08-01

    Hf-, Zr- and Sn-Beta zeolites effectively catalyze the coupled transfer hydrogenation and etherification of 5-(hydroxymethyl)furfural with primary and secondary alcohols into 2,5-bis(alkoxymethyl)furans, thus making it possible to generate renewable fuel additives without the use of external hydrogen sources or precious metals. Continuous flow experiments reveal nonuniform changes in the relative deactivation rates of the transfer hydrogenation and etherification reactions, which impact the observed product distribution over time. We found that the catalysts undergo a drastic deactivation for the etherification step while maintaining catalytic activity for the transfer hydrogenation step. (119) Sn and (29) Si magic angle spinning (MAS) NMR studies show that this deactivation can be attributed to changes in the local environment of the metal sites. Additional insights were gained by studying effects of various alcohols and water concentration on the catalytic reactivity.

  17. Insights into the interplay of Lewis and Brønsted acid catalysts in glucose and fructose conversion to 5-(hydroxymethyl)furfural and levulinic acid in aqueous media.

    PubMed

    Choudhary, Vinit; Mushrif, Samir H; Ho, Christopher; Anderko, Andrzej; Nikolakis, Vladimiros; Marinkovic, Nebojsa S; Frenkel, Anatoly I; Sandler, Stanley I; Vlachos, Dionisios G

    2013-03-13

    5-(Hydroxymethyl)furfural (HMF) and levulinic acid production from glucose in a cascade of reactions using a Lewis acid (CrCl3) catalyst together with a Brønsted acid (HCl) catalyst in aqueous media is investigated. It is shown that CrCl3 is an active Lewis acid catalyst in glucose isomerization to fructose, and the combined Lewis and Brønsted acid catalysts perform the isomerization and dehydration/rehydration reactions. A CrCl3 speciation model in conjunction with kinetics results indicates that the hydrolyzed Cr(III) complex [Cr(H2O)5OH](2+) is the most active Cr species in glucose isomerization and probably acts as a Lewis acid-Brønsted base bifunctional site. Extended X-ray absorption fine structure spectroscopy and Car-Parrinello molecular dynamics simulations indicate a strong interaction between the Cr cation and the glucose molecule whereby some water molecules are displaced from the first coordination sphere of Cr by the glucose to enable ring-opening and isomerization of glucose. Additionally, complex interactions between the two catalysts are revealed: Brønsted acidity retards aldose-to-ketose isomerization by decreasing the equilibrium concentration of [Cr(H2O)5OH](2+). In contrast, Lewis acidity increases the overall rate of consumption of fructose and HMF compared to Brønsted acid catalysis by promoting side reactions. Even in the absence of HCl, hydrolysis of Cr(III) decreases the solution pH, and this intrinsic Brønsted acidity drives the dehydration and rehydration reactions. Yields of 46% levulinic acid in a single phase and 59% HMF in a biphasic system have been achieved at moderate temperatures by combining CrCl3 and HCl.

  18. Dynamic model-based analysis of furfural and HMF detoxification by pure and mixed batch cultures of S. cerevisiae and S. stipitis.

    PubMed

    Hanly, Timothy J; Henson, Michael A

    2014-02-01

    Inhibitory compounds that result from biomass hydrolysis are an obstacle to the efficient production of second-generation biofuels. Fermentative microorganisms can reduce compounds such as furfural and 5-hydroxymethyl furfural (HMF), but detoxification is accompanied by reduced growth rates and ethanol yields. In this study, we assess the effects of these furan aldehydes on pure and mixed yeast cultures consisting of a respiratory deficient mutant of Saccharomyces cerevisiae and wild-type Scheffersomyces stipitis using dynamic flux balance analysis. Uptake kinetics and stoichiometric equations for the intracellular reduction reactions associated with each inhibitor were added to genome-scale metabolic reconstructions of the two yeasts. Further modification of the S. cerevisiae metabolic network was necessary to satisfactorily predict the amount of acetate synthesized during HMF reduction. Inhibitory terms that captured the adverse effects of the furan aldehydes and their corresponding alcohols on cell growth and ethanol production were added to attain qualitative agreement with batch experiments conducted for model development and validation. When the two yeasts were co-cultured in the presence of the furan aldehydes, inoculums that reduced the synthesis of highly toxic acetate produced by S. cerevisiae yielded the highest ethanol productivities. The model described here can be used to generate optimal fermentation strategies for the simultaneous detoxification and fermentation of lignocellulosic hydrolysates by S. cerevisiae and/or S. stipitis.

  19. Acquired tolerance and in situ detoxification of furfural and HMF through glucose metabolic pathways by Saccharomyces cerevisiae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lignocellulosic biomass conversion inhibitors furfural and HMF inhibit microbial growth and interfere with subsequent fermentation of ethanol. Numerous yeast genes were found to be associated with the inhibitor tolerance. However, little is known about system mechanisms of the tolerance and detoxi...

  20. The influence of HMF and furfural on redox-balance and energy-state of xylose-utilizing Saccharomyces cerevisiae

    PubMed Central

    2013-01-01

    Background Pretreatment of biomass for lignocellulosic ethanol production generates compounds that can inhibit microbial metabolism. The furan aldehydes hydroxymethylfurfural (HMF) and furfural have received increasing attention recently. In the present study, the effects of HMF and furfural on redox metabolism, energy metabolism and gene expression were investigated in anaerobic chemostats where the inhibitors were added to the feed-medium. Results By cultivating the xylose-utilizing Saccharomyces cerevisiae strain VTT C-10883 in the presence of HMF and furfural, it was found that the intracellular concentrations of the redox co-factors and the catabolic and anabolic reduction charges were significantly lower in the presence of furan aldehydes than in cultivations without inhibitors. The catabolic reduction charge decreased from 0.13(±0.005) to 0.08(±0.002) and the anabolic reduction charge decreased from 0.46(±0.11) to 0.27(±0.02) when HMF and furfural were present. The intracellular ATP concentration was lower when inhibitors were added, but resulted only in a modest decrease in the energy charge from 0.87(±0.002) to 0.85(±0.004) compared to the control. Transcriptome profiling followed by MIPS functional enrichment analysis of up-regulated genes revealed that the functional group “Cell rescue, defense and virulence” was over-represented when inhibitors were present compared to control cultivations. Among these, the ATP-binding efflux pumps PDR5 and YOR1 were identified as important for inhibitor efflux and possibly a reason for the lower intracellular ATP concentration in stressed cells. It was also found that genes involved in pseudohyphal growth were among the most up-regulated when inhibitors were present in the feed-medium suggesting nitrogen starvation. Genes involved in amino acid metabolism, glyoxylate cycle, electron transport and amino acid transport were enriched in the down-regulated gene set in response to HMF and furfural. It was

  1. Pulsed addition of HMF and furfural to batch-grown xylose-utilizing Saccharomyces cerevisiae results in different physiological responses in glucose and xylose consumption phase

    PubMed Central

    2013-01-01

    Background Pretreatment of lignocellulosic biomass generates a number of undesired degradation products that can inhibit microbial metabolism. Two of these compounds, the furan aldehydes 5-hydroxymethylfurfural (HMF) and 2-furaldehyde (furfural), have been shown to be an impediment for viable ethanol production. In the present study, HMF and furfural were pulse-added during either the glucose or the xylose consumption phase in order to dissect the effects of these inhibitors on energy state, redox metabolism, and gene expression of xylose-consuming Saccharomyces cerevisiae. Results Pulsed addition of 3.9 g L-1 HMF and 1.2 g L-1 furfural during either the glucose or the xylose consumption phase resulted in distinct physiological responses. Addition of furan aldehydes in the glucose consumption phase was followed by a decrease in the specific growth rate and the glycerol yield, whereas the acetate yield increased 7.3-fold, suggesting that NAD(P)H for furan aldehyde conversion was generated by acetate synthesis. No change in the intracellular levels of NAD(P)H was observed 1 hour after pulsing, whereas the intracellular concentration of ATP increased by 58%. An investigation of the response at transcriptional level revealed changes known to be correlated with perturbations in the specific growth rate, such as protein and nucleotide biosynthesis. Addition of furan aldehydes during the xylose consumption phase brought about an increase in the glycerol and acetate yields, whereas the xylitol yield was severely reduced. The intracellular concentrations of NADH and NADPH decreased by 58 and 85%, respectively, hence suggesting that HMF and furfural drained the cells of reducing power. The intracellular concentration of ATP was reduced by 42% 1 hour after pulsing of inhibitors, suggesting that energy-requiring repair or maintenance processes were activated. Transcriptome profiling showed that NADPH-requiring processes such as amino acid biosynthesis and sulfate and

  2. Furfural

    Integrated Risk Information System (IRIS)

    Furfural ; CASRN 98 - 01 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effects )

  3. Flow Injection Analysis of 5-(Hydroxymethyl)-2-furaldehyde in Honey by a Modified Winkler Method.

    PubMed

    Castoldi, Karine; Milani, Maria Izabel; Rossini, Eduardo L; Pezza, Leonardo; Pezza, Helena R

    2016-01-01

    One of the quality indicators for honey is 5-(hydroxymethyl)-2-furaldehyde (HMF), which is formed during the heating or aging of honey. The International Honey Commission recommends three methods for the determination of HMF in honey: the Winkler method, the White method, and determination by HPLC. The Winkler method uses the carcinogenic substance p-toluidine, which is not in accordance with the principles of Green Chemistry. The present work describes the determination of HMF in honey by flow injection analysis (FIA) using a modified Winkler method, replacing p-toluidine with p-aminobenzoic acid. The linear range was 1.00 to 40.0 mg L(-1), the limit of detection (LOD) was 0.43 mg L(-1), and the limit of quantification (LOQ) was 1.32 mg L(-1). The method is an efficient and environmentally friendly technique for the analysis of HMF in honey.

  4. Rapid and complete urinary elimination of (/sup 14/C)-5-hydroxymethyl-2-furaldehyde administered orally or intravenously to rats

    SciTech Connect

    Germond, J.E.; Philippossian, G.; Richli, U.; Bracco, I.; Arnaud, M.J.

    1987-01-01

    5-Hydroxymethyl-2-furaldehyde (HMF), is a major product of sugar degradation found in food and solutions used in parenteral nutrition. Labeled (/sup 14/C)HMF was synthesized by dehydration of (/sup 14/C)fructose on ion-exchange resin and administered per os (po) and intravenously (iv) to rats. Metabolic balance of radioactivity demonstrated that HMF or its metabolites are rapidly eliminated in the urine with a recovery of 95-100% after 24 h. Literature reported, in some cases, 50% retention in the body. HMF was completely converted to two metabolites, which have been identified by nuclear magnetic resonance (NMR) and mass spectroscopy (MS) as 5-hydroxymethyl-2-furoic acid and N-(5-hydroxymethyl-2-furoyl)glycine. Administration of high doses of HMF showed a similar rapid elimination, but a proportional reduction of the amount of the glycine conjugate produced. Whole-animal-body autoradiography confirm that shortly after administration radioactive material was present in the liver but was mostly in the kidney and the bladder. The only significant difference between po and iv administration was the presence of a higher level of radioactive material in the brain of iv-treated rats.

  5. Content and evolution of potential furfural compounds in commercial milk-based infant formula powder after opening the packet.

    PubMed

    Chávez-Servín, Jorge L; de la Torre Carbot, Karina; García-Gasca, Teresa; Castellote, Ana I; López-Sabater, M Carmen

    2015-01-01

    Potential furfural compounds were examined by RP-HPLC-DAD in 20 commercial milk-based powdered infant formula (IF) brands from local markets from Paris, France; DF, Mexico; Copenhagen, Denmark; England, UK; and Barcelona, Spain. We traced the evolution of these compounds after the packets had been opened at 0, 30 and 70 days of storage at room temperature (≈25 °C; minimum 23 °C and maximum 25.5 °C). All formula brands were analysed during the first 3-5 months of their shelf life. The mean values of all IFs for potential 5-hydroxymethyl-2-furaldehyde (HMF)+2-furaldehyde (F) were 1115.2 μg/100 g (just opened), 1157.6 μg/100 g (30 days) and 1344.5 μg/100 g of product (70 days). In general, slight increases of potential furfural contents were observed in most of the studied IFs, which suggests that the Maillard reaction increases after opening the packets. The main furfural compound found was HMF, as expected. The range of potential HMF consumed for an infant about 6 months old feeding only on formula was estimated between 0.63 mg and 3.25 mg per day.

  6. Pretreatment with 5-hydroxymethyl-2-furaldehyde blocks scopolamine-induced learning deficit in contextual and spatial memory in male mice.

    PubMed

    Lee, Younghwan; Gao, Qingtao; Kim, Eunji; Lee, Younghwa; Park, Se Jin; Lee, Hyung Eun; Jang, Dae Sik; Ryu, Jong Hoon

    2015-07-01

    5-Hydroxymethyl-2-furaldehyde (5-HMF) is a compound derived from the dehydration of certain sugars. The aim of the present study was to evaluate the effect of 5-HMF on the cognitive impairment induced by scopolamine, a muscarinic receptor antagonist. To measure various cognitive functions, we conducted the step-through passive avoidance task, the Y-maze task and the Morris water maze task. A single administration of 5-HMF (5 or 10mg/kg, p.o.) significantly attenuates scopolamine-induced cognitive impairment in these behavioral tasks without changes in locomotor activity, and the effect of 5-HMF on scopolamine-induced cognitive impairment was significantly reversed by a sub-effective dose of MK-801, an NMDA receptor antagonist. In addition, a single administration of 5-HMF (10mg/kg, p.o.) enhanced the cognitive performance of normal naïve mice in the passive avoidance task. Furthermore, Western blot analysis revealed that the levels of phosphorylated Ca(2+)/calmodulin-dependent protein kinase II-α (CaMKII) and extracellular signal-regulated kinases (ERK) were significantly enhanced by the single administration of 5-HMF in the hippocampal tissues. Taken together, the present study suggests that 5-HMF may block scopolamine-induced learning deficit and enhance cognitive function via the activation of NMDA receptor signaling, including CaMKII and ERK, and would be an effective candidate against cognitive disorders, such as Alzheimer's disease.

  7. A Possible Freshness Marker for Royal Jelly: Formation of 5-Hydroxymethyl-2-furaldehyde as a Function of Storage Temperature and Time.

    PubMed

    Ciulu, Marco; Floris, Ignazio; Nurchi, Valeria M; Panzanelli, Angelo; Pilo, Maria I; Spano, Nadia; Sanna, Gavino

    2015-04-29

    In this article we present a study of the variability of the concentration of 5-hydroxymethyl-2-furaldehyde (HMF) in natural royal jelly (RJ) as a function of its storage temperature (-18, 4, and 25 °C) and time (up to 9 months after harvesting). For this work HMF is evaluated using an RP-HPLC method we previously assessed. While all RJ samples stored at 4 and -18 °C always showed levels of HMF under the limit of detection (0.13 mg kg(-1)), samples kept at 25 °C showed an exponential increase in the concentration of HMF as a function of the storage time. This behavior and a number of desirable features of the analytical method used (ease of use in routine laboratories, availability of a complete validation protocol specifically developed for RJ, based on consolidated chemical knowledge) allow us to hypothesize the use of HMF as a possible, reliable freshness marker for RJ.

  8. Determination of the main impurities formed after acid hydrolysis of soybean extracts and the in vitro mutagenicity and genotoxicity studies of 5-ethoxymethyl-2-furfural.

    PubMed

    Nemitz, Marina C; Picada, Jaqueline N; da Silva, Juliana; Garcia, Ana Letícia H; Papke, Débora K M; Grivicich, Ivana; Steppe, Martin; von Poser, Gilsane L; Teixeira, Helder F

    2016-09-10

    Soybean acid hydrolyzed extracts are raw-materials widely used for manufacturing of pharmaceuticals and cosmetics products due to their high content of isoflavone aglycones. In the present study, the main sugar degradation products 5-hydroxymethyl-2-furfural (HMF) and 5-ethoxymethyl-2-furfural (EMF) were quantitatively determined after acid hydrolysis of extracts from different soybean cultivars by a validated liquid chromatography method. The furanic compounds determined in samples cover the range of 0.16-0.21mg/mL and 0.22-0.33mg/mL for HMF and EMF, respectively. Complementarily, due to the scarce literature regarding the EMF toxicology, this study also assessed the EMF mutagenicity by the Salmonella/microsome test and genotoxicity by the comet assay. The results revealed that EMF did not show mutagenicity at the range of 50-5000μg/plate in S. typhimurium strains TA98, TA97a, TA100, TA102 and TA1535, but induced DNA damage in HepG2 cells at non-cytotoxic doses of 0.1-1.3mg/mL, mainly by oxidative stress mechanisms. Based on literature of HMF genotoxicity, and considering the EMF genotoxicity results herein shown, purification procedures to remove these impurities from extracts are recommended during healthcare products development to ensure the security of the products.

  9. Analysis of biodegradation performance of furfural and 5-hydroxymethylfurfural by Amorphotheca resinae ZN1

    PubMed Central

    2014-01-01

    Background Furfural and 5-hydroxymethylfurfural (HMF) are the degradation products of lignocellulose during pretreatment operations and significantly inhibit the consequent enzymatic hydrolysis and fermentation processes. The biodetoxification fungus Amorphotheca resinae ZN1 had demonstrated its excellent capacity on degrading lignocellulose derived inhibitors and helped the fermentation processes to achieve high yield of ethanol and biochemicals. Analysis of the biological degradation performance of furfural and HMF by A. resinae ZN1 will provide essential information for their fast and complete removal from the pretreated lignocellulose materials and facilitate the consequent ethanol fermentation. Results The degradation performance of furfural and HMF by A. resinae ZN1 was investigated by capturing intermediate metabolic products at various culture conditions. A. resinae ZN1 converts furfural/HMF into furfuryl/HMF alcohols and furoic/HMF acids simultaneously at aerobic condition, and only the corresponding furfuryl/HMF alcohols are obtained at anaerobic condition. The existence of glucose accelerates the degradation rate of furfural and HMF by A. resinae ZN1 and the cell mass growth rate aerobically. Remarkably, glucose is not consumed before furfural or HMF is degraded to a low threshold concentration. The finding suggests that furfural or HMF has a substrate priority of utilization by A. resinae ZN1 than glucose. This property may help the detoxification of furfural and HMF to be operated without consuming glucose. Conclusions The biological degradation performance of furfural and HMF by A. resinae ZN1 was investigated experimentally. Oxygen supply is important on the complete biodegradation of furfural and HMF by A. resinae ZN1. Furfural or HMF has the priority of substrate utilization than glucose by A. resinae ZN1. This study provided important information for detoxification enhancement and strain modification. PMID:24708699

  10. Solvent effect on pathways and mechanisms for D-fructose conversion to 5-hydroxymethyl-2-furaldehyde: in situ 13C NMR study.

    PubMed

    Kimura, Hiroshi; Nakahara, Masaru; Matubayasi, Nobuyuki

    2013-03-14

    Noncatalytic reactions of D-fructose were kinetically investigated in dimethylsulfoxide (DMSO), water, and methanol as a function of time at temperatures of 30-150 °C by applying in situ (13)C NMR spectroscopy. The products were quantitatively analyzed with distinction of isomeric species by taking advantage of site-selective (13)C labeling technique. In DMSO, D-fructose was converted first into 3,4-dihydroxy-2-dihydroxymethyl-5-hydroxymethyltetrahydrofuran having no double bond in the ring, subsequently into 4-hydroxy-5-hydroxymethyl-4,5-dihydrofuran-2-carbaldehyde having one double bond through dehydration, and finally into 5-hydroxymethyl-2-furaldehyde (5-HMF) having two double bonds. No other reaction pathways were involved, as shown from the carbon mass balance. In water, 5-HMF, the final product in DMSO, was generated with the precursors undetected and furthermore transformed predominantly into formic and levulinic acids and slightly into 1,2,4-benzenetriol accompanied by polymerization. D-glucose was also produced through the reversible transformation of the reactant D-fructose. In methanol, some kinds of anhydro-D-fructoses were generated instead of 5-HMF. The reaction pathways can thus be controlled by taking advantage of the solvent effect. The D-fructose conversion reactions are of the first order with respect to the concentration of D-fructose and proceed on the order of minutes in DMSO but on the order of hours in water and methanol. The rate constant was three orders of magnitude larger in DMSO than in water or methanol.

  11. Investigation on the origin of 5-HMF in Shengmaiyin decoction by RP-HPLC method*

    PubMed Central

    Li, Ying-hua; Lu, Xiu-yang

    2005-01-01

    The origin of 5-HMF (5-hydroxymethyl-2-furaldehyde) in a Shengmaiyin decoction was investigated by the RP-HPLC method below. A C18 column (250 mm×4.6 mm, i.d. 5 μm) with a column temperature of 25 °C was used. The mobile phase was a mixture of ultra-pure water-acetonitrile (95:5, V/V) and the flow rate was 1.0 ml/min. The detection wavelength was 280 nm. The injection volume was 1 μl and the running time was about 20 min. The addition of Schisandra was regulated to assess the contribution of an acid environment to the production of 5-HMF. In order to confirm the role of saccharides in the production of 5-HMF, different amount of fructose was used. The 5-HMF level in decoctions of processed and unprocessed Schisandra was investigated in order to determine the origin of 5-HMF. The results showed that 5-HMF was derived mainly from the decoction of Schisandra only and not the mixed decoction of Ophionpogon and Schisandra. The appearance of 5-HMF is not simply the result of the decomposition of saccharides under the acid environment created by Schisandra, but the processing procedure plays an important role in the production of 5-HMF. PMID:16187416

  12. 5-Hydroxymethyl-oxazolidin-2-one antibacterials. Actelion Pharmaceuticals: WO2008062379.

    PubMed

    Phillips, Oludotun A; Sharaf, Leyla H

    2009-04-01

    The application, WO2008062379, claims chimeric compounds comprising chemically linked 5-hydroxymethyl-oxazolidinone and tetracyclic-quinolone moieties. The claimed compounds are potent expanded-range antibacterial agents against selected gram-positive and gram-negative bacteria, which may exhibit dual mode of action as inhibitors of topoisomarases IV and protein synthesis. The structures of the compounds suggest that the linkers are chemically and biochemically stable. This application represents part of recently initiated research efforts at Actelion.

  13. Over-expression of NADH-dependent oxidoreductase (fucO) for increasing furfural or 5-hydroxymethylfurfural tolerance

    SciTech Connect

    Miller, Elliot N.; Zhang, Xueli; Yomano, Lorraine P.; Wang, Xuan; Shanmugam, Keelnatham T.; Ingram, Lonnie O'Neal

    2015-10-13

    The subject invention pertains to the discovery that the NADH-dependent propanediol oxidoreductase (FucO) can reduce furfural. This allows for a new approach to improve furfural tolerance in bacterial and/or yeast cells used to produce desired products. Thus, novel biocatalysts (bacterial, fungal or yeast cells) exhibiting increased tolerance to furfural and 5-hydroxymethylfurfural (5-HMF) are provided as are methods of making and using such biocatalysts for the production of a desired product.

  14. Transcriptome analysis of Zymomonas mobilis ZM4 reveals mechanisms of tolerance and detoxification of phenolic aldehyde inhibitors from lignocellulose pretreatment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Phenolic aldehydes generated from lignocellulose pretreatment exhibited severe toxic inhibitions on microbial growth and fermentation. Numerous tolerance studies against furfural, 5-hydroxymethyl-2-furaldehyde (HMF), acetate, and ethanol were reported, but studies on inhibition of phenol...

  15. Multiple gene-mediated NAD(P)H-dependent aldehyde reduction is a mechanism of in situ detoxification of furfural and 5-hydroxymethylfurfural by Saccharomyces cerevisiae.

    PubMed

    Liu, Z Lewis; Moon, Jaewoong; Andersh, Brad J; Slininger, Patricia J; Weber, Scott

    2008-12-01

    Furfural and 5-hydroxymethylfurfural (HMF) are representative inhibitors generated from biomass pretreatment using dilute acid hydrolysis that interfere with yeast growth and subsequent fermentation. Few yeast strains tolerant to inhibitors are available. In this study, we report a tolerant strain, Saccharomyces cerevisiae NRRL Y-50049, which has enhanced biotransformation ability to convert furfural to furan methanol (FM), HMF to furan di-methanol (FDM), and produce a normal yield of ethanol. Our recent identification of HMF and development of protocol to synthesize the HMF metabolic conversion product FDM allowed studies on fermentation metabolic kinetics in the presence of HMF and furfural. Individual gene-encoding enzymes possessing aldehyde reduction activities demonstrated cofactor preference for NADH or NADPH. However, protein extract from whole yeast cells showed equally strong aldehyde reduction activities coupled with either cofactor. Deletion of a single candidate gene did not affect yeast growth in the presence of the inhibitors. Our results suggest that detoxification of furfural and HMF by the ethanologenic yeast S. cerevisiae strain Y-50049 likely involves multiple gene mediated NAD(P)H-dependent aldehyde reduction. Conversion pathways of furfural and HMF relevant to glycolysis and ethanol production were refined based on our findings in this study.

  16. 5-hydroxymethylation of the EBV genome regulates the latent to lytic switch

    PubMed Central

    Wille, Coral K.; Nawandar, Dhananjay M.; Henning, Amanda N.; Ma, Shidong; Oetting, Kayla M.; Lee, Dennis; Lambert, Paul; Johannsen, Eric C.; Kenney, Shannon C.

    2015-01-01

    Latent Epstein–Barr virus (EBV) infection and cellular hypermethylation are hallmarks of undifferentiated nasopharyngeal carcinoma (NPC). However, EBV infection of normal oral epithelial cells is confined to differentiated cells and is lytic. Here we demonstrate that the EBV genome can become 5-hydroxymethylated and that this DNA modification affects EBV lytic reactivation. We show that global 5-hydroxymethylcytosine (5hmC)-modified DNA accumulates during normal epithelial-cell differentiation, whereas EBV+ NPCs have little if any 5hmC-modified DNA. Furthermore, we find that increasing cellular ten–eleven translocation (TET) activity [which converts methylated cytosine (5mC) to 5hmC] decreases methylation, and increases 5hmC modification, of lytic EBV promoters in EBV-infected cell lines containing highly methylated viral genomes. Conversely, inhibition of endogenous TET activity increases lytic EBV promoter methylation in an EBV-infected telomerase-immortalized normal oral keratinocyte (NOKs) cell line where lytic viral promoters are largely unmethylated. We demonstrate that these cytosine modifications differentially affect the ability of the two EBV immediate-early proteins, BZLF1 (Z) and BRLF1 (R), to induce the lytic form of viral infection. Although methylation of lytic EBV promoters increases Z-mediated and inhibits R-mediated lytic reactivation, 5hmC modification of lytic EBV promoters has the opposite effect. We also identify a specific CpG-containing Z-binding site on the BRLF1 promoter that must be methylated for Z-mediated viral reactivation and show that TET-mediated 5hmC modification of this site in NOKs prevents Z-mediated viral reactivation. Decreased 5-hydroxymethylation of cellular and viral genes may contribute to NPC formation. PMID:26663912

  17. Effect of cellulosic sugar degradation products (furfural and hydroxymethylfurfural) on acetone-butanol-ethanol (ABE) fermentation using Clostridium beijerinckii P260

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Studies were performed to identify chemicals present in wheat straw hydrolysate (WSH) that enhance acetone butanol ethanol (ABE) productivity. These chemicals were identified as furfural and hydroxymethyl furfural (HMF). Control experiment resulted in the production of 21.09-21.66 gL**-1 ABE with a ...

  18. Enhanced biotransformation of furfural and hydroxymethylfurfural by newly developed ethanologenic yeast strains.

    PubMed

    Liu, Z Lewis; Slininger, Patricia J; Gorsich, Steve W

    2005-01-01

    Furfural and hydroxymethylfurfural (HMF) are representative inhibitors among many inhibitive compounds derived from biomass degradation and saccharification for bioethanol fermentation. Most yeasts, including industrial strains, are susceptible to these inhibitory compounds, especially when multiple inhibitors are present. Additional detoxification steps add cost and complexity to the process and generate additional waste products. To promote efficient bioethanol production, we studied the mechanisms of stress tolerance, particularly to fermentation inhibitors such as furfural and HMF. We recently reported a metabolite of 2,5-bis-hydroxymethylfuran as a conversion product of HMF and characterized a dose-dependent response of ethanologenic yeasts to inhibitors. In this study, we present newly adapted strains that demonstrated higher levels of tolerance to furfural and HMF. Saccharomyces cerevisiae 307-12H60 and 307-12H120 and Pichia stipitis 307 10H60 showed enhanced biotransformation ability to reduce HMF to 2,5-bis-hydroxymethylfuran at 30 and 60 mM, and S. cerevisiae 307-12-F40 converted furfural into furfuryl alcohol at significantly higher rates compared to the parental strains. Strains of S. cerevisiae converted 100% of HMF at 60 mM and S. cerevisiae 307-12-F40 converted 100% of furfural into furfuryl alcohol at 30 mM. The results of this study suggest a possible in situ detoxification of the inhibitors by using more inhibitor-tolerant yeast strains for bioethanol fermentation. The development of such tolerant strains provided a basis and useful materials for further studies on the mechanisms of stress tolerance.

  19. Study of hydroxymethylfurfural and furfural formation in cakes during baking in different ovens, using a validated multiple-stage extraction-based analytical method.

    PubMed

    Petisca, Catarina; Henriques, Ana Rita; Pérez-Palacios, Trinidad; Pinho, Olívia; Ferreira, Isabel M P L V O

    2013-12-15

    A procedure for extraction of hydroxymethylfurfural (HMF) and furfural from cakes was validated. Higher yield was achieved by multiple step extraction with water/methanol (70/30) and clarification with Carrez I and II reagents. Oven type and baking time strongly influenced HMF, moisture and volatile profile of model cakes, whereas furfural content was not significantly affected. No correlation was found between these parameters. Baking time influenced moisture and HMF formation in cakes from traditional and microwave ovens but not in steam oven cakes. Significant moisture decrease and HMF increase (3.63, 9.32, and 41.9 mg kg(-1)dw at 20, 40 and 60 min, respectively) were observed during traditional baking. Cakes baked by microwave also presented a significant increase of HMF (up to 16.84 mg kg(-1)dw at 2.5 min). Steam oven cakes possessed the highest moisture content and no significant differences in HMF and furfural. This oven is likely to form low HMF and furfural, maintaining cake moisture and aroma compounds.

  20. 1H NMR studies of the 5-(hydroxymethyl)-2'-deoxyuridine containing TF1 binding site.

    PubMed Central

    Pasternack, L B; Bramham, J; Mayol, L; Galeone, A; Jia, X; Kearns, D R

    1996-01-01

    The pyrimidine base 5-(hydroxymethyl)-2'-deoxyuridine (HmU) is a common nucleotide in SPO1 phage DNA. Numerous transcriptional proteins bind HmU-containing DNA preferentially implicating a regulatory function of HmU. We have investigated the conformation and dynamics of d-(5'-CHmUCHmUACACGHmUGHmUAGAG-OH-3')2 (HmU-DNA). This oligonucleotide mimics the consensus sequence of Transcription Factor 1 (TF1). The HmU-DNA was compared to the thymine-containing oligonucleotide. NOESY and DQF COSY spectroscopy provided resonance assignments of nonexchangeable and exchangeable protons, intranucleotide, internucleotide and intrastrand proton-proton distances, and dihedral angle constraints. Methylene protons of the hydroxymethyl group are nonequivalent protons and the hydroxymethyl group is not freely rotating. The hydroxymethyl group adopts a specific orientation with the OH group oriented on the 3' side of the plane of the base. Analysis of imino proton resonances and NOEs indicates additional end base pair fraying and a temperature-induced transition to a conformation in which the internal HmU-A base pairs are disrupted or have reduced lifetimes. Orientation of the hydroxymethyl group indicates the presence of internucleotide intrastrand hydrogen bonding between the HmU12C5 hydroxyl group and A13. All sugars in both DNAs show a C2'endo conformation (typical of B-DNA). PMID:8759005

  1. Synthesis of 5-Hydroxymethylcytidine- and 5-Hydroxymethyl-uridine-Modified RNA

    PubMed Central

    Riml, Christian; Micura, Ronald

    2016-01-01

    We report on the syntheses of 5-hydroxymethyl-uridine [5hm(rU)] and -cytidine [5hm(rC)] phosphoramidites and their incorporation into RNA by solid-phase synthesis. Deprotection of the oligonucleotides is accomplished in a straightforward manner using standard conditions, confirming the appropriateness of the acetyl protection used for the pseudobenzylic alcohol moieties. The approach provides robust access to 5hm(rC/U)-modified RNAs that await applications in pull-down experiments to identify potential modification enzymes. They will also serve as synthetic probes for the development of high-throughput-sequencing methods in native RNAs. 1Introduction2Protection Strategies Reported for the Synthesis of 5hm(dC)-Modified DNA3Synthesis of 5-Hydroxymethylpyrimidine-Modified RNA3.1Synthesis of 5hm(rC) Phosphoramidite3.2Synthesis of 5hm(rU) Phosphoramidite3.3Synthesis of 5hm(rC)- and 5hm(rU)-Modified RNA4Conclusions PMID:27413246

  2. 5-(hydroxymethyl)oxazoles: versatile scaffolds for combinatorial solid-phase synthesis of 5-substituted oxazoles.

    PubMed

    Grabowska, U; Rizzo, A; Farnell, K; Quibell, M

    2000-01-01

    A scheme combining the preparation of building blocks in solution followed by solid-phase combinatorial chemistry has been developed to side-chain diversify 5-(hydroxymethyl)oxazole scaffold (1) into aryl ethers, thioethers, sulfones, sulfonamides, and carboxamides. Protected heterocyclic scaffolds 2 were linked to the solid phase and N-terminal derivatized using active ester chemistry, providing chemset 4¿1-4,1-4¿. The free side-chain hydroxyl of 4 was smoothly converted to aryl ethers 6 under Mitsunobu conditions, with a broad range of substituted phenols. Alternatively, quantitative conversion of hydroxyl to bromide followed by displacement with alkyl and aryl thiols gave thioethers 8. Thioethers were optionally oxidized to sulfones 9. Bromide displacement by azide, followed by reduction to amine and acylation with a range of carboxylic acids and sulfonyl chlorides gave carboxamides 11 and sulfonamides 13, respectively. Crude purity at typically >90% was observed for each of the five modifications detailed. A series of 20 compounds, exemplifying each modification, was reprepared, purified, and fully characterized.

  3. Glycerol supplementation of the growth medium enhances in situ detoxification of furfural by Clostridium beijerinckii during butanol fermentation.

    PubMed

    Ujor, Victor; Agu, Chidozie Victor; Gopalan, Venkat; Ezeji, Thaddeus Chukwuemeka

    2014-01-01

    Lignocellulose-derived microbial inhibitors such as furfural and 5-hydroxymethyl furfural adversely affect fermentation of lignocellulosic biomass hydrolysates to fuels and chemicals due to their toxicity on fermenting microbes. To harness the potential of lignocellulose as a cheap source of fermentable sugars, in situ detoxification of furfural and other lignocellulose-derived microbial inhibitors is essential. To enhance in situ detoxification and tolerance of furfural by Clostridium beijerinckii NCIMB 8052 during acetone-butanol-ethanol (ABE) fermentation, the effect of glycerol on NADH/NADPH generation and ABE production by furfural (4, 5, and 6 g/L)-challenged cultures was investigated in this study. In all instances, beneficial outcomes were observed. For example, the fermentation medium supplemented with glycerol and subjected to 5 g/L furfural elicited up to 1.8- and 3-fold increases, respectively, in NADH and NADPH levels in C. beijerinckii 8052 relative to the control culture. These critical changes are the likely underpinnings for the glycerol-mediated 2.3-fold increase in the rate of detoxification of 5 g/L furfural, substrate consumption, and ABE production compared to the unsupplemented medium. Collectively, these results demonstrate that increased intracellular NADH/NADPH in C. beijerinckii 8052 due to glycerol utilization engenders favorable effects on many aspects of cellular metabolism, including enhanced furfural reduction and increased ABE production.

  4. YNL134C from Saccharomyces cerevisiae encodes a novel protein with aldehyde reductase activity for detoxification of furfural derived from lignocellulosic biomass.

    PubMed

    Zhao, Xianxian; Tang, Juan; Wang, Xu; Yang, Ruoheng; Zhang, Xiaoping; Gu, Yunfu; Li, Xi; Ma, Menggen

    2015-05-01

    Furfural and 5-hydroxymethylfurfural (HMF) are the two main aldehyde compounds derived from pentoses and hexoses, respectively, during lignocellulosic biomass pretreatment. These two compounds inhibit microbial growth and interfere with subsequent alcohol fermentation. Saccharomyces cerevisiae has the in situ ability to detoxify furfural and HMF to the less toxic 2-furanmethanol (FM) and furan-2,5-dimethanol (FDM), respectively. Herein, we report that an uncharacterized gene, YNL134C, was highly up-regulated under furfural or HMF stress and Yap1p and Msn2/4p transcription factors likely controlled its up-regulated expression. Enzyme activity assays showed that YNL134C is an NADH-dependent aldehyde reductase, which plays a role in detoxification of furfural to FM. However, no NADH- or NADPH-dependent enzyme activity was observed for detoxification of HMF to FDM. This enzyme did not catalyse the reverse reaction of FM to furfural or FDM to HMF. Further studies showed that YNL134C is a broad-substrate aldehyde reductase, which can reduce multiple aldehydes to their corresponding alcohols. Although YNL134C is grouped into the quinone oxidoreductase family, no quinone reductase activity was observed using 1,2-naphthoquinone or 9,10-phenanthrenequinone as a substrate, and phylogenetic analysis indicates that it is genetically distant to quinone reductases. Proteins similar to YNL134C in sequence from S. cerevisiae and other microorganisms were phylogenetically analysed.

  5. Characterization of two kinases involved in thiamine pyrophosphate and pyridoxal phosphate biosynthesis in Bacillus subtilis: 4-amino-5-hydroxymethyl-2methylpyrimidine kinase and pyridoxal kinase.

    PubMed

    Park, Joo-Heon; Burns, Kristin; Kinsland, Cynthia; Begley, Tadhg P

    2004-03-01

    Two Bacillus subtilis genes encoding two proteins (currently annotated ThiD and YjbV) were overexpressed and characterized. YjbV has 4-amino-5-hydroxymethyl-2-methylpyrimidine and 4-amino-5-hydroxymethyl-2-methylpyrimidine pyrophosphate kinase activity and should be reannotated ThiD, and B. subtilis ThiD has pyridoxine, pyridoxal, and pyridoxamine kinase activity and should be reannotated PdxK.

  6. Effects of Sodium Chloride, Potassium Chloride and Calcium Chloride on the Formation of α-Dicarbonyl Compounds, Furfurals and Development of Browning in Cookies during Baking.

    PubMed

    Kocadağlı, Tolgahan; Gökmen, Vural

    2016-10-02

    Effect of NaCl, KCl, CaCl2, NaHCO3, and NH4HCO3 on the formation of glucosone, 1-deoxyglucosone, 3-deoxyglucosone, glyoxal, methylglyoxal, diacetyl, 5-hydroxymethyl-2-furfural, 2-furfural and browning were investigated in cookies. Presence of 1.5% NaCl, 1% KCl, and 1% CaCl2 on flour basis had no effect on α-dicarbonyl compounds, except 1-deoxyglucosone increased in the presence of KCl and CaCl2. The increase in 5-hydroxymethyl-2-furfural formation in the presence of NaCl, KCl, and CaCl2 did not relate to 3-deoxyglucosone formation and pH changes. NaCl, KCl, and CaCl2 increased browning in cookies. Model reaction systems indicated that NaCl, KCl, and CaCl2 enhance browning by increasing furfurals in caramelization. NaCl, KCl, and CaCl2 decreased browning intensity in heated glucose-glycine system. Usage of CaCl2 in cookies may considerably increase furfurals but not α-dicarbonyl compounds. Sodium reduction can be obtained by replacement with potassium without sacrificing the desired consequences of caramelization in sugar rich bakeries.

  7. Semi-quantitative immunohistochemical detection of 5-hydroxymethyl-cytosine reveals conservation of its tissue distribution between amphibians and mammals.

    PubMed

    Almeida, Rimple D; Sottile, Virginie; Loose, Matthew; De Sousa, Paul A; Johnson, Andrew D; Ruzov, Alexey

    2012-02-01

    5-Hydroxymethyl-cytosine (5-hmC) is a form of modified cytosine, which has recently attracted a considerable attention due to its potential role in transcriptional regulation. According to several reports 5-hydroxymethyl-cytosine distribution is tissue-specific in mammals. Thus, 5-hmC is enriched in embryonic cell populations and in adult neuronal tissue. Here, we describe a novel method of semi-quantitative immunohistochemical detection of 5-hmC and utilize it to assess the levels of this modification in amphibian tissues. We show that, similar to mammalian embryos, 5-hmC is enriched in axolotl tadpoles compared with adult tissues. Our data demonstrate that 5-hmC distribution is tissue-specific in amphibians, and that strong 5-hmC enrichment in neuronal cells is conserved between amphibians and mammals. In addition, we identify 5-hmC-enriched cell populations that are distributed in amphibian skin and connective tissue in a mosaic manner. Our results illustrate that immunochemistry can be successfully used not only for spatial identification of cells enriched with 5-hmC, but also for the semi-quantitative assessment of the levels of this epigenetic modification in single cells of different tissues.

  8. Comparative transcriptome profiling analyses during the lag phase uncover YAP1, PDR1, PDR3, RPN4, and HSF1 as key regulatory genes in genomic adaptation to the lignocellulose derived inhibitor HMF for Saccharomyces cerevisiae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The yeast Saccharomyces cerevisiae is able to adapt and in situ detoxify lignocellulose derived inhibitors such as furfural and hydroxymethylfurfural (HMF). The length of lag phase for cell growth in response to the inhibitor challenge has been used to measure tolerance of strain performance. Mechan...

  9. Inhomogeneous Tsallis distributions in the HMF model

    NASA Astrophysics Data System (ADS)

    Chavanis, P.-H.; Campa, A.

    2010-08-01

    We study the maximization of the Tsallis functional at fixed mass and energy in the Hamiltonian Mean Field (HMF) model. We give a thermodynamical and a dynamical interpretation of this variational principle. This leads to q-distributions known as stellar polytropes in astrophysics. We study phase transitions between spatially homogeneous and spatially inhomogeneous equilibrium states. We show that there exists a particular index qc = 3 playing the role of a canonical tricritical point separating first and second order phase transitions in the canonical ensemble and marking the occurence of a negative specific heat region in the microcanonical ensemble. We apply our results to the situation considered by Antoni and Ruffo [Phys. Rev. E 52, 2361 (1995)] and show that the anomaly displayed on their caloric curve can be explained naturally by assuming that, in this region, the QSSs are polytropes with critical index qc = 3. We qualitatively justify the occurrence of polytropic (Tsallis) distributions with compact support in terms of incomplete relaxation and inefficient mixing (non-ergodicity). Our paper provides an exhaustive study of polytropic distributions in the HMF model and the first plausible explanation of the surprising result observed numerically by Antoni and Ruffo (1995). In the course of our analysis, we also report an interesting situation where the caloric curve presents both microcanonical first and second order phase transitions.

  10. A kinetic study on microwave-assisted conversion of cellulose and lignocellulosic waste into hydroxymethylfurfural/furfural.

    PubMed

    da Silva Lacerda, Viviane; López-Sotelo, Juan Benito; Correa-Guimarães, Adriana; Hernández-Navarro, Salvador; Sánchez-Bascones, Mercedes; Navas-Gracia, Luis M; Martín-Ramos, Pablo; Pérez-Lebeña, Eduardo; Martín-Gil, Jesús

    2015-03-01

    Native cellulose, lignocellulosic materials from Brazil (carnauba palm leaves and macauba pulp and shell) and pine nut shell from Spain have been studied as substrates for the production of HMF and furfural in a conventional microwave oven. In order to promote the dissolution of native cellulose, several ionic liquids, catalysts, organic solvents and water doses have been assessed. The most suitable mixture (5mL of choline chloride/oxalic acid, 2mL of sulfolane, 2mL of water, 0.02g of TiO2 and 0.1g of substrate) has been chosen to conduct kinetic studies at different reaction times (5-60min) and various temperatures (120-200°C) and to evaluate the best conditions for HMF+furfural production according to Seaman's model. The best production yields of HMF+furfural have been attained for native cellulose, with a yield of 53.24% when an ultrasonic pretreatment was used prior to a microwave treatment with stirring.

  11. Isolation of Malassezia furfur from a Cat

    PubMed Central

    Crespo, M. J.; Abarca, M. L.; Cabañes, F. J.

    1999-01-01

    During a survey of the occurrence of Malassezia species in the external ear canals of cats without otitis externa, Malassezia furfur was isolated. This is the first report of the isolation of M. furfur from cats. PMID:10203525

  12. Vortex-assisted liquid-liquid microextraction coupled with high performance liquid chromatography for the determination of furfurals and patulin in fruit juices.

    PubMed

    Abu-Bakar, Nur-Bahiyah; Makahleh, Ahmad; Saad, Bahruddin

    2014-03-01

    A fast and simple solvent microextraction technique using salting out-vortex-assisted liquid-liquid microextraction (salting out-VALLME) was developed for the extraction of furfurals (2-furfural (2-F), 3-furfural (3-F), 5-methylfurfural (5-MF) and 5-hydroxymethylfurfural (5-HMF)) and patulin (PAT) in fruit juice samples. The optimum extraction conditions for 5 mL sample were: extraction solvent, 1-hexanol; volume of extractant, 200 µL; vortex time, 45 s; salt addition, 20%. The simultaneous determination of the furfurals and PAT were investigated using high performance liquid chromatography coupled with diode array detector (HPLC-DAD). The separation was performed using ODS Hypersil C18 column (4.6 mm i.d × 250 mm, 5 μm) under gradient elution. The detection wavelengths used for all compounds were 280 nm except for 3-F (210 nm). The furfurals and PAT were successfully separated in less than 9 min. Good linearities (r(2)>0.99) were obtained within the range 1-5000 μg L(-1) for all compounds except for 3-F (10-5000 µg L(-1)) and PAT (0.5-100 μg L(-1)). The limits of detection (0.28-3.2 µg L(-1)) were estimated at S/N ratio of 3. The validated salting out-VALLME-HPLC method was applied for the analysis of furfurals and PAT in fruit juice samples (apple, mango and grape).

  13. Effects of furan derivatives on biohydrogen fermentation from wet steam-exploded cornstalk and its microbial community.

    PubMed

    Liu, Zhidan; Zhang, Chong; Wang, Linjun; He, Jianwei; Li, Baoming; Zhang, Yuanhui; Xing, Xin-Hui

    2015-01-01

    Understanding the role of furan derivatives, furfural (FUR) and 5-hydroxymethyl furfural (HMF), is important for biofuel production from lignocellulosic biomass. In this study, the effects of furan derivatives on hydrogen fermentation from wet steam-exploded cornstalk were investigated. The control experiments with only seed sludge indicated that HMF addition of up to 1g/L stimulated hydrogen production. Similar results were obtained using steam-exploded cornstalk as the feedstock. Hydrogen productivity was increased by up to 40% with the addition of HMF. In addition, over 90% of furan derivatives with an initial concentration below 1g/L were degraded. Pyosequencing showed that the addition of HMF and FUR resulted in different microbial communities. HMF led to a higher proportion of the genera Clostridium and Ruminococcaceae, supporting the increased hydrogen production. This study suggested that hydrogen fermentation could be a detoxifying step for steam-exploded cornstalk, and HMF and FUR exhibited different functions for hydrogen fermentation.

  14. Some furfural derivatives as nitrification inhibitors.

    PubMed

    Datta, A; Walia, S; Parmar, B S

    2001-10-01

    Three series of furfural derivatives, namely N-O-furfural oxime ethers, furfural Schiff bases (furfurylidene anilines), and furfural chalcones, have been synthesized and evaluated for nitrification inhibition activity in laboratory incubation studies in typic Ustocrept soil. Furfural oxime ethers and furfural Schiff bases showed potential activity, but furfural chalcones were only mildly active. N-O-ethyl furfural oxime among the oxime ethers, and furfurylidine-4-chloroaniline among the furfural Schiff bases, performed the best. These two compounds showed more than 50% nitrification inhibition on the 45th day at 5% dose as compared to 73% inhibition by nitrapyrin. Activity of furfural oxime ethers decreased with an increase in carbon atoms in the N-O-alkyl side chain. Introduction of a chlorine atom in the phenyl ring of furfurylidene anilines increased the persistence of their activity. N-O-Ethyl furfural oxime and furfurylidine-4-chloroaniline coated urea performed at par with their application in solution form. Ethyl and N-O-isopropyl oxime, as well as chloro- and nitro- substituted Schiff bases, did not reveal any phytotoxicity (adverse effect on germination) on chickpea seeds (Cicer arietinum) even at the highest dose (40 ppm, soil basis).

  15. Enhanced stabilization of collagen by furfural.

    PubMed

    Lakra, Rachita; Kiran, Manikantan Syamala; Usha, Ramamoorthy; Mohan, Ranganathan; Sundaresan, Raja; Korrapati, Purna Sai

    2014-04-01

    Furfural (2-furancarboxaldehyde), a product derived from plant pentosans, has been investigated for its interaction with collagen. Introduction of furfural during fibril formation enhanced the thermal and mechanical stability of collagen. Collagen films treated with furfural exhibited higher denaturation temperature (Td) (p<0.04) and showed a 3-fold increase in Young's modulus (p<0.04) at higher concentration. Furfural and furfural treated collagen films did not have any cytotoxic effect. Rheological characterization showed an increase in shear stress and shear viscosity with increasing shear rate for treated collagen. Circular dichroism (CD) studies indicated that the furfural did not have any impact on triple helical structure of collagen. Scanning electron microscopy (SEM) of furfural treated collagen exhibited small sized porous structure in comparison with untreated collagen. Thus this study provides an alternate ecologically safe crosslinking agent for improving the stability of collagen for biomedical and industrial applications.

  16. Simultaneous determination of furfural, acetic acid, and 5-hydroxymethylfurfural in corncob hydrolysates using liquid chromatography with ultraviolet detection.

    PubMed

    Dong, Bo-Yu; Chen, Ye-Fu; Zhao, Chang-Chun; Zhang, Shi-Jie; Guo, Xue-Wu; Xiao, Dong-Guang

    2013-01-01

    A single-laboratory validation study was conducted using HPLC for detecting and quantifying acetic acid, furfural, and 5-hydroxymethylfurfural (HMF) in corncob hydrolysates. A pretreatment procedure using dilute sulfuric acid was optimized for corncob hydrolysis. The final hydrolysates were analyzed by HPLC using a C18 RP column with aqueous 0.01% (v/v) H2SO4-CH3OH (95 + 5) as the mobile phase at a flow rate of 1 mL/min. The wavelengths for detecting the three compounds were changed to their optimal UV detection wavelengths at the time of elution. The wavelength detection adjustments were as follow: 205 nm (0 to 4 min); 284 nm (4 to 7 min); and 276 nm (7 to 10 min). Separation was achieved with a chromatographic run time of 10 min. The calibration curves for the three compounds had correlation coefficients (r2) > or = 99.8%. The analytical range, as defined by the calibration curves, was 0.5-10 mg/L for acetic acid, 0.4-22 mg/L for furfural, and 0.1-18 mg/L for HMF. The LODs for acetic acid, furfural, and HMF were estimated to be 0.05, 0.03, and 0.02 mg/L, respectively; the LOQs were 0.196, 0.135, and 0.074 mg/L, respectively. The RSD values for the intraday precision study ranged from 0.31 to 2.22%, and from 0.57 to 2.43% for the interday study. The mean recovery rates in all compounds were between 100.08 and 101.49%.

  17. Population pharmacokinetics of the 5-hydroxymethyl metabolite of tolterodine after administration of fesoterodine sustained release tablet in Western and East Asian populations.

    PubMed

    Oishi, Masayo; Tomono, Yoshiro; Yamagami, Hidetomi; Malhotra, Bimal

    2014-08-01

    This analysis was conducted to investigate factors that affect 5-hydroxymethyl tolterodine (5-HMT) pharmacokinetics after administration of fesoterodine sustained release tablets to Westerners and East Asians. Ten pharmacokinetic studies and three efficacy/safety studies in overactive bladder (OAB) patients were pooled for the population pharmacokinetic analysis. The plasma 5-HMT concentration data were described by a 1-compartment model with first order absorption and a lag time. Creatinine clearance (CLCR), hepatic impairment, CYP2D6 genotype, and concomitant medication with CYP3A inhibitor/inducer were identified as influential covariates. It was estimated that decreasing of CLCR from 80 to 15 mL/min resulted in a 39.5% reduction in 5-HMT apparent oral clearance (CL/F). Hepatic impairment, CYP2D6 poor metabolizer, and CYP3A inhibitor were estimated to reduce CL/F by about 60%, 40%, and 50%, respectively. CYP3A inducer resulted in about fourfold increase in CL/F. Although sex and Japanese ethnicity were selected as covariates on CL/F, each resulted in only about 10% decrease and increase of CL/F, respectively. Of the influential covariates of 5-HMT CL/F, CLCR, hepatic impairment, CYP2D6 genotype, and concomitant medication with CYP3A inhibitor/inducer were of significance, whereas sex and Japanese ethnicity covariates were considered not to have clinically significant impact on exposures of 5-HMT.

  18. Process for producing furan from furfural aldehyde

    DOEpatents

    Diebold, J.P.; Evans, R.J.

    1987-04-06

    A process of producing furan and derivatives thereof as disclosed. The process includes generating furfural aldehyde vapors and then passing those vapors over a zeolite catalyst at a temperature and for a residence time effective to decarbonylate the furfural aldehydes to form furans and derivatives thereof. The resultant furan vapors and derivatives are then separated. In a preferred form, the furfural aldehyde vapors are generated during the process of converting biomass materials to liquid and gaseous fuels.

  19. Process for producing furan from furfural aldehyde

    DOEpatents

    Diebold, James P.; Evans, Robert J.

    1988-01-01

    A process of producing furan and derivatives thereof is disclosed. The process includes generating furfural aldehyde vapors and then passing those vapors over a zeolite catalyst at a temperature and for a residence time effective to decarbonylate the furfural aldehydes to form furans and derivatives thereof. The resultant furan vapors and derivatives are then separated. In a preferred form, the furfural aldehyde vapors are generated during the process of converting biomass materials to liquid and gaseous fuels.

  20. Interconversion algorithm between mechanical and dielectric relaxation measurements for acetate of cis- and trans-2-phenyl-5-hydroxymethyl-1,3-dioxane.

    PubMed

    Garcia-Bernabé, A; Lidón-Roger, J V; Sanchis, M J; Díaz-Calleja, R; del Castillo, L F

    2015-10-01

    The dielectric and mechanical spectroscopies of acetate of cis- and trans-2-phenyl-5-hydroxymethyl-1,3-dioxane are reported in the frequency domain from 10(-2) to 10(6)Hz. This ester has been selected in this study for its predominant α relaxation with regard to the β relaxation, which can be neglected. This study consists of determining an interconversion algorithm between dielectric and mechanical measurements, given by using a relation between rotational and translational complex viscosities. These important viscosities were obtained from measures of the dielectric complex permittivity and by dynamic mechanical analysis, respectively. The definitions of rotational and translational viscosities were evaluated by means of fractional calculus, by using the fit parameters of the Havriliak-Negami empirical model obtained in the dielectric and mechanical characterization of the α relaxation. This interconversion algorithm is a generalization of the break of the Stokes-Einstein-Debye relationship. It uses a power law with an exponent defined as the shape factor, which modifies the translational viscosity. Two others factors are introduced for the interconversion, a shift factor, which displaces the translational viscosity in the frequency domain, and a scale factor, which makes equal values of the two viscosities. In this paper, the shape factor has been identified as the relation between the slopes of the moduli of the complex viscosities at higher frequency. This is interpreted as the degree of kinetic coupling between the molecular rotation and translational movements. Alternatively, another interconversion algorithm has been expressed by means of dielectric and mechanical moduli.

  1. Solvent Extraction of Furfural From Biomass

    NASA Technical Reports Server (NTRS)

    Humphrey, M. F.

    1984-01-01

    Solvent-extraction method reduces energy required to remove furfural produced during acid hydrolysis of biomass. Acid hydrolysis performed in vessel containing both solvents and reacting ingredients. With intimate contact between solvents and aqueous hydrolyis liqour, furfural removed form liquor almost as fast as it forms.

  2. Adsorption of HMF from water/DMSO solutions onto hydrophobic zeolites: experiment and simulation.

    PubMed

    Xiong, Ruichang; León, Marta; Nikolakis, Vladimiros; Sandler, Stanley I; Vlachos, Dionisios G

    2014-01-01

    The adsorption of 5-hydroxymethylfurfural (HMF), DMSO, and water from binary and ternary mixtures in hydrophobic silicalite-1 and dealuminated Y (DAY) zeolites at ambient conditions was studied by experiments and molecular modeling. HMF and DMSO adsorption isotherms were measured and compared to those calculated using a combination of grand canonical Monte Carlo and expanded ensemble (GCMC-EE) simulations. A method based on GCMC-EE simulations for dilute solutions combined with the Redlich-Kister (RK) expansion (GCMC-EE-RK) is introduced to calculate the isotherms over a wide range of concentrations. The simulations, using literature force fields, are in reasonable agreement with experimental data. In HMF/water binary mixtures, large-pore hydrophobic zeolites are much more effective for HMF adsorption but less selective because large pores allow water adsorption because of H2 O-HMF attraction. In ternary HMF/DMSO/water mixtures, HMF loading decreases with increasing DMSO fraction, rendering the separation of HMF from water/DMSO mixtures by adsorption difficult. The ratio of the energetic interaction in the zeolite to the solvation free energy is a key factor in controlling separation from liquid mixtures. Overall, our findings could have an impact on the separation and catalytic conversion of HMF and the rational design of nanoporous adsorbents for liquid-phase separations in biomass processing.

  3. A new β-glucosidase producing yeast for lower-cost cellulosic ethanol production from xylose-extracted corncob residues by simultaneous saccharification and fermentation.

    PubMed

    Liu, Z Lewis; Weber, Scott A; Cotta, Michael A; Li, Shi-Zhong

    2012-01-01

    This study reports a new yeast strain of Clavispora NRRL Y-50464 that is able to utilize cellobiose as sole source of carbon and produce sufficient native β-glucosidase enzyme activity for cellulosic ethanol production using SSF. In addition, this yeast is tolerant to the major inhibitors derived from lignocellulosic biomass pre-treatment such as 2-furaldehyde (furfural) and 5-(hydroxymethyl)-2-furaldehyde (HMF), and converted furfural into furan methanol in less than 12h and HMF into furan-2,5-dimethanol within 24h in the presence of 15 mM each of furfural and HMF. Using xylose-extracted corncob residue as cellulosic feedstock, an ethanol production of 23 g/l was obtained using 25% solids loading at 37 °C by SSF without addition of exogenous β-glucosidase. Development of this yeast aids renewable biofuels development efforts for economic consolidated SSF bio-processing.

  4. Value of furfural/ethanol coproduction from acid hydrolysis processes

    SciTech Connect

    Parker, S.; Calnon, M.; Feinberg, D.; Power, A.; Weiss, L.

    1983-08-01

    The benefits of two modifications in the acid hydrolysis of cellulosic feedstocks for the production of ethanol fuels were investigated: marketing of the by-product furfural and xylose fermentation. Preliminary analysis indicate that the furfural by-product furfural and xylose fermentation. Perliminary analyses indicate that the furfural by-product credit is more beneficial at a minimum net profit of $0.08/lb of furfural. For this credit to have a major impact on ethanol production costs, new markets for large quantities of furfural must be identified. Furfural can be an alternative feedstock for hydrocarbon-based commodity chemicals. The costs and profitabilities of producing five chemicals from furfurals as opposed to conventional hydrocarbon-based feedstocks were studied. The furfural processes for production of styrene and butadiene were found to be marginally competitive or not competitive. The furfural processes for adipic acid, maleic anhydride, and butanol could be competitive. Results of analysis by a computer model of the petrochemical industry indicate that with furfural markets additional to these three furfural processes, over 2.5 x 10/sup 9/ gal of ethanol could be marketed at about $1.00/gal. Converting the xylose stream to ethanol has about the same effect on the selling price of ethanol as the furfural credit. The greatest ethanol production will result from xylose fermentation, but the furfural credit offers large near-term profits and has a more diversified impact on reducing petroleum product demand. 6 figures, 17 tables.

  5. Ethanologenic bacteria with increased resistance to furfural

    DOEpatents

    Miller, Elliot Norman; Jarboe, Laura R.; Yomano, Lorraine P.; York, Sean W.; Shanmugam, Keelnatham; Ingram, Lonnie O'Neal

    2015-10-06

    The invention relates to bacterium that have increased resistance to furfural and methods of preparation. The invention also relates to methods of producing ethanol using the bacterium and corresponding kits.

  6. Lipase-catalyzed (trans)esterification of 5-hydroxy- methylfurfural and separation from HMF esters using deep-eutectic solvents.

    PubMed

    Krystof, Monika; Pérez-Sánchez, María; Domínguez de María, Pablo

    2013-04-01

    5-Hydroxymethylfurfural (HMF) is a valuable biomass-derived building block. Among possible HMF valorization products, a broad range of HMF esters can be synthesized. These HMF esters have found some promising applications, such as monomers, fuels, additives, surfactants, and fungicides, and thus several catalytic approaches for HMF (trans)esterifications have been reported. The intrinsic reactivity of HMF is challenging, forcing the use of mild reaction conditions to avoid by-product formation. This paper explores the lipase-catalyzed (trans)esterification of HMF with different acyl donors (carboxylic acids and methyl- and ethyl esters) mostly in solvent-free conditions. The results demonstrate that lipases may be promising alternatives for the synthesis of HMF esters-with high productivities and reactions at high substrate loadings-provided that robust systems for lipase immobilization are applied to assure an adequate reusability of the enzymes. Once (trans)esterifications have been conducted, the separation of unreacted HMF and HMF esters is performed by using deep-eutectic solvents (DES) as separation agents. DES are able to dissolve hydrogen-bond donors (e.g., HMF), whereas non-hydrogen-bond donors (in this case HMF esters) form a second phase. By using this approach, high ester purities (>99 %) and efficiencies (up to >90 % HMF ester recovery) in separations were obtained by using choline chloride-based DES.

  7. 5-HMF and carbohydrates content in stingless bee honey by CE before and after thermal treatment.

    PubMed

    Biluca, Fabíola C; Della Betta, Fabiana; de Oliveira, Gabriela Pirassol; Pereira, Lais Morilla; Gonzaga, Luciano Valdemiro; Costa, Ana Carolina Oliveira; Fett, Roseane

    2014-09-15

    This study aimed to assess 5-hydroximethylfurfural and carbohydrates (fructose, glucose, and sucrose) in 13 stingless bee honey samples before and after thermal treatment using a capillary electrophoresis method. The methods were validated for the parameters of linearity, matrix effects, precision, and accuracy. A factorial design was implemented to determine optimal thermal treatment conditions and then verify the postprocedural 5-HMF formation, but once 5-HMF were HMF, and carbohydrate levels ranged from 48.59% to 69.36%. In the same conditions of thermal treatment, Apis mellifera honey presented higher 5-HMF content than stingless bee honey. Results suggest that a high temperature related to briefer thermal treatment could be an efficient way to extend shelf life without affecting 5-HMF content in stingless bee honey.

  8. HMF-Geophysics: A Model for Collaborative Research in Hydrogeophysics

    NASA Astrophysics Data System (ADS)

    Knight, R.; Crook, N.; Bales, R.; Moore, J.; Papanicolaou, T.; Welty, C.

    2008-05-01

    CUAHSI is developing, with the support of the NSF, a Hydrologic Measurement Facility (HMF). HMF-Geophysics is the near-surface geophysics module of HMF. Over the three years of the NSF grant (2005-08) we will determine, through broad community consultation, how best to utilize geophysical instrumentation and engage geophysical expertise in addressing key challenges in the hydrologic sciences. Our goal is to put in place the infrastructure needed to develop and maintain partnerships between the hydrologic and geophysical communities so that geophysical methods are used in a way that represents the state-of-the-science. Our current model consists of a central "node" that conducts feasibility studies to determine how/if geophysical methods could be of use in a hydrologic research project. In addition to the central node we have developed a system of affiliated nodes, individuals at 14 institutions who have committed to support HMF-Geophysics activities by offering equipment, software, and expertise. Once a feasibility study has shown the value of geophysics at a particular site, we match the hydrology PI with one of the nodes to develop the full-scale research project. We have conducted feasibility studies at 6 sites: Reynolds Creek Watershed, the H.J. Andrews Experimental Forest, and four WATERS test- beds, the latter are described below. The objective of the Baltimore test-bed is to quantify the urban water cycle, with an emphasis on groundwater, using the Gwynns Falls watershed as a pilot study area. Electrical resistivity imaging, ground penetrating radar, and seismic refraction were assessed as a means of determining depth to bedrock or to the water table within the riparian zone of urbanized streams. A regional time-lapse microgravity survey was conducted at the 200 sq- km watershed scale to infer the storage change in the underlying aquifers. Research in the Crown of the Continent test-bed in Montana is focused on understanding the interactions between the

  9. Effects of honey HMF on enzyme activities and serum biochemical parameters of Wistar rats.

    PubMed

    Özkök, Duran; Silici, Sibel

    2016-10-01

    Hydroxymethylfurfural (HMF) is a by-product of thermal degradation of glucose and fructose. In this study, the effects of high HMF content of honey on biochemical parameters of rats were investigated. Experiments were conducted with 40 Wistar albino male rats, each weighing 250-350 g and covered a period of 5 weeks. The animals were divided into five groups. The first group was served as control group. HMF was injected subcutaneously at a dose of 200 mg/kg rat b.w. to the animals in group 2. Group 3 was fed with honey that contains 10 mg HMF/kg honey. In group 4 and 5, there were honeys that contain significantly high HMF content due to long storage period (181 mg HMF/kg honey) and heat process (140 mg HMF/kg honey). At the end of the feeding process, biochemical blood parameters of rats were investigated. It was observed that there were no differences among the glucose, triglyceride, HDL cholesterol, uric acid, Na, GGT, and ALP parameters of the groups. On the other hand, significant differences were observed among the cholesterol, LDL, BUN, creatinine, Ca, P, Mg, K, Cl, total bilirubin, LDH, CPK, AST, ALT, total protein, and pseudocholinesterase values of the rats. The highest adverse effects were obtained from group HMF, and it was followed by groups SH (stored honey) and HH (heated honey). It can be concluded that high HMF content of honey may affect the human health adversely; thus, HMF in honey must be controlled by beekeepers.

  10. Identification of the major metabolite of 2,5-bis(5-hydroxymethyl-2-thienyl)furan (NSC 652287), an antitumor agent, in the S9 subcellular fraction of dog liver cells.

    PubMed

    Phillip, Lawrence R; Jorden, Jean L; Rivera, Maria I; Wolfe, Tracy L; Upadhyayb, Kaye; Stinson, Sherman F

    2002-02-05

    Alpha-Terthienyl (1) is a trithiophene found widely distributed in plants. Other naturally occurring trithiophenes are less widely distributed, but nonetheless exhibit potent antiviral and cytotoxic activities. A synthetic analog of 1, 2,5-bis(5-hydroxymethyl-2-thienyl)furan (2; NSC 652287) has recently been shown to possess exceptional activity and selectivity against several cell lines of the National Cancer Institute (NCI) anticancer drug screen. When incubated with the S9 subcellular fraction of dog liver cells, the concentration of 2 was observed to decline as a function of time, with a concomitant increase in a significant, time-dependent concentration of an unknown entity. The results of electron-ionization mass spectrometric analysis of the metabolite indicate an increase in 14 amu over that of 2, leading to suspicions that either an oxidation or a methylation had occurred. Results of differential derivatization and accurate mass analysis allow us to propose that metabolism of 2 involves the biotransformation of one of the two hydroxymethyl groups of 2 into a carboxylic acid functionality. This is further supported by separate experiments involving chemical oxidation and S9 incubation of 5-[5-[5-hydroxymethyl-2-thienyl]-2-furanyl]-2-thiophenecarboxaldehyde: comparing the mass spectra and gas chromatographic retention times of the resulting products to those of the identified metabolite of 2 show all to be the same.

  11. Separating acetic acid from furol (furfural) by electrodialysis method

    SciTech Connect

    Guan, S.F.; Li, C.S. Ye, S.T.; Shen, S.Y.; Wang, Y.T.; Yu, S.H.

    1981-01-01

    Furfural production by hydrolysis of fibrous plant materials is accompanied by formation of acetic acid in amounts depending on the material used. The amount of acetic formed in the hydrolysis of the fruit shell of oil-tea camellia (Camellia oleosa) (an oilseed-bearing tree) is equal to the amount of furfural. The acetic acid can be separated from the furfural and concentrated to 10% by electrodialysis. A smaller amount of furfural is separated with acetic acid.

  12. Towards a new reference model of hmF2 for IRI

    NASA Astrophysics Data System (ADS)

    Gulyaeva, T. L.; Bradley, P. A.; Stanislawska, I.; Juchnikowski, G.

    2008-08-01

    A numerical model of the peak height of the F2 layer, hmF2_ top, is derived from the topside sounding database of 90,000 electron density profiles for a representative set of conditions provided by ISIS1, ISIS2, IK19 and Cosmos-1809 satellites for the period of 1969-1987. The model of regular hmF2 variations is produced in terms of local time, season, geomagnetic latitude, geodetic longitude and solar radio flux. No geomagnetic activity trends were discernible in the topside sounding data. The nighttime peak of hmF2_ top evident for mid-latitudes disappears near the geomagnetic equator where a maximum of hmF2_ top occurs at sunset hours when it can exceed 500 km at solar maximum. The hmF2 given by the IRI exceeds hmF2_ top at the low solar activities. The hmF2_ top, obtained by extrapolation of the first derivative of the topside profile to zero shows saturation similar to foF2 the greater the solar activity. The proposed model differs from hmF2 given by IRI based on M( 3000) F2 to hmF2 conversion by empirical relationships in terms of foF2, foE and R12 with these quantities mapped globally by the ITU-R (former CCIR) from ground-based ionosonde data. The differences can be attributed to the different techniques of the peak height derivation, different epochs and different global distribution of the source data as well as the different mathematical functions involved in the maps and the model presentation.

  13. Direct conversion from Jerusalem artichoke to hydroxymethylfurfural (HMF) using the Fenton reaction.

    PubMed

    Seo, Yeong Hwan; Han, Jong-In

    2014-05-15

    A simple method for hydroxymethylfurfural (HMF) production from non-crop biomass of the Jerusalem artichoke was developed using the Fenton reaction, in a mixture of 2-butanol and water. Four parameters (temperature, reaction time, Fe(2+) concentration, and H2O2 concentration) were identified as experimental factors, and HMF yield was selected as the response parameter. The experimental factors were optimised by employing Response Surface Methodology (RSM). The maximum HMF yield, of 46%, was obtained with a reaction time of 90 min, Fe(2+) concentration of 1.3 mM, and 0.47 M of H2O2 at 180 °C.

  14. Thermodynamics of the HMF model with a magnetic field

    NASA Astrophysics Data System (ADS)

    Chavanis, P. H.

    2011-04-01

    We study the thermodynamics of the Hamiltonian mean field (HMF) model with an external potential playing the role of a "magnetic field". If we consider only fully stable states, the caloric curve does not present any phase transition. However, if we take into account metastable states (for a restricted class of perturbations), we find a very rich phenomenology. In particular, the caloric curve displays a region of negative specific heat in the microcanonical ensemble in which the temperature decreases as the energy increases. This leads to ensembles inequivalence and to zeroth order phase transitions similar to the "gravothermal catastrophe" and to the "isothermal collapse" of self-gravitating systems. In the present case, they correspond to the reorganization of the system from an "anti-aligned" phase (magnetization pointing in the direction opposite to the magnetic field) to an "aligned" phase (magnetization pointing in the same direction as the magnetic field). We also find that the magnetic susceptibility can be negative in the microcanonical ensemble so that the magnetization decreases as the magnetic field increases. The magnetic curves can take various shapes depending on the values of energy or temperature. We describe first order phase transitions and hysteretic cycles involving positive or negative susceptibilities. We also show that this model exhibits gaps in the magnetization at fixed energy, resulting in ergodicity breaking.

  15. The Margin of Exposure of 5-Hydroxymethylfurfural (HMF) in Alcoholic Beverages

    PubMed Central

    Monakhova, Yulia B

    2012-01-01

    Objectives 5-Hydroxymethylfurfural (HMF) regularly occurs in foods and in alcoholic beverages. However, the risk of HMF associated with alcohol consumption has not been systematically studied, so that this study will provide the first quantitative risk assessment of HMF for consumers of alcoholic beverages. Methods Human dietary intake of HMF via alcoholic beverages in the European Union was estimated based on WHO alcohol consumption data combined with our own survey data (n=944) and literature data (n=147) about the HMF contents of different beverage groups (beer, wine, spirits and unrecorded alcohol). The risk assessment was conducted using the margin of exposure (MOE) approach. Results For olfactory epithelium metaplasia in female mice, a benchmark dose (BMD) of 127 mg/kg bodyweight (bw)/d and a BMD lower confidence limit (BMDL) of 79 mg/kg bw/d were calculated from National Toxicology Program oral long-term animal experiments. The average human exposure to HMF from alcoholic beverages was estimated at 6.0E-3 mg/kg bw/d, which is approximately 8.5% of the total dietary exposure. In comparison of the human exposure with BMDL, the MOE was 13,167 for average alcohol consumption scenarios, which is a value that would be generally assumed as safe for threshold based compounds. Conclusions The results show that the risk from HMF to the alcohol-consuming population is rather low and the priority for risk management (e.g. to reduce the contamination) is also low. Further toxicological research about HMF is required to further elucidate its mechanism. PMID:23106038

  16. Single-step conversion of cellulose to 5-hydroxymethylfurfural (HMF), a versatile platform chemical

    SciTech Connect

    Su, Yu; Brown, Heather M.; Huang, Xiwen; Zhou, Xiao Dong; Amonette, James E.; Zhang, Z. Conrad

    2009-06-20

    The ability to use cellulosic biomass as feedstock for the production of fuels and chemicals currently derived from petroleum depends critically on the development of effective low-temperature processes. While HMF, as a versatile platform chemical suitable for use in polymer synthesis or production of liquid biofuels, can currently be made from fructose and glucose, synthesis of HMF directly from raw natural cellulose represents the last major barrier toward the development of a sustainable HMF platform. Here we report an unprecedented single-step pathway that depolymerizes cellulose rapidly under mild conditions and converts the resulting glucose to hydroxymethylfurfural (HMF). A pair of metal chlorides (CuCl2 and CrCl2) dissolved in 1-ethyl-3-methylimidazolium chloride at temperatures of 80-120°C catalyzes cellulose depolymerization and the subsequent glucose conversion to HMF with 95% selectivity among recoverable products (at 56% HMF yield). Cellulose depolymerization, which can also be catalyzed by other metalchloride pairs such as CuCl2 paired with PdCl2, CrCl3, or FeCl3, occurs at a rate that is more than one order of magnitude faster than conventional acid-catalyzed hydrolysis. In contrast, single-metal chlorides at the same total loading showed low activity under similar conditions. Mechanistic studies suggest that the C2 hydrogen of the imidazolium ring is activated by the paired metal-chloride catalysts.

  17. Factors Affecting Furfural as a Nematicide on Turf

    PubMed Central

    Luc, J. E.; Crow, W. T.

    2013-01-01

    Recently a furfural nematicide Multiguard Protect EC was launched for use on turfgrasses in the United States. A series of greenhouse experiments were conducted to determine the concentration and exposure time required for this formulation to irreversibly affect Belonolaimus longicaudatus, and to study factors that might affect the practicality of furfural use in turfgrass systems. One experiment exposed B. longicaudatus to increasing concentrations of furfural (0 to 990 ppm) in vitro for either 24 or 48 hr, followed by inoculation onto bermudagrass. A second experiment evaluated effects of exposure of B. longicaudatus to increasing concentrations of furfural in soil solution on bermudagrass with or without an organic thatch layer. A third experiment evaluated effects on B. longicaudatus of increasing concentrations of furfural applied as a spray treatment to creeping bentgrass. Results from the in vitro exposure experiment found decreasing numbers of B. longicaudatus with increasing furfural concentration beginning with the lowest concentration tested (270 ppm). Belonolaimus longicaudatus were virtually eliminated with furfural concentrations ≥ 720 ppm. Similarly, exposure to increasing concentration of furfural in soil solution resulted in increasing reduction in numbers of B. longicaudatus. Presence of thatch slightly reduced the population density of B. longicaudatus. Spray application of furfural only reduced numbers of B. longicaudatus at the two highest rates (3,600 and 4,950 ppm). PMID:24379484

  18. Malassezia furfur meningitis associated with total parenteral nutrition subdural effusion.

    PubMed

    Rosales, Cecilia M; Jackson, Mary Anne; Zwick, David

    2004-01-01

    We present a case of Malassezia furfur meningitis arising in a very low birth weight infant with chronic lung disease, necrotizing enterocolitis, and intraventricular hemorrhage. M. furfur meningitis was probably acquired late following successful treatment for earlier systemic central line-associated M. furfur infection. M. furfur meningitis has only once been previously reported. Unlike the previous case where meningitis was secondary to widespread blood-borne dissemination, infection was limited to the leptomeninges and arose in association with extravasation of total parenteral nutrition (TPN) and intralipid fluid into subarachnoid space via peripheral scalp catheter.

  19. Eight new crystal structures of 5-(hydroxymethyl)uracil, 5-carboxyuracil and 5-carboxy-2-thiouracil: insights into the hydrogen-bonded networks and the predominant conformations of the C5-bound residues.

    PubMed

    Seiler, Vanessa Kristina; Hützler, Wilhelm Maximilian; Bolte, Michael

    2016-05-01

    In order to examine the preferred hydrogen-bonding pattern of various uracil derivatives, namely 5-(hydroxymethyl)uracil, 5-carboxyuracil and 5-carboxy-2-thiouracil, and for a conformational study, crystallization experiments yielded eight different structures: 5-(hydroxymethyl)uracil, C5H6N2O3, (I), 5-carboxyuracil-N,N-dimethylformamide (1/1), C5H4N2O4·C3H7NO, (II), 5-carboxyuracil-dimethyl sulfoxide (1/1), C5H4N2O4·C2H6OS, (III), 5-carboxyuracil-N,N-dimethylacetamide (1/1), C5H4N2O4·C4H9NO, (IV), 5-carboxy-2-thiouracil-N,N-dimethylformamide (1/1), C5H4N2O3S·C3H7NO, (V), 5-carboxy-2-thiouracil-dimethyl sulfoxide (1/1), C5H4N2O3S·C2H6OS, (VI), 5-carboxy-2-thiouracil-1,4-dioxane (2/3), 2C5H4N2O3S·3C6H12O3, (VII), and 5-carboxy-2-thiouracil, C10H8N4O6S2, (VIII). While the six solvated structures, i.e. (II)-(VII), contain intramolecular S(6) O-H...O hydrogen-bond motifs between the carboxy and carbonyl groups, the usually favoured R2(2)(8) pattern between two carboxy groups is formed in the solvent-free structure, i.e. (VIII). Further R2(2)(8) hydrogen-bond motifs involving either two N-H...O or two N-H...S hydrogen bonds were observed in three crystal structures, namely (I), (IV) and (VIII). In all eight structures, the residue at the ring 5-position shows a coplanar arrangement with respect to the pyrimidine ring which is in agreement with a search of the Cambridge Structural Database for six-membered cyclic compounds containing a carboxy group. The search confirmed that coplanarity between the carboxy group and the cyclic residue is strongly favoured.

  20. Method for selectively preparing 5-hydroxymethylfurfual (HMF) from biomass in polar aprotic solvents

    DOEpatents

    Dumesic, James A.; Huber, George W.; Weingarten, Ronen

    2016-01-26

    A method to produce 5-hydroxymethylfurfural (HMF) is described in which a reactant including cellulose, lignocellulose, or a combination thereof, in a reaction mixture of a polar, aprotic solvent and an acid is reacted for a time, at a temperature, and at a hydrogen ion concentration wherein at least a portion of the cellulose or lignocellulose present in the reactant is converted to HMF. The reaction mixture is initially substantially devoid of water. As the reaction proceeds, dehydration of intermediates causes the water concentration in the reaction mixture to rise to no more than about 0.2 wt % water.

  1. Antifungal effect of TONS504-photodynamic therapy on Malassezia furfur.

    PubMed

    Takahashi, Hidetoshi; Nakajima, Susumu; Sakata, Isao; Iizuka, Hajime

    2014-10-01

    Numerous reports indicate therapeutic efficacy of photodynamic therapy (PDT) against skin tumors, acne and for skin rejuvenation. However, few reports exist regarding its efficacy for fungal skin diseases. In order to determine the antifungal effect, PDT was applied on Malassezia furfur. M. furfur was cultured in the presence of a novel cationic photosensitizer, TONS504, and was irradiated with a 670-nm diode laser. TONS504-PDT showed a significant antifungal effect against M. furfur. The effect was irradiation dose- and TONS504 concentration-dependent and the maximal effect was observed at 100 J/cm2 and 1 μg/mL, respectively. In conclusion, TONS504-PDT showed antifungal effect against M. furfur in vitro, and may be a new therapeutic modality for M. furfur-related skin disorders.

  2. Malassezia furfur fingerprints as possible markers for human phylogeography.

    PubMed

    Gaitanis, George; Velegraki, Aristea; Alexopoulos, Evangelos C; Kapsanaki-Gotsi, Evangelia; Zisova, Lilia; Ran, Yuping; Zhang, Hao; Arsenis, George; Bassukas, Ioannis D; Faergemann, Jan

    2009-04-01

    Malassezia furfur was the first species described within the cosmopolitan yeast genus Malassezia, which now comprises 13 species. Reported isolation rates of these species from healthy and diseased human skin show geographic variations. PCR-fingerprinting with the wild-type phage M13 primer (5'-GAGGGTGGCGGTTCT-3') was applied to investigate phylogeographic associations of M. furfur strains isolated from Scandinavians residing permanently in Greece, in comparison to clinical isolates from Greek, Bulgarian and Chinese native residents. Seven M. furfur strains from Scandinavians were compared with the Neotype strain (CBS1878), CBS global collection strains (n=10) and clinical isolates from Greece (n=4), Bulgaria (n=15) and China (n=6). Scandinavian, Greek and Bulgarian M. furfur strains mostly formed distinct group clusters, providing initial evidence for an association with the host's geographical origin and with the underlying skin condition. These initial data address the hypothesis that M. furfur could be a eukaryotic candidate eligible for phylogeographic studies.

  3. Landau Damping in Sobolev Spaces for the Vlasov-HMF Model

    NASA Astrophysics Data System (ADS)

    Faou, Erwan; Rousset, Frédéric

    2016-02-01

    We consider the Vlasov-HMF (Hamiltonian Mean-Field) model. We consider solutions starting in a small Sobolev neighborhood of a spatially homogeneous state satisfying a linearized stability criterion (Penrose criterion). We prove that these solutions exhibit a scattering behavior to a modified state, which implies a nonlinear Landau damping effect with polynomial rate of damping.

  4. Power generation from furfural using the microbial fuel cell

    NASA Astrophysics Data System (ADS)

    Luo, Yong; Liu, Guangli; Zhang, Renduo; Zhang, Cuiping

    Furfural is a typical inhibitor in the ethanol fermentation process using lignocellulosic hydrolysates as raw materials. In the literature, no report has shown that furfural can be utilized as the fuel to produce electricity in the microbial fuel cell (MFC), a device that uses microbes to convert organic compounds to generate electricity. In this study, we demonstrated that electricity was successfully generated using furfural as the sole fuel in both the ferricyanide-cathode MFC and the air-cathode MFC. In the ferricyanide-cathode MFC, the maximum power densities reached 45.4, 81.4, and 103 W m -3, respectively, when 1000 mg L -1 glucose, a mixture of 200 mg L -1 glucose and 5 mM furfural, and 6.68 mM furfural were used as the fuels in the anode solution. The corresponding Coulombic efficiencies (CE) were 4.0, 7.1, and 10.2% for the three treatments, respectively. For pure furfural as the fuel, the removal efficiency of furfural reached up to 95% within 12 h. In the air-cathode MFC using 6.68 mM furfural as the fuel, the maximum values of power density and CE were 361 mW m -2 (18 W m -3) and 30.3%, respectively, and the COD removal was about 68% at the end of the experiment (about 30 h). Increase in furfural concentrations from 6.68 to 20 mM resulted in increase in the maximum power densities from 361 to 368 mW m -2, and decrease in CEs from 30.3 to 20.6%. These results indicated that some toxic and biorefractory organics such as furfural might still be suitable resources for electricity generation using the MFC technology.

  5. Stereochemistry of Furfural Reduction by a Saccharomyces cerevisiae Aldehyde Reductase That Contributes to In Situ Furfural Detoxification

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ari1p from Saccharomyces cerevisiae, recently identified as an intermediate subclass short-chain dehydrogenase/reductase, contributes in situ to the detoxification of furfural. Furfural inhibits efficient ethanol production by the yeast, particularly when the carbon source is acid-treated lignocell...

  6. Serum IgE reactivity to Malassezia furfur extract and recombinant M. furfur allergens in patients with atopic dermatitis.

    PubMed

    Zargari, A; Eshaghi, H; Bäck, O; Johansson, S; Scheynius, A

    2001-01-01

    IgE reactivity to the opportunistic yeast Malassezia furfur can be found in patients with atopic dermatitis (AD). We have previously cloned and expressed 6 recombinant allergens (rMal f 1, rMal f 5-9) from M. furfur. In the present study, we used ImmunoCAP to investigate whether these rMal f allergens can be useful in the diagnosis of M. furfur-associated AD compared with the M. furfur extract. A total of 156 adult patients with a clinical diagnosis of AD participated in the study. Sixty-four percent had increased total serum IgE levels, 79% had specific IgE antibodies to common inhalant allergens and 47% had IgE antibodies to M. furfur extract. IgE antibodies to any of the rMal f allergens were detected among 86 (55%) of the patients, 14 (16%) of whom did not react to the M. furfur extract. Any individual rMal f allergen detected between 32% and 89% of the patients ImmunoCAP-positive to the M. furfur extract, with the highest sensitivity for rMal f 9. Therefore, a couple of individual rMal f allergens can improve the diagnosis of M. furfur-associated IgE allergies in patients with AD.

  7. YC-1 [3-(5'-hydroxymethyl-2'-furyl)-1-benzyl indazole] inhibits neointima formation in balloon-injured rat carotid through suppression of expressions and activities of matrix metalloproteinases 2 and 9.

    PubMed

    Liu, Yi-Nan; Pan, Shiow-Lin; Peng, Chieh-Yu; Guh, Jih-Hwa; Huang, Dong-Ming; Chang, Ya-Ling; Lin, Chun-Hung; Pai, Hui-Chen; Kuo, Sheng-Chu; Lee, Fang-Yu; Teng, Che-Ming

    2006-01-01

    Matrix metalloproteinases (MMPs), particularly MMP-2 and MMP-9, and postrevascularization production of vascular smooth muscle cells may play key roles in development of arterial restenosis. We investigated the inhibitory effect of 3-(5'-hydroxymethyl-2'-furyl)-1-benzyl indazole (YC-1), a benzyl indazole compound, on MMP-2 and MMP-9 activity in a balloon-injury rat carotid artery model. Injury was induced by inserting a balloon catheter through the common carotid artery; after 14 days, histopathological analysis using immunostaining and Western blotting revealed significant restenosis with neointimal formation that was associated with enhanced protein expression of MMP-2 and MMP-9. However, these effects were dose-dependently reduced by orally administered YC-1 (1-10 mg/kg). In addition, gelatin zymography demonstrated that increased MMP-2 and MMP-9 activity was diminished by YC-1 treatment. On the other hand, YC-1 inhibited hydrolysis of the fluorogenic quenching substrate Mca-Pro-Leu-Gly-Leu-Dpa-Ala-Arg-NH(2) by recombinant MMP-2 and MMP-9 with IC(50) values = 2.07 and 8.20 muM, respectively. Reverse transcription-polymerase chain reaction analysis of MMP-2 and MMP-9 mRNA revealed that YC-1 significantly inhibited mRNA levels of MMPs. Finally, for the YC-1 treatment group, we did not observe elevation of cGMP levels using enzyme-linked immunosorbent assay, suggesting that YC-1 inhibition of neointimal formation is not through a cGMP-elevating pathway. These data show YC-1 suppression of neointimal formation is dependent on its influence on MMP-2 and MMP-9 protein, mRNA expression, and activity, but not through a cGMP-elevating effect. YC-1 shows therapeutic potential for treatment of restenosis after angioplasty.

  8. Field efficacy of furfural as a nematicide on turf.

    PubMed

    Crow, W T; Luc, J E

    2014-03-01

    A commercial formulation of furfural was recently launched in the United States as a turfgrass nematicide. Three field trials evaluated efficacy of this commercial formulation on dwarf bermudagrass putting greens infested primarily with Belonolaimus longicaudatus, Meloidogyne graminis, or both these nematodes, and in some cases with Mesocriconema ornatum or Helicotylenchus pseudorobustus. In all these trials, furfural improved turf health but did not reduce population densities of B. longicaudatus, M. graminis, or the other plant-parasitic nematodes present. In two additional field trials, efficacy of furfural at increasing depths in the soil profile (0 to 5 cm, 5 to 10 cm, and 10 to 15 cm) against B. longicaudatus on bermudagrass was evaluated. Reduction in population density of B. longicaudatus was observed in furfural-treated plots for depths below 5 cm on several dates during both trials. However, no differences in population densities of B. longicaudatus were observed between the furfural-treated plots and the untreated control for soil depth of 0 to 5 cm during either trial. These results indicate that furfural applications can improve health of nematode-infested turf and can reduce population density of plant-parasitic nematodes in turf systems. Although the degree to which turf improvement is directly caused by nematicidal effects is still unclear, furfural does appear to be a useful nematode management tool for turf.

  9. Field Efficacy of Furfural as a Nematicide on Turf

    PubMed Central

    Crow, W. T.; Luc, J. E.

    2014-01-01

    A commercial formulation of furfural was recently launched in the United States as a turfgrass nematicide. Three field trials evaluated efficacy of this commercial formulation on dwarf bermudagrass putting greens infested primarily with Belonolaimus longicaudatus, Meloidogyne graminis, or both these nematodes, and in some cases with Mesocriconema ornatum or Helicotylenchus pseudorobustus. In all these trials, furfural improved turf health but did not reduce population densities of B. longicaudatus, M. graminis, or the other plant-parasitic nematodes present. In two additional field trials, efficacy of furfural at increasing depths in the soil profile (0 to 5 cm, 5 to 10 cm, and 10 to 15 cm) against B. longicaudatus on bermudagrass was evaluated. Reduction in population density of B. longicaudatus was observed in furfural-treated plots for depths below 5 cm on several dates during both trials. However, no differences in population densities of B. longicaudatus were observed between the furfural-treated plots and the untreated control for soil depth of 0 to 5 cm during either trial. These results indicate that furfural applications can improve health of nematode-infested turf and can reduce population density of plant-parasitic nematodes in turf systems. Although the degree to which turf improvement is directly caused by nematicidal effects is still unclear, furfural does appear to be a useful nematode management tool for turf. PMID:24644368

  10. Malassezia furfur in infantile seborrheic dermatitis.

    PubMed

    Wananukul, Siriwan; Chindamporn, Ariya; Yumyourn, Poomjit; Payungporn, Sunchai; Samathi, Chanchuree; Poovorawan, Yong

    2005-01-01

    Our objective was to study both incidence and various strains of Malassezia in infantile seborrheic dermatitis (ISD). Sixty infants between 2 weeks and 2 years old with clinical diagnosis of ISD at the Department of Pediatrics, King Chulalongkorn Memorial Hospital from May 2002 to April 2003 were recruited. Malassezia spp. were isolated from cultured skin samples of the patients, genomic DNA was extracted and the ITS1 rDNA region was amplified. The PCR product was examined by agarose gel electrophoresis and DNA sequences were determined. The ITS1 sequences were also subjected to phylogenetic analysis and species identification. ISD is most commonly found in infants below the age of 2 months (64%), followed by those between 2 and 4 months (28%) old. Cultures yielded yeast-like colonies in 15 specimens. PCR yielded 200-bp products (Candida) in 3 patients and 300-bp products (Malassezia furfur) in 12 patients (18%). Sugar fermentation using API 20C aux performed on the three 200-bp PCR products yielded Candida species. M. furfur was the only Malassezia recovered from skin scrapings of children with ISD.

  11. Hydrogenation of furfural on polymer-containing catalysts

    SciTech Connect

    Karakhanov, E.A.; Neimerovets, E.B.; Pshezhetskii, V.S.; Dedov, A.G.

    1986-09-01

    The catalytic hydrogenation of furfural with molecular hydrogen has been investigated under mild conditions in the presence of metal complex catalysts with a polymeric macroligand. It has been shown that the reaction proceeds according to a consecutive scheme with the formation of furfuryl and tetrahydrofurfuryl alcohols. The kinetics of furfural hydrogenation has been investigated and the order of the reaction established; the rate constants of the first and second stages have been determined. The influence of the solvent and of the metal-to-polymer ratio on the furfural conversion have been investigated.

  12. Towards a new reference model of hmF2 for IRI

    NASA Astrophysics Data System (ADS)

    Gulyaeva, T. L.; Stanislawska, I.; Bradley, P. A.; Juchnikowski, G.

    For telecommunication system performance assessments and for aeronomical studies there are advantages in having reference maps of the quantity hmF2 which is the peak height of the F2 layer This profile parameter may be determined by two separate ways First it may be derived from true-height profile analyses of bottomside or topside ionospheric soundings for a representative set of conditions The particular attention is paid to the data sets provided by ISIS1 ISIS2 IK19 and Cosmos-1809 topside soundings for the period of 1969-1987 Empirical model of regular hmF2 variations based on these satellite data is produced in terms of geomagnetic latitude local time season and solar activity Second it can be determined by empirical relationships applied to the standard vertical-incidence ionospheric characteristics where true-height profiles are unavailable The corresponding values are given by IRI and other empirical formulae in terms of foF2 M 3000 F2 and foE applied to median values of these separate characteristics as already mapped globally by ITU-R former CCIR There remain certain disagreements between the relative accuracies of the different empirical relationships giving hmF2 but such techniques can only be regarded as approximate Nevertheless insofar as the separate ionospheric characteristics are already quantified this would enable hmF2 to be evaluated over a range of conditions throughout a solar cycle This paper examines the relative merits of the separate approaches and their relationship to a corresponding solar index and what

  13. Nature of the chemical reaction for furfural modified asphalt

    SciTech Connect

    Memon, G.M.; Chollar, B.H.

    1994-12-31

    Three of the most serious problems of asphalt pavements today are rutting, cracking, and susceptibility to moisture damage (stripping). Asphalt manufacturers have been mixing asphalts with polymers to produce polymer-modified asphalts with improved rheological properties. However, the costs for these improved polymer-modified asphalts are almost double that of regular asphalts. FHWA researchers have found that asphalt modified by the chemical, furfural (which is prepared by simple elimination reaction of aldopentoses obtained from oat hulls), exhibited better stripping properties and was less temperature susceptible than the virgin asphalt while costing less than polymer-modified asphalts. This paper discusses the possible structure of the furfural-modified asphalt, data for the virgin and furfural-modified asphalts and their Corbett fractions, data from a model reaction between phenol and furfural, and a possible explanation of this structure based on these data.

  14. [Taxonomy of Malassezia furfur: state of the art].

    PubMed

    Aspíroz, M C; Moreno, L A; Rubio, M C

    1997-12-01

    Malassezia furfur is a lipophilic yeast considered as a normal component of the human skin flora. Apart from pityriasis versicolor, M. furfur has been linked to several skin diseases such as seborrheic dermatitis, folliculitis or atopic dermatitis. Moreover, these yeasts have been reported as agent of invasive human diseases including pneumonia, catheter-associated sepsis and peritonitis. The existence of morphological, serological, metabolical, biochemical and karyotipical differences has been described among isolates of these yeasts. These observations gave arguments for a possible intraspecific division, and this hypothesis has been confirmed by the existence of six species within the formerly called M. furfur (lipid-dependent Malassezia strains): M. furfur, Malassezia sympodialis, Malassezia globosa, Malassezia obtusa, Malassezia restricta and Malassezia slooffiae.

  15. Synthesis of Furfural from Water Hyacinth (Eichornia croassipes)

    NASA Astrophysics Data System (ADS)

    Ismiyarto; Ngadiwiyana; windarti, T.; Purbowatiningrum, RS; Hapsari, M.; Rafi’ah, FH; Suyanti; Haq, MS

    2017-02-01

    Furfural has been prepared from hydrolysis of dried biomass of water hyacinth (Eichornia crassipes) by using diluted hydrochloric acid and sulphuric acid as catalysts. This process involved the conversion of the pentosane fraction in water hyacinth into pentose, and then pentose was cyclodehydrated into furfural. The reaction was conducted in a distillation set with receiving the flask that contains chloroform. Furfural was identified by fehling test which was then characterized using Fourier Transform Infra Red (FTIR) and Proton Nuclear Magnetic Resonance (1H-NMR), followed by Gas Chromatography with Mass Spectroscopy (GC-MS). The yield of furfural obtained using sulphuric acid catalyst was 0.38% and hydrochloric acid catalyst was 0.01% of dried biomass.

  16. In vitro Activity of Celery Essential Oil against Malassezia furfur.

    PubMed

    Chee, Hee Youn; Lee, Min Hee

    2009-03-01

    Antifungal activity of celery essential oil against Malassezia furfur was investigated using broth microdilution and vapor contact methods. Potent antifungal activity was evident using both methods. Fungicidal activity was revealed in the vapor contact method.

  17. Investigation of the vasorelaxant effects of 3-(5'-hydroxymethyl-2'-furyl)-1-benzyl indazole (YC-1) and diethylamine/nitric oxide (DEA/NO) on the human radial artery used as coronary bypass graft.

    PubMed

    Berkan, Ocal; Bagcivan, Ihsan; Kaya, Tijen; Yildirim, Kemal; Yildirim, Sahin; Doğan, Kasim

    2007-05-01

    The radial artery (RA) is used as a spastic coronary bypass graft. This study was designed to investigate the mechanism of vasorelaxant effects of YC-1 (3-(5'-hydroxymethyl-2'-furyl)-1-benzyl indazole), a nitric oxide (NO)-independent soluble guanylate cyclase (sGC) activator, and DEA/NO (diethylamine/nitric oxide), a NO-nucleophile adduct, on the human RA. RA segments (n = 25) were obtained from coronary artery bypass grafting patients and were divided into 3-4 mm vascular rings. Using the isolated tissue bath technique, the endothelium-independent vasodilatation function was tested in vitro by the addition of cumulative concentrations of YC-1 (10-10 to 3 x 10-7 mol/L) and DEA/NO (10-8 to 3 x 10-5 mol/L) following vasocontraction by phenylephrine in the presence or absence of 10-5 mol/L ODQ (1H-(1,2,4)oxadiazole(4,3-a)quinoxalin-1-one), the selective sGC inhibitor, 10-7 mol/L iberiotoxin, a blocker of Ca2+-activated K+ channels, or 10-5 mol/L ODQ plus 10-7 mol/L iberiotoxin. We also evaluated the effect of YC-1 and DEA/NO on the cGMP levels in vascular rings obtained from human radial artery (n = 6 for each drug). YC-1 (10-10 to 3 x 10-7 mol/L) and DEA/NO (10-8 to 3 x 10-5 mol/L) caused the concentration-dependent vasorelaxation in RA rings precontracted with phenylephrine (10-5 mol/L) (n = 20 for each drug). Pre-incubation of RA rings with ODQ, iberiotoxin, or ODQ plus iberiotoxin significantly inhibited the vasorelaxant effect of YC-1, but the inhibitor effect of ODQ plus iberiotoxin was significantly more than that of ODQ and iberiotoxin alone (p < 0.05). The vasorelaxant effect of DEA/NO almost completely abolished in the presence of ODQ and iberiotoxin plus ODQ, but did not significantly change in the presence of iberiotoxin alone (p > 0.05). The pEC50 value of DEA/NO was significantly lower than those for YC-1 (p < 0.01), with no change Emax values in RA rings. In addition, YC-1-stimulated RA rings showed more elevation in cGMP than that of DEA/NO (p < 0

  18. Furfural as a marker of cellulose degradation. A quantitative approach

    NASA Astrophysics Data System (ADS)

    Łojewski, Tomasz; Sawoszczuk, Tomasz; Łagan, Janusz Marek; Zięba, Katarzyna; Barański, Andrzej; Łojewska, Joanna

    2010-09-01

    Non-destructive methods of sampling during the physicochemical studies of historical objects such as old books and manuscripts seem to be an obvious choice. Since furfural has been shown to be one of the most abundant gaseous products of cellulose degradation, it can be considered as a convenient marker of degradation progress. The number of quantitative data concerning correlations between the emission of furfural and physicochemical and mechanical properties of paper is rather scarce in the literature. In the present studies, a model paper containing more than 99% of cellulose was aged inside closed vials at 90°C. Gaseous products of paper degradation were measured using sorption tubes filled with Tenax TA sorbent and GC-MS. The method has proved to be sufficiently sensitive for measuring furfural emission not only in accelerated degradation at 90°C but also during natural ageing of paper at room temperature even in relatively short time intervals of 2-28 days. The correlations between furfural emission and polymerization degree, pH, color, tear index, number of double folds and breaking length have been statistically confirmed at confidence level α=0.001. Basing on them it was possible to estimate the number of broken glycosidic bonds per one molecule of furfural formed during degradation—we found a value equal to 9.2.

  19. Immediate hypersensitivity to Malassezia furfur in patients with atopic dermatitis.

    PubMed

    Khosravi, A R; Hedayati, M T; Mansouri, P; Shokri, H; Moazzeni, M

    2007-07-01

    Atopic dermatitis (AD) is a chronic pruritic dermatitis that has unknown aetiology. It seems that Malassezia furfur has a role in pathogenesis of AD. The purpose of this study was to evaluate skin responses to M. furfur antigens in AD patients. Malassezia furfur was grown and the yeasts were broken. Cells were centrifuged and supernatants were used as crude extracts (CE). Protein components of CE were separated by sodium dodecylsulphate-polyacrylamide gel electrophoresis (SDS-PAGE). In addition, to fractionate CE antigens, gel filtration chromatography was performed. One hundred and fifteen AD patients were selected for skin-prick test (SPT). In SDS-PAGE, CE showed a total of 19 different protein bands (10-100 kDa). Chromatographic gel filtration with M. furfur proteins showed four major fractions (F). The protein pattern of F(1) (tube no. 40) was between 22 and 100 kDa and it was selected for SPT. In SPT, 49.6% and 42.6% patients showed positive reactions with CE and F(1) antigens respectively. The most positive results were obtained in 20-29 aged group (P < 0.001). The allergens of M. furfur may have a role in AD signs; it is suggested to use F(1) antigens in allergy tests.

  20. Psychiatric components of a Health Maintenance Facility (HMF) on Space Station

    NASA Technical Reports Server (NTRS)

    Santy, Patricia A.

    1987-01-01

    The operational psychiatric requirements for a comprehensive Health Maintenance Facility (HMF) on a permanently manned Space Station are examined. Consideration is given to the psychological health maintenance program designed for the diagnosis of mental distress in astronauts during flight and for prevention of mental breakdown. The types of mental disorders that can possibly affect the astronauts in flight are discussed, including various organic, psychotic, and affective mental disorders, as well as anxiety, adjustment, and somatoform/dissociative disorders. Special attention is given to therapeutic considerations for psychiatric operations on Space Station, such as restraints, psychopharmacology, psychotherapy, and psychosocial support.

  1. Simultaneous determination of 2-furfural and 5-methyl-2-furfural using corona discharge ion mobility spectrometry.

    PubMed

    Jafari, M T; Khayamian, T

    2009-06-01

    A novel technique, corona discharge ion mobility spectrometry (CD-IMS), was developed for the qualitative and quantitative determination of 2-furfural (F) and 5-methyl-2-furfural (MF) in aqueous solutions. The limits of detection (LODs) were 5.3 x 10(-3) microg/mL for F and 6.7 x 10(-3) microg/mL for MF. The linear dynamic ranges of 1.16 x 10(-2) to 1.04 microg/mL and 2.20 x 10(-2) to 1.10 microg/mL were obtained for F and MF, respectively. The relative standard deviation was below 12% for both compounds. In addition to analysis of the individual compound, simultaneous determination of F and MF was also investigated. It was realized that F imposes a matrix effect on the MF signal and vice versa. The standard addition method was used to deal with the matrix effect. The recovery of the compounds in the synthetic samples validates the capability of the method.

  2. Reaction pathways of glucose during esterification: effects of reaction parameters on the formation of humin type polymers.

    PubMed

    Hu, Xun; Lievens, Caroline; Larcher, Alfons; Li, Chun-Zhu

    2011-11-01

    The formation of humin-type polymers and other products during exposure of glucose to methanol/water mixtures with methanol/water mass ratios from 10 to 0.22 in the presence of the acid catalyst Amberlyst 70 was investigated. In water-rich medium (methanol/water mass ratio: 0.22), dehydration of glucose produced 5-(hydroxymethyl)furfural (HMF), furfural, and substantial amounts of polymer. In methanol-rich medium (methanol/water mass ratio: 10), the hydroxyl and carbonyl groups of glucose, HMF or furfural were protected via etherification and acetalisation. These protections stabilized these reactive compounds and significantly lowered the polymer formation (1.43% of the glucose loaded). The polymerization of glucose and HMF was also favored at high temperatures and long residence times. Conversely, high catalyst dosage mainly accelerated the conversion of glucose to methyl levulinate. Thus, the polymerization of glucose and HMF can be suppressed in methanol/water mixtures with high methanol ratios, at low temperatures and short residence times.

  3. Degradation of 5-hydroxymethylfurfural during yeast fermentation.

    PubMed

    Akıllıoglu, Halise Gül; Mogol, Burçe Ataç; Gökmen, Vural

    2011-12-01

    5-Hydroxymethyl furfural (HMF) may occur in malt in high quantities depending on roasting conditions. However, the HMF content of different types of beers is relatively low, indicating its potential for degradation during fermentation. This study investigates the degradation kinetics of HMF in wort during fermentation by Saccharomyces cerevisiae. The results indicated that HMF decreased exponentially as fermentation progressed. The first-order degradation rate of HMF was 0.693 × 10(-2) and 1.397 × 10(-2)min(-1) for wort and sweet wort, respectively, indicating that sugar enhances the activity of yeasts. In wort, HMF was converted into hydroxymethyl furfuryl alcohol by yeasts with a high yield (79-84% conversion). Glucose and fructose were utilised more rapidly by the yeasts in dark roasted malt than in pale malt (p<0.05). The conversion of HMF into hydroxymethyl furfuryl alcohol seems to be a primary activity of yeast cells, and presence of sugars in the fermentation medium increases this activity.

  4. Influence of roasting on the antioxidant activity and HMF formation of a cocoa bean model systems.

    PubMed

    Oliviero, Teresa; Capuano, Edoardo; Cämmerer, Bettina; Fogliano, Vincenzo

    2009-01-14

    During the roasting of cocoa beans chemical reactions lead to the formation of Maillard reaction (MR) products and to the degradation of catechin-containing compounds, which are very abundant in these seeds. To study the modifications occurring during thermal treatment of fat and antioxidant rich foods, such as cocoa, a dry model system was set up and roasted at 180 degrees C for different times. The role played in the formation of MR products and in the antioxidant activity of the system by proteins, catechin, and cocoa butter was investigated by varying the model system formulation. Results showed that the antioxidant activity decreased during roasting, paralleling catechin concentration, thus suggesting that this compound is mainly responsible for the antioxidant activity of roasted cocoa beans. Model system browning was significantly higher in the presence of catechin, which contributed to the formation of water-insoluble melanoidins, which are mainly responsible for browning. HMF concentration was higher in casein-containing systems, and its formation was strongly inhibited in the presence of catechin. No effects related to the degree of lipid oxidation could be observed. Data from model systems obtained by replacing fat with water showed a much lower rate of MR development and catechin degradation but the same inhibitory effect of catechin on HMF formation.

  5. Negative cross-reactivity of rabbit anti-Malassezia furfur antibodies with other yeasts.

    PubMed

    Chua, Kaw Bing; Devi, Shamala; Ng, Kee Peng; Hooi, Poh Sim; Na, Shiang Ling; Chua, Kerk Hsiang

    2005-12-01

    Anti-Malassezia furfur monospecific polyclonal antibodies was produced by repeated immunization of rabbit with Malassezia furfur yeast cells mixed with Freud adjuvant. The antibody titres of respective rabbit's serum samples prior to and after each immunization against M. furfur were assayed by indirect immunofluorescence technique using the M. furfur whole yeast antigen fixed in Teflon coated slides. The highest anti-M. furfur antibody titre achieved was 1 in 1280 dilution. At 1:20 dilution, none of the respective serum samples taken at various stages of immunization gave positive immunofluorescent staining against any of the other species of yeasts tested in this study. Anti-M. furfur monospecific polyclonal antibodies produced in rabbit in this study has the potential for diagnostic application in immunohistochemical detection of M. furfur in human tissues.

  6. [Adsorption mechanism of furfural onto modified rice husk charcoals].

    PubMed

    Deng, Yong; Wang, Xianhua; Li, Yunchao; Shao, Jing'ai; Yang, Haiping; Chen, Hanping

    2015-10-01

    To evaluate the absorptive characteristics of furfural onto biomass charcoals derived from rice husk pyrolysis, we studied the information of the structure and surface chemistry properties of the rice husk charcoals modified by thermal treatment under nitrogen and carbon dioxide flow and adsorption mechanism of furfural. The modified samples are labeled as RH-N2 and RH-CO2. Fresh rice husk charcoal sample (RH-450) and modified samples were characterized by elemental analysis, nitrogen adsorption-desorption isotherms, Fourier-transform infrared spectroscopy and Boehm titration. The results show that fresh rice husk charcoal obtained at 450 degrees C had a large number of organic groups on its surface and poor pore structure. After the modification under nitrogen and carbon dioxide flow, oxygenic organics in rice husk charcoals decompose further, leading to the reduction of acidic functional groups on charcoals surface, and the increase of the pyrone structures of the basic groups. Meanwhile, pore structure was improved significantly and the surface area was increased, especially for the micropores. This resulted in the increase of π-π dispersion between the surfaces of rice husk charcoals and furfural molecular. With making comprehensive consideration of π-π dispersion and pore structure, the best removal efficiency of furfural was obtained by rice husk charcoal modified under carbon dioxide flow.

  7. Furfural--a promising platform for lignocellulosic biofuels.

    PubMed

    Lange, Jean-Paul; van der Heide, Evert; van Buijtenen, Jeroen; Price, Richard

    2012-01-09

    Furfural offers a promising, rich platform for lignocellulosic biofuels. These include methylfuran and methyltetrahydrofuran, valerate esters, ethylfurfuryl and ethyltetrahydrofurfuryl ethers as well as various C(10)-C(15) coupling products. The various production routes are critically reviewed, and the needs for improvements are identified. Their relative industrial potential is analysed by defining an investment index and CO(2) emissions as well as determining the fuel properties for the resulting products. Finally, the most promising candidate, 2-methylfuran, was subjected to a road trial of 90,000 km in a gasoline blend. Importantly, the potential of the furfural platform relies heavily on the cost-competitive production of furfural from lignocellulosic feedstock. Conventional standalone and emerging coproduct processes-for example, as a coproduct of cellulosic ethanol, levulinic acid or hydroxymethyl furfural-are expensive and energetically demanding. Challenges and areas that need improvement are highlighted. In addition to providing a critical review of the literature, this paper also presents new results and analysis in this area.

  8. Physiological and molecular characterization of atypical isolates of Malassezia furfur.

    PubMed

    González, A; Sierra, R; Cárdenas, M E; Grajales, A; Restrepo, S; Cepero de García, M C; Celis, A

    2009-01-01

    The species constituting the genus Malassezia are considered to be emergent opportunistic yeasts of great importance. Characterized as lipophilic yeasts, they are found in normal human skin flora and sometimes are associated with different dermatological pathologies. We have isolated seven Malassezia species strains that have a different Tween assimilation pattern from the one typically used to differentiate M. furfur, M. sympodialis, and M. slooffiae from other Malassezia species. In order to characterize these isolates of Malassezia spp., we studied their physiological features and conducted morphological and molecular characterization by PCR-restriction fragment length polymorphism and sequencing of the 26S and 5.8S ribosomal DNA-internal transcribed spacer 2 regions in three strains from healthy individuals, four clinical strains, and eight reference strains. The sequence analysis of the ribosomal region was based on the Blastn algorithm and revealed that the sequences of our isolates were homologous to M. furfur sequences. To support these findings, we carried out phylogenetic analyses to establish the relationship of the isolates to M. furfur and other reported species. All of our results confirm that all seven strains are M. furfur; the atypical assimilation of Tween 80 was found to be a new physiological pattern characteristic of some strains isolated in Colombia.

  9. Differentiation of Malassezia furfur and Malassezia sympodialis by glycine utilization.

    PubMed

    Murai, T; Nakamura, Y; Kano, R; Watanabe, S; Hasegawa, A

    2002-06-01

    The genus Malassezia has been revised to include six lipophilic species and one nonlipophilic species. These Malassezia species have been investigated to differentiate their morphological and physiological characteristics. However, assimilation of amino acids as a nitrogen source by these species was not well elucidated. In the present study, isolates of Malassezia species were examined with a glycine medium (containing 7-266 mmol glycine, 7.4 mmol KH(2)PO(4), 4.1 mmol MgSO(4)7H(2)O, 29.6 mmol thiamine, 0.5% Tween-80 and 2% agar) and a modified Dixon glycine medium (0.6% peptone, 3.6% malt extract, 2% ox-bile, 1% Tween-40, 0.2% glycerol, 0.2% oleic acid, 7 mmol glycine and 2% agar). All M. furfur isolates developed on the glycine medium, assimilating glycine at concentrations of at least 7 mmol l(-1). However, the other six Malassezia species were unable to grow on the glycine medium. Also, many colonies of M. furfur grew rapidly, within 2-3 days on the modified Dixon glycine medium, although the other six species showed slow and poor development. From these results, it was suggested that M. furfur might be able to utilize glycine as a single nitrogen source, which the other Malassezia species could not. Therefore, glycine medium was recommended for the differentiation of M. furfur from other species of Malassezia.

  10. Chlorogenic acid increased acrylamide formation through promotion of HMF formation and 3-aminopropionamide deamination.

    PubMed

    Cai, Yun; Zhang, Zhenhua; Jiang, Shanshan; Yu, Miao; Huang, Caihuan; Qiu, Ruixia; Zou, Yueyu; Zhang, Qirui; Ou, Shiyi; Zhou, Hua; Wang, Yong; Bai, Weibing; Li, Yiqun

    2014-03-15

    This research was aimed to investigate why chlorogenic acid, presents at high concentrations in some food raw material, influences acrylamide formation. In the asparagine/glucose Maillard reaction system (pH=6.8), addition of chlorogenic acid significantly increased acrylamide formation and inhibited its elimination. In contrast, the quinone derivative of chlorogenic acid decreased acrylamide formation. Three mechanisms may be involved for increasing acrylamide formation by chlorogenic acid. Firstly, it increased the formation of HMF, which acts as a more efficient precursor than glucose to form acrylamide. Secondly, it decreased activation energy for conversion of 3-aminopropionamide (3-APA) to acrylamide (from 173.2 to 136.6kJ/mol), and enhances deamination from 3-APA. And thirdly, it prevented attack of the produced acrylamide from free radicals by keeping high redox potential during the Maillard reaction.

  11. In vitro antifungal susceptibility of Malassezia furfur from bloodstream infections.

    PubMed

    Iatta, Roberta; Figueredo, Luciana A; Montagna, Maria Teresa; Otranto, Domenico; Cafarchia, Claudia

    2014-11-01

    Fungaemia caused by Malassezia spp. in hospitalized patients requires prompt and appropriate therapy, but standard methods for the definition of the in vitro antifungal susceptibility have not been established yet. In this study, the in vitro susceptibility of Malassezia furfur from bloodstream infections (BSIs) to amphotericin B (AMB), fluconazole (FLC), itraconazole (ITC), posaconazole (POS) and voriconazole (VRC) was assessed using the broth microdilution (BMD) method of the Clinical and Laboratory Standards Institute (CLSI) with different media such as modified Sabouraud dextrose broth (SDB), RPMI and Christensen's urea broth (CUB). Optimal broth media that allow sufficient growth of M. furfur, and produce reliable and reproducible MICs using the CLSI BMD protocol were assessed. Thirty-six M. furfur isolates collected from BSIs of patients before and during AMB therapy, and receiving FLC prophylaxis, were tested. A good growth of M. furfur was observed in RPMI, CUB and SDB at 32 °C for 48 and 72 h. No statistically significant differences were detected between the MIC values registered after 48 and 72 h incubation. ITC, POS and VRC displayed lower MICs than FLC and AMB. These last two antifungal drugs showed higher and lower MICs, respectively, when the isolates were tested in SDB. SDB is the only medium in which it is possible to detect isolates with high FLC MICs in patients receiving FLC prophylaxis. A large number of isolates showed high AMB MIC values regardless of the media used. In conclusion, SDB might be suitable to determine triazole susceptibility. However, the media, the drug formulation or the breakpoints herein applied might not be useful for assessing the AMB susceptibility of M. furfur from BSIs.

  12. A high performance liquid chromatography method for determination of furfural in crude palm oil.

    PubMed

    Loi, Chia Chun; Boo, Huey Chern; Mohammed, Abdulkarim Sabo; Ariffin, Abdul Azis

    2011-09-01

    A modified steam distillation method was developed to extract furfural from crude palm oil (CPO). The collected distillates were analysed using high performance liquid chromatography (HPLC) coupled with an ultraviolet diode detector at 284nm. The HPLC method allowed identification and quantification of furfural in CPO. The unique thermal extraction of CPO whereby the fresh fruit bunches (FFB) are first subjected to steam treatment, distinguishes itself from other solvent-extracted or cold-pressed vegetable oils. The presence of furfural was also determined in the fresh palm oil from FFB (without undergoing the normal extraction process), palm olein, palm stearin, olive oil, coconut oil, sunflower oil, soya oil and corn oil. The chromatograms of the extracts were compared to that of standard furfural. Furfural was only detected in CPO. The CPO consignments obtained from four mills were shown to contain 7.54 to 20.60mg/kg furfural.

  13. Synthesis and structural features of U VI and V IV chelate complexes with (hhmmbH)Cl·H 2O [hhmmb = {3-hydroxyl-5-(hydroxymethyl)-2-methylpyridine-4-yl-methylene}benzohydrazide], a new Schiff base ligand derived from vitamin B6

    NASA Astrophysics Data System (ADS)

    Back, Davi Fernando; Ballin, Marco Aurélio; de Oliveira, Gelson Manzoni

    2009-10-01

    The Schiff base ligand {3-hydroxyl-5-(hydroxymethyl)-2-methylpyridine-4-yl-methylene}benzohydrazide hydrochloride monohydrated {(hhmmbH)Cl·H 2O} ( 1) was prepared by reaction of pyridoxine hydrochloride with benzoic acid hydrazide. The reaction of 1 with [VO(acac) 2] and triethylamine yields the neutral vanadium IV complex [VO 2(hhmmb)]·Py ( 2), with a distorted quadratic pyramidal configuration. The Schiff base 1 reacts also with UO 2(NO 3) 2·6H 2O and triethylamine under deprotonation giving the uranium VI cationic complexes [UO 2(hhmmb)(H 2O)Cl] + ( 3) and [UO 2(hhmmb)(CH 3OH)Cl] + ( 4), both showing the classical pentagonal bipyrimidal geometry of UO22+ complexes. The structural features of all compounds are discussed.

  14. Degradation of furfural (2-furaldehyde) to methane and carbon dioxide by an anaerobic consortium

    SciTech Connect

    Rivard, C.J.; Grohmann, K.

    1991-12-31

    Furfural, a byproduct formed during the thermal/chemical pretreatment of hemicellulosic biomass, was degraded to methane and carbon dioxide under anaerobic conditions. The consortium of anaerobic microbes responsible for the degradation was enriched using small continuously stirred tank reactor (CSTR) systems with daily batch feeding of biomass pretreatment liquor and continuous addition of furfural. Although the continuous infusion of furfural was initially inhibitory to the anaerobic CSTR system, adaptation of the consortium occurred rapidly with high rates of furfural addition. Addition rates of 7.35 mg furfural/700-mL reactor/d resulted in biogas productions of 375%, of that produced in control CSTR systems, fed the biomass pretreatment liquor only. The anaerobic CSTR system fed high levels of furfural was stable, with a sludge pH of 7.1 and methane gas composition of 69%, compared to the control CSTR, which had a pH of 7.2 and 77% methane. CSTR systems in which furfural was continuously added resulted in 80% of the theoretically expected biogas. Intermediates in the anaerobic biodegradation of furfural were determined by spike additions in serum-bottle assays using the enriched consortium from the CSTR systems. Furfural was converted to several intermediates, including furfuryl alcohol, furoic acid, and acetic acid, before final conversion to methane and carbon dioxide.

  15. Synthesis and Verification of Biobased Terephthalic Acid from Furfural

    NASA Astrophysics Data System (ADS)

    Tachibana, Yuya; Kimura, Saori; Kasuya, Ken-Ichi

    2015-02-01

    Exploiting biomass as an alternative to petrochemicals for the production of commodity plastics is vitally important if we are to become a more sustainable society. Here, we report a synthetic route for the production of terephthalic acid (TPA), the monomer of the widely used thermoplastic polymer poly(ethylene terephthalate) (PET), from the biomass-derived starting material furfural. Biobased furfural was oxidised and dehydrated to give maleic anhydride, which was further reacted with biobased furan to give its Diels-Alder (DA) adduct. The dehydration of the DA adduct gave phthalic anhydride, which was converted via phthalic acid and dipotassium phthalate to TPA. The biobased carbon content of the TPA was measured by accelerator mass spectroscopy and the TPA was found to be made of 100% biobased carbon.

  16. Synthesis and Verification of Biobased Terephthalic Acid from Furfural

    PubMed Central

    Tachibana, Yuya; Kimura, Saori; Kasuya, Ken-ichi

    2015-01-01

    Exploiting biomass as an alternative to petrochemicals for the production of commodity plastics is vitally important if we are to become a more sustainable society. Here, we report a synthetic route for the production of terephthalic acid (TPA), the monomer of the widely used thermoplastic polymer poly(ethylene terephthalate) (PET), from the biomass-derived starting material furfural. Biobased furfural was oxidised and dehydrated to give maleic anhydride, which was further reacted with biobased furan to give its Diels-Alder (DA) adduct. The dehydration of the DA adduct gave phthalic anhydride, which was converted via phthalic acid and dipotassium phthalate to TPA. The biobased carbon content of the TPA was measured by accelerator mass spectroscopy and the TPA was found to be made of 100% biobased carbon. PMID:25648201

  17. Synthesis and verification of biobased terephthalic acid from furfural.

    PubMed

    Tachibana, Yuya; Kimura, Saori; Kasuya, Ken-ichi

    2015-02-04

    Exploiting biomass as an alternative to petrochemicals for the production of commodity plastics is vitally important if we are to become a more sustainable society. Here, we report a synthetic route for the production of terephthalic acid (TPA), the monomer of the widely used thermoplastic polymer poly(ethylene terephthalate) (PET), from the biomass-derived starting material furfural. Biobased furfural was oxidised and dehydrated to give maleic anhydride, which was further reacted with biobased furan to give its Diels-Alder (DA) adduct. The dehydration of the DA adduct gave phthalic anhydride, which was converted via phthalic acid and dipotassium phthalate to TPA. The biobased carbon content of the TPA was measured by accelerator mass spectroscopy and the TPA was found to be made of 100% biobased carbon.

  18. LCA of bioethanol and furfural production from vetiver.

    PubMed

    Raman, Jegannathan Kenthorai; Gnansounou, Edgard

    2015-06-01

    In this study a prospective life cycle assessment of biorefinery system from vetiver leaves was carried out to know the environmental benefits of this system over conventional systems considering the geographical context of India. The composition of vetiver leaves from the experimental analysis revealed that vetiver is rich in cellulose (32.6%), hemicellulose (31.5%) and lignin (17.3%) that could be used as a feedstock for biorefinery. The comparative life cycle assessment results show that the carbon dioxide emission and fossil oil depletion could be reduced by 95% and 23% respectively in case of standalone bioethanol system, and 99% and 17% respectively in case of bioethanol and furfural system compared to that of conventional petrol and furfural systems. The sensitivity study indicates that the impact could be further reduced if vetiver biomass is used as a source of energy in biorefinery plant instead to the coal.

  19. Effect of Furfural on Saccharomyces carlsbergensis Growth, Physiology and Ethanol Production.

    PubMed

    Lopes da Silva, Teresa; Santo, Rui; Reis, Alberto; Passarinho, Paula C

    2016-12-17

    This work described the effect of furfural, a product resulting from the lignocellulosic material pretreatment, on Saccharomyces carlsbergensis growth and ethanol production. Flow cytometry was used to evaluate the yeast membrane potential, membrane integrity, reactive oxygen species production and lipid content. Above 0.3 g/L of furfural, a progressive decrease in the maximal specific growth rate was observed, reaching 53% of the value obtained in the absence of toxic when the cells were grown in the presence of 4 g/L of furfural. In general, the yeast biomass concentration and yield were less affected by the furfural presence than the specific growth rate, and a maximum reduction of 25% was observed for the assay at 4 g/L. The ethanol production was even less affected by the furfural presence than the yeast growth. At 4 g/L of furfural, the maximum ethanol concentration was reduced by only 10% relatively to the maximum ethanol concentration observed in the absence of toxic. At 5 g/L of furfural, the yeast cells were barely able to keep metabolic functions and produced a final ethanol concentration of 0.87 g/L although growth was undetectable. S. carlsbergensis membrane potential was affected by the furfural presence, concomitantly with the ethanol production. However, at 4 g/L, most of the yeast cells (90%) displayed the cytoplasmic membrane depolarized. The proportion of cells with increasing reactive oxygen species (ROS) production levels increased for the experiments at 0-4 g/L. For the experiment at 4.5 g/L of furfural, ROS production was observed for only 11% of the yeast cells. The yeast lipid content was also severely affected by the furfural presence. Both polar and neutral lipids decreased in the presence of furfural, and this reduction was more notorious during the stationary phase.

  20. Corn stover saccharification with concentrated sulfuric acid: effects of saccharification conditions on sugar recovery and by-product generation.

    PubMed

    Liu, Ze-Shen; Wu, Xiao-Lei; Kida, Kenji; Tang, Yue-Qin

    2012-09-01

    Although concentrated sulfuric acid saccharification is not a novel method for breaking down lignocellulosic biomass, the process by which saccharification affects biomass decomposition, sugar recovery, and by-product generation is not well studied. The present study employed Taguchi experimental design to study the effects of seven parameters on corn stover concentrated sulfuric acid saccharification. The concentration of sulfuric acid and the temperature of solubilization significantly affect corn stover decomposition. They also have significant effects on glucose and xylose recoveries. Low generation of furfural and 5-hydroxymethyl-2-furfural (5HMF) was noted and organic acids were the main by-products detected in the hydrolysate. Temperature also significantly affected the generation of levulinic acid and formic acid; however, acetic acid generation was not significantly influenced by all seven parameters. The ratio of acid to feedstock significantly affected glucose recovery, but not total sugar recovery. The corn stover hydrolysate was well fermented by both glucose- and xylose-fermenting yeast strains.

  1. Impacts of lignocellulose-derived inhibitors on L-lactic acid fermentation by Rhizopus oryzae.

    PubMed

    Zhang, Li; Li, Xin; Yong, Qiang; Yang, Shang-Tian; Ouyang, Jia; Yu, Shiyuan

    2016-03-01

    Inhibitors generated in the pretreatment and hydrolysis of corn stover and corn cob were identified. In general, they inhibited cell growth, lactate dehydrogenase, and lactic acid production but with less or no adverse effect on alcohol dehydrogenase and ethanol production in batch fermentation by Rhizopus oryzae. Furfural and 5-hydroxymethyl furfural (HMF) were highly toxic at 0.5-1 g L(-1), while formic and acetic acids at less than 4 g L(-1) and levulinic acid at 10 g L(-1) were not toxic. Among the phenolic compounds at 1 g L(-1), trans-cinnamic acid and syringaldehyde had the highest toxicity while syringic, ferulic and p-coumaric acids were not toxic. Although these inhibitors were present at concentrations much lower than their separately identified toxic levels, lactic acid fermentation with the hydrolysates showed much inferior performance compared to the control without inhibitor, suggesting synergistic or compounded effects of the lignocellulose-degraded compounds on inhibiting lactic acid fermentation.

  2. Cellulose Biorefinery Based on a Combined Catalytic and Biotechnological Approach for Production of 5-HMF and Ethanol.

    PubMed

    Sorokina, Ksenia N; Taran, Oxana P; Medvedeva, Tatiana B; Samoylova, Yuliya V; Piligaev, Alexandr V; Parmon, Valentin N

    2017-02-08

    In this study, a combination of catalytic and biotechnological processes was proposed for the first time for application in a cellulose biorefinery for the production of 5-hydroxymethylfurfural (5-HMF) and bioethanol. Hydrolytic dehydration of the mechanically activated microcrystalline cellulose over a carbon-based mesoporous Sibunt-4 catalyst resulted in moderate yields of glucose and 5-HMF (21.1-25.1 and 6.6-9.4 %). 5-HMF was extracted from the resulting mixture with isobutanol and subjected to ethanol fermentation. A number of yeast strains were isolated that also revealed high thermotolerance (up to 50 °C) and resistance to inhibitors found in the hydrolysates. The strains Kluyveromyces marxianus C1 and Ogataea polymorpha CBS4732 were capable of producing ethanol from processed catalytic hydrolysates of cellulose at 42 °C, with yields of 72.0±5.7 and 75.2±4.3 % from the maximum theoretical yield of ethanol, respectively.

  3. Biotransformation of 5-hydroxymethylfurfural (HMF) by Scheffersomyces stipitis during ethanol fermentation of hydrolysate of the seaweed Gelidium amansii.

    PubMed

    Ra, Chae Hun; Jeong, Gwi-Taek; Shin, Myung Kyo; Kim, Sung-Koo

    2013-07-01

    The seaweed, Gelidium amansii, was fermented to produce bioethanol. Optimal pretreatment condition was determined as 94 mM H2SO4 and 10% (w/v) seaweed slurry at 121°C for 60 min. The mono sugars of 43.5 g/L with 57.4% of conversion from total carbohydrate of 75.8 g/L with G. amansii slurry 100g dcw/L were obtained by thermal acid hydrolysis pretreatment and enzymatic saccharification. G. amansii hydrolysate was used as the substrate for ethanol production by separate hydrolysis and fermentation (SHF). The ethanol concentration of 20.5 g/L was produced by Scheffersomyces stipitis KCTC 7228. The effect of HMF on ethanol production by S. stipitis KCTC 7228 was evaluated and 5-hydroxymethylfurfural (HMF) was converted to 2,5-bis-hydroxymethylfuran. The accumulated 2,5-bis-hydroxymethylfuran in the medium did not affect galactose and glucose uptakes and ethanol production. Biotransformation of HMF to less inhibitory compounds by S. stipitis KCTC 7228 could enhance overall fermentation yields of seaweed hydrolysates to ethanol.

  4. High temperature dilute phosphoric acid pretreatment of corn stover for furfural and ethanol production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Furfural was produced from corn stover by one stage pretreatment process using dilute H3PO4 and solid residues following furfural production were used for ethanol production by Saccharomyces cerevisiae NRRL- Y2034. A series of experiments were conducted at varied temperatures (140-200 oC) and acid ...

  5. Value of Coproduction of Ethanol and Furfural from Acid Hydrolysis Processes

    SciTech Connect

    Parker, S.; Calnon, M.; Feinberg, D.; Power, A.; Weiss, L.

    1984-05-01

    In the acid hydrolysis of a cellulosic feedstock (wood, wood wastes, or crop residues), up to 3.65 lb of furfural may be coproduced with each gallon of ethanol for only the cost of recovering and purifying it. Each plant producing 50 x 106 gal/yr of ethanol would produce an amount of by-product furfural equal to the total current domestic production. Thus, the need arises for investigation into potentially suitable processes for deriving profitable end products from furfural and thus expanding the market. The objectives of this study were to determine the economic potential of five selected, large volume derivatives of furfural that could displace hydrocarbon-based chemicals, and the consequent value of furfural as a by-product to the cellulose hydrolysis process of ethanol production.

  6. Polymeric reaction between aldehyde group in furfural and phenolic derivatives from liquefaction of oil palm empty fruit bunch fiber as phenol-furfural resin

    NASA Astrophysics Data System (ADS)

    Masli, M. Z.; Zakaria, S.; Chia, C. H.; Roslan, R.

    2016-11-01

    Resinification of liquefied empty fruit bunch with furfural (LEFB-Fu) was performed. During the resinification process, the samples were taken every hour up to 4 hours. FTIR analysis of the samples was conducted to understand the progress of the reaction. It showed that the bands of 1512 cm-1 and 1692 cm-1 evolving and diminishing respectively, indicating the consumption of furfural. The postulation of polymerization was also proven as the increasing extent of substitution of aromatic ring observed.

  7. The potential of residues of furfural and biogas as calcareous soil amendments for corn seed production.

    PubMed

    Zhao, Yunchen; Yan, Zhibin; Qin, Jiahai; Ma, Zhijun; Zhang, Youfu; Zhang, Li

    2016-04-01

    Intensive corn seed production in Northwest of China produced large amounts of furfural residues, which represents higher treatment cost and environmental issue. The broad calcareous soils in the Northwest of China exhibit low organic matter content and high pH, which led to lower fertility and lower productivity. Recycling furfural residues as soil organic and nutrient amendment might be a promising agricultural practice to calcareous soils. A 3-year field study was conducted to evaluate the effects of furfural as a soil amendment on corn seed production on calcareous soil with compared to biogas residues. Soil physical-chemical properties, soil enzyme activities, and soil heavy metal concentrations were assessed in the last year after the last application. Corn yield was determined in each year. Furfural residue amendments significantly decreased soil pH and soil bulk density. Furfural residues combined with commercial fertilizers resulted in the greater cumulative on soil organic matter, total phosphorus, available phosphorus, available potassium, and cation exchange capacity than that of biogas residue. Simultaneously, urease, invertase, catalase, and alkaline phosphatase increased even at the higher furfural application rates. Maize seed yield increased even with lower furfural residue application rates. Furfural residues resulted in lower Zn concentration and higher Cd concentration than that of biogas residues. Amendment of furfural residues led to higher soil electrical conductivity (EC) than that of biogas residues. The addition of furfural residues to maize seed production may be considered to be a good strategy for recycling the waste, converting it into a potential resource as organic amendment in arid and semi-arid calcareous soils, and may help to reduce the use of mineral chemical fertilizers in these soils. However, the impact of its application on soil health needs to be established in long-term basis.

  8. Metabolic Engineering of Raoultella ornithinolytica BF60 for Production of 2,5-Furandicarboxylic Acid from 5-Hydroxymethylfurfural.

    PubMed

    Hossain, Gazi Sakir; Yuan, Haibo; Li, Jianghua; Shin, Hyun-Dong; Wang, Miao; Du, Guocheng; Chen, Jian; Liu, Long

    2017-01-01

    2,5-Furandicarboxylic acid (FDCA) is an important renewable biotechnological building block because it serves as an environmentally friendly substitute for terephthalic acid in the production of polyesters. Currently, FDCA is produced mainly via chemical oxidation, which can cause severe environmental pollution. In this study, we developed an environmentally friendly process for the production of FDCA from 5-hydroxymethyl furfural (5-HMF) using a newly isolated strain, Raoultella ornithinolytica BF60. First, R. ornithinolytica BF60 was identified by screening and was isolated. Its maximal FDCA titer was 7.9 g/liter, and the maximal molar conversion ratio of 5-HMF to FDCA was 51.0% (mol/mol) under optimal conditions (100 mM 5-HMF, 45 g/liter whole-cell biocatalyst, 30°C, and 50 mM phosphate buffer [pH 8.0]). Next, dcaD, encoding dicarboxylic acid decarboxylase, was mutated to block FDCA degradation to furoic acid, thus increasing FDCA production to 9.2 g/liter. Subsequently, aldR, encoding aldehyde reductase, was mutated to prevent the catabolism of 5-HMF to HMF alcohol, further increasing the FDCA titer, to 11.3 g/liter. Finally, the gene encoding aldehyde dehydrogenase 1 was overexpressed. The FDCA titer increased to 13.9 g/liter, 1.7 times that of the wild-type strain, and the molar conversion ratio increased to 89.0%.

  9. Facile electrochemical method and corresponding automated instrument for the detection of furfural in insulation oil.

    PubMed

    Wang, Ruili; Huang, Xinjian; Wang, Lishi

    2016-02-01

    Determining the concentration of furfural contained in the insulation oil of a transformer has been established as a method to evaluate the health status of the transformer. However, the detection of furfural involves the employment of expensive instruments and/or time-consuming laboratorial operations. In this paper, we proposed a convenient electrochemical method to make the detection. The quantification of furfural was realized by extraction of furfural from oil phase to aqueous phase followed by reductive detection of furfural with differential pulse voltammetry (DPV) at a mercury electrode. This method is very sensitive and the limit of detection, corresponding to furfural contained in oil, is estimated to be 0.03 μg g(-1). Furthermore, excellent linearity can be obtained in the range of 0-10 μg g(-1). These features make the method very suitable for the determination of furfural in real situation. A fully automated instrument that can perform the operations of extraction and detection was developed, and this instrument enables the whole measurement to be finished within eight minutes. The methodology and the instrument were tested with real samples, and very favorable agreement between results obtained with this instrument and HPLC indicates that the proposed method along with instrument can be employed as a facile tool to diagnose the health status of aged transformers.

  10. FudC, a protein primarily responsible for furfural detoxification in Corynebacterium glutamicum.

    PubMed

    Tsuge, Yota; Kudou, Motonori; Kawaguchi, Hideo; Ishii, Jun; Hasunuma, Tomohisa; Kondo, Akihiko

    2016-03-01

    Lignocellulosic hydrolysates contain compounds that inhibit microbial growth and fermentation, thereby decreasing the productivity of biofuel and biochemical production. In particular, the heterocyclic aldehyde furfural is one of the most toxic compounds found in these hydrolysates. We previously demonstrated that Corynebacterium glutamicum converts furfural into the less toxic compounds furfuryl alcohol and 2-furoic acid. To date, however, the genes involved in these oxidation and reduction reactions have not been identified in the C. glutamicum genome. Here, we show that Cgl0331 (designated FudC) is mainly responsible for the reduction of furfural into furfuryl alcohol in C. glutamicum. Deletion of the gene encoding FudC markedly diminished the in vivo reduction of furfural to furfuryl alcohol. Purified His-tagged FudC protein from Escherichia coli was also shown to convert furfural into furfuryl alcohol in an in vitro reaction utilizing NADPH, but not NADH, as a cofactor. Kinetic measurements demonstrated that FudC has a high affinity for furfural but has a narrow substrate range for other aldehydes compared to the protein responsible for furfural reduction in E. coli.

  11. Extreme furfural tolerance of a soil bacterium Enterobacter cloacae GGT036.

    PubMed

    Choi, Sun Young; Gong, Gyeongtaek; Park, Hong-Sil; Um, Youngsoon; Sim, Sang Jun; Woo, Han Min

    2015-01-10

    Detoxification process of cellular inhibitors including furfural is essential for production of bio-based chemicals from lignocellulosic biomass. Here we isolated an extreme furfural-tolerant bacterium Enterobacter cloacae GGT036 from soil sample collected in Mt. Gwanak, Republic of Korea. Among isolated bacteria, only E. cloacae GGT036 showed cell growth with 35 mM furfural under aerobic culture. Compared to the maximal half inhibitory concentration (IC50) of well-known industrial strains Escherichia coli (24.9 mM furfural) and Corynebacterium glutamicum (10 mM furfural) based on the cell density, IC50 of E. cloacae GGT036 (47.7 mM) was significantly higher after 24 h, compared to E. coli and C. glutamicum. Since bacterial cell growth was exponentially inhibited depending on linearly increased furfural concentrations in the medium, we concluded that E. cloacae GGT036 is an extreme furfural-tolerant bacterium. Recently, the complete genome sequence of E. cloacae GGT036 was announced and this could provide an insight for engineering of E. cloacae GGT036 itself or other industrially relevant bacteria.

  12. Evaluation of a nonsteroidal topical cream in a guinea pig model of Malassezia furfur infection.

    PubMed

    Nalamothu, Vijendra; O'Leary, Ann L; Kandavilli, Sateesh; Fraser, Joanne; Pandya, Vishvabhavan

    2009-01-01

    Malassezia furfur is an important causal factor for seborrheic dermatitis, and topical antifungal therapy is an effective treatment approach. This study assessed the antifungal activity of Promiseb Topical Cream (Promius Pharma, LLC, Bridgewater, NJ), a novel nonsteroidal prescription medical device cream, in the M furfur-infected skin model for guinea pigs. Guinea pigs (N = 28) were divided into 4 groups and infected with M furfur for 7 days. On day 8, the first group of animals was sacrificed. The scrapings of inoculation site on each animal were tested for the presence of the organism, and the skin was excised for quantitation of M furfur. The second group was left untreated. The remaining 2 groups were treated with one of the test agents (Promiseb) and the positive control product (ciclopirox olamine cream, 0.77%; Loprox, Medicis, Scottsdale, AZ) each once daily for 3 days. At the end of treatment, animals were sacrificed and analyzed similarly to the first group. M furfur was recovered from all animals in the first group. Visual signs of infection, such as erythema and edema, were not observed in the infected animals at the end of the study. In the animals treated for 3 days with the test agents, the M furfur counts were reduced to below the limit of quantitation. Both test agents were equally effective in substantially reducing the density of M furfur compared with the untreated control.

  13. Genetic and biological features of catheter-associated Malassezia furfur from hospitalized adults.

    PubMed

    Kaneko, Takamasa; Murotani, Makiko; Ohkusu, Kiyofumi; Sugita, Takashi; Makimura, Koichi

    2012-01-01

    Malassezia furfur, an etiological agent of catheter-associated fungemia, requires long-chain fatty acids for in vitro growth. We examined the applicability of rDNA sequence analysis, autoaggregation testing in liquid culture, utilization of parenteral lipid emulsions, and phospholipase activity for discrimination of catheter-associated M. furfur strains. The rDNA sequence types of catheter-associated M. furfur strains were distinct from those of other isolates. All M. furfur isolates recovered from blood culture bottles and the tips of catheters from patients receiving fat emulsion therapy were type I-3. Only M. furfur isolate GIFU 01 from a blood culture bottle showed no autoaggregation in liquid culture. All strains of M. furfur examined grew well on Sabouraud's dextrose agar supplemented with Intralipid lipid emulsion as compared to individual Tweens (20, 40, 60, 80) and Cremophor EL. A high percentage of type I-3 M. furfur strains (80.0%) showed very high phospholipase activity compared to type I-1 and I-4 strains obtained from healthy skin of the same subjects or healthy control subjects (20.0% and 0.0%, respectively). The blood culture bottle isolate GIFU 01 showed very high lipolytic enzymes activity for Intralipid but no phospholipase activity. These results suggest that particular factors, such as non-autoaggregation and very high lipolytic enzyme activity for parenteral lipid emulsions, play important roles in the growth and pathogenicity of Malassezia-related sepsis.

  14. Molecular characterization of the thi3 gene involved in thiamine biosynthesis in Zea mays: cDNA sequence and enzymatic and structural properties of the recombinant bifunctional protein with 4-amino-5-hydroxymethyl-2-methylpyrimidine (phosphate) kinase and thiamine monophosphate synthase activities.

    PubMed

    Rapala-Kozik, Maria; Olczak, Mariusz; Ostrowska, Katarzyna; Starosta, Agata; Kozik, Andrzej

    2007-12-01

    A thiamine biosynthesis gene, thi3, from maize Zea mays has been identified through cloning and sequencing of cDNA and heterologous overexpression of the encoded protein, THI3, in Escherichia coli. The recombinant THI3 protein was purified to homogeneity and shown to possess two essentially different enzymatic activities of HMP(-P) [4-amino-5-hydroxymethyl-2-methylpyrimidine (phosphate)] kinase and TMP (thiamine monophosphate) synthase. Both activities were characterized in terms of basic kinetic constants, with interesting findings that TMP synthase is uncompetitively inhibited by excess of one of the substrates [HMP-PP (HMP diphosphate)] and ATP. A bioinformatic analysis of the THI3 sequence suggested that these activities were located in two distinct, N-terminal kinase and C-terminal synthase, domains. Models of the overall folds of THI3 domains and the arrangements of active centre residues were obtained with the SWISS-MODEL protein modelling server, on the basis of the known three-dimensional structures of Salmonella enterica serotype Typhimurium HMP(-P) kinase and Bacillus subtilis TMP synthase. The essential roles of Gln98 and Met134 residues for HMP kinase activity and of Ser444 for TMP synthase activity were experimentally confirmed by site-directed mutagenesis.

  15. Organic Carbonates: Efficient Extraction Solvents for the Synthesis of HMF in Aqueous Media with Cerium Phosphates as Catalysts.

    PubMed

    Dibenedetto, Angela; Aresta, Michele; di Bitonto, Luigi; Pastore, Carlo

    2016-01-08

    We describe a process for the selective conversion of C6 -polyols into 5-hydroxymethylfurfural (5-HMF) in biphasic systems of organic carbonate/water (OC/W), with cerium(IV) phosphates as catalysts. Different reaction parameters such as the OC/W ratio, catalyst loading, reaction time, and temperature, were investigated for the dehydration of fructose. Under the best reaction conditions, a yield of 67.7 % with a selectivity of 93.2 % was achieved at 423 K after 6 h of reaction using [(Ce(PO4)1.5 (H2 O)(H3 O)0.5 (H2 O)0.5)] as the catalyst. A maximum yield of 70 % with the same selectivity was achieved after 12 h. At the end of the reaction, the catalyst was removed by centrifugation, the organic phase was separated from water and evaporated in vacuo (with solvent recovery), and solid 5-HMF was isolated (purity >99 %). The recovery and reuse of the catalyst and the relationship between the structure of the OC and the efficiency of the extraction are discussed. The OC/W system influences the lifetime of the catalysts positively compared to only water.

  16. Competitive adsorption of furfural and phenolic compounds onto activated carbon in fixed bed column.

    PubMed

    Sulaymon, Abbas H; Ahmed, Kawther W

    2008-01-15

    For a multicomponent competitive adsorption of furfural and phenolic compounds, a mathematical model was builtto describe the mass transfer kinetics in a fixed bed column with activated carbon. The effects of competitive adsorption equilibrium constant, axial dispersion, external mass transfer, and intraparticle diffusion resistance on the breakthrough curve were studied for weakly adsorbed compound (furfural) and strongly adsorbed compounds (parachlorophenol and phenol). Experiments were carried out to remove the furfural and phenolic compound from aqueous solution. The equilibrium data and intraparticle diffusion coefficients obtained from separate experiments in a batch adsorber, by fitting the experimental data with theoretical model. The results show that the mathematical model includes external mass transfer and pore diffusion using nonlinear isotherms and provides a good description of the adsorption process for furfural and phenolic compounds in a fixed bed adsorber.

  17. Influence of Biomass Pretreatment Process Time on Furfural Extraction from Birch Wood

    NASA Astrophysics Data System (ADS)

    Brazdausks, Prans; Puke, Maris; Vedernikovs, Nikolajs; Kruma, Irena

    2013-12-01

    Furfural is a biomass derived-chemical that can be used to replace petrochemicals. In this study, dilute sulphuric acid hydrolysis was used for hemicelluloses secession from birch wood. The reaction was investigated at different biomass treatment times (10-90 min, increasing it by 10 min). We found that the greatest amount of furfural 1.4-2.6%, which is 9.7-17.7% from theoretical possible yield, was formed in the first 30 min of the beginning of birch wood pentoses monosaccharide dehydration, but the greatest yield of furfural 10.3%, which is 70.0% from the theoretical yield, can be obtained after 90 min. Given that furfural yield generally does not exceed 50% from the theoretical amount, the result can be considered as very good.

  18. Electron- and photon-impact ionization of furfural

    NASA Astrophysics Data System (ADS)

    Jones, D. B.; Ali, E.; Nixon, K. L.; Limão-Vieira, P.; Hubin-Franskin, M.-J.; Delwiche, J.; Ning, C. G.; Colgan, J.; Murray, A. J.; Madison, D. H.; Brunger, M. J.

    2015-11-01

    The He(i) photoelectron spectrum of furfural has been investigated, with its vibrational structure assigned for the first time. The ground and excited ionized states are assigned through ab initio calculations performed at the outer-valence Green's function level. Triple differential cross sections (TDCSs) for electron-impact ionization of the unresolved combination of the 4a″ + 21a' highest and next-highest occupied molecular orbitals have also been obtained. Experimental TDCSs are recorded in a combination of asymmetric coplanar and doubly symmetric coplanar kinematics. The experimental TDCSs are compared to theoretical calculations, obtained within a molecular 3-body distorted wave framework that employed either an orientation average or proper TDCS average. The proper average calculations suggest that they may resolve some of the discrepancies regarding the angular distributions of the TDCS, when compared to calculations employing the orbital average.

  19. Electron- and photon-impact ionization of furfural

    SciTech Connect

    Jones, D. B.; Ali, E.; Madison, D. H. E-mail: madison@mst.edu; Nixon, K. L.; Limão-Vieira, P. E-mail: madison@mst.edu; Hubin-Franskin, M.-J.; Delwiche, J.; Ning, C. G.; Colgan, J.; Murray, A. J.; and others

    2015-11-14

    The He(I) photoelectron spectrum of furfural has been investigated, with its vibrational structure assigned for the first time. The ground and excited ionized states are assigned through ab initio calculations performed at the outer-valence Green’s function level. Triple differential cross sections (TDCSs) for electron-impact ionization of the unresolved combination of the 4a″  +  21a′ highest and next-highest occupied molecular orbitals have also been obtained. Experimental TDCSs are recorded in a combination of asymmetric coplanar and doubly symmetric coplanar kinematics. The experimental TDCSs are compared to theoretical calculations, obtained within a molecular 3-body distorted wave framework that employed either an orientation average or proper TDCS average. The proper average calculations suggest that they may resolve some of the discrepancies regarding the angular distributions of the TDCS, when compared to calculations employing the orbital average.

  20. Catalytic conversion of cellulose to chemicals in ionic liquid.

    PubMed

    Tao, Furong; Song, Huanling; Chou, Lingjun

    2011-01-03

    A simple and effective route for the production of 5-hydroxymethyl furfural (HMF) and furfural from microcrystalline cellulose (MCC) has been developed. CoSO(4) in an ionic liquid, 1-(4-sulfonic acid) butyl-3-methylimidazolium hydrogen sulfate (IL-1), was found to be an efficient catalyst for the hydrolysis of cellulose at 150°C, which led to 84% conversion of MCC after 300min reaction time. In the presence of a catalytic amount of CoSO(4), the yields of HMF and furfural were up to 24% and 17%, respectively; a small amount of levulinic acid (LA) and reducing sugars (8% and 4%, respectively) were also generated. Dimers of furan compounds were detected as the main by-products through HPLC-MS, and with the help of mass spectrometric analysis, the components of gas products were methane, ethane, CO, CO(2,) and H(2). A mechanism for the CoSO(4)-IL-1 hydrolysis system was proposed and IL-1 was recycled for the first time, which exhibited favorable catalytic activity over five repeated runs. This catalytic system may be valuable to facilitate energy-efficient and cost-effective conversion of biomass into biofuels and platform chemicals.

  1. Characterization and fermentation of dilute-acid hydrolyzates from wood

    SciTech Connect

    Taherzadeh, M.J.; Niklasson, C.; Liden, G.; Eklund, R.; Gustafsson, L.

    1997-11-01

    Dilute-acid hydrolyzates from alder, aspen, birch, willow, pine, and spruce were fermented without prior detoxification. The hydrolyzates were prepared by a one-stage hydrolysis process using sulfuric acid (5 g/L) at temperatures between 188 and 234 C and with a holding time of 7 min. The fermentations were carried out anaerobically by Saccharomyces cerevisiae (10 g of d.w./L) at a temperature of 30 C and an initial pH of 5.5. The fermentabilities were quite different for the different wood species, and only hydrolyzates of spruce produced at 188 and 198 C, hydrolyzates of pine produced at 188 C, and hydrolyzates of willow produced at 198 C could be completely fermented within 24 h. From the sum of the concentrations of the known inhibitors furfural and 5-(hydroxymethyl)furfural (HMF), a good prediction of the maximum ethanol production rate could be obtained, regardless of the origin of the hydrolyzate. Furthermore, in hydrolyzates that fermented well, furfural and HMF were found to be taken up and converted by the yeast, concomitant with the uptake of glucose.

  2. Comparison of ionospheric F2 peak parameters foF2 and hmF2 with IRI2001 at Hainan

    NASA Astrophysics Data System (ADS)

    Wang, X.; Shi, J. K.; Wang, G. J.; Gong, Y.

    2009-06-01

    Monthly median values of foF2, hmF2 and M(3000)F2 parameters, with quarter-hourly time interval resolution for the diurnal variation, obtained with DPS4 digisonde at Hainan (19.5°N, 109.1°E; Geomagnetic coordinates: 178.95°E, 8.1°N) are used to investigate the low-latitude ionospheric variations and comparisons with the International Reference Ionosphere (IRI) model predictions. The data used for the present study covers the period from February 2002 to April 2007, which is characterized by a wide range of solar activity, ranging from high solar activity (2002) to low solar activity (2007). The results show that (1) Generally, IRI predictions follow well the diurnal and seasonal variation patterns of the experimental values of foF2, especially in the summer of 2002. However, there are systematic deviation between experimental values and IRI predictions with either CCIR or URSI coefficients. Generally IRI model greatly underestimate the values of foF2 from about noon to sunrise of next day, especially in the afternoon, and slightly overestimate them from sunrise to about noon. It seems that there are bigger deviations between IRI Model predictions and the experimental observations for the moderate solar activity. (2) Generally the IRI-predicted hmF2 values using CCIR M(3000)F2 option shows a poor agreement with the experimental results, but there is a relatively good agreement in summer at low solar activity. The deviation between the IRI-predicted hmF2 using CCIR M(3000)F2 and observed hmF2 is bigger from noon to sunset and around sunrise especially at high solar activity. The occurrence time of hmF2 peak (about 1200 LT) of the IRI model predictions is earlier than that of observations (around 1500 LT). The agreement between the IRI hmF2 obtained with the measured M(3000)F2 and the observed hmF2 is very good except that IRI overestimates slightly hmF2 in the daytime in summer at high solar activity and underestimates it in the nighttime with lower values near

  3. Photocatalytic degradation of furfural in aqueous solution by N-doped titanium dioxide nanoparticles.

    PubMed

    Veisi, Farzaneh; Zazouli, Mohammad Ali; Ebrahimzadeh, Mohammad Ali; Charati, Jamshid Yazdani; Dezfoli, Amin Shiralizadeh

    2016-11-01

    The photocatalytic degradation of furfural in aqueous solution was investigated using N-doped titanium dioxide nanoparticles under sunlight and ultraviolet radiation (N-TiO2/Sun and N-TiO2/UV) in a lab-scale batch photoreactor. The N-TiO2 nanoparticles prepared using a sol-gel method were characterized using XRD, X-ray photoelectron spectroscopy (XPS), and SEM analyses. Using HPLC to monitor the furfural concentration, the effect of catalyst dosage, contact time, initial solution pH, initial furfural concentration, and sunlight or ultraviolet radiation on the degradation efficiency was studied. The efficiency of furfural removal was found to increase with increased reaction time, nanoparticle loading, and pH for both processes, whereas the efficiency decreased with increased furfural concentration. The maximum removal efficiencies for the N-TiO2/UV and N-TiO2/Sun processes were 97 and 78 %, respectively, whereas the mean removal efficiencies were 80.71 ± 2.08 % and 62.85 ± 2.41 %, respectively. In general, the degradation and elimination rate of furfural using the N-TiO2/UV process was higher than that using the N-TiO2/Sun process.

  4. Flux control-based design of furfural-resistance strains of Saccharomyces cerevisiae for lignocellulosic biorefinery.

    PubMed

    Unrean, Pornkamol

    2016-12-26

    We have previously developed a dynamic flux balance analysis of Saccharomyces cerevisiae for elucidation of genome-wide flux response to furfural perturbation (Unrean and Franzen, Biotechnol J 10(8):1248-1258, 2015). Herein, the dynamic flux distributions were analyzed by flux control analysis to identify target overexpressed genes for improved yeast robustness against furfural. The flux control coefficient (FCC) identified overexpressing isocitrate dehydrogenase (IDH1), a rate-controlling flux for ethanol fermentation, and dicarboxylate carrier (DIC1), a limiting flux for cell growth, as keys of furfural-resistance phenotype. Consistent with the model prediction, strain characterization showed 1.2- and 2.0-fold improvement in ethanol synthesis and furfural detoxification rates, respectively, by IDH1 overexpressed mutant compared to the control. DIC1 overexpressed mutant grew at 1.3-fold faster and reduced furfural at 1.4-fold faster than the control under the furfural challenge. This study hence demonstrated the FCC-based approach as an effective tool for guiding the design of robust yeast strains.

  5. A novel method for furfural recovery via gas stripping assisted vapor permeation by a polydimethylsiloxane membrane

    PubMed Central

    Hu, Song; Guan, Yu; Cai, Di; Li, Shufeng; Qin, Peiyong; Karim, M. Nazmul; Tan, Tianwei

    2015-01-01

    Furfural is an important platform chemical with a wide range of applications. However, due to the low concentration of furfural in the hydrolysate, the conventional methods for furfural recovery are energy-intensive and environmentally unfriendly. Considering the disadvantages of pervaporation (PV) and distillation in furfural separation, a novel energy-efficient ‘green technique’, gas stripping assisted vapor permeation (GSVP), was introduced in this work. In this process, the polydimethylsiloxane (PDMS) membrane was prepared by employing water as solvent. Coking in pipe and membrane fouling was virtually non-existent in this new process. In addition, GSVP was found to achieve the highest pervaporation separation index of 216200 (permeate concentration of 71.1 wt% and furfural flux of 4.09 kgm−2h−1) so far, which was approximately 2.5 times higher than that found in pervaporation at 95°C for recovering 6.0 wt% furfural from water. Moreover, the evaporation energy required for GSVP decreased by 35% to 44% relative to that of PV process. Finally, GSVP also displayed more promising potential in industrial application than PV, especially when coupled with the hydrolysis process or fermentation in biorefinery industry. PMID:25819091

  6. A novel method for furfural recovery via gas stripping assisted vapor permeation by a polydimethylsiloxane membrane.

    PubMed

    Hu, Song; Guan, Yu; Cai, Di; Li, Shufeng; Qin, Peiyong; Karim, M Nazmul; Tan, Tianwei

    2015-03-30

    Furfural is an important platform chemical with a wide range of applications. However, due to the low concentration of furfural in the hydrolysate, the conventional methods for furfural recovery are energy-intensive and environmentally unfriendly. Considering the disadvantages of pervaporation (PV) and distillation in furfural separation, a novel energy-efficient 'green technique', gas stripping assisted vapor permeation (GSVP), was introduced in this work. In this process, the polydimethylsiloxane (PDMS) membrane was prepared by employing water as solvent. Coking in pipe and membrane fouling was virtually non-existent in this new process. In addition, GSVP was found to achieve the highest pervaporation separation index of 216200 (permeate concentration of 71.1 wt% and furfural flux of 4.09 kg m(-2) h(-1)) so far, which was approximately 2.5 times higher than that found in pervaporation at 95°C for recovering 6.0 wt% furfural from water. Moreover, the evaporation energy required for GSVP decreased by 35% to 44% relative to that of PV process. Finally, GSVP also displayed more promising potential in industrial application than PV, especially when coupled with the hydrolysis process or fermentation in biorefinery industry.

  7. A novel method for furfural recovery via gas stripping assisted vapor permeation by a polydimethylsiloxane membrane

    NASA Astrophysics Data System (ADS)

    Hu, Song; Guan, Yu; Cai, Di; Li, Shufeng; Qin, Peiyong; Karim, M. Nazmul; Tan, Tianwei

    2015-03-01

    Furfural is an important platform chemical with a wide range of applications. However, due to the low concentration of furfural in the hydrolysate, the conventional methods for furfural recovery are energy-intensive and environmentally unfriendly. Considering the disadvantages of pervaporation (PV) and distillation in furfural separation, a novel energy-efficient `green technique', gas stripping assisted vapor permeation (GSVP), was introduced in this work. In this process, the polydimethylsiloxane (PDMS) membrane was prepared by employing water as solvent. Coking in pipe and membrane fouling was virtually non-existent in this new process. In addition, GSVP was found to achieve the highest pervaporation separation index of 216200 (permeate concentration of 71.1 wt% and furfural flux of 4.09 kgm-2h-1) so far, which was approximately 2.5 times higher than that found in pervaporation at 95°C for recovering 6.0 wt% furfural from water. Moreover, the evaporation energy required for GSVP decreased by 35% to 44% relative to that of PV process. Finally, GSVP also displayed more promising potential in industrial application than PV, especially when coupled with the hydrolysis process or fermentation in biorefinery industry.

  8. Furfural and glucose can enhance conversion of xylose to xylitol by Candida magnoliae TISTR 5663.

    PubMed

    Wannawilai, Siwaporn; Lee, Wen-Chien; Chisti, Yusuf; Sirisansaneeyakul, Sarote

    2017-01-10

    Xylitol production from xylose by the yeast Candida magnoliae TISTR 5663 was enhanced by supplementing the fermentation medium with furfural (300mg/L) and glucose (3g/L with an initial mass ratio of glucose to xylose of 1:10) together under oxygen limiting conditions. In the presence of furfural and glucose, the final concentration of xylitol was unaffected relative to control cultures but the xylitol yield on xylose increased by about 5%. Supplementation of the culture medium with glucose alone at an initial concentration of 3g/L, stimulated the volumetric and specific rates of xylose consumption and the rate of xylitol production from xylose. In a culture medium containing 30g/L xylose, 300mg/L furfural and 3g/L glucose, the volumetric production rate of xylitol was 1.04g/L h and the specific production rate was 0.169g/g h. In the absence of furfural and glucose, the volumetric production rate of xylitol was ∼35% lower and the specific production rate was nearly 30% lower. In view of these results, xylose-containing lignocellulosic hydrolysates contaminated with furfural can be effectively used for producing xylitol by fermentation so long as the glucose-to-xylose mass ratio in the hydrolysate does not exceed 1:10 and the furfural concentration is ≤300mg/L.

  9. Evaluation of cellulases produced from four fungi cultured on furfural residues and microcrystalline cellulose.

    PubMed

    Liu, Hui-Qin; Feng, Yue; Zhao, Dan-Qing; Jiang, Jian-Xin

    2012-06-01

    Four fungal strains-Trichoderma viride, Aspergillus niger, Trichoderma koningii, and Trichoderma reesei-were selected for cellulase production using furfural residues and microcrystalline cellulose (MCC) as the substrates. The filter paper activity (FPA) of the supernatant from each fungus was measured, and the performance of the enzymes from different fungal strains was compared. Moreover, the individual activities of the three components of the cellulase system, i.e., β-glucosidase, endoglucanase, and exoglucanase were evaluated. T. koningii showed the highest activity (27.81 FPU/ml) on furfural residues, while T. viride showed an activity of 21.61 FPU/ml on MCC. The FPA of the crude enzyme supernatant from T. koningii was 30% higher on furfural residues than on MCC. T. koningii and T. viride exhibited high stability and productivity and were chosen for cellulases production. The crystallinity index (CrI) of the furfural residues varied after digested by the fungi. The results indicated differences in the functioning of the cellulase system from each fungus. In the case of T. koningii, T. reesei and T. viride, furfural residues supported a better environment for cellulase production than MCC. Moreover, the CrI of the furfural residues decreased, indicating that this material was largely digested by the fungi. Thus, our results suggest that it may be possible to use the cellulases produced from these fungi for the simultaneous saccharification and fermentation of lignocellulosic materials in ethanol production.

  10. Reduction of furfural to furfuryl alcohol by ethanologenic strains of bacteria and its effect on ethanol production from xylose.

    PubMed

    Gutiérrez, Tony; Buszko, Marian L; Ingram, Lonnie O; Preston, James F

    2002-01-01

    The ethanologenic bacteria Escherichia coli strains KO11 and LYO1, and Klebsiella oxytoca strain P2, were investigated for their ability to metabolize furfural. Using high performance liquid chromatography and 13C-nuclear magnetic resonance spectroscopy, furfural was found to be completely biotransformed into furfuryl alcohol by each of the three strains with tryptone and yeast extract as sole carbon sources. This reduction appears to be constitutive with NAD(P)H acting as electron donor. Glucose was shown to be an effective source of reducing power. Succinate inhibited furfural reduction, indicating that flavins are unlikely participants in this process. Furfural at concentrations >10 mM decreased the rate of ethanol formation but did not affect the final yield. Insight into the biochemical nature of this furfural reduction process may help efforts to mitigate furfural toxicity during ethanol production by ethanologenic bacteria.

  11. Over-expression of a putative oxidoreductase (UcpA) for increasing furfural or 5-hydroxymethylfurfural tolerance

    DOEpatents

    Wang, Xuan; Miller, Elliot N.; Yomano, Lorraine P.; Shanmugam, Keelnatham T.; Ingram, Lonnie O'Neal

    2016-05-24

    The subject invention pertains to overexpression of a putative oxidoreductase (ucpA) for increasing furfural tolerance in genetically modified microorganisms. Genetically modified microorganisms capable of overexpressing UcpA are also provided. Increased expression of ucpA was shown to increase furfural tolerance by 50%, and to permit the fermentation of sugars to products in the presence of 15 mM furfural.

  12. PREFACE: 19th International Conference on the Application of High Magnetic Fields in Semiconductor Physics and Nanotechnology (HMF-19)

    NASA Astrophysics Data System (ADS)

    Muraki, Koji; Takeyama, Shojiro

    2011-12-01

    This volume contains invited and contributed papers from the 19th International Conference on the Application of High Magnetic Fields in Semiconductor Physics and Nanotechnology (HMF-19) held in Fukuoka, Japan, from 1-6 August 2010. This conference was mainly sponsored by the Tokyo University-'Horiba International fund', which was donated by Dr Masao Horiba, the founder of Horiba Ltd. The scientific program of HMF-19 consisted of 37 invited talks, 24 contributed talks, and 83 posters, which is available from the conference homepage http://www.hmf19.iis.u-tokyo.ac.jp/index.html. Each manuscript submitted for publication in this volume has been independently reviewed. The Editor is very grateful to all the reviewers for their quick responses and helpful reports and to all the authors for their submissions and patience for the delay in the editorial process. Finally, the Editor would like to express his sincere gratitude to all the individuals involved in the conference organization and all the attendees, who made this conference so successful. Koji Muraki Conference photograph Committees Chair Conference chairS Takeyama(ISSP-UT) Conference secretary T Machida (IIS-UT) Program chair K Muraki (NTT) Local organizing chair K Oto (Chiba Univ.) Advisory Committee International Domestic L Brey (ES) T Ando (TIT) Z H Chen (CN) Y Hirayama (Tohoku Univ.) S Das Sarma (US) G Kido (NIMS) L Eaves (GB) N Miura (JP) J P Eisenstein (US) J Nitta (Tohoku Univ.) K Ensslin (CH) T Takamasu (NIMS) J Furdyna (US) G M Gusev (BR) I Kukushkin (RU) Z D Kvon (RU) G Landwehr (DE) J C Maan (NL) A H MacDonald (US) N F Oliveira Jr (BR) A Pinczuk (US) J C Portal (FR) A Sachrajda (CA) M K Sanyal(IN) R Stepniewski(PL) Program Committee Chair: K Muraki(NTT) International Domestic G Bauer (AU) H Ajiki (Osaka Univ.) G Boebinger (US) H Aoki (Hongo, UT) S Ivanov (RU) K Nomura (RIKEN) K von Klitzing (DE) T Okamoto (Hongo, UT) R Nicholas (GB) T Osada (ISSP-UT ) M Potemski (FR) N Studart (BR) U Zeitler (NL

  13. Furfural Determination with Disposable Polymer Films and Smartphone-Based Colorimetry for Beer Freshness Assessment.

    PubMed

    Rico-Yuste, Alberto; González-Vallejo, Victoria; Benito-Peña, Elena; de Las Casas Engel, Tomás; Orellana, Guillermo; Moreno-Bondi, María Cruz

    2016-04-05

    We have developed disposable color-changing polymeric films for quantification of furfural-a freshness indicator-in beer using a smartphone-based reader. The films are prepared by radical polymerization of 4-vinylaniline, as a furfural-sensitive indicator monomer, 2-hydroxymethyl methacrylate as a comonomer, and ethylene dimethyl methacrylate (EDMA) as a cross-linker. The sensing mechanism is based on the Stenhouse reaction in which aniline and furfural react in acidic media with the generation of a deep red cyanine derivative, absorbing at 537 nm, which is visible to the naked eye. The colorimetric response has been monitored using either a portable fiber-optic spectrophotometer or the built-in camera of a smartphone. Under the optimized conditions, a linear response to furfural in beer was obtained in the 39 to 500 μg L(-1) range, with a detection limit of 12 μg L(-1), thus improving the performance of other well-established colorimetric or chromatographic methods. The novel films are highly selective to furfural, and no cross-reactivity has been observed from other volatile compounds generated during beer aging. A smartphone application (app), developed for Android platforms, measures the RGB color coordinates of the sensing membranes after exposure to the analyte. Following data processing, the signals are converted into concentration values by preloaded calibration curves. The method has been applied to determination of furfural in pale lager beers with different storage times at room temperature. A linear correlation (r > 0.995) between the storage time and the furfural concentration in the samples has been confirmed; our results have been validated by HPLC with diode-array detection.

  14. Polyamine Transporters and Polyamines Increase Furfural Tolerance during Xylose Fermentation with Ethanologenic Escherichia coli Strain LY180

    PubMed Central

    Geddes, Ryan D.; Wang, Xuan; Yomano, Lorraine P.; Miller, Elliot N.; Zheng, Huabao; Shanmugam, Keelnatham T.

    2014-01-01

    Expression of genes encoding polyamine transporters from plasmids and polyamine supplements increased furfural tolerance (growth and ethanol production) in ethanologenic Escherichia coli LY180 (in AM1 mineral salts medium containing xylose). This represents a new approach to increase furfural tolerance and may be useful for other organisms. Microarray comparisons of two furfural-resistant mutants (EMFR9 and EMFR35) provided initial evidence for the importance of polyamine transporters. Each mutant contained a single polyamine transporter gene that was upregulated over 100-fold (microarrays) compared to that in the parent LY180, as well as a mutation that silenced the expression of yqhD. Based on these genetic changes, furfural tolerance was substantially reconstructed in the parent, LY180. Deletion of potE in EMFR9 lowered furfural tolerance to that of the parent. Deletion of potE and puuP in LY180 also decreased furfural tolerance, indicating functional importance of the native genes. Of the 8 polyamine transporters (18 genes) cloned and tested, half were beneficial for furfural tolerance (PotE, PuuP, PlaP, and PotABCD). Supplementing AM1 mineral salts medium with individual polyamines (agmatine, putrescine, and cadaverine) also increased furfural tolerance but to a smaller extent. In pH-controlled fermentations, polyamine transporter plasmids were shown to promote the metabolism of furfural and substantially reduce the time required to complete xylose fermentation. This increase in furfural tolerance is proposed to result from polyamine binding to negatively charged cellular constituents such as nucleic acids and phospholipids, providing protection from damage by furfural. PMID:25063650

  15. Dehydration of xylose to furfural over MCM-41-supported niobium-oxide catalysts.

    PubMed

    García-Sancho, Cristina; Sádaba, Irantzu; Moreno-Tost, Ramón; Mérida-Robles, Josefa; Santamaría-González, José; López-Granados, Manuel; Maireles-Torres, Pedro

    2013-04-01

    A series of silica-based MCM-41-supported niobium-oxide catalysts are prepared, characterized by using XRD, N2 adsorption-desorption, X-ray photoelectron spectroscopy, Raman spectroscopy, and pyridine adsorption coupled to FTIR spectroscopy, and tested for the dehydration of D-xylose to furfural. Under the operating conditions used all materials are active in the dehydration of xylose to furfural (excluding the MCM-41 silica support). The xylose conversion increases with increasing Nb2 O5 content. At a loading of 16 wt % Nb2 O5 , 74.5 % conversion and a furfural yield of 36.5 % is achieved at 170 °C, after 180 min reaction time. Moreover, xylose conversion and furfural yield increase with the reaction time and temperature, attaining 82.8 and 46.2 %, respectively, at 190 °C and after 100 min reaction time. Notably, the presence of NaCl in the reaction medium further increases the furfural yield (59.9 % at 170 °C after 180 min reaction time). Moreover, catalyst reutilization is demonstrated by performing at least three runs with no loss of catalytic activity and without the requirement for an intermediate regeneration step. No significant niobium leaching is observed, and a relationship between the structure of the catalyst and the activity is proposed.

  16. Rapid determination of furfural in biomass hydrolysate by full evaporation headspace gas chromatography.

    PubMed

    Li, Hailong; Chai, Xin-Sheng; Zhan, Huaiyu; Fu, Shiyu

    2010-11-26

    This paper reports a full evaporation (FE) headspace gas chromatographic (HS-GC) method for rapid determination of furfural in the biomass hydrolysate. The data show that a near-complete mass transfer of furfural in the sample from biomass hydrolysate to the vapor phase (headspace) was achieved within 3 min at 105°C when a very small (<40 μL) sample was added to a 20 mL headspace sample vial. The acid-catalyzed furfural decomposition under these conditions was negligible. The furfural in the vapor phase was then determined by HS-GC using a flame ionization detector. The results showed that the method has an excellent measurement precision (RSD<0.5%) and accuracy (recovery=100.2±1.7%) for furfural quantification in carbohydrate hydrolysate samples. The method requires no sample pretreatment, so it is simple, rapid and accurate, and suitable for applications in lignocellulosic biomass conversion to fuel ethanol or other high value-added products.

  17. Acid-catalysed xylose dehydration into furfural in the presence of kraft lignin.

    PubMed

    Lamminpää, Kaisa; Ahola, Juha; Tanskanen, Juha

    2015-02-01

    In this study, the effects of kraft lignin (Indulin AT) on acid-catalysed xylose dehydration into furfural were studied in formic and sulphuric acids. The study was done using D-optimal design. Three variables in both acids were included in the design: time (20-80 min), temperature (160-180°C) and initial lignin concentration (0-20 g/l). The dependent variables were xylose conversion, furfural yield, furfural selectivity and pH change. The results showed that the xylose conversion and furfural yield decreased in sulphuric acid, while in formic acid the changes were minor. Additionally, it was showed that lignin has an acid-neutralising capacity, and the added lignin increased the pH of reactant solutions in both acids. The pH rise was considerably lower in formic acid than in sulphuric acid. However, the higher pH did not explain all the changes in conversion and yield, and thus lignin evidently inhibits the formation of furfural.

  18. Azole susceptibility of Malassezia pachydermatis and Malassezia furfur and tentative epidemiological cut-off values.

    PubMed

    Cafarchia, Claudia; Iatta, Roberta; Immediato, Davide; Puttilli, Maria Rita; Otranto, Domenico

    2015-09-01

    This study aims to determine the minimal inhibitory concentration (MIC) distribution and the epidemiological cut-off values (ECVs) of Malassezia pachydermatis and Malassezia furfur isolates for fluconazole (FLZ), itraconazole (ITZ), posaconazole (POS), and voriconazole (VOR). A total of 62 M. pachydermatis strains from dogs with dermatitis and 78 M. furfur strains from humans with bloodstream infections (BSI) were tested by a modified broth microdilution Clinical and Laboratory Standards Institute (CLSI) method. ITZ and POS displayed lower MICs than VOR and FLZ, regardless of the Malassezia species. The MIC data for azoles of M. pachydermatis were four two-fold dilutions lower than those of M. furfur. Based on the ECVs, about 94% of Malassezia strains might be categorized within susceptible population for all azoles, except for FLZ, and azole cross-resistance was detected in association with FLZ in M. pachydermatis but not in M. furfur.The study proposes, for the first time, tentative azole ECVs for M. pachydermatis and M. furfur for monitoring the emergence of isolates with decreased susceptibilities and shows that the azole MIC distribution varied according to the Malassezia species tested, thus suggesting the usefulness of determining the susceptibility profile for effective treatment of each species.

  19. Malassezia furfur in a case of onychomycosis: colonizer or etiologic agent?

    PubMed

    Chowdhary, Anuradha; Randhawa, H S; Sharma, Sonal; Brandt, Mary E; Kumar, Sunil

    2005-02-01

    The etiologic role of Malassezia furfur in onychomycosis is a contentious diagnostic problem because its keratinolytic ability has never been verified. This case report describes the isolation of M. furfur from the infected nails of a child clinically diagnosed with onychomycosis, and discusses the role of this organism as an etiologic agent/colonizer. The patient presented with subungual hyperkeratosis and onycholysis without associated paronychia. Budding yeast cells compatible with M. furfur were repeatedly demonstrated in KOH wet mounts of damaged nails, histopathology of hematoxylin and eosin (H&E) and periodic acid-Schiff (PAS) stained sections showed penetration of fungal elements between deeper layers of keratin, and numerous colonies of M. furfur were isolated on three consecutive occasions from nail specimens collected from different areas of hand and toenail lesions. No evidence of nail invasion by dermatophytic or nondermatophytic filamentous fungi were found by direct microscopy or culture. Microscopy and culture were negative following 12 weeks of ketoconazole treatment, which resulted in growth of healthy nail plates with normal beds. We can infer from these observations that M.furfur was an etiologic agent rather than a colonizer in the patient's nails even though direct keratinolytic character of this fungus was not demonstrated.

  20. Ketoconazole inhibits Malassezia furfur morphogenesis in vitro under filamentation optimized conditions.

    PubMed

    Youngchim, Sirida; Nosanchuk, Joshua D; Chongkae, Siriporn; Vanittanokom, Nongnuch

    2017-01-01

    Malassezia furfur, a constituent of the normal human skin flora, is an etiological agent of pityriasis versicolor, which represents one of the most common human skin diseases. Under certain conditions, both exogenous and endogenous, the fungus can transition from a yeast form to a pathogenic mycelial form. To develop a standardized medium for reproducible production of the mycelial form of M. furfur to develop and optimize susceptibility testing for this pathogen, we examined and characterized variables, including kojic acid and glycine concentration, agar percentage, and pH, to generate a chemically defined minimal medium on which specific inoculums of M. furfur generated the most robust filamentation. Next, we examined the capacity of ketoconazole to inhibit the formation of M. furfur mycelial form. Both low and high, 0.01, 0.05 and 0.1 µg/ml concentrations of ketoconazole significantly inhibited filamentation at 11.9, 54.5 and 86.7%, respectively. Although ketoconazole can have a direct antifungal effect on both M. furfur yeast and mycelial cells, ketoconazole also has a dramatic impact on suppressing morphogenesis. Since mycelia typified the pathogenic form of Malassezia infection, the capacity of ketoconazole to block morphogenesis may represent an additional important effect of the antifungal.

  1. Biofilm, adherence, and hydrophobicity as virulence factors in Malassezia furfur.

    PubMed

    Angiolella, Letizia; Leone, Claudia; Rojas, Florencia; Mussin, Javier; de Los Angeles Sosa, María; Giusiano, Gustavo

    2017-03-09

    Malassezia species are natural inhabitants of the healthy skin. However, under certain conditions, they may cause or exacerbate several skin diseases. The ability of this fungus to colonize or infect is determined by complex interactions between the fungal cell and its virulence factors. This study aims to evaluate "in vitro" the hydrophobicity levels, the adherence on a plastic surface and the biofilm formation of 16 clinical isolates of Malassezia furfur. Cellular surface hydrophobicity (CSH) levels were determined by two-phase system. The biofilm formation was determined by tetrazolium salt (XTT) reduction assay and by Scanning Electron Microscopy (SEM). Results showed many isolates were hydrophobic, adherent, and producers of biofilm on abiotic surfaces with different capacity. SEM observations confirmed an abundant extracellular matrix after 48 h of biofilm formation. About 63% of strains with high production of biofilm showed medium to high percentage of hydrophobicity and/or adherence. In addition, it has been demonstrated a correlation between hydrophobicity, adherence, and biofilm formation in about 60% of strains examined. These important virulence factors could be responsible of this yeast changing from a commensal to a pathogenic status.

  2. New organic aerogels based upon a phenolic-furfural reaction

    SciTech Connect

    Hrubesh, L.W.

    1994-09-01

    The aqueous polycondensation of (1) resorcinol with formaldehyde and (2) melamine with formaldehyde are two proven synthetic routes for the formation of organic aerogels. Recently, we have discovered a new type of organic aerogel based upon a phenolic-furfural (PF) reaction. This sol-gel polymerization has a major advantage over past approaches since it can be conducted in alcohol (e.g., 1-propanol), thereby eliminating the need for a solvent exchange step prior to supercritical drying from carbon dioxide. The resultant aerogels are dark brown in color and can be converted to a carbonized version upon pyrolysis in an inert atmosphere. BET surface areas of 350--600 m{sup 2}/g have been measured, and transmission electron microscopy reveals an interconnected structure of irregularly-shaped particles or platelets with {approximately}10 nm dimensions. Thermal conductivities as low as 0.015 W/m-K have been recorded for PF aerogels under ambient conditions. This paper describes the chemistry-structure-property relationships of these new materials in detail.

  3. Pre-treatment step with Leuconostoc mesenteroides or L. pseudomesenteroides strains removes furfural from Zymomonas mobilis ethanolic fermentation broth

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Furfural (furan-2-carboxaldehyde), formed during dilute acid hydrolysis of biomass, is an inhibitor of growth and ethanol production by Zymomonas mobilis. The present study used a biological pre-treatment to reduce that amount of furfural in a model biofuel fermentation broth. The pre-treatment in...

  4. A combined process of adsorption and Fenton-like oxidation for furfural removal using zero-valent iron residue.

    PubMed

    Li, Furong; Bao, Jianguo; Zhang, Tian C; Lei, Yutian

    2015-01-01

    In this study, the feasibility of using a combined adsorption and Fenton-like oxidation process (with zero-valent iron (ZVI) residue from heat wraps as an absorbent and catalyst) to remove furfural in the solution was evaluated. The influencing parameters (e.g. pH, H2O2 concentration, initial furfural concentration) and the reusability of ZVI residue (to replace the iron powder) were estimated. The ZVI residue was found to have much better adsorption effect on furfural at pH 2.0 compared with pH 6.7. For Fenton-like reaction alone with ZVI residue, the highest furfural removal of 97.5% was observed at the concentration of 0.176 mol/L H2O2, and all of the samples had >80% removal efficiency at different initial furfural concentrations of 2, 10, 20, 30 and 40 mmol/L. However, with a combined adsorption and Fenton-like oxidation, the removal efficiency of furfural was nearly 100% for all treatments. The ZVI residue used for furfural removal was much better than that of iron powder in the Fenton-like reaction at a seven-cycle experiment. This study suggests the combined process of adsorption and Fenton-like oxidation using ZVI residue is effective for the treatment of furfural in the liquid.

  5. Optimization of prehydrolysis time and substrate feeding to improve ethanol production by simultaneous saccharification and fermentation of furfural process residue.

    PubMed

    He, Jianlong; Zhang, Wenbo; Liu, Xiaoyan; Xu, Ning; Xiong, Peng

    2016-11-01

    Ethanol is a very important industrial chemical. In order to improve ethanol productivity using Saccharomyces cerevisiae in fermentation from furfural process residue, we developed a process of simultaneous saccharification and fermentation (SSF) of furfural process residue, optimizing prehydrolysis cellulase loading concentration, prehydrolysis time, and substrate feeding strategy. The ethanol concentration obtained from the optimized process was 19.3 g/L, corresponding 76.5% ethanol yield, achieved by running SSF for 48 h from 10% furfural process residue with prehydrolysis at 50°C for 4 h and cellulase loading of 15 FPU/g furfural process residue. For higher ethanol concentrations, fed-batch fermentation was performed. The optimized fed-batch process increased the ethanol concentration to 37.6 g/L, 74.5% yield, obtained from 10% furfural process residue with two additions of 5% substrate at 12 and 24 h.

  6. Genotyping by RAPD-PCR analyses of Malassezia furfur strains from pityriasis versicolor and seborrhoeic dermatitis patients.

    PubMed

    Gandra, Rinaldo F; Simão, Rita C G; Matsumoto, Flávia E; da Silva, Bosco C M; Ruiz, Luciana S; da Silva, Eriques G; Gambale, Walderez; Paula, Claudete R

    2006-10-01

    Malassezia furfur is lypophilic yeast commonly associate with dermatological disorders. In the present work, we described the isolation of 47 M. furfur strains from three groups of patients: pityriasis versicolor (21 isolates), seborrhoeic dermatitis (15 isolates) and seborrhoeic dermatitis of the HIV positive patients (11 isolates). To investigate the identity of the strains at molecular level, DNA genomic of M. furfur strains were prepared and used to RAPD-PCR analyses. RAPD assay were carried out using two decamer primers and bands pattern generated were analyzed by an Unweighted Pair-Group Method (UPGMA). Dendrogram established a distinct differentiation between M. furfur isolates from pityriasis versicolor and seborrhoeic dermatitis patients with or without AIDS. We concluded that RAPD typing presented a high discriminatory power between strains studied in this work and can be applied in epidemiological investigation of skin disease causing by M. furfur.

  7. Production of furfural from xylose at atmospheric pressure by dilute sulfuric acid and inorganic salts.

    PubMed

    Rong, Chunguang; Ding, Xuefeng; Zhu, Yanchao; Li, Ying; Wang, Lili; Qu, Yuning; Ma, Xiaoyu; Wang, Zichen

    2012-03-01

    In this paper, the dehydration of xylose to furfural was carried out under atmospheric pressure and at the boiling temperature of a biphasic mixture of toluene and an aqueous solution of xylose, with sulfuric acid as catalyst plus an inorganic salt (NaCl or FeCl(3)) as promoter. The best yield of furfural was 83% under the following conditions: 150 mL of toluene and 10 mL of aqueous solution of 10% xylose (w/w), 10% H(2)SO(4) (w/w), 2.4g NaCl , and heating for 5h. FeCl(3) as promoter was found to be more efficient than NaCl. The addition of DMSO to the aqueous phase in the absence of an inorganic salt was shown to improve the yield of furfural.

  8. Low acid hydrothermal fractionation of Giant Miscanthus for production of xylose-rich hydrolysate and furfural.

    PubMed

    Kim, Tae Hyun; Ryu, Hyun Jin; Oh, Kyeong Keun

    2016-10-01

    Low acid hydrothermal (LAH) fractionation was developed for the effective recovery of hemicellulosic sugar (mainly xylose) from Miscanthus sacchariflorus Goedae-Uksae 1 (M. GU-1). The xylose yield was maximized at 74.75% when the M. GU-1 was fractionated at 180°C and 0.3wt.% of sulfuric acid for 10min. At this condition, the hemicellulose (mainly xylan) degradation was 86.41%. The difference between xylan degradation and xylose recovery yield, i.e., xylan loss, was 11.66%, as indicated by the formation of decomposed products. The furfural, the value added biochemical product, was also obtained by 0.42g/L at this condition, which was 53.82% of furfural production yield based on the xylan loss. After then, the furfural production continued to increase to a maximum concentration of 1.87g/L, at which point the xylan loss corresponded to 25.87%.

  9. Excitation of vibrational quanta in furfural by intermediate-energy electrons.

    PubMed

    Jones, D B; Neves, R F C; Lopes, M C A; da Costa, R F; Varella, M T do N; Bettega, M H F; Lima, M A P; García, G; Blanco, F; Brunger, M J

    2015-12-14

    We report cross sections for electron-impact excitation of vibrational quanta in furfural, at intermediate incident electron energies (20, 30, and 40 eV). The present differential cross sections are measured over the scattered electron angular range 10°-90°, with corresponding integral cross sections subsequently being determined. Furfural is a viable plant-derived alternative to petrochemicals, being produced via low-temperature plasma treatment of biomass. Current yields, however, need to be significantly improved, possibly through modelling, with the present cross sections being an important component of such simulations. To the best of our knowledge, there are no other cross sections for vibrational excitation of furfural available in the literature, so the present data are valuable for this important molecule.

  10. Excitation of vibrational quanta in furfural by intermediate-energy electrons

    SciTech Connect

    Jones, D. B.; Neves, R. F. C.; Lopes, M. C. A.; Costa, R. F. da; Varella, M. T. do N.; Bettega, M. H. F.; Lima, M. A. P.; García, G.; and others

    2015-12-14

    We report cross sections for electron-impact excitation of vibrational quanta in furfural, at intermediate incident electron energies (20, 30, and 40 eV). The present differential cross sections are measured over the scattered electron angular range 10°–90°, with corresponding integral cross sections subsequently being determined. Furfural is a viable plant-derived alternative to petrochemicals, being produced via low-temperature plasma treatment of biomass. Current yields, however, need to be significantly improved, possibly through modelling, with the present cross sections being an important component of such simulations. To the best of our knowledge, there are no other cross sections for vibrational excitation of furfural available in the literature, so the present data are valuable for this important molecule.

  11. Differential Expression of Extracellular Lipase and Protease Activities of Mycelial and Yeast Forms in Malassezia furfur.

    PubMed

    Juntachai, Weerapong; Kajiwara, Susumu

    2015-10-01

    Malassezia furfur is a dimorphic yeast that is part of the human skin microflora. This fungus is a pathogen of a certain skin diseases, such as pityriasis versicolor, and in rare cases causes systemic infection in neonates. However, the role of dimorphism in the pathogenicity remains unclear. A modified induction medium (IM) was successfully able to induce mycelial growth of M. furfur under both solid and liquid condition. Filamentous elements with branching hyphae were observed when cultured in the IM. Furthermore, addition of bovine fetus serum into the liquid IM did not promote hyphal formation; on the contrary, it retrograded hyphae to the yeast form. Plate-washing assay showed that M. furfur hyphae did not possess the ability of invasive growth. Secretory proteins from both yeast and hyphal forms were isolated, and lipase and protease activities were analyzed. Intriguingly, the hyphal form showed higher activities than those of the yeast form, particularly the protease activity.

  12. Adaptive laboratory evolution of ethanologenic Zymomonas mobilis strain tolerant to furfural and acetic acid inhibitors.

    PubMed

    Shui, Zong-Xia; Qin, Han; Wu, Bo; Ruan, Zhi-yong; Wang, Lu-shang; Tan, Fu-Rong; Wang, Jing-Li; Tang, Xiao-Yu; Dai, Li-Chun; Hu, Guo-Quan; He, Ming-Xiong

    2015-07-01

    Furfural and acetic acid from lignocellulosic hydrolysates are the prevalent inhibitors to Zymomonas mobilis during cellulosic ethanol production. Developing a strain tolerant to furfural or acetic acid inhibitors is difficul by using rational engineering strategies due to poor understanding of their underlying molecular mechanisms. In this study, strategy of adaptive laboratory evolution (ALE) was used for development of a furfural and acetic acid-tolerant strain. After three round evolution, four evolved mutants (ZMA7-2, ZMA7-3, ZMF3-2, and ZMF3-3) that showed higher growth capacity were successfully obtained via ALE method. Based on the results of profiling of cell growth, glucose utilization, ethanol yield, and activity of key enzymes, two desired strains, ZMA7-2 and ZMF3-3, were achieved, which showed higher tolerance under 7 g/l acetic acid and 3 g/l furfural stress condition. Especially, it is the first report of Z. mobilis strain that could tolerate higher furfural. The best strain, Z. mobilis ZMF3-3, has showed 94.84% theoretical ethanol yield under 3-g/l furfural stress condition, and the theoretical ethanol yield of ZM4 is only 9.89%. Our study also demonstrated that ALE method might also be used as a powerful metabolic engineering tool for metabolic engineering in Z. mobilis. Furthermore, the two best strains could be used as novel host for further metabolic engineering in cellulosic ethanol or future biorefinery. Importantly, the two strains may also be used as novel-tolerant model organisms for the genetic mechanism on the "omics" level, which will provide some useful information for inverse metabolic engineering.

  13. Development and Evaluation of Cefadroxil Drug Loaded Biopolymeric Films Based on Chitosan-Furfural Schiff Base

    PubMed Central

    Dixit, Ritu B.; Uplana, Rahul A.; Patel, Vishnu A.; Dixit, Bharat C.; Patel, Tarosh S.

    2010-01-01

    Cefadroxil drug loaded biopolymeric films of chitosan-furfural schiff base were prepared by reacting chitosan with furfural in presence of acetic acid and perchloric acid respectively for the external use. Prepared films were evaluated for their strength, swelling index, thickness, drug content, uniformity, tensile strength, percent elongation, FTIR spectral analysis and SEM. The results of in vitro diffusion studies revealed that the films exhibited enhanced drug diffusion as compared to the films prepared using untreated chitosan. The films also demonstrated good to moderate antibacterial activities against selective gram positive and gram negative bacteria. PMID:21179325

  14. Molybdenum carbide as a highly selective deoxygenation catalyst for converting furfural to 2-methylfuran.

    PubMed

    Xiong, Ke; Lee, Wen-Sheng; Bhan, Aditya; Chen, Jingguang G

    2014-08-01

    Selectively cleaving the C=O bond outside the furan ring of furfural is crucial for converting this important biomass-derived molecule to value-added fuels such as 2-methylfuran. In this work, a combination of density functional theory (DFT) calculations, surface science studies, and reactor evaluation identified molybdenum carbide (Mo2 C) as a highly selective deoxygenation catalyst for converting furfural to 2-methylfuran. These results indicate the potential application of Mo2 C as an efficient catalyst for the selective deoxygenation of biomass-derived oxygenates including furanics and aromatics.

  15. Tracking thermal degradation on passion fruit juice through Nuclear Magnetic Resonance and chemometrics.

    PubMed

    Soares, Marcia Valeria L; Alves Filho, Elenilson G; Silva, Lorena Mara A; Novotny, Etelvino Henrique; Canuto, Kirley Marques; Wurlitzer, Nedio Jair; Narain, Narendra; de Brito, Edy Sousa

    2017-03-15

    Thermal food processing mainly aims to control microorganism in order to extend its shelf life. However, it may induce chemical and nutritional changes in foodstuff. The Nuclear Magnetic Resonance (NMR) coupled to multivariate analysis was used to evaluate the effect of different thermal processing conditions (85 and 140°C for 4; 15; 30; and 60s) on the passion fruit juice using an Armfield pasteurizer. Through this approach it was possible to identify the changes in the juice composition. The temperature and the time lead to a hydrolysis of the sucrose to glucose and fructose. Additionally, juice submitted to 140°C for 60s results in the degradation of the sucrose and the formation of 5-(hydroxymethyl)-2-furfural (HMF). Despite no novel chemical marker has been identified, the (1)H NMR chemometrics approach may contribute in the choice of the temperature and time to be employed in the juice processing.

  16. Fluorescence excitation-emission matrix spectroscopy as a tool for determining quality of sparkling wines.

    PubMed

    Elcoroaristizabal, Saioa; Callejón, Raquel M; Amigo, Jose M; Ocaña-González, Juan A; Morales, M Lourdes; Ubeda, Cristina

    2016-09-01

    Browning in sparkling wines was assessed by the use of excitation-emission fluorescence spectroscopy combined with PARAllel FACtor analysis (PARAFAC). Four different cava sparkling wines were monitored during an accelerated browning process and subsequently storage. Fluorescence changes observed during the accelerated browning process were monitored and compared with other conventional parameters: absorbance at 420nm (A420) and the content of 5-hydroxymethyl-2-furfural (5-HMF). A high similarity of the spectral profiles for all sparkling wines analyzed was observed, being explained by a four component PARAFAC model. A high correlation between the third PARAFAC factor (465/530nm) and the commonly used non-enzymatic browning indicators was observed. The fourth PARAFAC factor (280/380nm) gives us also information about the browning process following a first order kinetic reaction. Hence, excitation-emission fluorescence spectroscopy, together with PARAFAC, provides a faster alternative for browning monitoring to conventional methods, as well as useful key indicators for quality control.

  17. Comprehensive NMR analysis of compositional changes of black garlic during thermal processing.

    PubMed

    Liang, Tingfu; Wei, Feifei; Lu, Yi; Kodani, Yoshinori; Nakada, Mitsuhiko; Miyakawa, Takuya; Tanokura, Masaru

    2015-01-21

    Black garlic is a processed food product obtained by subjecting whole raw garlic to thermal processing that causes chemical reactions, such as the Maillard reaction, which change the composition of the garlic. In this paper, we report a nuclear magnetic resonance (NMR)-based comprehensive analysis of raw garlic and black garlic extracts to determine the compositional changes resulting from thermal processing. (1)H NMR spectra with a detailed signal assignment showed that 38 components were altered by thermal processing of raw garlic. For example, the contents of 11 l-amino acids increased during the first step of thermal processing over 5 days and then decreased. Multivariate data analysis revealed changes in the contents of fructose, glucose, acetic acid, formic acid, pyroglutamic acid, cycloalliin, and 5-(hydroxymethyl)furfural (5-HMF). Our results provide comprehensive information on changes in NMR-detectable components during thermal processing of whole garlic.

  18. Space and time-resolved probing of heterogeneous catalysis reactions using lab-on-a-chip.

    PubMed

    Navin, Chelliah V; Krishna, Katla Sai; Theegala, Chandra S; Kumar, Challa S S R

    2016-03-14

    Probing catalytic reactions on a catalyst surface in real time is a major challenge. Herein, we demonstrate the utility of a continuous flow millifluidic chip reactor coated with a nanostructured gold catalyst as an effective platform for in situ investigation of the kinetics of catalytic reactions by taking 5-(hydroxymethyl)furfural (HMF) to 2,5-furandicarboxylic acid (FDCA) conversion as a model reaction. The idea conceptualized in this paper can not only dramatically change the ability to probe the time-resolved kinetics of heterogeneous catalysis reactions but also used for investigating other chemical and biological catalytic processes, thereby making this a broad platform for probing reactions as they occur within continuous flow reactors.

  19. Sequential hydrothermal fractionation of yeast Cryptococcus curvatus biomass.

    PubMed

    Miao, Chao; Chakraborty, Moumita; Dong, Tao; Yu, Xiaochen; Chi, Zhanyou; Chen, Shulin

    2014-07-01

    A sequential hydrothermal liquefaction (SEQHTL) process was evaluated in this work for fractionating different component of yeast biomass. Sugar and protein were separated first at a lower temperature, and the remaining biomass was then converted to bio-oil at a higher temperature. The separated aqueous products were investigated to be recycled as a carbon and nitrogen sources for the yeast culture. In the first step of SEQHTL, the temperature effect on the yield of sugar/protein and inhibitory compounds (acetic acid and 5-hydroxymethyl furfural (5HMF)) was investigated. The highest yields of sugar and protein and a minimal level of inhibitory compounds were obtained at 180°C. At the second step of SEQHTL, the highest bio-oil yield was achieved at 240°C. In comparison to the one-step hydrothermal liquefaction process, SEQHTL produced a higher quality bio-oil with higher fatty acid and lower nitrogen contents.

  20. The Empirical Canadian High Arctic Ionospheric Model (E-CHAIM): NmF2 and hmF2 specification

    NASA Astrophysics Data System (ADS)

    Themens, David; Jayachandran, Thayyil

    2016-07-01

    It is well known that the IRI suffers reduced accuracy in its representation of monthly median ionospheric variability at high latitudes (Themens et al. 2014, Themens et al. 2016). These inaccuracies are believed to stem from a historical lack of data from these regions. Now, roughly thirty and forty years after the development of the original URSI and CCIR foF2 maps, respectively, there exists a much larger dataset of high latitude observations of ionospheric electron density. These new measurements come in the form of new ionosonde deployments, such as those of the Canadian High Arctic Ionospheric Network, the CHAMP, GRACE, and COSMIC radio occultation missions, and the construction of the Poker Flat, Resolute, and EISCAT Incoherent Scatter Radars systems. These new datasets afford an opportunity to revise the IRI's representation of the high latitude ionosphere. For this purpose, we here introduce the Empirical Canadian High Arctic Ionospheric Model (E-CHAIM), which will incorporate all of the above datasets, as well as the older observation records, into a new climatological representation of the high latitude ionosphere. In this presentation, we introduce the NmF2 and hmF2 portions of the model and present a validation of the new model with respect to ionosonde observations in Alert, Canada. A comparison with respect to IRI performance will also be presented.

  1. An update global model of hmF2 from values estimated from ionosonde and COSMIC/FORMOSAT-3 radio occultation

    NASA Astrophysics Data System (ADS)

    Zhang, Man-Lian; Liu, Libo; Wan, Weixing; Ning, Baiqi

    2014-02-01

    In this paper, we present our recent work on developing an updated global model of the ionospheric F2 peak height hmF2 parameter by combining data from the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC/FORMOSAT-3) radio occultation (RO) measurements and from the extended global ionosonde stations. In particular, 10 Chinese ionosonde stations' data are newly introduced into this study. The modeling technique used is based on a two-layer empirical orthogonal function (EOF) expansion. Global distributions of hmF2 maps calculated using the newly constructed global model and the one provided by the International Reference Ionosphere model (IRI-ITU-R) are compared with the global distributions of hmF2 obtained by the COSMIC RO measurements and quantitative statistical analysis of the differences between the model results and those of the COSMIC RO measurements is made for the low (2008) and high (2012) solar activity years. The obtained average root-mean-square differences (RMSEs) for our model are 27.7 km (11.1%) and 31.0 km (9.8%), respectively for the years 2008 and 2012, whereas those for the IRI-ITU-R model are 39.9 km (16.9%) and 35.0 km (11.6%), respectively. Comparison of the results calculated both by our model and the IRI-ITU-R model with the digisonde observation is also made. The comparisons show that the newly constructed global hmF2 model can reproduce reasonably well the observations and perform better than IRI-ITU-R model.

  2. Toll-like receptor 2 (TLR2) mediates intracellular signalling in human keratinocytes in response to Malassezia furfur.

    PubMed

    Baroni, Adone; Orlando, Manuela; Donnarumma, Giovanna; Farro, Pietro; Iovene, Maria Rosaria; Tufano, Maria Antonietta; Buommino, Elisabetta

    2006-01-01

    Toll-like receptors (TLRs) are crucial players in the innate immune response to microbial invaders. The lipophilic yeast Malassezia furfur has been implicated in the triggering of scalp lesions in psoriasis. The aim of the present study was to assess the role of TLRs in the defence against M. furfur infection. The expression of the myeloid differentiation factor 88 (MyD88) gene, which is involved in the signalling pathway of many TLRs, was also analysed. In addition, a possible correlation of antimicrobial peptides of the beta-defensin family to TLRs was tested. Human keratinocytes infected with M. furfur and a variety of M. furfur-positive psoriatic skin biopsies were analysed by RT-PCR, for TLRs, MyD88, human beta-defensin 2 (HBD-2), HBD-3 and interleukin-8 (IL-8) mRNA expression. When keratinocytes were infected with M. furfur, an up-regulation for TLR2, MyD88, HBD-2, HBD-3 and IL-8 mRNA was demonstrated, compared to the untreated cells. The same results were obtained when psoriatic skin biopsies were analysed. The M. furfur-induced increase in HBD-2 and IL-8 gene expression is inhibited by anti-TLR2 neutralising antibodies, suggesting that TLR2 is involved in the M. furfur-induced expression of these molecules. These findings suggest the importance of TLRs in skin protection against fungi and the importance of keratinocytes as a component of innate immunity.

  3. An update global model of hmF2 from values estimated from COSMIC/FORMOSAT-3 radio occultation and ionosonde data

    NASA Astrophysics Data System (ADS)

    Zhang, Man-Lian; Liu, Libo; Ning, Baiqi; Wan, Weixing

    We present our recent work on developing an updated global model of the ionospheric F2 peak height hmF2 parameter by combining data from the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC/FORMOSAT-3) radio occultation (RO) measurements and from the extended global ionosonde stations. In particular, 10 Chinese ionosonde stations’ data are newly introduced into this study. The modeling technique used is based on a two-layer empirical orthogonal function (EOF) expansion. Global distributions of hmF2 maps calculated using our newly constructed global model and the one provided by the International Reference Ionosphere model (IRI-ITU-R) are compared with the global distributions of hmF2 obtained by the COSMIC/FORMOSAT-3 RO measurements and quantitative statistical analysis of the differences between the model results and those of the COSMIC/FORMOSAT-3 RO measurements is made for the low (2008) and high (2012) solar activity years. The obtained average root-mean-square differences (RMSDs) for our model are 27.7km (11.1%) and 31.0km (9.8%), respectively for the years 2008 and 2012, whereas those for the IRI-ITU-R model are 39.9km (16.9%) and 35.0km (11.6%), respectively. Comparison of the results calculated both by our model and the IRI-ITU-R model with the digisonde observations is also made.

  4. Role of Brønsted acid in selective production of furfural in biomass pyrolysis.

    PubMed

    Zhang, Haiyan; Liu, Xuejun; Lu, Meizhen; Hu, Xinyue; Lu, Leigang; Tian, Xiaoning; Ji, Jianbing

    2014-10-01

    In this work, the role of Brønsted acid for furfural production in biomass pyrolysis on supported sulfates catalysts was investigated. The introduction of Brønsted acid was shown to improve the degradation of polysaccharides to intermediates for furfural, which did not work well when only Lewis acids were used in the process. Experimental results showed that CuSO4/HZSM-5 catalyst exhibited the best performance for furfural (28% yield), which was much higher than individual HZSM-5 (5%) and CuSO4 (6%). The optimum reaction conditions called for the mass ratio of CuSO4/HZSM-5 to be 0.4 and the catalyst/biomass mass ratio to be 0.5. The recycled catalyst exhibited low productivity (9%). Analysis of the catalysts by Py-IR revealed that the CuSO4/HZSM-5 owned a stronger Brønsted acid intensity than HZSM-5 or the recycled CuSO4/HZSM-5. Therefore, the existence of Brønsted acid is necessary to achieve a more productive degradation of biomass for furfural.

  5. Synthesis of the insecticide prothrin and its analogues from biomass-derived 5-(Chloromethyl) furfural

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Prothrin, a synthetic pyrethroid insecticide, was synthesized from the biomass-derived platform chemical 5 (chloromethyl)furfural in six steps and overall 65% yield. Two structural analogues of prothrin were also prepared following the same synthetic approach. Preliminary testing of these furan-base...

  6. Antityrosinase and antimicrobial activities of furfuryl alcohol, furfural and furoic acid.

    PubMed

    Chai, Wei-Ming; Liu, Xuan; Hu, Yong-Hua; Feng, Hui-Ling; Jia, Yu-Long; Guo, Yun-Ji; Zhou, Han-Tao; Chen, Qing-Xi

    2013-06-01

    The inhibitory kinetics of furfuryl alcohol, furfural and furoic acid on mushroom tyrosinase have been investigated. The results showed that these furan compounds were reversible inhibitors of the enzyme. Furthermore, furfuryl alcohol and furfural were found to be mixed-type inhibitors while furoic acid is uncompetitive inhibitor. The inhibition constants have been confirmed and the order of the inhibiting ability was furfural>furoic acid>furfuryl alcohol. They indicate that the functional groups on the furan ring play a crucial role in the inhibition on the enzyme. In addition, it was also found that these furan compounds could inhibit the proliferation of Salmonella bacteria and Bacillus subtilis to different extents. The minimum inhibitory concentration (MIC) values of furfuryl alcohol, furfural and furoic acid against B. subtilis and S. bacteria were 0.115, 0.027, 0.015 and 0.115, 0.029, 0.009 μM, respectively. The minimum bactericidal concentration (MBC) values of that were 0.115, 0.027, 0.015 and 0.231, 0.121, 0.030 μM, respectively.

  7. The Role of L-DOPA on Melanization and Mycelial Production in Malassezia Furfur

    PubMed Central

    Youngchim, Sirida; Nosanchuk, Joshua D.; Pornsuwan, Soraya; Kajiwara, Susumu; Vanittanakom, Nongnuch

    2013-01-01

    Melanins are synthesized by organisms of all biological kingdoms and comprise a heterogeneous class of natural pigments. Certain of these polymers have been implicated in the pathogenesis of several important human fungal pathogens. This study investigated whether the fungal skin pathogen Malassezia furfur produces melanin or melanin-like compounds. A melanin-binding monoclonal antibody (MAb) labelled in vitro cultivated yeast cells of M. furfur. In addition, melanization of Malassezia yeasts and hyphae was detected by anti-melanin MAb in scrapings from patients with pityriasis versicolor. Treatment of Malassezia yeasts with proteolytic enzymes, denaturant and concentrated hot acid yielded dark particles and electron spin resonance spectroscopy revealed that these particles contained a stable free radical compound, consistent with their identification as melanins. Malassezia yeasts required phenolic compounds, such as L-DOPA, in order to synthesize melanin. L-DOPA also triggered hyphal formation in vitro when combined with kojic acid, a tyrosinase inhibitor, in a dose-dependent manner. In this respect, L-DOPA is thought to be an essential substance that is linked to both melanization and yeast-mycelial transformation in M. furfur. In summary, M. furfur can produce melanin or melanin-like compounds in vitro and in vivo, and the DOPA melanin pathway is involved in cell wall melanization. PMID:23762233

  8. Seborrheic dermatitis flare in a Dutch male due to commensal Malassezia furfur overgrowth.

    PubMed

    Ran, Yuping; He, Xiaodan; Zhang, Hao; Dai, Yaling; Li, Lina; Bulmer, G S

    2008-09-01

    This is a case of seborrheic dermatitis (SD) barbae from which Malassezia furfur (M. furfur) was isolated. The patient was a 57-year-old Dutch male, who was hospitalized for fever and weakness of extremities. He presented with symmetrical erythema with an abundance of greasy chaffy scales on his beard area. No reasons were detected for his fever following a routine search. M. furfur was identified through mycological examination, including direct microscopic examination, culture, Tween test, esculine splitting test and DNA sequencing, of samples from the skin lesions. The patient was treated with oral itraconazole capsules (200 mg, b.i.d. for 8 days, then 200 mg o.d. for 13 days), washing his scalp and face with 2% ketoconazole shampoo (once a day) and topical application of a cream containing 1% naftifine hydrochloride and 0.25% ketoconazole (b.i.d.). After treatment the fever subsided and the SD lesion gradually healed. M. furfur was not isolated again from skin scrapings and 7 days later therapy was terminated and no recurrence was noted after one week follow-up since the cessation of treatment.

  9. The role of L-DOPA on melanization and mycelial production in Malassezia furfur.

    PubMed

    Youngchim, Sirida; Nosanchuk, Joshua D; Pornsuwan, Soraya; Kajiwara, Susumu; Vanittanakom, Nongnuch

    2013-01-01

    Melanins are synthesized by organisms of all biological kingdoms and comprise a heterogeneous class of natural pigments. Certain of these polymers have been implicated in the pathogenesis of several important human fungal pathogens. This study investigated whether the fungal skin pathogen Malassezia furfur produces melanin or melanin-like compounds. A melanin-binding monoclonal antibody (MAb) labelled in vitro cultivated yeast cells of M. furfur. In addition, melanization of Malassezia yeasts and hyphae was detected by anti-melanin MAb in scrapings from patients with pityriasis versicolor. Treatment of Malassezia yeasts with proteolytic enzymes, denaturant and concentrated hot acid yielded dark particles and electron spin resonance spectroscopy revealed that these particles contained a stable free radical compound, consistent with their identification as melanins. Malassezia yeasts required phenolic compounds, such as L-DOPA, in order to synthesize melanin. L-DOPA also triggered hyphal formation in vitro when combined with kojic acid, a tyrosinase inhibitor, in a dose-dependent manner. In this respect, L-DOPA is thought to be an essential substance that is linked to both melanization and yeast-mycelial transformation in M. furfur. In summary, M. furfur can produce melanin or melanin-like compounds in vitro and in vivo, and the DOPA melanin pathway is involved in cell wall melanization.

  10. Catalytic hydrolysis of cellulose into furans

    NASA Astrophysics Data System (ADS)

    Shi, Chengmei; Tao, Furong; Cui, Yuezhi

    2016-12-01

    Chromium chloride in 4-(3-methylimidazolium-1-yl)butane-1-sulfonic acid hydrogen sulfate (IL-1) was found to effectively catalyze the hydrolysis of microcrystalline cellulose (MCC) at 150°C for 300 min to achieve 87.8% conversion to a slate of products. With a catalytic amount of CrCl3, the yields of 5-hydroxymethyl furfural (HMF) and furfural were up to 32.4 and 15.2%, respectively, small molecules levulinic acid (LA, 10.8%) and the total reducing sugars (TRS, 10.7%) were also generated. Through LC-MSD analysis and mass spectra, dimer of furan compounds as the main by-products were speculated, and the components of gas products were methane, ethane, CO, CO2, and H2. We suggested that IL-1 and CrCl3 exhibited a coordination interaction; the formation of the intermediate via the hydride shift played a key role in the formation of HMF. The catalyst was recycled and exhibited constant activity for five successive trials.

  11. Multivariate optimization of headspace trap for furan and furfural simultaneous determination in sponge cake.

    PubMed

    Cepeda-Vázquez, Mayela; Blumenthal, David; Camel, Valérie; Rega, Barbara

    2017-03-01

    Furan, a possibly carcinogenic compound to humans, and furfural, a naturally occurring volatile contributing to aroma, can be both found in thermally treated foods. These process-induced compounds, formed by close reaction pathways, play an important role as markers of food safety and quality. A method capable of simultaneously quantifying both molecules is thus highly relevant for developing mitigation strategies and preserving the sensory properties of food at the same time. We have developed a unique reliable and sensitive headspace trap (HS trap) extraction method coupled to GC-MS for the simultaneous quantification of furan and furfural in a solid processed food (sponge cake). HS Trap extraction has been optimized using an optimal design of experiments (O-DOE) approach, considering four instrumental and two sample preparation variables, as well as a blocking factor identified during preliminary assays. Multicriteria and multiple response optimization was performed based on a desirability function, yielding the following conditions: thermostatting temperature, 65°C; thermostatting time, 15min; number of pressurization cycles, 4; dry purge time, 0.9min; water / sample amount ratio (dry basis), 16; and total amount (water + sample amount, dry basis), 10g. The performances of the optimized method were also assessed: repeatability (RSD: ≤3.3% for furan and ≤2.6% for furfural), intermediate precision (RSD: 4.0% for furan and 4.3% for furfural), linearity (R(2): 0.9957 for furan and 0.9996 for furfural), LOD (0.50ngfuran gsample dry basis(-1) and 10.2ngfurfural gsample dry basis(-1)), LOQ (0.99ngfuran gsample dry basis(-1) and 41.1ngfurfural gsample dry basis(-1)). Matrix effect was observed mainly for furan. Finally, the optimized method was applied to other sponge cakes with different matrix characteristics and levels of analytes.

  12. Noontime Latitudinal Behavior of the Ionospheric Peak Parameters (foF2 and hmF2) to the Variation of Solar Energy Input for the American Sector

    NASA Astrophysics Data System (ADS)

    Cabassa-Miranda, E.; Garnett Marques Brum, C.

    2013-12-01

    We are presenting a statistical study of the behavior of the noontime F2 peak parameters (foF2 and hmF2) to the variation of solar energy input based on digisonde data and EUV-UV solar emissions registered by SOHO satellite for geomagnetic quiet-to-normal condition. For this, we selected digisonde data from fourteen different stations spread along the American sector (ten of them located above and four below the equator). These registers were collected from 2000 to 2012 and encompass the last unusual super minimum period.

  13. Comparison of NmF2 and hmF2 values derived from IRI and FORMOSAT-3/COSMIC ionospheric radio occultations

    NASA Astrophysics Data System (ADS)

    Brunini, Claudio; Limberger, Marco; Schmidt, Michael; Dettmering, Denise; Wenjing, Liang

    2014-05-01

    The electron density, NmF2, and the height, hmF2, of the ionospheric F2 peak are key parameters for modeling the electron density distribution in the ionosphere (e.g. within the International Reference Ionosphere (IRI) model), for radio-communication forecast (e.g. in the radio-communication sector of the International Telecommunication Union Recommendations (ITU-R)), and other space weather related issues. A commonly applied procedure to compute the values of these parameters, in case that direct measurements are not available, is the use of the ITU-R global maps which were established in the early 60s but still belong to the ITU-R standards. Accompanying the efforts the community is making to update those maps, we have recently presented a technique based on the assimilation of FORMOSAT-3/COSMIC (F3/C) ionospheric radio occultations (IRO) in the La Plata Ionospheric Model (LPIM). The global mean error of our maps, estimated by the data assimilation algorithm, ranged from 0.5×10**10 el/m3 and 3.6×10**10 el/m3 for NmF2 (which is equivalent to approximately 7% of the value of the estimated parameter), and from 2.0 to 5.6 km for hmF2 (around 2 %), depending on the solar activity. Further, we compared the NmF2 and hmF2 values retrieved with our technique to the ones computed by IRI, and found systematic differences between both estimations. The comparison has been made for low solar activity and showed systematic differences up to 50% for NmF2 and 12% for hmF2. It seems reasonable to conjecture that the aforementioned differences are caused by systematic errors in IRI as well as in the F3/C IRO + LPIM. Hence, a comparison to a third data source could help to assess the contribution of each party. In this paper we compared the vertical Total Electron Content (vTEC) provided by the Jason mission to the corresponding values derived from F3/C IRO + LPIM and from IRI. We found that approximately 50% of the systematic differences reported in our previous paper could be

  14. Evaluation of prototype Advanced Life Support (ALS) pack for use by the Health Maintenance Facility (HMF) on Space Station Freedom (SSF)

    NASA Technical Reports Server (NTRS)

    Krupa, Debra T.; Gosbee, John; Murphy, Linda; Kizzee, Victor D.

    1991-01-01

    The purpose is to evaluate the prototype Advanced Life Support (ALS) Pack which was developed for the Health Maintenance Facility (HMF). This pack will enable the Crew Medical Officer (CMO) to have ready access to advanced life support supplies and equipment for time critical responses to any situation within the Space Station Freedom. The objectives are: (1) to evaluate the design of the pack; and (2) to collect comments for revision to the design of the pack. The in-flight test procedures and other aspects of the KC-135 parabolic test flight to simulate weightlessness are presented.

  15. Impact of direct and indirect application of rising furfural concentrations on viability, infectivity and reproduction of the root-knot nematode, Meloidogyne incognita in Pisum sativum.

    PubMed

    Abdelnabby, Hazem; Wang, Yunhe; Xiao, Xueqiong; Wang, Gaofeng; Yang, Fan; Xiao, Yannong

    2016-07-01

    The gradual withdraw of several broadly used nematicides from market has enhanced the need to develop sustainable and eco-friendly alternatives with nematicidal properties. Furfural is one of the promising alternatives to fill this need. Baseline information about the impact of furfural on egg hatch, penetration potential and ultrastructure of nematode is lacking. In this study, the reagent-grade (purity ≥ 99.0%) of furfural was applied against Meloidogyne incognita. In vitro tests showed gradual reduction in either the rate of egg hatch or second stage juvenile (J2) viability of M. incognita when immersed in concentrations ranging from 0 to 10.0 μl/ml furfural. The mean EC50 for J2 and egg hatch was 0.37 and 0.27 μl/ml furfural, respectively. Furfural, even at low concentrations, resulted in a considerable suppression in egg hatch. Hatch was <5% after 8 days at 0.63 μl/ml furfural. The same furfural concentrations after 12 h caused 57.25% loss of viability in J2. Moreover, the penetration rate of juveniles to pea roots was suppressed when furfural was even applied at low rates. In pot experiments, furfural was applied as liquid (direct) or vapor (indirect) treatments at rates of 0-1.5 ml/kg soil. Significant reduction in galling, egg production and population density of M. incognita observed when furfural was applied at rates >0.2 ml/kg soil. No adverse effect was detected on plants or free-living nematodes as a result of furfural application. Liquid furfural proved to have superior juvenile-suppressive effect whereas its vapor has such superiority against eggs. Scanning electron microscope (SEM) study showed irregular appearance of the body surface accompanied with some cuticle disfigurement of furfural-treated juveniles. These results indicated that furfural can adversely affect egg hatch, juvenile viability, penetration potential and ultrastructure of M. incognita. Furfural may therefore be of a considerable potential as an appropriate

  16. Organic carbon aerogels from the sol-gel polymerization of phenolic-furfural mixtures

    DOEpatents

    Pekala, Richard W.

    1998-04-28

    The sol-gel polymerization of a phenolic-furfural mixture in dilute solution leads to a highly cross-linked network that can be supercritically dried to form a high surface area foam. These porous materials have cell/pore sizes .ltoreq.1000 .ANG., and although they are dark brown in color, they can be classified as a new type of aerogel. The phenolic-furfural aerogel can be pyrolyzed in an inert atmosphere at 1050.degree. C. to produce carbon aerogels. This new aerogel may be used for thermal insulation, chromatographic packing, water filtration, ion-exchange, and carbon electrodes for energy storage devices, such as batteries and double-layer capacitors.

  17. Organic aerogels from the sol-gel polymerization of phenolic-furfural mixtures

    DOEpatents

    Pekala, R.W.

    1995-12-19

    The sol-gel polymerization of a phenolic-furfural mixture in dilute solution leads to a highly cross-linked network that can be supercritically dried to form a high surface area foam. These porous materials have cell/pore sizes{<=}1000{angstrom}, and although they are dark brown in color, they can be classified as a new type of aerogel. The phenolic-furfural aerogel can be pyrolyzed in an inert atmosphere at 1050 C to produce carbon aerogels. This new aerogel may be used for thermal insulation, chromatographic packing, water filtration, ion-exchange, and carbon electrodes for energy storage devices, such as batteries and double-layer capacitors. 8 figs.

  18. Organic aerogels from the sol-gel polymerization of phenolic-furfural mixtures

    DOEpatents

    Pekala, R.W.

    1996-09-17

    The sol-gel polymerization of a phenolic-furfural mixture in dilute solution leads to a highly cross-linked network that can be supercritically dried to form a high surface area foam. These porous materials have cell/pore sizes {<=}1,000{angstrom}, and although they are dark brown in color, they can be classified as a new type of aerogel. The phenolic-furfural aerogel can be pyrolyzed in an inert atmosphere at 1,050 C to produce carbon aerogels. This new aerogel may be used for thermal insulation, chromatographic packing, water filtration, ion-exchange, and carbon electrodes for energy storage devices, such as batteries and double-layer capacitors. 8 figs.

  19. Organic carbon aerogels from the sol-gel polymerization of phenolic-furfural mixtures

    DOEpatents

    Pekala, R.W.

    1998-04-28

    The sol-gel polymerization of a phenolic-furfural mixture in dilute solution leads to a highly cross-linked network that can be supercritically dried to form a high surface area foam. These porous materials have cell/pore sizes {<=}1000 {angstrom}, and although they are dark brown in color, they can be classified as a new type of aerogel. The phenolic-furfural aerogel can be pyrolyzed in an inert atmosphere at 1050 C to produce carbon aerogels. This new aerogel may be used for thermal insulation, chromatographic packing, water filtration, ion-exchange, and carbon electrodes for energy storage devices, such as batteries and double-layer capacitors. 8 figs.

  20. DSC and curing kinetics study of epoxy grouting diluted with furfural -acetone slurry

    NASA Astrophysics Data System (ADS)

    Yin, H.; Sun, D. W.; Li, B.; Liu, Y. T.; Ran, Q. P.; Liu, J. P.

    2016-07-01

    The use of furfural-acetone slurry as active diluents of Bisphenol-A epoxy resin (DGEBA) groutings has been studied by dynamic and non-isothermal DSC for the first time. Curing kinetics study was investigated by non-isothermal differential scanning calorimetries at different heating rates. Activation enery (Ea) was calculated based on Kissinger and Ozawa Methods, and the results showed that Ea increased from 58.87 to 71.13KJ/mol after the diluents were added. The furfural-acetone epoxy matrix could cure completely at the theoretical curing temperature of 365.8K and the curing time of 139mins, which were determined by the kinetic model parameters.

  1. Organic aerogels from the sol-gel polymerization of phenolic-furfural mixtures

    DOEpatents

    Pekala, Richard W.

    1995-01-01

    The sol-gel polymerization of a phenolic-furfural mixture in dilute solution leads to a highly cross-linked network that can be supercritically dried to form a high surface area foam. These porous materials have cell/pore sizes.ltoreq.1000.ANG., and although they are dark brown in color, they can be classified as a new type of aerogel. The phenolic-furfural aerogel can be pyrolyzed in an inert atmosphere at 1050.degree. C. to produce carbon aerogels. This new aerogel may be used for thermal insulation, chromatographic packing, water filtration, ion-exchange, and carbon electrodes for energy storage devices, such as batteries and double-layer capacitors.

  2. Organic aerogels from the sol-gel polymerization of phenolic-furfural mixtures

    DOEpatents

    Pekala, Richard W.

    1996-01-01

    The sol-gel polymerization of a phenolic-furfural mixture in dilute solution leads to a highly cross-linked network that can be supercritically dried to form a high surface area foam. These porous materials have cell/pore sizes .ltoreq.1000.ANG., and although they are dark brown in color, they can be classified as a new type of aerogel. The phenolic-furfural aerogel can be pyrolyzed in an inert atmosphere at 1050.degree. C. to produce carbon aerogels. This new aerogel may be used for thermal insulation, chromatographic packing, water filtration, ion-exchange, and carbon electrodes for energy storage devices, such as batteries and double-layer capacitors.

  3. Nano TiO2 film electrode for electrocatalytic reduction of furfural in ionic liquids

    NASA Astrophysics Data System (ADS)

    Chu, Daobao; Hou, Yuanyuan; He, Jianguo; Xu, Mai; Wang, Yuqing; Wang, Shuxi; Wang, Jian; Zha, Longwu

    2009-10-01

    Nanoporous TiO2 having enhanced surface area was synthesized by sol-gel method. An "environmental friendly" method for production of furfuryl alcohol was presented by electrocatalytic reduction of furfural to furfuryl alcohol in ionic liquid medium at the surface of nanoporous TiO2 film electrode. The heterogeneous catalytic redox behaviour of a nanoporous TiO2 film electrode surface was investigated by cyclic voltammetry (CV). It was found that the catalytic reduction of furfural by Ti(IV)/Ti(III) redox system on the nanoporous TiO2 film surface. The electrode reaction mechanism is called catalytic (EC') mechanism, current density can reach 38 mA/cm2 and yielding an overall conversion efficiency of 61.7%.

  4. Synthesis of renewable fine-chemical building blocks by reductive coupling between furfural derivatives and terpenes.

    PubMed

    Nicklaus, Céline M; Minnaard, Adriaan J; Feringa, Ben L; de Vries, Johannes G

    2013-09-01

    Sugar and Spice…: The use of renewable resources to produce fine chemicals is an underdeveloped area. A waste-free technology will be necessary to further convert platform chemicals, readily available from biomass. We show that furfurals, which can be obtained from C5 sugars, can be coupled with terpenes in up to 95% yield through ruthenium-catalyzed reductive couplings developed by Krische et al.

  5. Synthesis of the Insecticide Prothrin and Its Analogues from Biomass-Derived 5-(Cloromethyl)furfural

    DTIC Science & Technology

    2013-12-19

    insecticide prothrin (4) alongside five-step routes to analogues 5 and 6. The naturally occurring insecticide pyrethrum, isolated from flowers of...Synthesis of the Insecticide Prothrin and Its Analogues from Biomass-Derived 5‑(Chloromethyl)furfural Fei Chang,† Saikat Dutta,† James J. Becnel...Jacksonville, Florida 32212, United States *S Supporting Information ABSTRACT: Prothrin, a synthetic pyrethroid insecticide , was synthesized from the biomass

  6. Improved methods for isolation and enumeration of Malassezia furfur from human skin.

    PubMed Central

    Leeming, J P; Notman, F H

    1987-01-01

    A medium for the isolation and enumeration of Malassezia furfur is described. Incubation at 34 degrees C yielded geometric mean counts (in CFU per square centimeter) of 2.6 X 10(3) on the forehead, 8.5 X 10(2) on the cheek, and 9.6 X 10(3) on the back. These counts compared favorably with microscopic counts and greatly exceeded those obtained with previously described media. PMID:3667925

  7. Integral elastic, electronic-state, ionization, and total cross sections for electron scattering with furfural

    NASA Astrophysics Data System (ADS)

    Jones, D. B.; da Costa, R. F.; Varella, M. T. do N.; Bettega, M. H. F.; Lima, M. A. P.; Blanco, F.; García, G.; Brunger, M. J.

    2016-04-01

    We report absolute experimental integral cross sections (ICSs) for electron impact excitation of bands of electronic-states in furfural, for incident electron energies in the range 20-250 eV. Wherever possible, those results are compared to corresponding excitation cross sections in the structurally similar species furan, as previously reported by da Costa et al. [Phys. Rev. A 85, 062706 (2012)] and Regeta and Allan [Phys. Rev. A 91, 012707 (2015)]. Generally, very good agreement is found. In addition, ICSs calculated with our independent atom model (IAM) with screening corrected additivity rule (SCAR) formalism, extended to account for interference (I) terms that arise due to the multi-centre nature of the scattering problem, are also reported. The sum of those ICSs gives the IAM-SCAR+I total cross section for electron-furfural scattering. Where possible, those calculated IAM-SCAR+I ICS results are compared against corresponding results from the present measurements with an acceptable level of accord being obtained. Similarly, but only for the band I and band II excited electronic states, we also present results from our Schwinger multichannel method with pseudopotentials calculations. Those results are found to be in good qualitative accord with the present experimental ICSs. Finally, with a view to assembling a complete cross section data base for furfural, some binary-encounter-Bethe-level total ionization cross sections for this collision system are presented.

  8. Highly efficient transformation system for Malassezia furfur and Malassezia pachydermatis using Agrobacterium tumefaciens-mediated transformation.

    PubMed

    Celis, A M; Vos, A M; Triana, S; Medina, C A; Escobar, N; Restrepo, S; Wösten, H A B; de Cock, H

    2017-03-01

    Malassezia spp. are part of the normal human and animal mycobiota but are also associated with a variety of dermatological diseases. The absence of a transformation system hampered studies to reveal mechanisms underlying the switch from the non-pathogenic to pathogenic life style. Here we describe, a highly efficient Agrobacterium-mediated genetic transformation system for Malassezia furfur and M. pachydermatis. A binary T-DNA vector with the hygromycin B phosphotransferase (hpt) selection marker and the green fluorescent protein gene (gfp) was introduced in M. furfur and M. pachydermatis by combining the transformation protocols of Agaricus bisporus and Cryptococcus neoformans. Optimal temperature and co-cultivation time for transformation were 5 and 7days at 19°C and 24°C, respectively. Transformation efficiency was 0.75-1.5% for M. furfur and 0.6-7.5% for M. pachydermatis. Integration of the hpt resistance cassette and gfp was verified using PCR and fluorescence microscopy, respectively. The T-DNA was mitotically stable in approximately 80% of the transformants after 10 times sub-culturing in the absence of hygromycin. Improving transformation protocols contribute to study the biology and pathophysiology of Malassezia.

  9. Inhibitory effect of formulated lemongrass shampoo on Malassezia furfur: a yeast associated with dandruff.

    PubMed

    Wuthi-Udomlert, Mansuang; Chotipatoomwan, Ployphand; Panyadee, Sasikan; Gritsanapan, Wandee

    2011-03-01

    Lemongrass (Cymbopogon citratus Stapf) has been used in cooking and in many traditional medicines; the essential oil contains citral as a major constituent. This study evaluated the antifungal activity of lemongrass oil against Malassezia furfur, an opportunistic yeast associated with dandruff, by using a broth dilution assay. From the minimum fungicidal concentration (MFC) obtained, the oil was then incorporated at different percentages into shampoo formulations. The formulated shampoos were kept at room temperature (28 degrees-30 degrees C) and under accelerated condition (45 degrees C). At the end of the first and sixth weeks, after preparation, all formulations were tested again and the appearance was recorded. Selection of an appropriate formula was based on antifungal activity against M. furfur, the physical appearance, the chemical properties and stability of the formula. Two percent lemongrass oil shampoo provided the required qualities necessary for commercial use. After being kept for 6 weeks at 28 degrees-30 degrees C and 45 degrees C, this formulated shampoo gave MFCs against M. furfur of 75 microl/ml and 18.75 microl/ml, respectively.

  10. Antifungal activity of the aqueous extract of Ilex paraguariensis against Malassezia furfur.

    PubMed

    Filip, Rosana; Davicino, Roberto; Anesini, Claudia

    2010-05-01

    Malassezia furfur is a lipodependent, dimorphic and saprophyte fungus which causes pityriasis versicolor, dandruff and seborrheic dermatitis in humans. The drugs available to treat this fungal infection are few. These drugs are highly toxic and are costly when used in prolonged treatments. For these reasons, it is necessary to find new compounds to treat these infections. Ilex paraguariensis St Hilaire is a plant that grows in Argentina, Brazil and Paraguay. The aim of this study was to evaluate the effect of the aqueous extract of Ilex paraguariensis on the growth of M. furfur. High performance liquid chromatography (HPLC) was employed to identify and isolate compounds of I. paraguariensis and the agar-well diffusion method was used to assess the antifungal activity of the extract. The fungicidal/fungistatic effect was evaluated by the modified Thompson assay. The results demonstrated that the aqueous extract of Ilex paraguariensis (1000 mg/ml) possesses inhibitory activity against M. furfur. This antimalassezial activity was equivalent to 2.7 microg/ml of ketoconazole. Therefore, the topical use of Ilex paraguariensis extract as alternative antifungal agent can be suggested.

  11. Pityriazepin and other potent AhR ligands isolated from Malassezia furfur yeast.

    PubMed

    Mexia, Nikitia; Gaitanis, Georgios; Velegraki, Aristea; Soshilov, Anatoly; Denison, Michael S; Magiatis, Prokopios

    2015-04-01

    Malassezia furfur yeast strains isolated from diseased human skin preferentially biosynthesize indole alkaloids which can be detected in the human skin and are highly potent activators of the aryl hydrocarbon receptor (AhR) and AhR-dependent gene expression. Chemical analysis of an EtOAc extract of a M. furfur strain obtained from diseased human skin and grown on l-tryptophan agar revealed several known AhR active tryptophan metabolites along with a previously unidentified compound, pityriazepin. While its structure resembled that of the known alkaloid pityriacitrin, the comprised pyridine ring had been transformed into an azepinone. The indoloazepinone scaffold of pityriazepin is extremely rare in nature and has only been reported once previously. Pityriazepin, like the other isolated compounds, was found to be a potent activator of the AhR-dependent reporter gene assay in recombinant cell lines derived from four different species, although significant species differences in relative potency were observed. The ability of pityriazepin to competitively bind to the AhR and directly stimulate AhR DNA binding classified it as a new naturally-occurring potent AhR agonist. M. furfur produces an expanded collection of extremely potent naturally occurring AhR agonists, which produce their biological effects in a species-specific manner.

  12. The role of drug efflux pumps in Malassezia pachydermatis and Malassezia furfur defence against azoles.

    PubMed

    Iatta, Roberta; Puttilli, Maria Rita; Immediato, Davide; Otranto, Domenico; Cafarchia, Claudia

    2017-03-01

    This study aims to evaluate the effect of efflux pump modulators (EPMs) on the minimal inhibitory concentration (MIC) of fluconazole (FLZ) and voriconazole (VOR) in Malassezia furfur and Malassezia pachydermatis. The in vitro efficacy of azoles, in combination with EPMs (ie haloperidol-HAL, promethazine-PTZ and cyclosporine A-CYS), against 21 M. furfur from bloodstream infection patients and 14 M. pachydermatis from the skin of dogs with dermatitis, was assessed using a broth microdilution chequerboard analysis. Data were analysed using the model-fractional inhibitory concentration index (FICI) method. The MIC of FLZ and VOR of Malassezia spp. decreased in the presence of sub-inhibitory concentrations of HAL and/or PTZ. The synergic effect was observed only in strains with FLZ MIC≥128 μg/mL for M. furfur, FLZ MIC≥64 μg/mL for M. pachydermatis and VOR MIC≥4 μg/mL in both Malassezia spp. These results suggest that the drug efflux pumps are involved as defence mechanisms to azole drugs in Malassezia yeast. The synergism might be related to an increased expression of efflux pump genes, eventually resulting in azole resistance phenomena. Finally, the above FLZ and VOR MIC values might be considered the cut-off to discriminate susceptible and resistant strains.

  13. Characterization of tryptophan aminotransferase 1 of Malassezia furfur, the key enzyme in the production of indolic compounds by M. furfur.

    PubMed

    Preuss, Janina; Hort, Wiebke; Lang, Sarah; Netsch, Anette; Rahlfs, Stefan; Lochnit, Günter; Jortzik, Esther; Becker, Katja; Mayser, Peter A

    2013-11-01

    Malassezia yeasts are responsible for the widely distributed skin disease Pityriasis versicolor (PV), which is characterized by a hyper- or hypopigmentation of affected skin areas. For Malassezia furfur, it has been shown that pigment production relies on tryptophan metabolism. A tryptophan aminotransferase was found to catalyse the initial catalytic step in pigment formation in the model organism Ustilago maydis. Here, we describe the sequence determination, recombinant production and biochemical characterization of tryptophan aminotransferase MfTam1 from M. furfur. The enzyme catalyses the transamination from l-tryptophan to keto acids such as α-ketoglutarate with Km values for both substrates in the low millimolar range. Furthermore, MfTam1 presents a temperature optimum at 40°C and a pH optimum at 8.0. MfTam1 activity is highly dependent on pyridoxal phosphate (PLP), whereas compounds interfering with PLP, such as cycloserine (CS) and aminooxyacetate, inhibit the MfTam1 reaction. CS is known to reverse hyperpigmentation in PV. Thus, the results of the present study give a deeper insight into the role of MfTam1 in PV pathogenesis and as potential target for the development of novel PV therapeutics.

  14. NMR structure and comparison of the archaeal histone HFoB from the mesophile Methanobacterium formicicum with HMfB from the hyperthermophile Methanothermus fervidus.

    PubMed

    Zhu, W; Sandman, K; Lee, G E; Reeve, J N; Summers, M F

    1998-07-28

    The solution-state structure of the recombinant archaeal histone rHFoB, from the mesophile Methanobacterium formicicum, has been determined by two- and three-dimensional (3D) proton homonuclear correlated nuclear magnetic resonance (NMR) methods. On the basis of 951 nuclear Overhauser effect (NOE)-derived distance restraints, rHFoB monomers form the histone fold and assemble into symmetric (rHFoB)2 dimers that have a structure consistent with assembly into archaeal nucleosomes. rHFoB exhibits approximately 78% sequence homology with rHMfB from the hyperthermophile Methanothermus fervidus, and the results obtained demonstrate that these two proteins have very similar 3D structures, with a root-mean-square deviation for backbone atoms of 0.65 +/- 0.13 A2. (rHFoB)2 dimers however unfold at lower temperatures and require a higher salt environment for stability than (rHMfB)2 dimers, and comparing the structures, we predict that these differences result from unfavorable surface-located ionic interactions and a larger, more solvent-accessible cavity adjacent to residue G36 in the hydrophobic core of (rHFoB)2.

  15. Clostridium thermocellum Transcriptomic Profiles after Exposure to Furfural or Heat Stress

    SciTech Connect

    Wilson, Charlotte M; Yang, Shihui; Rodriguez, Jr., Miguel; Ma, Qin; Johnson, Courtney M; Dice, Lezlee T; Xu, Ying; Brown, Steven D

    2013-01-01

    Background The thermophilic anaerobe Clostridium thermocellum is a candidate consolidated bioprocessing (CBP)biocatalyst for cellulosic ethanol production. It is capable of both cellulose solubilization and its fermentation to produce lignocellulosic ethanol. Intolerance to stresses routinely encountered during industrial fermentations may hinder the commercial development of this organism. A previous C. thermocellum ethanol stress study showed that largest transcriptomic response was in genes and proteins related to nitrogen uptake and metabolism. Results In this study, C. thermocellum was grown to mid-exponential phase and treated with furfural or heat to a final concentration of 3 g.L-1 or 68 C respectively to investigate general and specific physiological and regulatory stress responses. Samples were taken at 10, 30, 60 and 120 min post-shock, and from untreated control fermentations, for transcriptomic analyses and fermentation product determinations and compared to a published dataset from an ethanol stress study. Urea uptake genes were induced following furfural stress, but not to the same extent as ethanol stress and transcription from these genes was largely unaffected by heat stress. The largest transcriptomic response to furfural stress was genes for sulfate transporter subunits and enzymes in the sulfate assimilatory pathway, although these genes were also affected late in the heat and ethanol stress responses. Lactate production was higher in furfural treated culture, although the lactate dehydrogenase gene was not differentially expressed under this condition. Other redox related genes such as a copy of the rex gene, a bifunctional acetaldehyde-CoA/alcohol dehydrogenase and adjacent genes did show lower expression after furfural stress compared to the control, heat and ethanol fermentation profiles. Heat stress induced expression from chaperone related genes and overlap was observed with the responses to the other stresses. This study suggests the

  16. Main and interaction effects of acetic acid, furfural, and p-hydroxybenzoic acid on growth and ethanol productivity of yeasts.

    PubMed

    Palmqvist, E; Grage, H; Meinander, N Q; Hahn-Hägerdal, B

    1999-04-05

    The influence of the factors acetic acid, furfural, and p-hydroxybenzoic acid on the ethanol yield (YEtOH) of Saccharomyces cerevisiae, bakers' yeast, S. cerevisiae ATCC 96581, and Candida shehatae NJ 23 was investigated using a 2(3)-full factorial design with 3 centrepoints. The results indicated that acetic acid inhibited the fermentation by C. shehatae NJ 23 markedly more than by bakers' yeast, whereas no significant difference in tolerance towards the compounds was detected between the S. cerevisiae strains. Furfural (2 g L-1) and the lignin derived compound p-hydroxybenzoic acid (2 g L-1) did not affect any of the yeasts at the cell mass concentration used. The results indicated that the linear model was not adequate to describe the experimental data (the p-values of curvatures were 0.048 for NJ 23 and 0.091 for bakers' yeast). Based on the results from the 2(3)-full factorial experiment, an extended experiment was designed based on a central composite design to investigate the influence of the factors on the specific growth rate (mu), biomass yield (Yx), volumetric ethanol productivity (QEtOH), and YEtOH. Bakers' yeast was chosen in the extended experiment due to its better tolerance towards acetic acid, which makes it a more interesting organism for use in industrial fermentations of lignocellulosic hydrolysates. The inoculum size was reduced in the extended experiment to reduce any increase in inhibitor tolerance that might be due to a large cell inoculum. By dividing the experiment in blocks containing fermentations performed with the same inoculum preparation on the same day, much of the anticipated systematic variation between the experiments was separated from the experimental error. The results of the fitted model can be summarised as follows: mu was decreased by furfural (0-3 g L-1). Furfural and acetic acid (0-10 g L-1) also interacted negatively on mu. Furfural concentrations up to 2 g L-1 stimulated Yx in the absence of acetic acid whereas higher

  17. Reaction pathways of furfural, furfuryl alcohol and 2-methylfuran on Cu(111) and NiCu bimetallic surfaces

    SciTech Connect

    Xiong, Ke; Wan, Weiming; Chen, Jingguang G.

    2016-02-23

    Hydrodeoxygenation (HDO) is an important reaction for converting biomass-derived furfural to value-added 2-methylfuran, which is a promising fuel additive. In this work, the HDO of furfural to produce 2-methylfuran occurred on the NiCu bimetallic surfaces prepared on either Ni(111) or Cu(111). The reaction pathways of furfural were investigated on Cu(111) and Ni/Cu(111) surfaces using density functional theory (DFT) calculations, temperature programmed desorption (TPD) and high resolution electron energy loss spectroscopy (HREELS) experiments. These studies provided mechanistic insights into the effects of bimetallic formation on enhancing the HDO activity. Specifically, furfural weakly adsorbed on Cu(111), while it strongly adsorbed on Ni/Cu(111) through an η2(C,O) configuration which led to the HDO of furfural on Ni/Cu(111). Lastly, the ability to dissociate H2 on Ni/Cu(111) is also an important factor for enhancing the HDO activity over Cu(111).

  18. Reaction pathways of furfural, furfuryl alcohol and 2-methylfuran on Cu(111) and NiCu bimetallic surfaces

    NASA Astrophysics Data System (ADS)

    Xiong, Ke; Wan, Weiming; Chen, Jingguang G.

    2016-10-01

    Hydrodeoxygenation (HDO) is an important reaction for converting biomass-derived furfural to value-added 2-methylfuran, which is a promising fuel additive. In this work, the HDO of furfural to produce 2-methylfuran occurred on the NiCu bimetallic surfaces prepared on either Ni(111) or Cu(111). The reaction pathways of furfural were investigated on Cu(111) and Ni/Cu(111) surfaces using density functional theory (DFT) calculations, temperature-programmed desorption (TPD) and high-resolution electron energy loss spectroscopy (HREELS) experiments. These studies provided mechanistic insights into the effects of bimetallic formation on enhancing the HDO activity. Specifically, furfural weakly adsorbed on Cu(111), while it strongly adsorbed on Ni/Cu(111) through an η2(C,O) configuration, which led to the HDO of furfural on Ni/Cu(111). The ability to dissociate H2 on Ni/Cu(111) is also an important factor for enhancing the HDO activity over Cu(111).

  19. Reaction pathways of furfural, furfuryl alcohol and 2-methylfuran on Cu(111) and NiCu bimetallic surfaces

    DOE PAGES

    Xiong, Ke; Wan, Weiming; Chen, Jingguang G.

    2016-02-23

    Hydrodeoxygenation (HDO) is an important reaction for converting biomass-derived furfural to value-added 2-methylfuran, which is a promising fuel additive. In this work, the HDO of furfural to produce 2-methylfuran occurred on the NiCu bimetallic surfaces prepared on either Ni(111) or Cu(111). The reaction pathways of furfural were investigated on Cu(111) and Ni/Cu(111) surfaces using density functional theory (DFT) calculations, temperature programmed desorption (TPD) and high resolution electron energy loss spectroscopy (HREELS) experiments. These studies provided mechanistic insights into the effects of bimetallic formation on enhancing the HDO activity. Specifically, furfural weakly adsorbed on Cu(111), while it strongly adsorbed on Ni/Cu(111)more » through an η2(C,O) configuration which led to the HDO of furfural on Ni/Cu(111). Lastly, the ability to dissociate H2 on Ni/Cu(111) is also an important factor for enhancing the HDO activity over Cu(111).« less

  20. Dynamic flux balancing elucidates NAD(P)H production as limiting response to furfural inhibition in Saccharomyces cerevisiae.

    PubMed

    Pornkamol, Unrean; Franzen, Carl J

    2015-08-01

    Achieving efficient and economical lignocellulose-based bioprocess requires a robust organism tolerant to furfural, a major inhibitory compound present in lignocellulosic hydrolysate. The aim of this study was to develop a model that could generate quantitative descriptions of cell metabolism for elucidating the cell's adaptive response to furfural. Such a modelling tool could provide strategies for the design of more robust cells. A dynamic flux balance (dFBA) model of Saccharomyces cerevisiae was created by coupling a kinetic fermentation model with a previously published genome-scale stoichiometric model. The dFBA model was used for studying intracellular and extracellular flux responses to furfural perturbations under steady state and dynamic conditions. The predicted effects of furfural on dynamic flux profiles agreed well with previously published experimental results. The model showed that the yeast cell adjusts its metabolism in response to furfural challenge by increasing fluxes through the pentose phosphate pathway, TCA cycle, and proline and serine biosynthesis in order to meet the high demand of NAD(P)H cofactors. The model described here can be used to aid in systematic optimization of the yeast, as well as of the fermentation process, for efficient lignocellulosic ethanol production.

  1. [Effect of acetic acid, furfural and 5-hydroxymethylfurfural on production of 2,3-butanediol by Klebsiella oxytoca].

    PubMed

    Wu, Jing; Cheng, Keke; Li, Wenying; Feng, Jie; Zhang, Jian'an

    2013-03-01

    To get the tolerability and consumption of Klebsiella oxytoca on major inhibitors in lignocelluloses hydrolysate, we studied the effect of acetic acid, furfural and 5-hydroxymethylfurfural on production of 2,3-butanediol by Klebsiella oxytoca. The metabolites of furfural and 5-hydroxymethylfurfural were measured. The results show that when acetic acid, furfural and 5-hydroxymethylfurfural was individually added, tolerance threshold for Klebsiella oxytoca was 30 g/L, 4 g/L and 5 g/L, respectively. Acetic acid was likely used as substrate to produce 2,3-butanediol. The yield of 2,3-butanediol increased when acetic acid concentration was lower than 30 g/L. In the fermentation, more than 70% 5-hydroxymethylfurfural was converted to 2,5-furandimethanol. All furfural and the rest of 5-hydroxymethylfurfural were metabolized by Klebsiella oxytoca. It showed that in the detoxification process of 2,3-butanediol production using lignocelluloses hydrolysate, furfural should be given priority to remove and a certain concentration of acetic acid is not need to removal.

  2. The impact of furfural concentrations and substrate-to-biomass ratios on biological hydrogen production from synthetic lignocellulosic hydrolysate using mesophilic anaerobic digester sludge.

    PubMed

    Akobi, Chinaza; Hafez, Hisham; Nakhla, George

    2016-12-01

    This study evaluated the impact of furfural (a furan derivative) on hydrogen production rates and yields at initial substrate-to-microorganism ratios (S°/X°) of 4, 2, 1, and 0.5gCOD/gVSS and furfural concentrations of 4, 2, 1, and 0.5g/L. Fermentation studies were carried out in batches using synthetic lignocellulosic hydrolysate as substrate and mesophilic anaerobic digester sludge as seed. Contrary to other literature studies where furfural was inhibitory, this study showed that furfural concentrations of up to 1g/L enhanced hydrogen production with yields as high as 19% from the control (batch without furfural). Plots of hydrogen yields against gfurfural/gsugars and hydrogen yields versus gfurfural/gbiomass showed negative linear correlation indicating that these parameters influence biohydrogen production. Regression analysis indicated that gfurfural/gsugarsinitial exerted a greater effect on the degree of inhibition of hydrogen production than gfurfural/gVSSfinal.

  3. Field-aligned neutral wind bias correction scheme for global ionospheric modeling at midlatitudes by assimilating FORMOSAT-3/COSMIC hmF2 data under geomagnetically quiet conditions

    NASA Astrophysics Data System (ADS)

    Sun, Yang-Yi; Matsuo, Tomoko; Maruyama, Naomi; Liu, Jann-Yenq

    2015-04-01

    This study demonstrates the usage of a data assimilation procedure, which ingests the FORMOSAT-3/COSMIC (F3/C) hmF2 observations to correct the model wind biases to enhance the capability of the new global Ionosphere Plasmasphere Electrodynamics (IPE) model under geomagnetically quiet conditions. The IPE model is built upon the field line interhemispheric plasma model with a realistic geomagnetic field model and empirical model drivers. The hmF2 observed by the F3/C radio occultation technique is utilized to adjust global thermospheric field-aligned neutral winds (i.e., a component of the thermospheric neutral wind parallel to the magnetic field) at midlatitudes according to a linear relationship between time differentials of the field-aligned wind and hmF2. The adjusted winds are further applied to drive the IPE model. The comparison of the modeled electron density with the observations of F3/C and ground-based GPS receivers at the 2012 March equinox suggests that the modeled electron density can be significantly improved in the midlatitude regions of the Southern Hemisphere, if the wind correction scheme is applied. Moreover, the F3/C observation, the IPE model, and the wind bias correction scheme are applied to study the 2012 Southern Hemisphere Midlatitude Summer Nighttime Anomaly (southern MSNA)/Weddell Sea Anomaly (WSA) event at December solstice for examining the role of the neutral winds in controlling the longitudinal variation of the southern MSNA/WSA behavior. With the help of the wind bias correction scheme, the IPE model better tracks the F3/C-observed eastward movement of the southern MSNA/WSA feature. The apparent eastward movement of the southern MSNA/WSA features in the local time coordinate is primarily caused by the longitudinal variation in the declination angle of the geomagnetic field that controls the field-aligned projection of both geographic meridional and zonal components of the neutral wind. Both the IPE simulations and the F3/C

  4. Catalytic conversion of corncob and corncob pretreatment hydrolysate to furfural in a biphasic system with addition of sodium chloride.

    PubMed

    Qing, Qing; Guo, Qi; Zhou, Linlin; Wan, Yilun; Xu, Youqing; Ji, Huilong; Gao, Xiaohang; Zhang, Yue

    2017-02-01

    Catalytic conversion of corncob pretreatment hydrolysate and raw corncob into furfural in a modified biphasic system by SO4(2-)/SnO2(-) MMT solid catalyst has been developed. The influence of the organic solvent type, organic to water phase ratio, sodium chloride concentration, reaction temperature and time on the furfural production were comparatively evaluated. The results showed that furfural yields of 81.7% and 66.1% were achieved at 190°C for 15mins and 190°C for 20mins, respectively, for corncob pretreatment hydrolysate and raw corncob by this solid catalyst. The solid catalyst used in this study exhibited good stability and high efficiency applied in the modified biphasic system in addition to excellent recyclability. The proposed catalytic system displayed high performance for catalytic conversion of lignocellulosic biomass into important platform chemicals and has great potential in industrial application.

  5. Genetic polymorphism of Malassezia furfur isolates from Han and Tibetan ethnic groups in China using DNA fingerprinting.

    PubMed

    Zhang, Hao; Zhang, Ruifeng; Ran, Yuping; Dai, Yaling; Lu, Yao; Wang, Peng

    2010-12-01

    Reported isolation rates of Malassezia yeast from human skin show geographic variations. In China, the populations of the Han (1,182.95 million) and Tibetan (5.41 million) ethnic groups are distributed over 9.6 and 3.27 million square kilometers respectively, making biodiversity research feasible and convenient. Malassezia furfur clinical strains (n = 29) isolated from different individuals, with or without associated dermatoses, of these two ethnic groups (15 Han and 12 Tibetan) were identified and analyzed with DNA fingerprinting using single primers specific to minisatellites. Using the Bionumerics software, we found that almost all M. furfur clinical isolates and type strains formed five distinct group clusters according to their associated skin diseases and the ethnic groups of the patients. These findings are the first to focus on the genetic diversity and relatedness of M. furfur in the Tibetan and Han ethnic groups in China and reveal genetic variation associated with related diseases, host ethnicity and geographic origin.

  6. Malassezin, a novel agonist of the aryl hydrocarbon receptor from the yeast Malassezia furfur, induces apoptosis in primary human melanocytes.

    PubMed

    Krämer, Hans-Joachim; Podobinska, Monika; Bartsch, Andrea; Battmann, Achim; Thoma, Wiebke; Bernd, August; Kummer, Wolfgang; Irlinger, Bernhard; Steglich, Wolfgang; Mayser, Peter

    2005-05-01

    Pityriasis versicolor is the most common skin mycosis in humans worldwide. Yeasts of the genus Malassezia, particularly M. furfur, a saprophyte occurring widely on human skin, are generally regarded as the causative agents. Pityriasis versicolor is often accompanied by a long-lasting depigmentation that persists even after successful antimycotic therapy. M. furfur is able to convert tryptophan into a variety of indole alkaloids, some of them showing biological properties that correlate well with certain clinical features of pityriasis versicolor. This suggests a possible role for these compounds in the depigmentation process. We now report that human melanocytes undergo apoptosis when exposed to the crude mixture of tryptophan metabolites from M. furfur. The active compound was identified as malassezin, previously isolated by us from the same source and characterized as an agonist of the aryl hydrocarbon (Ah) receptor. The compound could, therefore, contribute to the marked depigmentation observed during the course of pityriasis versicolor.

  7. MfLIP1, a gene encoding an extracellular lipase of the lipid-dependent fungus Malassezia furfur.

    PubMed

    Brunke, Sascha; Hube, Bernhard

    2006-02-01

    Malassezia furfur is a dimorphic fungus and a member of the normal cutaneous microflora of humans. However, it is also a facultative pathogen, associated with a wide range of skin diseases. One unusual feature of M. furfur is an absolute dependency on externally provided lipids which the fungus hydrolyses by lipolytic activity to release fatty acids necessary for both growth and pathogenicity. In this study, the cloning and characterization of the first gene encoding a secreted lipase of M. furfur possibly associated with this activity are reported. The gene, MfLIP1, shows high sequence similarity to other known extracellular lipases, but is not a member of a lipase gene family in M. furfur. MfLIP1 consists of 1464 bp, encoding a protein with a molecular mass of 54.3 kDa, a conserved lipase motif and an N-terminal signal peptide of 26 aa. By using a genomic library, two other genes were identified flanking MfLIP1, one of them encoding a putative secreted catalase, the other a putative amine oxidase. The cDNA of MfLIP1 was expressed in Pichia pastoris and the biochemical properties of the recombinant lipase were analysed. MfLip1 is most active at 40 degrees C and the pH optimum was found to be 5.8. The lipase hydrolysed lipids, such as Tweens, frequently used as the source of fatty acids in M. furfur media, and had minor esterase activity. Furthermore, the lipase is inhibited by different bivalent metal ions. This is the first molecular description of a secreted lipase from M. furfur.

  8. Mechanistic Insights into the Structure-Dependent Selectivity of Catalytic Furfural Conversion on Platinum Catalysts

    SciTech Connect

    Cai, Qiuxia; Wang, Jianguo; Wang, Yang-Gang; Mei, Donghai

    2015-11-01

    The effects of structure and size on the selectivity of catalytic furfural conversion over supported Pt catalysts in the presence of hydrogen have been studied using first principles density functional theory (DFT) calculations and microkinetic modeling. Four Pt model systems, i.e., periodic Pt(111), Pt(211) surfaces, as well as small nanoclusters (Pt13 and Pt55) are chosen to represent the terrace, step, and corner sites of Pt nanoparticles. Our DFT results show that the reaction routes for furfural hydrogenation and decarbonylation are strongly dependent on the type of reactive sites, which lead to the different selectivity. On the basis of the size-dependent site distribution rule, we correlate the site distributions as a function of the Pt particle size. Our microkinetic results indicate the critical particle size that controls the furfural selectivity is about 1.0 nm, which is in good agreement with the reported experimental value under reaction conditions. This work was supported by National Basic Research Program of China (973 Program) (2013CB733501) and the National Natural Science Foundation of China (NSFC-21306169, 21176221, 21136001, 21101137 and 91334103). This work was also partially supported by the US Department of Energy (DOE), the Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for DOE by Battelle. Computing time was granted by the grand challenge of computational catalysis of the William R. Wiley Environmental Molecular Sciences Laboratory (EMSL). EMSL is a national scientific user facility located at Pacific Northwest National Laboratory (PNNL) and sponsored by DOE’s Office of Biological and Environmental Research.

  9. [Isolation of Malassezia furfur from the groin abscess of a renal transplant patient].

    PubMed

    Zhao, Hong-mei; Ran, Yu-ping; Jiang, Xian; Zeng, Wei; Xiong, Lin; Dai, Ya-lin; Du, Xiao-ping; Yang, Guo

    2005-01-01

    We report here the discovery of Malassezia furfur from a groin abscess of a renal transplant patient. A 33-year-old male patient was admitted to our hospital because of a high fever and a persistent inflammatory nodule on his right groin for one week. He had received a renal transplant 3 years before and remained on immunosuppressive agents. He was treated with broad-spectrum antibiotics after hospitalization but the nodule formed a large abscess and then a deep ulcer instead of resolving. Examination of the culture by light microscopy revealed ovoid budding yeasts displaying collar-shaped structure. Subculture of the primary colonies onto Sabouraud's dextrose agar and medium containing rapeseed oil resulted in growth only on the medium containing rapeseed oil. All of the isolates was identified as Malassezia furfur. The pathogenicity of the isolates was tested in mice by intravenous injection of (3-5) x 10(8) cfu per mouse after immunosuppression with 500 mg/kg of prednisone intraporitoneally on day-2. In the mouse model, micro-abscess and inflammatory reaction and oval yeasts with budding were noted in histopathologic section of the viscera of the mice. A rib-like or serrate-like structure of the inner side of cell wall, characteristic for Malassezia spp., was observed by transmission electron microscopy. The patient received oral fluconazole and topical amphotericin B. The isolate before antifungal therapy was sensitive to both fluconazole and amphotericin B, while the isolate after antifungal treatment was only sensitive to amphotericin B. Proteinase activity of the isolates increased 1.43 times after antifungal treatment. This case indicated the invasive power of M. furfur in deep infection. Renal transplantation and reception of long-term immunosuppressive treatment are risk factors for the invasive infection of this fungus.

  10. Determination of carboxylic acids, carbohydrates, glycerol, ethanol, and 5-HMF in beer by high-performance liquid chromatography and UV-refractive index double detection.

    PubMed

    Castellari, M; Sartini, E; Spinabelli, U; Riponi, C; Galassi, S

    2001-06-01

    A high-performance liquid chromatographic method is proposed for the simultaneous separation of main carboxylic acids, carbohydrates, ethanol, glycerol, and 5-HMF in beer by direct injection. A column packed with a sulfonated divinyl benzene-styrene copolymer and an isocratic elution with 0.0045N sulfuric acid and acetonitrile (6%, v/v) are employed. UV and refractive index detectors connected in series are also used to reduce the matrix interference of phenolic compounds. In conditions described, nine compounds are quantitated in a single chromatographic run without any pretreatment except for sample dilution and filtration before injection. Precision, accuracy, linearity of response, limit of detection, and limit of quantitation are also evaluated for each compound. Satisfactory results are obtained to justify the application of this method to all phases of beer production for process and quality control.

  11. Kinetics of vapor-phase hydrogenation of furfural on a copper-chromium catalyst

    SciTech Connect

    Borts, M.S.; Gil'chenok, N.D.; Gurevich, G.S.; Ignat'ev, V.M.

    1986-08-01

    This paper studies the principal kinetic relationships of hydrogenation of furfural to furfuryl alcohol, which must be known for development of the industrial process. Prelininary experiments showed that at linear velocities of the vapor-gas stream (calculated for the free cross section of the reactor) above 0.26 matsec and with an average catalyst particle size less than 0.30 mm neither external nor internal diffusio resistance has any effect. In all the subsequent experiments a 0.20-0.25-mm catalyst fraction was used at a linear vapor-gas velocity of 0.50 m/sec, when the reaction proceeded with kinetic control.

  12. Effect of Furfural, Vanillin and Syringaldehyde on Candida guilliermondii Growth and Xylitol Biosynthesis

    NASA Astrophysics Data System (ADS)

    Kelly, Christine; Jones, Opal; Barnhart, Christopher; Lajoie, Curtis

    Xylitol is a five-carbon sugar alcohol with established commercial use as an alternative sweetener and can be produced from hemicellulose hydrolysate. However, there are difficulties with microbiological growth and xylitol biosynthesis on hydrolysate because of the inhibitors formed from hydrolysis of hemicellulose. This research focused on the effect of furfural, vanillin, and syringaldehyde on growth of Candida guilliermondii and xylitol accumulation from xylose in a semi-synthetic medium in microwell plate and bioreactor cultivations. All three compounds reduced specific growth rate, increased lag time, and reduced xylitol production rate. In general, increasing concentration of inhibitor increased the severity of inhibition, except in the case of 0.5 g vanillin per liter, which resulted in a faster late batch phase growth rate and increased biomass yield. At concentrations of 1 g/1 or higher, furfural was the least inhibitory to growth, followed by syringaldehyde. Vanillin most severely reduced specific growth rate. All three inhibitors reduced xylitol production rate approximately to the same degree.

  13. Effect of furfural, vanillin and syringaldehyde on Candida guilliermondii growth and xylitol biosynthesis.

    PubMed

    Kelly, Christine; Jones, Opal; Barnhart, Christopher; Lajoie, Curtis

    2008-03-01

    Xylitol is a five-carbon sugar alcohol with established commercial use as an alternative sweetener and can be produced from hemicellulose hydrolysate. However, there are difficulties with microbiological growth and xylitol biosynthesis on hydrolysate because of the inhibitors formed from hydrolysis of hemicellulose. This research focused on the effect of furfural, vanillin, and syringaldehyde on growth of Candida guilliermondii and xylitol accumulation from xylose in a semi-synthetic medium in microwell plate and bioreactor cultivations. All three compounds reduced specific growth rate, increased lag time, and reduced xylitol production rate. In general, increasing concentration of inhibitor increased the severity of inhibition, except in the case of 0.5 g vanillin per liter, which resulted in a faster late batch phase growth rate and increased biomass yield. At concentrations of 1 g/l or higher, furfural was the least inhibitory to growth, followed by syringaldehyde. Vanillin most severely reduced specific growth rate. All three inhibitors reduced xylitol production rate approximately to the same degree.

  14. Glycine as a regulator of tryptophan-dependent pigment synthesis in Malassezia furfur.

    PubMed

    Barchmann, Thorsten; Hort, Wiebke; Krämer, Hans-Joachim; Mayser, Peter

    2011-01-01

    The effects of the addition of different amino nitrogens on growth, morphology and secondary metabolism of Malassezia furfur were investigated. After primary culture on Dixon agar, M. furfur CBS 1878 was transferred into a fluid medium together with the nitrogen sources, glycine (Gly) or tryptophan (Trp), or a combination of both. Growth was measured by means of a direct cell counting method and pigment synthesis was photometrically assessed. Addition of glycine resulted in an exponential increase in biomass, but not in pigment production. Tryptophan as the sole nitrogen source caused distinct brown staining of the medium, without increasing biomass. Simultaneous equimolar addition of both amino acids resulted in an initial increase in biomass as a sign of preferential metabolism of glycine, followed by a growth plateau and pigment production which, caused by higher biomass, occurred more rapidly than after addition of tryptophan alone. The yeast-cell morphology changed from round to oval. Addition of glycine to the tryptophan-containing liquid culture stopped pigment formation with simultaneous growth induction. These in vitro on-off phenomena depending on the nitrogen source might be significant in the pathogenesis of pityriasis versicolor: hyperhidrosis followed by preferential consumption of individual nitrogen sources such as glycine with exponential growth and thereafter transamination of tryptophan and TRP-dependent pigment synthesis.

  15. Malassezia furfur induces the expression of beta-defensin-2 in human keratinocytes in a protein kinase C-dependent manner.

    PubMed

    Donnarumma, Giovanna; Paoletti, Iole; Buommino, Elisabetta; Orlando, Manuela; Tufano, Maria Antonietta; Baroni, Adone

    2004-04-01

    Antimicrobial peptides of the beta-defensin family are expressed in all human epithelial tissues tested to date and have recently been the subject of vigorous investigation. Their localization and characteristics support the hypothesis that these peptides play a role in mucosal and skin defense. The lipophilic yeast Malassezia furfur is a saprophyte found in normal human cutaneous flora. Malassezia furfur is not only a saprophyte, but is also associated with several diseases such as Malassezia folliculitis, seborrheic dermatitis and some forms of atopic dermatitis, psoriasis and confluent and reticulate papillomatosis. Little is known about the mechanism by which M. furfur overcomes the natural barrier of the skin. To further define the role of the beta-defensins in the innate human skin immune response, we analyzed the mRNA expression of two human beta-defensins HBD-1 and HBD-2 in human keratinocytes treated with M. furfur. In addition, we looked into how M. furfur of TGF-beta1 and IL-10, cytokines that interfere with the development of protective cell immunity, regulate their expression. Finally, we examined the signal transduction mechanisms involved during M. furfur uptake. Cultured human keratinocytes were treated with M. furfur. The mRNA and protein expression were analyzed, respectively, by reverse transcriptase polymerase chain reaction (RT-PCR) and Western blotting. Our data demonstrate that M. furfur does not modify HBD-1 expression, whereas it up-regulates, via protein kinase C (PKC), the expression of HBD-2, TGFbeta-1 and IL-10 48 h after treatment. Our results suggest that beta-defensins are integral components of innate host defenses. They play an essential part in the resistance of the human skin surfaces against M. furfur uptake and other microbial invasion.

  16. Selective Hydrogenation of Furfural to Furfuryl Alcohol in the Presence of a Recyclable Cobalt/SBA-15 Catalyst.

    PubMed

    Audemar, Maïté; Ciotonea, Carmen; De Oliveira Vigier, Karine; Royer, Sébastien; Ungureanu, Adrian; Dragoi, Brindusa; Dumitriu, Emil; Jérôme, François

    2015-06-08

    The hydrogenation of furfural to furfuryl alcohol was performed in the presence of a Co/SBA-15 catalyst. High selectivity (96 %) at a conversion higher than 95 % is reported over this catalytic system. As the conversion of furfural to furfuryl alcohol occurs over metallic Co sites, the effect of reduction temperature, H2 pressure, and reaction temperature were studied. Optimum reaction conditions were: 150 °C, 1.5 h, 2.0 MPa of H2 . The catalyst was recyclable, and furfuryl alcohol was recovered with a purity higher than 90 %. The effect of the solvent concentration was also studied. With a minimum of 50 wt % of solvent, the selectivity to furfuryl alcohol and the conversion of furfural remained high (both over 80 %). Likewise, the activity of the catalyst is maintained even in pure furfural, which confirms the real potential of the proposed catalytic system. This catalyst was also used in the hydrogenation of levulinic acid to produce γ-valerolactone selectively.

  17. Tacrolimus does not alter the production of several cytokines and antimicrobial peptide in Malassezia furfur-infected-keratinocytes.

    PubMed

    Balato, Anna; Paoletti, Iole; De Gregorio, Vincenza; Cantelli, Mariateresa; Ayala, Fabio; Donnarumma, Giovanna

    2014-03-01

    Topical immunosuppressant therapy is widely used in the treatment of inflammatory skin diseases, such as atopic dermatitis and psoriasis. Besides its beneficial therapeutic effects, application of topical anti-inflammatory drugs may render the epidermis more vulnerable to invading pathogens by suppressing innate immune responses in keratinocytes (KCs). Cytokines, chemokines and antimicrobial peptides (AMPs) produced by epithelial cells enable them to participate in innate and acquired immune responses. The aim of the present work was to study the influence of tacrolimus (FK506) on KCs infected with Malassezia furfur (M. furfur), evaluating the expression of pro-inflammatory cytokines IL-1α and IL-6, chemokine IL-8, anti-inflammatory cytokines transforming growth factor beta1 (TGF-β1) and IL-10 and AMP β-defensin-2. Human KCs were obtained from surgical specimens of normal adult skin. The expression of mRNAs in KCs: FK506-treated, FK506-treated and M. furfur-infected as well as only M. furfur-infected was quantified by real-time quantitative polymerase chain reaction. Next, the production of the AMP β-defensin-2 and of the above-mentioned pro-inflammatory and anti-inflammatory cytokines was evaluated using enzyme-linked immunosorbent assay. In this study, FK506 did not alter cytokine and AMP production by KCs; this led us to hypothesise that it may not enhance the risk of mycotic skin infections.

  18. Integrated phospholipidomics and transcriptomics analysis of Saccharomyces cerevisiae with enhanced tolerance to a mixture of acetic acid, furfural, and phenol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A mixture of acetic acid, furfural and phenol (AFP), three representative lignocellulose derived inhibitors, significantly inhibited the growth and bioethanol production of Saccharomyces cerevisiae. In order to uncover mechanisms behind the enhanced tolerance of an inhibitor-tolerant S.cerevisiae s...

  19. Detoxification of Eucheuma spinosum Hydrolysates with Activated Carbon for Ethanol Production by the Salt-Tolerant Yeast Candida tropicalis.

    PubMed

    Ra, Chae Hun; Jung, Jang Hyun; Sunwoo, In Young; Kang, Chang Han; Jeong, Gwi-Taek; Kim, Sung-Koo

    2015-06-01

    The objective of this study was to optimize the slurry contents and salt concentrations for ethanol production from hydrolysates of the seaweed Eucheuma spinosum. A monosaccharide concentration of 44.2 g/l as 49.6% conversion of total carbohydrate of 89.1 g/l was obtained from 120 g dw/l seaweed slurry. Monosaccharides from E. spinosum slurry were obtained by thermal acid hydrolysis and enzymatic hydrolysis. Addition of activated carbon at 2.5% (w/v) and the adsorption time of 2 min were used in subsequent adsorption treatments to prevent the inhibitory effect of HMF. The adsorption surface area of the activated carbon powder was 1,400-1,600 m(2)/g and showed selectivity to 5-hydroxymethyl furfural (HMF) from monosaccharides. Candida tropicalis KCTC 7212 was cultured in yeast extract, peptone, glucose, and high-salt medium, and exposed to 80, 90, 100, and 110 practical salinity unit (psu) salt concentrations in the lysates. The 100 psu salt concentration showed maximum cell growth and ethanol production. The ethanol fermentations with activated carbon treatment and use of C. tropicalis acclimated to a high salt concentration of 100 psu produced 17.9 g/l of ethanol with a yield (YEtOH) of 0.40 from E. spinosum seaweed.

  20. Physicochemical characterization of pure persimmon juice: nutritional quality and food acceptability.

    PubMed

    González, Eva; Vegara, Salud; Martí, Nuria; Valero, Manuel; Saura, Domingo

    2015-03-01

    Technological process for production of non-astringent persimmon (Diospyros kaki Thunb. cv. "Rojo Brillante") juice was described. The degree of fruit ripening expressed as color index (CI) varied between 12.37 and 16.33. Persimmon juice was characterized by determining physicochemical quality parameters as yield, total soluble solids (TSS), pH, titratable acidity (TA), organic acids, and main sugars. A thermal treatment of 90 ºC for 10 s was effective in controlling naturally occurring microorganisms for at least 105 d of storage without significantly affecting production of soluble brown pigments (BPs) and 5-hydroxymethyl furfural (5-HMF), total phenolic compounds (TPC), antioxidant capacity and acceptability of juice by panelists. Storage time affected all and each of the above parameters, reducing BPs, TPC and antioxidant capacity but increasing 5-HMF content. Refrigerated storage enhanced the acceptability of the juices. This information may be used by the juice industry as a starting point for production of pure persimmon juices.

  1. Effects of furan derivatives and phenolic compounds on electricity generation in microbial fuel cells

    NASA Astrophysics Data System (ADS)

    Catal, Tunc; Fan, Yanzhen; Li, Kaichang; Bermek, Hakan; Liu, Hong

    Lignocellulosic biomass is an attractive fuel source for MFCs due to its renewable nature and ready availability. Furan derivatives and phenolic compounds could be potentially formed during the pre-treatment process of lignocellulosic biomass. In this study, voltage generation from these compounds and the effects of these compounds on voltage generation from glucose in air-cathode microbial fuel cells (MFCs) were examined. Except for 5-hydroxymethyl furfural (5-HMF), all the other compounds tested were unable to be utilized directly for electricity production in MFCs in the absence of other electron donors. One furan derivate, 5-HMF and two phenolic compounds, trans-cinnamic acid and 3,5-dimethoxy-4-hydroxy-cinnamic acid did not affect electricity generation from glucose at a concentration up to 10 mM. Four phenolic compounds, including syringaldeyhde, vanillin, trans-4-hydroxy-3-methoxy, and 4-hydroxy cinnamic acids inhibited electricity generation at concentrations above 5 mM. Other compounds, including 2-furaldehyde, benzyl alcohol and acetophenone, inhibited the electricity generation even at concentrations less than 0.2 mM. This study suggests that effective electricity generation from the hydrolysates of lignocellulosic biomass in MFCs may require the employment of the hydrolysis methods with low furan derivatives and phenolic compounds production, or the removal of some strong inhibitors prior to the MFC operation, or the improvement of bacterial tolerance against these compounds through the enrichment of new bacterial cultures or genetic modification of the bacterial strains.

  2. Overexpression of the yeast transcription activator Msn2 confers furfural resistance and increases the initial fermentation rate in ethanol production.

    PubMed

    Sasano, Yu; Watanabe, Daisuke; Ukibe, Ken; Inai, Tomomi; Ohtsu, Iwao; Shimoi, Hitoshi; Takagi, Hiroshi

    2012-04-01

    Lignocellulosic biomass is a promising source for bioethanol production, because it is abundant worldwide and has few competing uses. However, the treatment of lignocelllulosic biomass with weak acid to release cellulose and hemicellulose generates many kinds of byproducts including furfural and 5-hydroxymethylfurfural, which inhibit fermentation by yeast, because they generate reactive oxygen species (ROS) in cells. In order to acquire high tolerance to oxidative stress in bioethanol yeast strains, we focused on the transcription activator Msn2 of Saccharomyces cerevisiae, which regulates numerous genes involved in antioxidative stress responses, and constructed bioethanol yeast strains that overexpress Msn2 constitutively. The Msn2-overexpressing bioethanol strains showed tolerance to oxidative stress, probably due to the high-level expression of various antioxidant enzyme genes. Unexpectedly, these strains showed ethanol sensitivity compared with the control strain, probably due to imbalance of the expression level between Msn2 and Msn4. In the presence of furfural, the engineered strains exhibited reduced intracellular ROS levels, and showed rapid growth compared with the control strain. The fermentation test in the presence of furfural revealed that the Msn2-overexpressing strains showed improvement of the initial rate of fermentation. Our results indicate that overexpression of the transcription activator Msn2 in bioethanol yeast strains confers furfural tolerance by reducing the intracellular ROS levels and enhances the initial rate of fermentation in the presence of furfural, suggesting that these strains are capable of adapting rapidly to various compounds that inhibit fermentation by inducing ROS accumulation. Our results not only promise to improve bioethanol production from lignocellulosic biomass, but also provide novel insights for molecular breeding of industrial yeast strains.

  3. Antimicrobial and anti-inflammatory effects of Cecropin A(1-8)-Magainin2(1-12) hybrid peptide analog p5 against Malassezia furfur infection in human keratinocytes.

    PubMed

    Ryu, Sunhyo; Choi, Soon-Yong; Acharya, Samudra; Chun, Young-Jin; Gurley, Catherine; Park, Yoonkyung; Armstrong, Cheryl A; Song, Peter I; Kim, Beom-Joon

    2011-08-01

    The lipophilic fungus Malassezia furfur (M. furfur) is a commensal microbe associated with several chronic diseases such as pityriasis versicolor, folliculitis, and seborrheic dermatitis. Because M. furfur-related diseases are difficult to treat and require prolonged use of medications, the treatment for M. furfur-related skin diseases is supposed to gain control over M. furfur growth and the inflammation associated with it, as well as to prevent secondary infections. In this study, we investigated the antifungal and anti-inflammatory effects of cecropin A(1-8)-magainin 2(1-12) hybrid peptide analog P5 on M. furfur. The minimal inhibitory concentration of P5 against M. furfur was 0.39 μM, making it 3-4 times more potent than commonly used antifungal agents such as ketoconazole (1.5 μM) or itraconazole (1.14 μM). P5 efficiently inhibited the expression of IL-8 and Toll-like receptor 2 in M. furfur-infected human keratinocytes without eukaryotic cytotoxicity at its fungicidal concentration. Moreover, P5 significantly downregulated NF-κB activation and intracellular calcium fluctuation, which are closely related with enhanced responses of keratinocyte inflammation induced by M. furfur infection. Taken together, these observations suggest P5 may be a potential therapeutic agent for M. furfur-associated human skin diseases because of its distinct antifungal and anti-inflammatory action.

  4. Quantifying second generation ethanol inhibition: Design of Experiments approach and kinetic model development.

    PubMed

    Schneiderman, Steven J; Johnson, Roger W; Menkhaus, Todd J; Gilcrease, Patrick C

    2015-03-01

    While softwoods represent a potential feedstock for second generation ethanol production, compounds present in their hydrolysates can inhibit fermentation. In this study, a novel Design of Experiments (DoE) approach was used to identify significant inhibitory effects on Saccharomyces cerevisiae D5A for the purpose of guiding kinetic model development. Although acetic acid, furfural and 5-hydroxymethyl furfural (HMF) were present at potentially inhibitory levels, initial factorial experiments only identified ethanol as a significant rate inhibitor. It was hypothesized that high ethanol levels masked the effects of other inhibitors, and a subsequent factorial design without ethanol found significant effects for all other compounds. When these non-ethanol effects were accounted for in the kinetic model, R¯(2) was significantly improved over an ethanol-inhibition only model (R¯(2)=0.80 vs. 0.76). In conclusion, when ethanol masking effects are removed, DoE is a valuable tool to identify significant non-ethanol inhibitors and guide kinetic model development.

  5. Composting of food waste subjected to hydrothermal pretreatment and inoculated with Paecilomyces sp. FA13.

    PubMed

    Nakasaki, Kiyohiko; Mimoto, Hiroshi; Tran, Quyen Ngoc Minh; Oinuma, Akiko

    2015-03-01

    Food waste collected from restaurants, convenience stores, and food-processing factories was mixed with sawdust and subjected to hydrothermal pretreatment at 180°C for 30min to prepare compost raw material. Furan compounds such as 5-HMF (5-hydroxymethyl furfural) and furfural were produced at concentration levels of approximately 8 and 0.5mg/g-ds, respectively, through hydrothermal pretreatment. The furan compounds inhibited the activity of composting microorganisms, thus delaying the start of organic matter degradation during composting. A newly identified fungus, Paecilomyces sp. FA13, which possesses the ability to degrade furan compounds, was isolated and used as an inoculum for the composting of the raw material prepared by hydrothermal pretreatment. By inoculating the FA13 into the compost raw material at 10(5)CFU/g-ds, the degradation of furan compounds was accelerated. As a result, bacterial activity, which contributed to composting, was enhanced, significantly promoting the start of vigorous degradation of organic materials.

  6. NmF2 and hmF2 measurements at 95° E and 127° E around the EIA northern crest during 2010-2014

    NASA Astrophysics Data System (ADS)

    Kalita, Bitap Raj; Bhuyan, Pradip Kumar; Yoshikawa, Akimasa

    2015-11-01

    The characteristics of the F2 layer parameters NmF2 and hmF2 over Dibrugarh (27.5° N, 95° E, 17° N geomagnetic, 43° dip) measured by a Canadian Advanced Digital Ionosonde (CADI) for the period of August 2010 to July 2014 are reported for the first time from this low mid-latitude station lying within the daytime peak of the longitudinal wave number 4 structure of equatorial anomaly (EIA) around the northern edge of anomaly crest. Equinoctial asymmetry is clearly observed at all solar activity levels whereas the midday winter anomaly is observed only during high solar activity years and disappears during the temporary dip in solar activity in 2013 but forenoon winter anomaly can be observed even at moderate solar activity. The NmF2/hmF2 variations over Dibrugarh are compared with that of Okinawa (26.5° N, 127° E, 17° N geomagnetic), and the eastward propagation speed of the wave number 4 longitudinal structure from 95° E to 127° E is estimated. The speed is found to be close to the theoretical speed of the wave number 4 (WN4) structure. The correlation of daily NmF2 over Dibrugarh and Okinawa with solar activity exhibits diurnal and seasonal variations. The highest correlation in daytime is observed during the forenoon hours in equinox. The correlation of daily NmF2 (linear or non-linear) with solar activity exhibits diurnal variation. A tendency for amplification with solar activity is observed in the forenoon and late evening period of March equinox and the postsunset period of December solstice. NmF2 saturation effect is observed only in the midday period of equinox. Non-linear variation of neutral composition at higher altitudes and variation of recombination rates with solar activity via temperature dependence may be related to the non-linear trend. The noon time maximum NmF2 over Dibrugarh exhibits better correlation with equatorial electrojet (EEJ) than with solar activity and, therefore, new low-latitude NmF2 index is proposed taking both solar

  7. Furfural resin-based bio-nanocomposites reinforced by reactive nanocrystalline cellulose

    NASA Astrophysics Data System (ADS)

    Wang, C.; Sun, S.; Zhao, G.; He, B.; Xiao, H.

    2009-07-01

    The work presented herein has been focused on reinforcing the furfural resins (FA) by reactive-modified nanocrystalline cellulose (NCC) in an attempt to create a bio-nanocomposite completely based on natural resources. FA prepolymers were synthesized with an acid catalyst, and NCC was rendered reactive via the grafting of maleic anhydride (MAH). The resulting NCC and nanocomposites were characterized using TEM, SEM and FT-IR. It was found that NCC appeared to be spherical in shape with diameters under 100 nm. FT-IR confirmed that there were hydrogen and esterification bonding between MAH and NCC or FA prepolymer. After solidified with paratoluenesulfonic acid, NCC-reinforced FA resin composites showed granular cross-section while FA resin with layered structures. Mechanical property tests indicated that NCC-reinforced FA resin composites possessed the improved tensile and flexural strengths, in comparison with FA resin.

  8. Comparison of hydrophilic variation and bioethanol production of furfural residues after delignification pretreatment.

    PubMed

    Bu, Lingxi; Tang, Yong; Xing, Yang; Zhang, Weiming; Shang, Xinhui; Jiang, Jianxin

    2014-01-01

    Furfural residue (FR) is a waste lignocellulosic material with enormous potential for bioethanol production. In this study, bioethanol production from FR after delignification was compared. Hydrophilic variation was measured by conductometric titration to detect the relationship between hydrophilicity and bioethanol production. It was found that ethanol yield increased as delignification enhanced, and it reached up to 75.6% of theoretical yield for samples with 8.7% lignin. The amount of by-products decreased as delignification increased. New inflection points appeared in conductometric titration curves of samples that were partially delignified, but they vanished in the curves of the highly delignified samples. Total charges and carboxyl levels increased after slight delignification, and they decreased upon further delignification. These phenomena suggested some new hydrophilic groups were formed during pretreated delignification, which would be beneficial to enzymatic hydrolysis. However, some newly formed groups may act as toxicant to the yeast during simultaneous saccharification and fermentation.

  9. Selective hydrogenation of furfural to furfuryl alcohol over catalysts prepared via sonochemistry.

    PubMed

    Huang, Weiping; Li, Hong; Zhu, Baolin; Feng, Yunfeng; Wang, Shurong; Zhang, Shoumin

    2007-01-01

    Copper-chromite oxide and TiO2-supported copper-chromite oxide catalysts are prepared by various methods. They are characterized with ICP, BET, XRD, XPS, SEM, and TEM, etc. Their catalytic performance for liquid phase hydrogenation of furfural to furfuryl alcohol is also valuated. The catalysts prepared by ultrasound exhibit good performance. Catalytic activity of TiO2-supported catalysts is higher than that of catalyst without TiO2, notwithstanding they are all prepared by ultrasound. It is worth stressing that after reduced the TiO2-supported catalysts, which are X-ray amorphous, display good performance at 140 degrees C, while the catalysts without TiO2 show no activity under the same condition. Obtained results indicate that the catalytic performance of catalysts depends upon the amount of reducible copper ions and the activity decay is related to the loss of metal elements on the surface of catalyst.

  10. Absolute photoionization cross sections of furanic fuels: 2-ethylfuran, 2-acetylfuran and furfural.

    PubMed

    Smith, Audrey R; Meloni, Giovanni

    2015-11-01

    Absolute photoionization cross sections of the molecules 2-ethylfuran, 2-acetylfuran and furfural, including partial ionization cross sections for the dissociative ionized fragments, are measured for the first time. These measurements are important because they allow fuel quantification via photoionization mass spectrometry and the development of quantitative kinetic modeling for the complex combustion of potential fuels. The experiments are carried out using synchrotron photoionization mass spectrometry with an orthogonal time-of-flight spectrometer used for mass analysis at the Advanced Light Source of Lawrence Berkeley National Laboratory. The CBS-QB3 calculations of adiabatic ionization energies and appearance energies agree well with the experimental results. Several bond dissociation energies are also derived and presented.

  11. The 2009-2012 Ionosonde and IRI2012 Variability of foF 2, hmF 2, M3000F2, B 0, B1 Parameters over Warsaw

    NASA Astrophysics Data System (ADS)

    Szwabowski, Michał; Dziak-Jankowska, Beata; Pożoga, Mariusz; Tomasik, Łukasz

    2016-08-01

    This paper presents comparisons of variability and accordance of ionospheric parameters foF2, hmF2, M3000 F2, B0, B1 over the middle latitude station in Warsaw (52.21°N, 21.06°E). Examination included observational data from Space Research Centre ionosonde in Poland and International Reference Ionosphere (IRI) 2012 model, for the time period of increasing solar activity from 2009 to 2012. The analysis concerned: trend, monthly median differences in twenty-four hours variability, local minima and maxima. Results are presented as tables of semi-annual data, and plots of difference in four-year period. The study indicated good agreement of foF2 and hmF2 parameters. Underestimations of B1 and M3000 F2, variability of B0 parameter in Bil-2000, Gul-1987, and ABT- 2009 option, were taken into consideration.

  12. AhR ligands, malassezin, and indolo[3,2-b]carbazole are selectively produced by Malassezia furfur strains isolated from seborrheic dermatitis.

    PubMed

    Gaitanis, George; Magiatis, Prokopios; Stathopoulou, Konstantina; Bassukas, Ioannis D; Alexopoulos, Evangelos C; Velegraki, Aristea; Skaltsounis, Alexios-Leandros

    2008-07-01

    Malassezia yeasts are connected with seborrheic dermatitis (SD) whereas M. furfur pathogenicity is associated with the production of bioactive indoles. In this study, the production of indoles by M. furfur isolates from healthy and diseased skin was compared, the respective HPLC patterns were analyzed, and substances that are preferentially synthesized by strains isolated from SD lesions were isolated and characterized. Malassezin, pityriacitrin, indole-3-carbaldehyde, and indolo[3,2-b]carbazole (ICZ) were isolated by HPLC from extracts of M. furfur grown in L-tryptophan agar, and identified by nuclear magnetic resonance and mass spectroscopy. Of these, ICZ, a potent ligand of the aryl hydrocarbon receptor (AhR), is described for the first time to our knowledge as a M. furfur metabolite. HPLC-photodiode array detection analysis of strain extracts from 7 healthy subjects and 10 SD patients showed that M. furfur isolates from only SD patients consistently produce malassezin and ICZ. This discriminatory production of AhR agonists provides initial evidence for a previously unreported mechanism triggering development of SD and indicates that the variable pathogenicity patterns recorded for M. furfur-associated SD conditions may be attributed to selective production (P<0.001) of measurable bioactive indoles.

  13. Positive atopy patch test reaction to Malassezia furfur in atopic dermatitis correlates with a T helper 2-like peripheral blood mononuclear cells response.

    PubMed

    Johansson, Catharina; Eshaghi, Hojjat; Linder, Maria Tengvall; Jakobson, Eva; Scheynius, Annika

    2002-06-01

    The yeast Malassezia furfur belongs to the normal cutaneous flora, but is also a triggering allergen that can contribute to atopic dermatitis. To illuminate the effect of circulating allergen-specific T cells in atopic dermatitis, the peripheral mononuclear cell response was correlated with the in vivo skin prick test and atopy patch test reactivity to M. furfur. None of 16 healthy controls showed any positive in vivo reaction. The 40 atopic dermatitis patients, of whom 18 had serum IgE reactivity to M. furfur, were subdivided according to their in vivo reaction to M. furfur extract into three groups: skin prick test positive/atopy patch test positive (n = 12), skin prick test positive/atopy patch test negative (n = 12), and skin prick test negative/atopy patch test negative (n = 16). The skin prick test positive/atopy patch test positive and the skin prick test positive/atopy patch test negative groups had a significantly higher peripheral mononuclear cell stimulation index than the healthy controls. Interestingly, the stimulation index values in the skin prick test positive/atopy patch test positive group were significantly higher than in the skin prick test positive/atopy patch test negative group. In the M. furfur skin prick test positive atopic dermatitis patients (n = 24) a correlation was found between stimulation index and the M. furfur atopy patch test reactions, but not between stimulation index and M. furfur-specific serum IgE levels. Skin prick test positive and/or atopy patch test positive reactions to the recombinant M. furfur allergens rMal f 1, rMal f 5, and rMal f 6 were observed in 7, 14, and 16 of the 40 atopic dermatitis patients, respectively. Further, there was a correlation between production of the T helper 2-related cytokines interleukins 4, 5, and 13 and stimulation index to M. furfur extract, but not between the T helper 1-related interferon-gamma and stimulation index to M. furfur extract. Our data strongly suggest a relationship between

  14. In vitro activity of two amphotericin B formulations against Malassezia furfur strains recovered from patients with bloodstream infections.

    PubMed

    Iatta, Roberta; Immediato, Davide; Montagna, Maria Teresa; Otranto, Domenico; Cafarchia, Claudia

    2015-04-01

    Although guidelines for the treatment of Malassezia furfur fungemia are not yet defined, clinical data suggest that amphotericin B (AmB) is effective for treating systemic infections. In the absence of clinical breakpoints for Malassezia yeasts, epidemiological cut-off values (ECVs) are useful to discriminate between isolates with and without drug resistance. This study aimed to compare the distribution of minimal inhibitory concentration (MIC) and the ECVs for AmB of both deoxycholate (d-AmB) and liposomal (l-AmB) formulations of M. furfur isolates. The 84 M. furfur strains analyzed, which included 56 from blood, sterile sites and catheters, and 28 from skin, were isolated from patients with bloodstream infections. MICs were determined by the modified broth microdilution method of the Clinical and Laboratory Standards Institute (CLSI). The l-AmB MIC and the ECVs were two-fold lower than those of d-AmB and a lower l-AmB mean MIC value was found for blood isolates than from skin. The ECVs for l-AmB and d-AmB were 8 mg/l and 32 mg/l, respectively. Three strains (3.6%) showed l-AmB MIC higher than ECV (MIC > 8 mg/l) of which two were isolated from the catheter tip of patients treated with micafugin, l-Amb and fluconazole, and one from skin. The results showed that the l-AmB might be employed for assessing the in vitro antifungal susceptibility of M. furfur by a modified CLSI protocol and that ECVs might be useful for detecting the emergence of resistance.

  15. Adsorption of hydraulic fracturing fluid components 2-butoxyethanol and furfural onto granular activated carbon and shale rock.

    PubMed

    Manz, Katherine E; Haerr, Gregory; Lucchesi, Jessica; Carter, Kimberly E

    2016-12-01

    The objective of this study was to understand the adsorption ability of a surfactant and a non-surfactant chemical additive used in hydraulic fracturing onto shale and GAC. Experiments were performed at varying temperatures and sodium chloride concentrations to establish these impacts on the adsorption of the furfural (a non-surfactant) and 2-Butoxyethanol (2-BE) (a surfactant). Experiments were carried out in continuously mixed batch experiments with Langmuir and Freundlich isotherm modeling. The results of the experiments showed that adsorption of these compounds onto shale does not occur, which may allow these compounds to return to the surface in flowback and produced waters. The adsorption potential for these chemicals onto GAC follows the assumptions of the Langmuir model more strongly than those of the Freundlich model. The results show uptake of furfural and 2-BE occurs within 23 h in the presence of DI water, 0.1 mol L(-1) sodium chloride, and in lab synthesized hydraulic fracturing brine. Based on the data, 83% of the furfural and 62% of the 2-BE was adsorbed using GAC.

  16. Catalytic Transfer Hydrogenation of Furfural to 2-Methylfuran and 2-Methyltetrahydrofuran over Bimetallic Copper-Palladium Catalysts.

    PubMed

    Chang, Xin; Liu, An-Feng; Cai, Bo; Luo, Jin-Yue; Pan, Hui; Huang, Yao-Bing

    2016-12-08

    The catalytic transfer hydrogenation of furfural to the fuel additives 2-methylfuran (2-MF) and 2-methyltetrahydrofuran (2-MTHF) was investigated over various bimetallic catalysts in the presence of the hydrogen donor 2-propanol. Of all the as-prepared catalysts, bimetallic Cu-Pd catalysts showed the highest catalytic activities towards the formation of 2-MF and 2-MTHF with a total yield of up to 83.9 % yield at 220 °C in 4 h. By modifying the Pd ratios in the Cu-Pd catalyst, 2-MF or 2-MTHF could be obtained selectively as the prevailing product. The other reaction conditions also had a great influence on the product distribution. Mechanistic studies by reaction monitoring and intermediate conversion revealed that the reaction proceeded mainly through the hydrogenation of furfural to furfuryl alcohol, which was followed by deoxygenation to 2-MF in parallel to deoxygenation/ring hydrogenation to 2-MTHF. Finally, the catalyst showed a high reactivity and stability in five catalyst recycling runs, which represents a significant step forward toward the catalytic transfer hydrogenation of furfural.

  17. Highly selective hydrogenation of furfural to furfuryl alcohol over Pt nanoparticles supported on g-C3N4 nanosheets catalysts in water

    PubMed Central

    Chen, Xiufang; Zhang, Ligang; Zhang, Bo; Guo, Xingcui; Mu, Xindong

    2016-01-01

    Graphitic carbon nitride nanosheets were investigated for developing effective Pt catalyst supports for selective hydrogenation of furfural to furfuryl alcohol in water. The nanosheets with an average thickness of about 3 nm were synthesized by a simple and green method through thermal oxidation etching of bulk g-C3N4 in air. Combined with the unique feature of nitrogen richness and locally conjugated structure, the g-C3N4 nanosheets with a high surface area of 142 m2 g−1 were demonstrated to be an excellent supports for loading small-size Pt nanoparticles. Superior furfural hydrogenation activity in water with complete conversion of furfural and high selectivity of furfuryl alcohol (>99%) was observed for g-C3N4 nanosheets supported Pt catalysts. The large specific surface area, uniform dispersion of Pt nanoparticles and the stronger furfural adsorption ability of nanosheets contributed to the considerable catalytic performance. The reusability tests showed that the novel Pt catalyst could maintain high activity and stability in the furfural hydrogenation reaction. PMID:27328834

  18. Co-production of furfural and acetic acid from corncob using ZnCl2 through fast pyrolysis in a fluidized bed reactor.

    PubMed

    Oh, Seung-Jin; Jung, Su-Hwa; Kim, Joo-Sik

    2013-09-01

    Corncob was pyrolyzed using ZnCl2 in a pyrolysis plant equipped with a fluidized bed reactor to co-produce furfural and acetic acid. The effects of reaction conditions, the ZnCl2 content and contacting method of ZnCl2 with corncob on the yields of furfural and acetic acid were investigated. The pyrolysis was performed within the temperature range between 310 and 410°C, and the bio-oil yield were 30-60 wt% of the product. The furfural yield increased up to 8.2 wt%. The acetic acid yield was maximized with a value of 13.1 wt%. A lower feed rate in the presence of ZnCl2 was advantageous for the production of acetic acid. The fast pyrolysis of a smaller corncob sample mechanically mixed with 20 wt% of ZnCl2 gave rise to a distinct increase in furfural. A high selectivity for furfural and acetic acid in bio-oil would make the pyrolysis of corncob with ZnCl2 very economically attractive.

  19. Highly selective hydrogenation of furfural to furfuryl alcohol over Pt nanoparticles supported on g-C3N4 nanosheets catalysts in water

    NASA Astrophysics Data System (ADS)

    Chen, Xiufang; Zhang, Ligang; Zhang, Bo; Guo, Xingcui; Mu, Xindong

    2016-06-01

    Graphitic carbon nitride nanosheets were investigated for developing effective Pt catalyst supports for selective hydrogenation of furfural to furfuryl alcohol in water. The nanosheets with an average thickness of about 3 nm were synthesized by a simple and green method through thermal oxidation etching of bulk g-C3N4 in air. Combined with the unique feature of nitrogen richness and locally conjugated structure, the g-C3N4 nanosheets with a high surface area of 142 m2 g‑1 were demonstrated to be an excellent supports for loading small-size Pt nanoparticles. Superior furfural hydrogenation activity in water with complete conversion of furfural and high selectivity of furfuryl alcohol (>99%) was observed for g-C3N4 nanosheets supported Pt catalysts. The large specific surface area, uniform dispersion of Pt nanoparticles and the stronger furfural adsorption ability of nanosheets contributed to the considerable catalytic performance. The reusability tests showed that the novel Pt catalyst could maintain high activity and stability in the furfural hydrogenation reaction.

  20. Highly selective hydrogenation of furfural to furfuryl alcohol over Pt nanoparticles supported on g-C3N4 nanosheets catalysts in water.

    PubMed

    Chen, Xiufang; Zhang, Ligang; Zhang, Bo; Guo, Xingcui; Mu, Xindong

    2016-06-22

    Graphitic carbon nitride nanosheets were investigated for developing effective Pt catalyst supports for selective hydrogenation of furfural to furfuryl alcohol in water. The nanosheets with an average thickness of about 3 nm were synthesized by a simple and green method through thermal oxidation etching of bulk g-C3N4 in air. Combined with the unique feature of nitrogen richness and locally conjugated structure, the g-C3N4 nanosheets with a high surface area of 142 m(2) g(-1) were demonstrated to be an excellent supports for loading small-size Pt nanoparticles. Superior furfural hydrogenation activity in water with complete conversion of furfural and high selectivity of furfuryl alcohol (>99%) was observed for g-C3N4 nanosheets supported Pt catalysts. The large specific surface area, uniform dispersion of Pt nanoparticles and the stronger furfural adsorption ability of nanosheets contributed to the considerable catalytic performance. The reusability tests showed that the novel Pt catalyst could maintain high activity and stability in the furfural hydrogenation reaction.

  1. The cell wall galactomannan antigen from Malassezia furfur and Malassezia pachydermatis contains beta-1,6-linked linear galactofuranosyl residues and its detection has diagnostic potential.

    PubMed

    Shibata, Nobuyuki; Saitoh, Tomomi; Tadokoro, Yukari; Okawa, Yoshio

    2009-10-01

    Lipophilic yeasts of the genus Malassezia are associated with several skin diseases, such as pityriasis versicolor, Malassezia folliculitis, seborrhoeic dermatitis and atopic dermatitis, and are also increasingly associated with catheter-related fungaemia. The cell wall components of pathogenic micro-organisms behave as an antigen and/or ligand of the innate immune response. Live cells of Malassezia furfur and Malassezia pachydermatis did not react with an anti-alpha-1,2-mannoside antibody. However, they showed a strong hydrophobicity and reactivity with an anti-beta-1,3-glucan antibody compared to those of C. albicans. The cell wall polysaccharides of M. furfur and M. pachydermatis were isolated and their structures analysed by (1)H and (13)C NMR experiments. Both polysaccharides were shown to be beta-1,6-linked linear galactofuranosyl polymers with a small amount of mannan. The presence of galactomannan on cells of Malassezia species has not been described previously. The galactomannan did not react with an anti-Aspergillus fumigatus monoclonal antibody which has specificity for beta-1,5-linked galactofuranosyl residues. An anti-M. furfur antibody strongly reacted with the galactomannans of M. furfur and M. pachydermatis, but did not react with the galactomannans of Trichophyton rubrum, A. fumigatus or Fonsecaea pedrosoi. The characteristics of the anti-M. furfur antibody suggest that there is potential for diagnosis of Malassezia infections by antigen detection.

  2. Analysis of differentially expressed genes associated with tryptophan-dependent pigment synthesis in M. furfur by cDNA subtraction technology.

    PubMed

    Hort, W; Lang, S; Brunke, S; Mayser, P; Hube, B

    2009-05-01

    Malassezia species are associated with pityriasis versicolor (PV) and its depigmented variant pityriasis versicolor alba (PVa), widespread fungal skin infections in humans. The pathogenesis of PV and PVa remains unclear, including their clinical and histological symptoms such as hyper- and depigmentation, reduced responsiveness to ultraviolet radiation and lack of inflammatory reaction despite high fungal load. Pigments produced by M. furfur are possibly involved in the pathogenesis of PV. In vitro, M. furfur produces a wide range of pigments and fluorochromes when cultured with tryptophan as the sole nitrogen source. We have begun to analyse the molecular basis of pigment production by searching for genes associated with tryptophan-based pigment production. A suppression subtractive hybridization (SSH) protocol was used to identify genes expressed in M. furfur cells producing pigments, but not in non-induced cells. SSH was performed 3 and 5 h after onset of pigment induction. Up-regulation of genes in the pigment-producing cells was confirmed by reverse northern analysis. More than 1,500 cDNA sequences of both the indicated time points were analysed. We identified a wide variety of genes associated with metabolism and several genes with unknown function are specifically expressed during pigment production. Furthermore, a fraction of genes possibly involved in different steps of the newly discovered indolic pathway of M. furfur were expressed in pigment producing cells. These data provide the first molecular insight into pigment production of M. furfur.

  3. Co-expression of TAL1 and ADH1 in recombinant xylose-fermenting Saccharomyces cerevisiae improves ethanol production from lignocellulosic hydrolysates in the presence of furfural.

    PubMed

    Hasunuma, Tomohisa; Ismail, Ku Syahidah Ku; Nambu, Yumiko; Kondo, Akihiko

    2014-02-01

    Lignocellulosic biomass dedicated to bioethanol production usually contains pentoses and inhibitory compounds such as furfural that are not well tolerated by Saccharomyces cerevisiae. Thus, S. cerevisiae strains with the capability of utilizing both glucose and xylose in the presence of inhibitors such as furfural are very important in industrial ethanol production. Under the synergistic conditions of transaldolase (TAL) and alcohol dehydrogenase (ADH) overexpression, S. cerevisiae MT8-1X/TAL-ADH was able to produce 1.3-fold and 2.3-fold more ethanol in the presence of 70 mM furfural than a TAL-expressing strain and a control strain, respectively. We also tested the strains' ability by mimicking industrial ethanol production from hemicellulosic hydrolysate containing fermentation inhibitors, and ethanol production was further improved by 16% when using MT8-1X/TAL-ADH compared to the control strain. Transcript analysis further revealed that besides the pentose phosphate pathway genes TKL1 and TAL1, ADH7 was also upregulated in response to furfural stress, which resulted in higher ethanol production compared to the TAL-expressing strain. The improved capability of our modified strain was based on its capacity to more quickly reduce furfural in situ resulting in higher ethanol production. The co-expression of TAL/ADH genes is one crucial strategy to fully utilize undetoxified lignocellulosic hydrolysate, leading to cost-competitive ethanol production.

  4. Precultivation of Bacillus coagulans DSM2314 in the presence of furfural decreases inhibitory effects of lignocellulosic by-products during L(+)-lactic acid fermentation.

    PubMed

    van der Pol, Edwin; Springer, Jan; Vriesendorp, Bastienne; Weusthuis, Ruud; Eggink, Gerrit

    2016-12-01

    By-products resulting from thermo-chemical pretreatment of lignocellulose can inhibit fermentation of lignocellulosic sugars to lactic acid. Furfural is such a by-product, which is formed during acid pretreatment of lignocellulose. pH-controlled fermentations with 1 L starting volume, containing YP medium and a mixture of lignocellulosic by-products, were inoculated with precultures of Bacillus coagulans DSM2314 to which 1 g/L furfural was added. The addition of furfural to precultures resulted in an increase in L(+)-lactic acid productivity by a factor 2 to 1.39 g/L/h, an increase in lactic acid production from 54 to 71 g and an increase in conversion yields of sugar to lactic acid from 68 to 88 % W/W in subsequent fermentations. The improved performance was not caused by furfural consumption or conversion, indicating that the cells acquired a higher tolerance towards this by-product. The improvement coincided with a significant elongation of B. coagulans cells. Via RNA-Seq analysis, an upregulation of pathways involved in the synthesis of cell wall components such as bacillosamine, peptidoglycan and spermidine was observed in elongated cells. Furthermore, the gene SigB and genes promoted by SigB, such as NhaX and YsnF, were upregulated in the presence of furfural. These genes are involved in stress responses in bacilli.

  5. Production of furfural from xylose, water-insoluble hemicelluloses and water-soluble fraction of corncob via a tin-loaded montmorillonite solid acid catalyst.

    PubMed

    Li, Huiling; Ren, Junli; Zhong, Linjie; Sun, Runcang; Liang, Lei

    2015-01-01

    The conversion of xylose, water-insoluble hemicelluloses (WIH) and water-soluble fraction (WSF) of corncob to furfural was performed using montmorillonite with tin ions (Sn-MMT) containing double acid sites as a solid acid catalyst. The co-existence of Lewis acids and Brønsted acids in Sn-MMT was shown to improve the furfural yield and selectivity. 76.79% furfural yield and 82.45% furfural selectivity were obtained from xylose using Sn-MMT as a catalyst in a biphasic system with 2-s-butylphenol (SBP) as the organic extracting layer and dimethyl sulfoxide (DMSO) as the co-solvent in contact with an aqueous phase saturated with NaCl (SBP/NaCl-DMSO) at 180°C for 30min. Furthermore, Sn-MMT also demonstrated the excellent catalytic performance in the conversion of pentose-rich materials of corncob and 39.56% and 54.15% furfural yields can be directly obtained from WIH and WSF in the SBP/NaCl-DMSO system, respectively.

  6. Association of 5-hydroxymethylation and 5-methylation of DNA cytosine with tissue-specific gene expression

    PubMed Central

    Ponnaluri, V. K. Chaithanya; Ehrlich, Kenneth C.; Zhang, Guoqiang; Lacey, Michelle; Johnston, Douglas; Pradhan, Sriharsa; Ehrlich, Melanie

    2017-01-01

    ABSTRACT Differentially methylated or hydroxymethylated regions (DMRs) in mammalian DNA are often associated with tissue-specific gene expression but the functional relationships are still being unraveled. To elucidate these relationships, we studied 16 human genes containing myogenic DMRs by analyzing profiles of their epigenetics and transcription and quantitatively assaying 5-hydroxymethylcytosine (5hmC) and 5-methylcytosine (5mC) at specific sites in these genes in skeletal muscle (SkM), myoblasts, heart, brain, and diverse other samples. Although most human promoters have little or no methylation regardless of expression, more than half of the genes that we chose to study—owing to their myogenic DMRs—overlapped tissue-specific alternative or cryptic promoters displaying corresponding tissue-specific differences in histone modifications. The 5mC levels in myoblast DMRs were significantly associated with 5hmC levels in SkM at the same site. Hypermethylated myogenic DMRs within CDH15, a muscle- and cerebellum-specific cell adhesion gene, and PITX3, a homeobox gene, were used for transfection in reporter gene constructs. These intragenic DMRs had bidirectional tissue-specific promoter activity that was silenced by in vivo-like methylation. The CDH15 DMR, which was previously associated with an imprinted maternal germline DMR in mice, had especially strong promoter activity in myogenic host cells. These findings are consistent with the controversial hypothesis that intragenic DNA methylation can facilitate transcription and is not just a passive consequence of it. Our results support varied roles for tissue-specific 5mC- or 5hmC-enrichment in suppressing inappropriate gene expression from cryptic or alternative promoters and in increasing the plasticity of gene expression required for development and rapid responses to tissue stress or damage. PMID:27911668

  7. Furfural modified asphalt obtained by using a Lewis acid as a catalyst

    SciTech Connect

    Memon, G.M.

    1996-12-31

    Asphalt is solid or semi-solid at room temperature, becomes soft and starts flowing upon heating, and becomes hard and brittle at very low temperatures. States have been facing problems such as cracking, rutting, and asphalt adhesion to aggregates in their asphaltic pavements for years. Many polymer additives have been used in asphalt to reduce these problems, but little work has been done using chemically modified products of asphalt to attempt to solve these serious problems of asphalt pavements. The above mentioned problems decrease the life of the pavements, resulting in an increase of maintenance and/or replacement costs. There are two types of cracking which can occur in asphalt pavement; one related to load, and the other related to thermal stress. The load-related cracking is known as fatigue cracking and is defined as fracture under repeated or cyclic stress having a maximum value of less than the tensile strength of the material. The thermal cracking occurs due to pavement shrinkage at low temperature causing the shrinkage stresses to exceed the tensile strength. FHWA researchers have found furfural to be a suitable candidate for functional group modification of asphalt. The modified product shows improved performance as well as improved rheological properties.

  8. Comparison between liquid and solid acids catalysts on reducing sugars conversion from furfural residues via pretreatments.

    PubMed

    Lin, Keying; Ma, Baojun; Sun, Yuan; Liu, Wanyi

    2014-09-01

    Liquid sulphuric acid is adopted and compared with carbon-based sulfonated solid acids (coal tar-based and active carbon-based) for furfural residues conversion into reducing sugars. The optimum hydrolysis conditions of liquid acid are at 4% of sulphuric acid, 25:1 of liquid and solid ratio, 175°C of reaction temperature and 120 min of reaction time. The reducing sugar yields are reached over 60% on liquid acid via NaOH/H2O2, NaOH/microwave and NaOH/ultrasonic pretreatments, whereas only over 30% on solid acids. The TOFs (turnover number frequency) via NaOH/H2O2 pretreatments are 0.093, 0.020 and 0.023 h(-1) for liquid sulphuric acid, coal tar-based and active carbon-based solid acids catalysts, respectively. Considering the efficiency, cost and environment factors, the liquid and solid acids have their own advantages of potential commercial application values.

  9. Furfural-based polymers for the sealing of reactor vessels dumped in the Arctic Kara Sea

    SciTech Connect

    HEISER,J.H.; COWGILL,M.G.; SIVINTSEV,Y.V.; ALEXANDROV,V.P.; DYER,R.S.

    1996-10-07

    Between 1965 and 1988, 16 naval reactor vessels were dumped in the Arctic Kara Sea. Six of the vessels contained spent nuclear fuel that had been damaged during accidents. In addition, a container holding {approximately} 60% of the damaged fuel from the No. 2 reactor of the atomic icebreaker Lenin was dumped in 1967. Before dumping, the vessels were filled with a solidification agent, Conservant F, in order to prevent direct contact between the seawater and the fuel and other activated components, thereby reducing the potential for release of radionuclides into the environment. The key ingredient in Conservant F is furfural (furfuraldehyde). Other constituents vary, depending on specific property requirements, but include epoxy resin, mineral fillers, and hardening agents. In the liquid state (prior to polymerization) Conservant F is a low viscosity, homogeneous resin blend that provides long work times (6--9 hours). In the cured state, Conservant F provides resistance to water and radiation, has high adhesion properties, and results in minimal gas evolution. This paper discusses the properties of Conservant F in both its cured and uncured states and the potential performance of the waste packages containing spent nuclear fuel in the Arctic Kara Sea.

  10. Vapor phase hydrogenation of furfural over nickel mixed metal oxide catalysts derived from layered double hydroxides

    SciTech Connect

    Sulmonetti, Taylor P.; Pang, Simon H.; Claure, Micaela Taborga; Lee, Sungsik; Cullen, David A.; Agrawal, Pradeep K.; Jones, Christopher W.

    2016-05-01

    The hydrogenation of furfural is investigated over various reduced nickel mixed metal oxides derived from layered double hydroxides (LDHs) containing Ni-Mg-Al and Ni-Co-Al. Upon reduction, relatively large Ni(0) domains develop in the Ni-Mg-Al catalysts, whereas in the Ni-Co-Al catalysts smaller metal particles of Ni(0) and Co(0), potentially as alloys, are formed, as evidenced by XAS, XPS, STEM and EELS. All the reduced Ni catalysts display similar selectivities towards major hydrogenation products (furfuryl alcohol and tetrahydrofurfuryl alcohol), though the side products varied with the catalyst composition. The 1.1Ni-0.8Co-Al catalyst showed the greatest activity per titrated site when compared to the other catalysts, with promising activity compared to related catalysts in the literature. The use of base metal catalysts for hydrogenation of furanic compounds may be a promising alternative to the well-studied precious metal catalysts for making biomass-derived chemicals if catalyst selectivity can be improved in future work by alloying or tuning metal-oxide support interactions.

  11. Vapor phase hydrogenation of furfural over nickel mixed metal oxide catalysts derived from layered double hydroxides

    DOE PAGES

    Sulmonetti, Taylor P.; Pang, Simon H.; Claure, Micaela Taborga; ...

    2016-03-09

    The hydrogenation of furfural is investigated over various reduced nickel mixed metal oxides derived from layered double hydroxides (LDHs) containing Ni-Mg-Al and Ni-Co-Al. Upon reduction, relatively large Ni(0) domains develop in the Ni-Mg-Al catalysts, whereas in the Ni-Co-Al catalysts smaller metal particles of Ni(0) and Co(0), potentially as alloys, are formed, as evidenced by XAS, XPS, STEM and EELS. All the reduced Ni catalysts display similar selectivities towards major hydrogenation products (furfuryl alcohol and tetrahydrofurfuryl alcohol), though the side products varied with the catalyst composition. The 1.1Ni-0.8Co-Al catalyst showed the greatest activity per titrated site when compared to the othermore » catalysts, with promising activity compared to related catalysts in the literature. In conclusion, the use of base metal catalysts for hydrogenation of furanic compounds may be a promising alternative to the well-studied precious metal catalysts for making biomass-derived chemicals if catalyst selectivity can be improved in future work by alloying or tuning metal-oxide support interactions.« less

  12. Vapor phase hydrogenation of furfural over nickel mixed metal oxide catalysts derived from layered double hydroxides

    SciTech Connect

    Sulmonetti, Taylor P.; Pang, Simon H.; Claure, Micaela Taborga; Lee, Sungsik; Cullen, David A.; Agrawal, Pradeep K.; Jones, Christopher W.

    2016-03-09

    The hydrogenation of furfural is investigated over various reduced nickel mixed metal oxides derived from layered double hydroxides (LDHs) containing Ni-Mg-Al and Ni-Co-Al. Upon reduction, relatively large Ni(0) domains develop in the Ni-Mg-Al catalysts, whereas in the Ni-Co-Al catalysts smaller metal particles of Ni(0) and Co(0), potentially as alloys, are formed, as evidenced by XAS, XPS, STEM and EELS. All the reduced Ni catalysts display similar selectivities towards major hydrogenation products (furfuryl alcohol and tetrahydrofurfuryl alcohol), though the side products varied with the catalyst composition. The 1.1Ni-0.8Co-Al catalyst showed the greatest activity per titrated site when compared to the other catalysts, with promising activity compared to related catalysts in the literature. In conclusion, the use of base metal catalysts for hydrogenation of furanic compounds may be a promising alternative to the well-studied precious metal catalysts for making biomass-derived chemicals if catalyst selectivity can be improved in future work by alloying or tuning metal-oxide support interactions.

  13. Selective One-Pot Production of High-Grade Diesel-Range Alkanes from Furfural and 2-Methylfuran over Pd/NbOPO4.

    PubMed

    Xia, Qineng; Xia, Yinjiang; Xi, Jinxu; Liu, Xiaohui; Zhang, Yongguang; Guo, Yong; Wang, Yanqin

    2017-02-22

    A one-pot method for the selective production of high-grade diesel-range alkanes from biomass-derived furfural and 2-methylfuran (2-MF) was developed by combining the hydroxyalkylation/alkylation (HAA) condensation of furfural with 2-MF and the subsequent hydrodeoxygenation (HDO) over a multifunctional Pd/NbOPO4 catalyst. The effects of various reaction conditions as well as a variety of solid-acid catalysts and metal-loaded NbOPO4 catalysts were systematically investigated to optimize the reaction conditions for both reactions. Under the optimal reaction conditions up to 89.1 % total yield of diesel-range alkanes was obtained from furfural and 2-MF by this one-pot method.

  14. In vitro antifungal activity of extracts obtained from Hypericum perforatum adventitious roots cultured in a mist bioreactor against planktonic cells and biofilm of Malassezia furfur.

    PubMed

    Simonetti, Giovanna; Tocci, Noemi; Valletta, Alessio; Brasili, Elisa; D'Auria, Felicia Diodata; Idoux, Alicia; Pasqua, Gabriella

    2016-01-01

    Xanthone-rich extracts from Hypericum perforatum root cultures grown in a Mist Bioreactor as antifungal agents against Malassezia furfur. Extracts of Hypericum perforatum roots grown in a bioreactor showed activity against planktonic cells and biofilm of Malassezia furfur. Dried biomass, obtained from roots grown under controlled conditions in a ROOTec mist bioreactor, has been extracted with solvents of increasing polarity (i.e. chloroform, ethyl acetate and methanol). The methanolic fraction was the richest in xanthones (2.86 ± 0.43 mg g(-1) DW) as revealed by HPLC. The minimal inhibitory concentration of the methanol extract against M. furfur planktonic cells was 16 μg mL(-1). The inhibition percentage of biofilm formation, at a concentration of 16 μg mL(-1), ranged from 14% to 39%. The results show that H. perforatum root extracts could be used as new antifungal agents in the treatment of Malassezia infections.

  15. Effects of Soluble Lignin on the Formic Acid-Catalyzed Formation of Furfural: A Case Study for the Upgrading of Hemicellulose.

    PubMed

    Dussan, Karla; Girisuta, Buana; Lopes, Marystela; Leahy, James J; Hayes, Michael H B

    2016-03-08

    A comprehensive study is presented on the conversion of hemicellulose sugars in liquors obtained from the fractionation of Miscanthus, spruce bark, sawdust, and hemp by using formic acid. Experimental tests with varying temperature (130-170 °C), formic acid concentration (10-80 wt%), carbohydrate concentrations, and lignin separation were carried out, and experimental data were compared with predictions obtained by reaction kinetics developed in a previous study. The conversions of xylose and arabinose into furfural were inherently affected by the presence of polymeric soluble lignin, decreasing the maximum furfural yields observed experimentally by up to 24%. These results were also confirmed in synthetic mixtures of pentoses with Miscanthus and commercial alkali lignin. This observation was attributed to side reactions involving intermediate stable sugar species reacting with solubilized lignin during the conversion of xylose into furfural.

  16. Investigation of thermochemistry associated with the carbon-carbon coupling reactions of furan and furfural using ab initio methods.

    PubMed

    Liu, Cong; Assary, Rajeev S; Curtiss, Larry A

    2014-06-26

    Upgrading furan and small oxygenates obtained from the decomposition of cellulosic materials via formation of carbon-carbon bonds is critical to effective conversion of biomass to liquid transportation fuels. Simulation-driven molecular level understanding of carbon-carbon bond formation is required to design efficient catalysts and processes. Accurate quantum chemical methods are utilized here to predict the reaction energetics for conversion of furan (C4H4O) to C5-C8 ethers and the transformation of furfural (C5H6O2) to C13-C26 alkanes. Furan can be coupled with various C1 to C4 low molecular weight carbohydrates obtained from the pyrolysis via Diels-Alder type reactions in the gas phase to produce C5-C8 cyclic ethers. The computed reaction barriers for these reactions (∼25 kcal/mol) are lower than the cellulose activation or decomposition reactions (∼50 kcal/mol). Cycloaddition of C5-C8 cyclo ethers with furans can also occur in the gas phase, and the computed activation energy is similar to that of the first Diels-Alder reaction. Furfural, obtained from biomass, can be coupled with aldehydes or ketones with α-hydrogen atoms to form longer chain aldol products, and these aldol products can undergo vapor phase hydrocycloaddition (activation barrier of ∼20 kcal/mol) to form the precursors of C26 cyclic hydrocarbons. These thermochemical studies provide the basis for further vapor phase catalytic studies required for upgrading of furans/furfurals to longer chain hydrocarbons.

  17. Determination of furfurals in Manuka honey using piston-cylinder liquid-liquid extraction and gas chromatography.

    PubMed

    Gras, K; Luong, J; Gras, R; Cortes, H J; Shellie, R A

    2014-10-03

    A rapid analytical approach for the direct measurement of furfurals such as 2-furfural and 5-methyl-2-furfural at parts-per-billion level in Manuka honey is described. The approach employs a piston-cylinder based liquid-liquid extraction device using chloroform extraction solvent. This device substantially reduces extraction time by a factor of 120 times compared to solid phase micro-extraction and reduces solvent consumption by a factor of 25 times compared to liquid-liquid extraction with mechanical agitation. A recently commercialised capillary column offering a high degree of inertness permits separation and detection of the analytes at ultra-trace level without derivatisation. A three-port planar microfluidic device with a mid-point pressure is also incorporated to back-flush heavier compounds in the matrix to improve column longevity and overall system cleanliness. With this approach, analysis is conducted in less than 7min. Repeatability of retention times for all compounds is less than 0.1% (n=20). The compounds cited can be analysed over a range from 1ng/g to 10μg/g in honey with a 5ng/g limit of quantification (LOQ) and correlation coefficients of at least 0.999. Relative precision is less than 2.8% RSD (n=20) at 50ng/g level with analyte extraction efficiency of greater than 99% (n=3) over a range from 5ng/g to 10μg/g in the matrix described. The analytical system requires only minimal maintenance and is suitable for remote site deployment. Under the analytical conditions established and with a practical LOQ of 5ng/g, 100 samples can be analysed before septum/liner/o-ring replacements are needed. As a preventive measure, the pre-column can be replaced once every six months to maintain chromatographic fidelity.

  18. Efficient solid acid catalyst containing Lewis and Brønsted Acid sites for the production of furfurals.

    PubMed

    Mazzotta, Michael G; Gupta, Dinesh; Saha, Basudeb; Patra, Astam K; Bhaumik, Asim; Abu-Omar, Mahdi M

    2014-08-01

    Self-assembled nanoparticulates of porous sulfonated carbonaceous TiO2 material that contain Brønsted and Lewis acidic sites were prepared by a one-pot synthesis method. The material was characterized by XRD, FTIR spectroscopy, NH3 temperature-programmed desorption, pyridine FTIR spectroscopy, field-emission scanning electron microscopy, high-resolution transmission electron microscopy, N2 -sorption, atomic absorbance spectroscopy, and inductively coupled plasma optical emission spectroscopy. The carbonaceous heterogeneous catalyst (Glu-TsOH-Ti) with a Brønsted-to-Lewis acid density ratio of 1.2 and more accessible acid sites was effective to produce 5-hydroxymethylfurfural and furfural from biomass-derived mono- and disaccharides and xylose in a biphasic solvent that comprised water and biorenewable methyltetrahydrofuran. The catalyst was recycled in four consecutive cycles with a total loss of only 3 % activity. Thus, Glu-TsOH-Ti, which contains isomerization and dehydration catalytic sites and is based on a cheap and biorenewable carbon support, is a sustainable catalyst for the production of furfurals, platform chemicals for biofuels and chemicals.

  19. Effect of Different Flours on the Formation of Hydroxymethylfurfural, Furfural, and Dicarbonyl Compounds in Heated Glucose/Flour Systems

    PubMed Central

    Mesías, Marta; Morales, Francisco J.

    2017-01-01

    Traditional cereal-based foods usually include wheat flour in their formulations; however, the search for new products with new ingredients providing different properties to foods is widely pursued by food companies. Replacement of wheat by other flours can modify both nutritional properties and organoleptic characteristics of the final baked food, but can also impact the formation of potentially harmful compounds. The effect of the type of flour on the formation of furfurals and dicarbonyl compounds was studied in a dough model system during baking that contains water or glucose in order to promote the Maillard reaction and caramelization. The formation of methylglyoxal and glyoxal was significantly reduced in spelt and teff formulations compared to wheat flour formulations, respectively. In contrast, samples formulated with oat, teff, and rye showed a significant increase in the levels of 3-deoxyglucosone. Similarly, spelt and teff formulations presented significantly higher concentrations of hydroxymethylfurfural, and spelt, teff, and rye presented higher concentrations of furfural. Therefore, the formation of process contaminants and undesirable compounds in new food products formulated with different flours replacing the traditional wheat flour should be considered carefully in terms of food safety. PMID:28231092

  20. A ship-in-a-bottle strategy to synthesize encapsulated intermetallic nanoparticle catalysts: Exemplified for furfural hydrogenation

    SciTech Connect

    Maligal-Ganesh, Raghu V.; Xiao, Chaoxian; Goh, Tian Wei; Wang, Lin -Lin; Gustafson, Jeffrey; Pei, Yuchen; Qi, Zhiyuan; Johnson, Duane D.; Zhang, Shiran; Tao, Franklin; Huang, Wenyu

    2016-01-28

    In this paper, intermetallic compounds are garnering increasing attention as efficient catalysts for improved selectivity in chemical processes. Here, using a ship-in-a-bottle strategy, we synthesize single-phase platinum-based intermetallic nanoparticles (NPs) protected by a mesoporous silica (mSiO2) shell by heterogeneous reduction and nucleation of Sn, Pb, or Zn in mSiO2-encapsulated Pt NPs. For selective hydrogenation of furfural to furfuryl alcohol, a dramatic increase in activity and selectivity is observed when intermetallic NPs catalysts are used in comparison to Pt@mSiO2. Among the intermetallic NPs, PtSn@mSiO2 exhibits the best performance, requiring only one-tenth of the quantity of Pt used in Pt@mSiO2 for similar activity and near 100% selectivity to furfuryl alcohol. A high-temperature oxidation–reduction treatment easily reverses any carbon deposition-induced catalyst deactivation. X-ray photoelectron spectroscopy shows the importance of surface composition to the activity, whereas density functional theory calculations reveal that the enhanced selectivity on PtSn compared to Pt is due to the different furfural adsorption configurations on the two surfaces.

  1. Furfural production from rice husk using sulfuric acid and a solid acid catalyst through a two-stage process.

    PubMed

    Ren, Suxia; Xu, Haiyan; Zhu, Jinling; Li, Shunqing; He, Xiaofeng; Lei, Tingzhou

    2012-10-01

    This study aimed to optimize the conditions for furfural production from rice husk via a two-stage process: acid hydrolysis followed by dehydration using an orthogonal test design and response surface methodology, respectively. Orthogonal test design was utilized in the hydrolysis step; optimum conditions were as follows: 2.5% sulfuric acid (mass fraction), 110°C reaction temperature, sulfuric acid to rice husk (L/S) ratio of 8 (g/mL), and a reaction time of 3h. According to the Box-Behnken design, the temperature, amount of catalyst, extractant volume, and reaction time were chosen as four important factors with three levels for the dehydration step. Conditions were further optimized by response surface analysis. The results showed that the optimal conditions were 177°C, 120 mL extractant volume, 2.1g of catalyst, and a reaction time of 4.8h. Under the optimal conditions, the furfural yield reached 8.9%, which is consistent with the estimated value, 8.97%.

  2. A ship-in-a-bottle strategy to synthesize encapsulated intermetallic nanoparticle catalysts: Exemplified for furfural hydrogenation

    DOE PAGES

    Maligal-Ganesh, Raghu V.; Xiao, Chaoxian; Goh, Tian Wei; ...

    2016-01-28

    In this paper, intermetallic compounds are garnering increasing attention as efficient catalysts for improved selectivity in chemical processes. Here, using a ship-in-a-bottle strategy, we synthesize single-phase platinum-based intermetallic nanoparticles (NPs) protected by a mesoporous silica (mSiO2) shell by heterogeneous reduction and nucleation of Sn, Pb, or Zn in mSiO2-encapsulated Pt NPs. For selective hydrogenation of furfural to furfuryl alcohol, a dramatic increase in activity and selectivity is observed when intermetallic NPs catalysts are used in comparison to Pt@mSiO2. Among the intermetallic NPs, PtSn@mSiO2 exhibits the best performance, requiring only one-tenth of the quantity of Pt used in Pt@mSiO2 for similarmore » activity and near 100% selectivity to furfuryl alcohol. A high-temperature oxidation–reduction treatment easily reverses any carbon deposition-induced catalyst deactivation. X-ray photoelectron spectroscopy shows the importance of surface composition to the activity, whereas density functional theory calculations reveal that the enhanced selectivity on PtSn compared to Pt is due to the different furfural adsorption configurations on the two surfaces.« less

  3. Monitoring of Low Levels of Furfural in Power Transformer Oil with a Sensor System Based on a POF-MIP Platform

    PubMed Central

    Cennamo, Nunzio; De Maria, Letizia; D’Agostino, Girolamo; Zeni, Luigi; Pesavento, Maria

    2015-01-01

    In this work an innovative, miniaturized and low cost optical chemical sensor (POF-MIP platform), based on a molecular imprinted polymer (MIP) and surface plasmon resonance in a plastic optical fiber (POF), is presented and preliminarily tested for monitoring of furfural (furan-2-carbaldehyde) in transformer oil. To this end, the optical platform was coupled to an MIP layer, highly selective for furfural. The ability of the developed sensor to directly detect furfural in the insulating oil was investigated. The detection limit of the sensor has been found to be 9 ppb, with a linear response up to about 30 ppb. However there is a sensible response up to 0.15 ppm. Because of the small linearity range, the Hill equation is suggested for the quantification. The sensor has been effectively tested in real oil samples collected from aged electrical equipment removed from service. The assessed concentration of furfural is in good agreement with that evaluated by a high pressure liquid chromatography (HLPC) method, confirming the good selectivity of the proposed sensor. PMID:25871719

  4. Monitoring of low levels of furfural in power transformer oil with a sensor system based on a POF-MIP platform.

    PubMed

    Cennamo, Nunzio; De Maria, Letizia; D'Agostino, Girolamo; Zeni, Luigi; Pesavento, Maria

    2015-04-13

    In this work an innovative, miniaturized and low cost optical chemical sensor (POF-MIP platform), based on a molecular imprinted polymer (MIP) and surface plasmon resonance in a plastic optical fiber (POF), is presented and preliminarily tested for monitoring of furfural (furan-2-carbaldehyde) in transformer oil. To this end, the optical platform was coupled to an MIP layer, highly selective for furfural. The ability of the developed sensor to directly detect furfural in the insulating oil was investigated. The detection limit of the sensor has been found to be 9 ppb, with a linear response up to about 30 ppb. However there is a sensible response up to 0.15 ppm. Because of the small linearity range, the Hill equation is suggested for the quantification. The sensor has been effectively tested in real oil samples collected from aged electrical equipment removed from service. The assessed concentration of furfural is in good agreement with that evaluated by a high pressure liquid chromatography (HLPC) method, confirming the good selectivity of the proposed sensor.

  5. Tuning the synthesis of platinum-copper nanoparticles with a hollow core and porous shell for the selective hydrogenation of furfural to furfuryl alcohol

    NASA Astrophysics Data System (ADS)

    Huang, Shuangshuang; Yang, Nating; Wang, Shibin; Sun, Yuhan; Zhu, Yan

    2016-07-01

    Pt-Cu nanoparticles constructed with a hollow core and porous shell have been synthesized in which Pt-Cu cages with multiporous outermost shells are formed at the initial stage and then the Pt and Cu atoms in solution continuously fed these hollow-core of cages by passing through the porous tunnels of the outermost shells, finally leading to the formation of hollow structures with different sizes. Furthermore, these hollow-core Pt-Cu nanoparticles are more effective than the solid-core Pt-Cu nanoparticles for the catalytic hydrogenation of furfural toward furfuryl alcohol. The former can achieve almost 100% conversion of furfural with 100% selectivity toward the alcohol.Pt-Cu nanoparticles constructed with a hollow core and porous shell have been synthesized in which Pt-Cu cages with multiporous outermost shells are formed at the initial stage and then the Pt and Cu atoms in solution continuously fed these hollow-core of cages by passing through the porous tunnels of the outermost shells, finally leading to the formation of hollow structures with different sizes. Furthermore, these hollow-core Pt-Cu nanoparticles are more effective than the solid-core Pt-Cu nanoparticles for the catalytic hydrogenation of furfural toward furfuryl alcohol. The former can achieve almost 100% conversion of furfural with 100% selectivity toward the alcohol. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr03894h

  6. Omics-based approaches reveal phospholipids remodeling of Rhizopus oryzae responding to furfural stress for fumaric acid-production from xylose.

    PubMed

    Pan, Xinrong; Liu, Huanhuan; Liu, Jiao; Wang, Cheng; Wen, Jianping

    2016-12-01

    In order to relieve the toxicity of furfural on Rhizopus oryzae fermentation, the molecular mechanism of R. oryzae responding to furfural stress for fumaric acid-production was investigated by omics-based approaches. In metabolomics analysis, 29 metabolites including amino acid, sugars, polyols and fatty acids showed significant changes for maintaining the basic cell metabolism at the cost of lowering fumaric acid production. To further uncover the survival mechanism, lipidomics was carried out, revealing that phosphatidylcholine, phosphatidylglycerol, phosphatidylinositol and polyunsaturated acyl chains might be closely correlated with R. oryzae's adapting to furfural stress. Based on the above omics analysis, lecithin, inositol and soybean oil were exogenously supplemented separately with an optimized concentration in the presence of furfural, which increased fumaric acid titer from 5.78g/L to 10.03g/L, 10.05g/L and 12.13g/L (increased by 73.5%, 73.8% and 110%, respectively). These findings provide a methodological guidance for hemicellulose-fumaric acid development.

  7. Catalytic transfer hydrogenation for stabilization of bio-oil oxygenates: reduction of p-cresol and furfural over bimetallic Ni-Cu catalysts using isopropanol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transfer hydrogenation and hydrodeoxygenation of model bio-oil compounds (p-cresol and furfural) and bio-oils derived from biomass via traditional pyrolysis and tail-gas reactive pyrolysis (TGRP) were conducted. Mild batch reaction conditions were employed, using isopropanol as a hydrogen donor over...

  8. Differentially expressed genes associated with tryptophan-dependent pigment synthesis in Malassezia furfur--a comparison with the recently published genome of Malassezia globosa.

    PubMed

    Lang, S K; Hort, W; Mayser, P

    2011-07-01

    Malassezia (M.) furfur, a commensal organism found on the human skin, produces a wide range of pigments and fluorochromes when cultured with tryptophan as a sole nitrogen source. Some compounds of this pigment metabolism may provide an explanation for clinical characteristics of pityriasis versicolor (PV), a frequent skin disease in humans characterised by long-lasting pigmentary changes. Malassezia globosa is currently regarded as the causative agent of PV, but tryptophan-dependent pigment production has not yet been demonstrated in this species. In a previous study, we identified M. furfur genes that were differentially expressed 3 and 5 h, respectively, after induction of tryptophan-dependent pigment production. The recent publication of the genome of M. globosa prompted us to check the M. furfur sequences for homologues in M. globosa. The 3-h pool contained 79 sequences and the 5-h pool contained 91 sequences. A translated vs. translated BLAST search resulted in 62 sequences (78%) of the 3-h pool and 61 sequences (67%) of the 5-h pool showing similarity to a sequence from M. globosa. It appears that M. globosa possesses homologues to most of the genes that are differentially expressed during pigment production in M. furfur.

  9. Modulation of perfusion and oxygenation by red blood cell oxygen affinity during acute anemia.

    PubMed

    Cabrales, Pedro; Tsai, Amy G; Intaglietta, Marcos

    2008-03-01

    Responses to exchange transfusion using red blood cells (RBCs) with modified hemoglobin (Hb) oxygen (O(2)) affinity were studied in the hamster window chamber model during acute anemia to determine its role on microvascular perfusion and tissue oxygenation. Allosteric effectors were introduced in the RBCs by electroporation. Inositol hexaphosphate (IHP) and 5-hydroxymethyl-2-furfural (5HMF) were used to decrease and increase Hb-O(2) affinity. In vitro P50s (partial pressure of O(2) at 50% Hb saturation) were modified to 10, 25, 45, and 50 mm Hg (normal P50 is 32 mm Hg). Allosteric effectors also decreased the Hill coefficient. Anemic condition was induced by isovolemic hemodilution exchanges using 6% dextran 70 kD to 18% hematocrit (Hct). Modified RBCs (at 18% Hct in 5% albumin solution) were infused by exchange transfusion of 35% of blood volume. Systemic parameters, microvascular perfusion, capillary perfusion (functional capillary density, FCD), and microvascular Po(2) levels were measured. RBcs with P50 of 45 mm Hg increased tissue Po(2) and decreased O(2) delivery (Do(2)) and extraction (Vo(2)) and RBCs with P50 of 60 mmHg reduced FCD, microvascular flow, tissue Po(2), Do(2) and Vo(2). Erythrocytes with increased Hb-O(2) affinity maintained hemodynamic conditions, Do(2) and decreased tissue Po(2). This study shows that in an anemic condition, maximal tissue Po(2) does not correspond to maximal Do(2) and Vo(2).

  10. The pyridoindole antioxidant stobadine inhibited glycation-induced absorbance and fluorescence changes in albumin.

    PubMed

    Stefek, M; Drozdikova, I; Vajdova, K

    1996-03-01

    We studied the effect of the pyridoindole antioxidant stobadine on glycation-induced absorbance and fluorescence changes in bovine serum albumin (BSA), used as a model protein. Incubation of BSA (4 mg/ml) with glucose (100-400 mM) in 0.12 M phosphate buffer, pH 7.4, in the presence of 100 microM Cu2+ at 37 degrees C resulted in a time-dependent increase of absorbance (320 nm) and fluorescence (excitation 350 nm, emission 415 nm). The process was found to be dependent on the presence of oxygen and transition metal ions, but equimolar iron could not fully substitute for the activity of copper. The glucose-induced chromo- and fluorophore formation was reduced significantly by stobadine. For 200 mM glucose, in 7- and 14-day incubations, 51%-60% inhibition was obtained at a stobadine concentration of 0.1 mM, and the effect leveled off at higher concentrations of the drug. No inhibition was observed with N-acetyl stobadine, a derivative with restricted antioxidant activity. Since stobadine did not affect the Amadori product formation determined by the thiobarbituric acid (TBA) method as 5-hydroxymethyl furfural (5-HMF) released in boiling oxalic acid, the inhibitory action of stobadine may be explained by its interference with metal-catalyzed oxidation reactions following after the glycation step. The results obtained suggest that antioxidant therapy could be used to limit the damage from adverse glycation-induced processes in diabetes mellitus.

  11. Identification of a Small Molecule that Increases Hemoglobin Oxygen Affinity and Reduces SS Erythrocyte Sickling

    PubMed Central

    2015-01-01

    Small molecules that increase the oxygen affinity of human hemoglobin may reduce sickling of red blood cells in patients with sickle cell disease. We screened 38 700 compounds using small molecule microarrays and identified 427 molecules that bind to hemoglobin. We developed a high-throughput assay for evaluating the ability of the 427 small molecules to modulate the oxygen affinity of hemoglobin. We identified a novel allosteric effector of hemoglobin, di(5-(2,3-dihydro-1,4-benzodioxin-2-yl)-4H-1,2,4-triazol-3-yl)disulfide (TD-1). TD-1 induced a greater increase in oxygen affinity of human hemoglobin in solution and in red blood cells than did 5-hydroxymethyl-2-furfural (5-HMF), N-ethylmaleimide (NEM), or diformamidine disulfide. The three-dimensional structure of hemoglobin complexed with TD-1 revealed that monomeric units of TD-1 bound covalently to β-Cys93 and β-Cys112, as well as noncovalently to the central water cavity of the hemoglobin tetramer. The binding of TD-1 to hemoglobin stabilized the relaxed state (R3-state) of hemoglobin. TD-1 increased the oxygen affinity of sickle hemoglobin and inhibited in vitro hypoxia-induced sickling of red blood cells in patients with sickle cell disease without causing hemolysis. Our study indicates that TD-1 represents a novel lead molecule for the treatment of patients with sickle cell disease. PMID:25061917

  12. Kinetic study of the thermal hydrolysis of Agave salmiana for mezcal production.

    PubMed

    Garcia-Soto, M J; Jimenez-Islas, H; Navarrete-Bolanos, J L; Rico-Martinez, R; Miranda-Lopez, R; Botello-Alvarez, J E

    2011-07-13

    The kinetics of the thermal hydrolysis of the fructans of Agave salmiana were determined during the cooking step of mezcal production in a pilot autoclave. Thermal hydrolysis was achieved at different temperatures and cooking times, ranging from 96 to 116 °C and from 20 to 80 h. A simple kinetic model of the depolymerization of fructans to monomers and other reducing sugars and of the degradation of reducing sugars to furans [principally 5-(hydroxymethyl)furfural, HMF] was developed. From this model, the rate constants of the reactions were calculated, as well as the pre-exponential factors and activation energies of the Arrhenius equation. The model was found to fit the experimental data well. The tradeoff between a maximum fructan hydrolysis and a critical furan concentration in allowing for the best ethanol yield during fermentation was investigated. The results indicated that the thermal hydrolysis of agave was optimal, from the point of view of ethanol yield in the ensuing fermentation, in the temperature range of 106-116 °C and the cooking range time of 6-14 h. The optimal conditions corresponded to a fructan hydrolysis of 80%, producing syrups with furan and reducing sugar concentrations of 1 ± 0.1 and 110 ± 10 g/L, respectively.

  13. Hydrothermal Syntheses of Colloidal Carbon Spheres from Cyclodextrins

    SciTech Connect

    Shin, Yongsoon; Wang, Li Q.; Bae, In-Tae; Arey, Bruce W.; Exarhos, Gregory J.

    2008-09-18

    Colloidal carbon spheres have been prepared from aqueous alpha-, beta-, and gamma-cyclodextrin (CD) solutions in closed systems under hydrothermal conditions at 160 oC. Both liquid and solid-state 13C NMR spectra taken for samples at different reaction times have been used to monitor the dehydration and carbonization pathways. CD slowly hydrolyzes to glucose and forms 5-hydroxymethyl furfural (HMF) followed by carbonization into colloidal carbon spheres. The isolated carbon spheres are 70-150 nm in diameter, exhibit a core-shell structure, and are comprised of a condensed core (C=C) peppered with resident chemical functionalities including carboxylate and hydroxyl groups. Evidence from 13C solid-state NMR and FT-IR spectra reveal that the evolving carbon spheres show a gradual increase in the amount of aromatic carbon as a function of reaction time and that the carbon spheres generated from gamma-CD contain significantly higher aromatic carbon than those derived from alpha- and beta-CD.

  14. [Simultaneous determination of 11 constituents in Citrus reticulate 'Chachi' by high performance liquid chromatography].

    PubMed

    Ye, Xiaolan; Song, Fenyun; Fan, Guorong; Wu, Fuhai

    2015-04-01

    An HPLC method was developed for the simultaneous determination of 11 constituents, 5-hydroxymethyl furfural (5-HMF), vicenin-2, hesperidin, hesperetin, isosinensetin, sinensetin, tetramethyl-O-isoscutellarein (TEOS), nobiletin, 3, 5, 6, 7, 8, 3', 4'-heptamethoxy- flavone (HEPTA), tangeretin, 5-demethylnobiletin in Citrus reticulate 'Chachi'. The separation was conducted on a Hanbon Benatach C18 column (250 mm x 4.6 mm, 5 µm) with acetonitrile and 0.2% formic acid as mobile phases with gradient elution. The flow rate was 1.0 mL/min. The detection wavelength was 280 nm. The column temperature was 25 °C. The results showed that the correlation coefficients (r) between concentration and chromatographic peak area of the 11 constituents were over 0.998 in the selected linear ranges. The limits of detection (LODs, S/N = 3) and limits of quantification (LOQs, S/N = 10) of the 11 constituents were in the range of 0.0125-1.25 mg/L and 0.0502-4.99 mg/L, respectively. The average recoveries (n = 3) of the 11 constituents were in the range of 96.4%-102.4% and the RSDs were 0.25%-4.01%. The developed method has been successfully applied for the analysis of eight samples from different cultivation regions in Guangdong Province. This method is simple, accurate and effective for the simultaneous determination of the 11 components, and suitable for the quality control of Citrus reticulate 'Chachi'.

  15. CEDAR Electrodynamics Thermosphere Ionosphere (ETI) Challenge for Systematic Assessment of Ionosphere/Thermosphere Models: NmF2, hmF2, and Vertical Drift Using Ground-Based Observations

    NASA Technical Reports Server (NTRS)

    Shim, J. S.; Kuznetsova, M.; Rastatter, L.; Hesse, M.; Bilitza, D.; Butala, M.; Codrescu, M.; Emery, B.; Foster, B.; Fuller-Rowell, T.; Huba, J.; Mannucci, A. J.; Pi, X.; Ridley, A.; Scherliess, L.; Schunk, R. W.; Stephens, P.; Thompson, D. C.; Zhu, L.; Anderson, D.; Chau, J. L.; Sojka, J. J.; Rideout, B.

    2011-01-01

    Objective quantification of model performance based on metrics helps us evaluate the current state of space physics modeling capability, address differences among various modeling approaches, and track model improvements over time. The Coupling, Energetics, and Dynamics of Atmospheric Regions (CEDAR) Electrodynamics Thermosphere Ionosphere (ETI) Challenge was initiated in 2009 to assess accuracy of various ionosphere/thermosphere models in reproducing ionosphere and thermosphere parameters. A total of nine events and five physical parameters were selected to compare between model outputs and observations. The nine events included two strong and one moderate geomagnetic storm events from GEM Challenge events and three moderate storms and three quiet periods from the first half of the International Polar Year (IPY) campaign, which lasted for 2 years, from March 2007 to March 2009. The five physical parameters selected were NmF2 and hmF2 from ISRs and LEO satellites such as CHAMP and COSMIC, vertical drifts at Jicamarca, and electron and neutral densities along the track of the CHAMP satellite. For this study, four different metrics and up to 10 models were used. In this paper, we focus on preliminary results of the study using ground-based measurements, which include NmF2 and hmF2 from Incoherent Scatter Radars (ISRs), and vertical drifts at Jicamarca. The results show that the model performance strongly depends on the type of metrics used, and thus no model is ranked top for all used metrics. The analysis further indicates that performance of the model also varies with latitude and geomagnetic activity level.

  16. Microwave-Assisted Selective Hydrogenation of Furfural to Furfuryl Alcohol Employing a Green and Noble Metal-Free Copper Catalyst.

    PubMed

    Romano, Pedro N; de Almeida, João M A R; Carvalho, Yuri; Priecel, Peter; Falabella Sousa-Aguiar, Eduardo; Lopez-Sanchez, Jose A

    2016-12-20

    Green, inexpensive, and robust copper-based heterogeneous catalysts achieve 100 % conversion and 99 % selectivity in the conversion of furfural to furfuryl alcohol when using cyclopentyl-methyl ether as green solvent and microwave reactors at low H2 pressures and mild temperatures. The utilization of pressurized microwave reactors produces a 3-4 fold increase in conversion and an unexpected enhancement in selectivity as compared to the reaction carried out at the same conditions using conventional autoclave reactors. The enhancement in catalytic rate produced by microwave irradiation is temperature dependent. This work highlights that using microwave irradiation in the catalytic hydrogenation of biomass-derived compounds is a very strong tool for biomass upgrade that offers immense potential in a large number of transformations where it could be a determining factor for commercial exploitation.

  17. Two-dimensional character of internal rotation of furfural and other five-member heterocyclic aromatic aldehydes

    NASA Astrophysics Data System (ADS)

    Bataev, Vadim A.; Pupyshev, Vladimir I.; Godunov, Igor A.

    2016-05-01

    The features of nuclear motion corresponding to the rotation of the formyl group (CHO) are studied for the molecules of furfural and some other five-member heterocyclic aromatic aldehydes by the use of MP2/6-311G** quantum chemical approximation. It is demonstrated that the traditional one-dimensional models of internal rotation for the molecules studied have only limited applicability. The reason is the strong kinematic interaction of the rotation of the CHO group and out-of-plane CHO deformation that is realized for the molecules under consideration. The computational procedure based on the two-dimensional approximation is considered for low lying vibrational states as more adequate to the problem.

  18. Catalytic Transfer Hydrogenation of Furfural to Furfuryl Alcohol over Nitrogen-Doped Carbon-Supported Iron Catalysts.

    PubMed

    Li, Jiang; Liu, Jun-Ling; Zhou, Hong-Jun; Fu, Yao

    2016-06-08

    Iron-based heterogeneous catalysts, which were generally prepared by pyrolysis of iron complexes on supports at elevated temperature, were found to be capable of catalyzing the transfer hydrogenation of furfural (FF) to furfuryl alcohol (FFA). The effects of metal precursor, nitrogen precursor, pyrolysis temperature, and support on catalytic performance were examined thoroughly, and a comprehensive study of the reaction parameters was also performed. The highest selectivity of FFA reached 83.0 % with a FF conversion of 91.6 % under the optimal reaction condition. Catalyst characterization suggested that iron cations coordinated by pyridinic nitrogen functionalities were responsible for the enhanced catalytic activity. The iron catalyst could be recycled without significant loss of catalytic activity for five runs, and the destruction of the nitrogen-iron species, the presence of crystallized Fe2 O3 phase, and the pore structure change were the main reasons for catalyst deactivation.

  19. Simultaneous saccharification and cofermentation of lignocellulosic residues from commercial furfural production and corn kernels using different nutrient media

    PubMed Central

    2011-01-01

    Background As the supply of starch grain and sugar cane, currently the main feedstocks for bioethanol production, become limited, lignocelluloses will be sought as alternative materials for bioethanol production. Production of cellulosic ethanol is still cost-inefficient because of the low final ethanol concentration and the addition of nutrients. We report the use of simultaneous saccharification and cofermentation (SSCF) of lignocellulosic residues from commercial furfural production (furfural residue, FR) and corn kernels to compare different nutritional media. The final ethanol concentration, yield, number of live yeast cells, and yeast-cell death ratio were investigated to evaluate the effectiveness of integrating cellulosic and starch ethanol. Results Both the ethanol yield and number of live yeast cells increased with increasing corn-kernel concentration, whereas the yeast-cell death ratio decreased in SSCF of FR and corn kernels. An ethanol concentration of 73.1 g/L at 120 h, which corresponded to a 101.1% ethanol yield based on FR cellulose and corn starch, was obtained in SSCF of 7.5% FR and 14.5% corn kernels with mineral-salt medium. SSCF could simultaneously convert cellulose into ethanol from both corn kernels and FR, and SSCF ethanol yield was similar between the organic and mineral-salt media. Conclusions Starch ethanol promotes cellulosic ethanol by providing important nutrients for fermentative organisms, and in turn cellulosic ethanol promotes starch ethanol by providing cellulosic enzymes that convert the cellulosic polysaccharides in starch materials into additional ethanol. It is feasible to produce ethanol in SSCF of FR and corn kernels with mineral-salt medium. It would be cost-efficient to produce ethanol in SSCF of high concentrations of water-insoluble solids of lignocellulosic materials and corn kernels. Compared with prehydrolysis and fed-batch strategy using lignocellulosic materials, addition of starch hydrolysates to cellulosic

  20. Antioxidant effects of isorhamnetin 3,7-di-O-beta-D-glucopyranoside isolated from mustard leaf (Brassica juncea) in rats with streptozotocin-induced diabetes.

    PubMed

    Yokozawa, Takako; Kim, Hyun Young; Cho, Eun Ju; Choi, Jae Sue; Chung, Hae Young

    2002-09-11

    To investigate the effects of isorhamnetin 3,7-di-O-beta-D-glucopyranoside (isorhamnetin diglucoside), a major flavonoid compound of mustard leaf, on oxidative stress due to diabetes mellitus, in vivo and in vitro studies were carried out. Oral administration of isorhamnetin diglucoside (10 or 20 mg/kg of body weight/day for 10 days) to rats with streptozotocin-induced diabetes significantly reduced serum levels of glucose and 5-(hydroxymethyl)furfural (5-HMF), which is glycosylated with hemoglobin and is an indicator of oxidative stress. After intraperitoneal administration, isorhamnetin diglucoside did not show these activities. In addition, after oral administration, the thiobarbituric acid-reactive substance levels of serum, and liver and kidney mitochondria declined significantly compared with the control group in a dose-dependent manner, whereas after intraperitoneal administration these levels fell only slightly. On the basis of the oral and intraperitoneal results, it was hypothesized that isorhamnetin diglucoside was converted to its metabolite in vivo, and its conversion to its aglycone, isorhamnetin, by beta-glucosidase was confirmed; isorhamnetin acted as an antioxidant. Moreover, it was observed that isorhamnetin diglucoside had no effect on the 1,1-diphenyl-2-picrylhydrazyl radical, whereas isorhamnetin showed a potent antioxidant effect in vitro. In addition, intraperitoneal administration of isorhamnetin reduced serum glucose and 5-HMF levels. Furthermore, lipid peroxidation in blood, liver, and kidney associated with diabetes mellitus declined after the administration of isorhamnetin. These results suggest that isorhamnetin diglucoside is metabolized in vivo by intestinal bacteria to isorhamnetin and that isorhamnetin plays an important role as an antioxidant.

  1. Electronic excitation of furfural as probed by high-resolution vacuum ultraviolet spectroscopy, electron energy loss spectroscopy, and ab initio calculations

    SciTech Connect

    Ferreira da Silva, F.; Lange, E.; Limão-Vieira, P. E-mail: michael.brunger@flinders.edu.au; Jones, N. C.; Hoffmann, S. V.; Hubin-Franskin, M.-J.; Delwiche, J.; Brunger, M. J. E-mail: michael.brunger@flinders.edu.au; and others

    2015-10-14

    The electronic spectroscopy of isolated furfural (2-furaldehyde) in the gas phase has been investigated using high-resolution photoabsorption spectroscopy in the 3.5–10.8 eV energy-range, with absolute cross section measurements derived. Electron energy loss spectra are also measured over a range of kinematical conditions. Those energy loss spectra are used to derive differential cross sections and in turn generalised oscillator strengths. These experiments are supported by ab initio calculations in order to assign the excited states of the neutral molecule. The good agreement between the theoretical results and the measurements allows us to provide the first quantitative assignment of the electronic state spectroscopy of furfural over an extended energy range.

  2. Tuning the synthesis of platinum-copper nanoparticles with a hollow core and porous shell for the selective hydrogenation of furfural to furfuryl alcohol.

    PubMed

    Huang, Shuangshuang; Yang, Nating; Wang, Shibin; Sun, Yuhan; Zhu, Yan

    2016-08-07

    Pt-Cu nanoparticles constructed with a hollow core and porous shell have been synthesized in which Pt-Cu cages with multiporous outermost shells are formed at the initial stage and then the Pt and Cu atoms in solution continuously fed these hollow-core of cages by passing through the porous tunnels of the outermost shells, finally leading to the formation of hollow structures with different sizes. Furthermore, these hollow-core Pt-Cu nanoparticles are more effective than the solid-core Pt-Cu nanoparticles for the catalytic hydrogenation of furfural toward furfuryl alcohol. The former can achieve almost 100% conversion of furfural with 100% selectivity toward the alcohol.

  3. Electronic excitation of furfural as probed by high-resolution vacuum ultraviolet spectroscopy, electron energy loss spectroscopy, and ab initio calculations.

    PubMed

    Ferreira da Silva, F; Lange, E; Limão-Vieira, P; Jones, N C; Hoffmann, S V; Hubin-Franskin, M-J; Delwiche, J; Brunger, M J; Neves, R F C; Lopes, M C A; de Oliveira, E M; da Costa, R F; Varella, M T do N; Bettega, M H F; Blanco, F; García, G; Lima, M A P; Jones, D B

    2015-10-14

    The electronic spectroscopy of isolated furfural (2-furaldehyde) in the gas phase has been investigated using high-resolution photoabsorption spectroscopy in the 3.5-10.8 eV energy-range, with absolute cross section measurements derived. Electron energy loss spectra are also measured over a range of kinematical conditions. Those energy loss spectra are used to derive differential cross sections and in turn generalised oscillator strengths. These experiments are supported by ab initio calculations in order to assign the excited states of the neutral molecule. The good agreement between the theoretical results and the measurements allows us to provide the first quantitative assignment of the electronic state spectroscopy of furfural over an extended energy range.

  4. Pityriarubins, novel highly selective inhibitors of respiratory burst from cultures of the yeast Malassezia furfur: comparison with the bisindolylmaleimide arcyriarubin A.

    PubMed

    Krämer, Hans-Joachim; Kessler, Dino; Hipler, Ute-Christina; Irlinger, Bernhard; Hort, Wiebke; Bödeker, Rolf-Hasso; Steglich, Wolfgang; Mayser, Peter

    2005-12-01

    Pityriasis versicolor is the most common skin mycosis in humans worldwide. Yeasts of the genus Malassezia, particularly M. furfur, a saprophyte occurring widely on human skin, are generally regarded as the causative agents. M. furfur is able to convert tryptophan into a variety of indole alkaloids, some of them showing biological properties that correlate well with certain clinical features of pityriasis versicolor. This suggests a possible role for these compounds in the pathophysiology of the disease. We here report that the novel pityriarubins A, B and C, isolated from cultures of the yeast, inhibit respiratory burst in human neutrophils, activated by various agents, in a highly selective, unexpected manner. The release of 5-lipoxygenase products after challenge of neutrophils with the calcium ionophore A23187 is also inhibited in a dose-dependent manner. These activities reflect the close structural relationship of pityriarubins to bisindolylmaleimides, which have recently gained great interest as protein kinase inhibitors.

  5. A one-pot method for the selective conversion of hemicellulose from crop waste into C5 sugars and furfural by using solid acid catalysts.

    PubMed

    Sahu, Ramakanta; Dhepe, Paresh Laxmikant

    2012-04-01

    We present a solid-acid catalyzed one-pot method for the selective conversion of solid hemicellulose without its separation from other lignocellulosic components, such as cellulose and lignin. The reactions were carried out in aqueous and biphasic media to yield xylose, arabinose, and furfural. To overcome the drawbacks posed by mineral acid methods in converting hemicelllulose, we used heterogeneous catalysts that work at neutral pH. In a batch reactor, these heterogeneous catalysts, such as solid acids (zeolites, clays, metal oxides etc.), resulted in >90 % conversion of hemicellulose. It has been shown that the selectivity for the products can be tuned by changing the reaction conditions, for example, a reaction carried out in water at 170 °C for 1 h with HBeta (Si/Al=19) and HUSY (Si/Al=15) catalysts gave yields of 62 and 56 % for xylose and arabinose, respectively. With increased reaction time (6 h) and in presence of only water, HUSY resulted in yields of 30 % xylose + arabinose and 18 % furfural. However, in a biphasic reaction system (water + p-xylene, 170 °C, 6 h) yields of 56 % furfural with 17 % xylose+arabinose could be achieved. It was shown that with the addition of organic solvent the furfural yield could be increased from 18 to 56 %. Under optimized reaction conditions, >90 % carbon balance was observed. The study revealed that catalysts were recyclable with a 20 % drop in activity for each subsequent run. It was observed that temperature, pressure, reaction time, substrate to catalyst ratio, solvent, and so forth had an effect on product formation. The catalysts were characterized by means of X-ray diffraction, temperature-programmed desorption of NH(3), inductively coupled plasma spectroscopy, elemental analysis, and solid-state NMR ((29)Si, (27)Al) spectroscopy techniques.

  6. Effects of van der Waals density functional corrections on trends in furfural adsorption and hydrogenation on close-packed transition metal surfaces

    NASA Astrophysics Data System (ADS)

    Liu, Bin; Cheng, Lei; Curtiss, Larry; Greeley, Jeffrey

    2014-04-01

    The hydrogenation of furfural to furfuryl alcohol on Pd(111), Cu(111) and Pt(111) is studied with both standard Density Functional Theory (DFT)-GGA functionals and with van der Waals-corrected density functionals. VdW-DF functionals, including optPBE, optB88, optB86b, and Grimme's method, are used to optimize the adsorption configurations of furfural, furfuryl alcohol, and related intermediates resulting from hydrogenation of furfural, and the results are compared to corresponding values determined with GGA functionals, including PW91 and PBE. On Pd(111) and Pt(111), the adsorption geometries of the intermediates are not noticeably different between the two classes of functionals, while on Cu(111), modest changes are seen in both the perpendicular distance and the orientation of the aromatic ring with respect to the planar surface. In general, the binding energies increase substantially in magnitude as a result of van der Waals contributions on all metals. In contrast, however, dispersion effects on the kinetics of hydrogenation are relatively small. It is found that activation barriers are not significantly affected by the inclusion of dispersion effects, and a Brønsted-Evans-Polanyi relationship developed solely from PW91 calculations on Pd(111) is capable of describing corresponding results on Cu(111) and Pt(111), even when the dispersion effects are included. Finally, the reaction energies and barriers derived from the dispersion-corrected and pure GGA calculations are used to plot simple potential energy profiles for furfural hydrogenation to furfuryl alcohol on the three considered metals, and an approximately constant downshift of the energetics due to the dispersion corrections is observed.

  7. Effects of van der Waals Density Functional Corrections on Trends in Furfural Adsorption and Hydrogenation on Close-Packed Transition Metal Surfaces

    SciTech Connect

    Liu, Bin; Cheng, Lei; Curtiss, Larry A.; Greeley, Jeffrey P.

    2014-04-01

    The hydrogenation of furfural to furfuryl alcohol on Pd(111), Cu(111) and Pt(111) is studied with both standard Density Functional Theory (DFT)-GGA functionals and with van der Waals-corrected density functionals. VdWDF functionals, including optPBE, optB88, optB86b, and Grimme's method, are used to optimize the adsorption configurations of furfural, furfuryl alcohol, and related intermediates resulting from hydrogenation of furfural, and the results are compared to corresponding values determined with GGA functionals, including PW91 and PBE. On Pd(111) and Pt(111), the adsorption geometries of the intermediates are not noticeably different between the two classes of functionals, while on Cu(111), modest changes are seen in both the erpendicular distance and the orientation of the aromatic ringwith respect to the planar surface. In general, the binding energies increase substantially in magnitude as a result of van derWaals contributions on all metals. In contrast, however, dispersion effects on the kinetics of hydrogenation are relatively small. It is found that activation barriers are not significantly affected by the inclusion of dispersion effects, and a Brønsted–Evans–Polanyi relationship developed solely fromPW91 calculations on Pd(111) is capable of describing corresponding results on Cu(111) and Pt(111), even when the dispersion effects are included. Finally, the reaction energies and barriers derived from the dispersion-corrected and pure GGA calculations are used to plot simple potential energy profiles for furfural hydrogenation to furfuryl alcohol on the three considered metals, and an approximately constant downshift of the energetics due to the dispersion corrections is observed.

  8. First-principles quantum mechanical investigations: Catalytic reactions of furfural on Pd(111) and at the water/Pd(111) interface

    NASA Astrophysics Data System (ADS)

    Xue, Wenhua

    Bio-oils have drawn more and more attention from scientists as a promising new clean, cheap energy source. One of the most interesting relevant issues is the effect of catalysts on the catalytic reactions that are used for producing bio-oils. Furfural, as a very important intermediate during these reactions, has attracted significant studies. However, the effect of catalysts, including particularly the liquid/solid interface formed by a metal catalyst and liquid water, in the catalytic reactions involving furfural still remains elusive. In this research, we performed ab initio molecular dynamics simulations and first-principles density-functional theory calculations to investigate the atomic-scale mechanisms of catalytic hydrogenation of furfural on the palladium surface and at the liquid/state interface formed by the palladium surface and liquid water. We studied all the possible mechanisms that lead to formation of furfuryl alcohol (FOL), formation of tetrahydrofurfural (THFAL), and formation of tetrahydrofurfurfuryl alcohol (THFOL). We found that liquid water plays a significant role in the hydrogenation reactions. During the reaction in the presence of water and the palladium catalyst, in particular, water directly participates in the hydrogenation of the aldehyde group of furfural and facilitates the formation of FOL by reducing the activation energy. Our calculations show that water provides hydrogen for the hydrogenation of the aldehyde group, and at the same time, a pre-existing hydrogen atom, which is resulted from dissociation of molecular hydrogen (experimentally, molecular hydrogen is always supplied for hydrogenation) on the palladium surface, is bonded to water, making the water molecule intact in structure. In the absence of water, on the other hand, formation of FOL and THFAL on the palladium surface involves almost the same energy barriers, suggesting a comparable selectivity. Overall, as water reduces the activation energy for the formation of FOL

  9. Kinetic features of xylan de-polymerization in production of xylose monomer and furfural during acid pretreatment for kenaf, forage sorghums and sunn hemp feedstocks

    SciTech Connect

    Kamireddy, Srinivas Reddy; Kozliak, Evguenii I.; Tucker, Melvin; Ji, Yun

    2014-08-01

    A kinetic study of acid pretreatment was conducted for sorghum non-brown mid rib (SNBMR) (Sorghum bicolor L Moench), sorghum-brown mid rib (SBMR), sunn hemp (Crotalaria juncea L) and kenaf (Gossypiumhirsutum L), focusing on rates of xylose monomer and furfural formation. The kinetics was investigated using two independent variables, reaction temperature (150 and 160°C) and acid concentration (1 and 2 wt%), with a constant dry biomass loading of 10 wt% and a treatment time up to 20 min while sampling the mixture every 2 min. The experimental data were fitted using a two-step kinetic model based on irreversible pseudo first order kinetics at each step. Varied kinetic orders on the acid concentration, ranging from 0.2 to >3, were observed for both xylose and furfural formation, the values depending on the feedstock. The crystallinity index of raw biomass was shown to be a major factor influencing the rate of both xylose and furfural formation. As a result, a positive correlation was observed between the activation energy and biomass crystallinity index for xylose formation.

  10. Optimization of a Dynamic Headspace-Thermal Desorption-Gas Chromatography/Mass Spectrometry procedure for the determination of furfurals in vinegars.

    PubMed

    Manzini, Simona; Durante, Caterina; Baschieri, Carlo; Cocchi, Marina; Sighinolfi, Simona; Totaro, Sara; Marchetti, Andrea

    2011-08-15

    The use of a Dynamic Headspace System (DHS) device combined with a Thermal Desorption Unit (TDU) interfaced to a Gas Chromatography/Mass Spectrometry (GC/MS) system is proposed for the determination of furfurals in oenological products. An experimental design protocol has been employed for the optimization of the instrumental settings concerning DHS and TDU extraction and desorption steps. It has been possible to individuate the following optimized conditions: incubation temperature 40°C, purge volume 800 mL, dry volume 1500 mL, TDU hold time 5 min and incubation time 10 min. The performance of two different SPE sorbents, namely Tenax TA and Tenax GR used for the furfurals trapping, was investigated too. The developed DHS sampling procedure showed good reproducibility values with a RSD% lower than 10% for all the monitored species. The optimized experimental settings have been used to determine furfurals in several vinegar samples obtained by traditional procedure starting from cooked grape musts, i.e. in Aceto Balsamico Tradizionale di Modena (ABTM). In fact, the control of these species is extremely important for quality and safety issues.

  11. Kinetic features of xylan de-polymerization in production of xylose monomer and furfural during acid pretreatment for kenaf, forage sorghums and sunn hemp feedstocks

    DOE PAGES

    Kamireddy, Srinivas Reddy; Kozliak, Evguenii I.; Tucker, Melvin; ...

    2014-08-01

    A kinetic study of acid pretreatment was conducted for sorghum non-brown mid rib (SNBMR) (Sorghum bicolor L Moench), sorghum-brown mid rib (SBMR), sunn hemp (Crotalaria juncea L) and kenaf (Gossypiumhirsutum L), focusing on rates of xylose monomer and furfural formation. The kinetics was investigated using two independent variables, reaction temperature (150 and 160°C) and acid concentration (1 and 2 wt%), with a constant dry biomass loading of 10 wt% and a treatment time up to 20 min while sampling the mixture every 2 min. The experimental data were fitted using a two-step kinetic model based on irreversible pseudo first ordermore » kinetics at each step. Varied kinetic orders on the acid concentration, ranging from 0.2 to >3, were observed for both xylose and furfural formation, the values depending on the feedstock. The crystallinity index of raw biomass was shown to be a major factor influencing the rate of both xylose and furfural formation. As a result, a positive correlation was observed between the activation energy and biomass crystallinity index for xylose formation.« less

  12. Effects of AV119, a natural sugar from avocado, on Malassezia furfur invasiveness and on the expression of HBD-2 and cytokines in human keratinocytes.

    PubMed

    Donnarumma, Giovanna; Buommino, Elisabetta; Baroni, Adone; Auricchio, Lucia; De Filippis, Anna; Cozza, Valentina; Msika, Philippe; Piccardi, Nathalie; Tufano, Maria Antonietta

    2007-11-01

    AV119 is a patented blend of two sugars from avocado that can induce human beta-defensin-2 production by normal human keratinocytes. In this study, we analysed the effect of AV119 on growth and invasiveness of Malassezia furfur, a dimorphic, lipid-dependent yeast that is part of the normal human cutaneous commensal flora. The ability to modulate the expression of the proinflammatory and immunomodulatory cytokines in normal human keratinocytes was also investigated. Microbiological assay demonstrated that this sugar induced the aggregation of yeast cells and inhibited the invasiveness of M. furfur, without affecting its growth. Real-time PCR analysis demonstrated that AV119 was able to modulate the HBD-2 response in treated keratinocytes, reaching a maximum after 48-h treatment, and to induce the recovery of a satisfactory proinflammatory response in human keratinocytes. As AV119 can induce aggregation of yeast cells, thus inhibiting their penetration into the keratinocytes, the sugar could be used in the preparation of cosmetics or pharmacological drugs to inhibit colonization of the skin by pathogenic strains of M. furfur.

  13. Changes of NmF2 and hmF2 over Biak (1°S, 136°E) during total solar eclipse on March 9, 2016

    NASA Astrophysics Data System (ADS)

    Anggarani, Sefria; Asnawi, Jiyo; Dear, Varuliantor; Ekawati, Sri

    2016-11-01

    Ionospheric responses to solar eclipse is interesting to learn. In this paper, we presented ionspheric F2 responses to total solar eclipse on March 9, 2016 over Indonesia from Biak station (-1 ° 136.0 °) which is within the obscuration 86.55%. The total solar eclipse over Biak occurred at 00:58 UT (09:58 local time) in F2 layer height of ionosphere (h ≈ 300 km). Observation of the ionospheric F2 over Biak during the total solar eclipse investigated using ionosonde with 15 minutes resolution. Ionization and recombination processes that occur in the ionosphere proceed by solar radiation. At the time of the ionosphere receives solar radiation, ionization process dominated in the F2 layer. Diurnal ionosphere parameters changed following the solar radiation. During the solar eclipse, the process of ionization in the F2 layer disturbed. Total solar eclipse on March 9, 2016 affected almost simultaneous decrease in maximum electron density (NmF2) ∼52% and increase hmF2 ∼24% at the elapsed time of totality observed from Biak Station.

  14. N-(furfural) chitosan hydrogels based on Diels-Alder cycloadditions and application as microspheres for controlled drug release.

    PubMed

    Montiel-Herrera, Marcelino; Gandini, Alessandro; Goycoolea, Francisco M; Jacobsen, Neil E; Lizardi-Mendoza, Jaime; Recillas-Mota, Maricarmen; Argüelles-Monal, Waldo M

    2015-09-05

    In this study, chitosan was chemically modified by reductive amination in a two-step process. The synthesis of N-(furfural) chitosan (FC) was confirmed by FT-IR and (1)H NMR analysis, and the degrees of substitution were estimated as 8.3 and 23.8%. The cross-linkable system of bismaleimide (BM) and FC shows that FC shared properties of furan-maleimide chemistry. This system produced non-reversible hydrogel networks by Diels-Alder cycloadditions at 85 °C. The system composed of BM and FC (23.8% substitution) generated stronger hydrogel networks than those of FC with an 8.3% degree of substitution. Moreover, the FC-BM system was able to produce hydrogel microspheres. Environmental scanning electron microscopy revealed the surface of the microspheres to be non-porous with small protuberances. In water, the microspheres swelled, increasing their volume by 30%. Finally, microspheres loaded with methylene blue were able to release the dye gradually, obeying second-order kinetics for times less than 600 min. This behavior suggests that diffusion is governed by the relaxation of polymer chains in the swelled state, thus facilitating drug release outside the microspheres.

  15. Pityriacitrin--a potent UV filter produced by Malassezia furfur and its effect on human skin microflora.

    PubMed

    Machowinski, Angelika; Krämer, Hans-Joachim; Hort, Wiebke; Mayser, Peter

    2006-09-01

    In Malassezia furfur, tryptophan as the main nitrogen source induces production of the potent ultraviolet-absorbing indole compound pityriacitrin. An in vitro study about the effects of pityriacitrin on other human skin microorganisms is presented, with special focus on Candida albicans and staphylococci in which its toxicity and UV-protective capacity were investigated. Candida albicans was irradiated with UVB light either in the presence or in the absence of pityriacitrin (11 mmol) and the growth rate was determined. A UVB dose of 1 J cm(-2) caused death of the fungi without pityriacitrin, whereas those in the presence of pityriacitrin showed almost unaffected growth. A diffusion test in staphylococci revealed no antibiotic effects of pityriacitrin. For testing of an ultraviolet-protective effect, staphylococci were either inoculated and irradiated in a plate model for visual assessment of growth or inoculated and irradiated in square quartz cylinders for quantitative measurement of cell density, each time in the absence or presence of pityriacitrin. Cell density of the bacterial suspensions exhibited nearly no influence of pityriacitrin on growth rates, while again a UV-protective effect was observed. In summary, pityriacitrin has an ultraviolet-protective effect on Candida albicans and staphylococci with no toxicity in the range tested.

  16. Protein engineering of GRE2 from Saccharomyces cerevisiae for enhanced detoxification of 5-hydroxymethylfurfural

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Furfural and 5-hydroxymethylfurfural (HMF) are representative inhibitors generated by lignocellulosic biomass pretreatment such as dilute acid hydrolysis that inhibit microbial growth and interfere with subsequent fermentation. It is possible to in situ detoxify these inhibitory compounds using tole...

  17. A Novel NADPH-Dependent Aldehyde Reductase Gene from Saccharomyces cerevisiae NRRL Y-12632 Involved in the Detoxification of Aldehyde Inhibitors Derived from Lignocellulosic Biomass Conversion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aldehyde inhibitors such as furfural, 5-hydroxymethylfurfural (HMF), anisaldehyde, benzaldehyde, cinnamaldehyde, and phenylaldehyde are commonly generated during lignocellulosic biomass conversion process for low-cost cellulosic ethanol production that interferes with subsequent microbial growth and...

  18. Evolutionarily Engineered Ethanologenic Yeast Detoxifies Lignocellulosic Biomass Conversion Inhibitors by Reprogrammed Pathways

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lignocellulosic biomass conversion inhibitors furfural and HMF inhibit microbial growth and interfere with subsequent fermentation of ethanol, posing significant challenges for a sustainable cellulosic ethanol conversion industry. Numerous yeast genes were found to be associated with the inhibitor ...

  19. Protein Engineering of GRE2 from Saccharomyces cerevisiae for Enhanced Detoxification of 5-hydroxymethylfurfural

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Furfural and 5-hydroxymethylfurfural (HMF) are representative inhibitors generated by lignocellulosic biomass pretreatment such as dilute acid hydrolysis that inhibit microbial growth and subsequent fermentation. It is possible to in situ detoxify these inhibitory compounds using tolerant Saccharom...

  20. Production of levulinic acid, furfural, and gamma valerolactone from C.sub.5 and C.sub.6 carbohydrates in mono- and biphasic systems using gamma-valerolactone as a solvent

    DOEpatents

    Dumesic, James A.; Alonso, David Martin; Gurbuz, Elif I.; Wettstein, Stephanie G.

    2013-03-19

    A method to make levulinic acid (LA), furfural, or gamma-valerolactone (GVL). React cellulose (and/or other C.sub.6 carbohydrates) or xylose (and/or other C.sub.5 carbohydrates) or combinations thereof in a monophasic reaction medium comprising GVL and an acid; or (ii) a biphasic reaction system comprising an organic layer comprising GVL, and a substantially immiscible aqueous layer. At least a portion of the cellulose (and/or other C.sub.6 carbohydrates), if present, is converted to LA and at least a portion of the xylose (and/or other C.sub.5 carbohydrates), if present, is converted into furfural.

  1. Effects of particulate matter exposure on blood 5-hydroxymethylation: results from the Beijing truck driver air pollution study.

    PubMed

    Sanchez-Guerra, Marco; Zheng, Yinan; Osorio-Yanez, Citlalli; Zhong, Jia; Chervona, Yana; Wang, Sheng; Chang, Dou; McCracken, John P; Díaz, Anaite; Bertazzi, Pier Alberto; Koutrakis, Petros; Kang, Choong-Min; Zhang, Xiao; Zhang, Wei; Byun, Hyang-Min; Schwartz, Joel; Hou, Lifang; Baccarelli, Andrea A

    2015-01-01

    Previous studies have reported epigenetic changes induced by environmental exposures. However, previous investigations did not distinguish 5-methylcytosine (5mC) from a similar oxidative form with opposite functions, 5-hydroxymethylcytosine (5hmC). Here, we measured blood DNA global 5mC and 5hmC by ELISA and used adjusted mixed-effects regression models to evaluate the effects of ambient PM10 and personal PM2.5 and its elemental components-black carbon (BC), aluminum (Al), calcium (Ca), potassium (K), iron (Fe), sulfur (S), silicon (Si), titanium (Ti), and zinc (Zn)-on blood global 5mC and 5hmC levels. The study was conducted in 60 truck drivers and 60 office workers in Beijing, China from The Beijing Truck Driver Air Pollution Study at 2 exams separated by one to 2 weeks. Blood 5hmC level (0.08%) was ∼83-fold lower than 5mC (6.61%). An inter-quartile range (IQR) increase in same-day PM10 was associated with increases in 5hmC of 26.1% in office workers (P = 0.004), 20.2% in truck drivers (P = 0.014), and 21.9% in all participants combined (P < 0.001). PM10 effects on 5hmC were increasingly stronger when averaged over 4, 7, and 14 d preceding assessment (up to 132.6% for the 14-d average in all participants, P < 0.001). PM10 effects were also significant after controlling for multiple testing (family-wise error rate; FWER < 0.05). 5hmC was not correlated with personal measures of PM2.5 and elemental components (FWER > 0.05). 5mC showed no correlations with PM10, PM2.5, and elemental components measures (FWER > 0.05). Our study suggests that exposure to ambient PM10 affects 5hmC over time, but not 5mC. This finding demonstrates the need to differentiate 5hmC and 5mC in environmental studies of DNA methylation.

  2. Effects of particulate matter exposure on blood 5-hydroxymethylation: results from the Beijing truck driver air pollution study

    PubMed Central

    Sanchez-Guerra, Marco; Zheng, Yinan; Osorio-Yanez, Citlalli; Zhong, Jia; Chervona, Yana; Wang, Sheng; Chang, Dou; McCracken, John P; Díaz, Anaite; Bertazzi, Pier Alberto; Koutrakis, Petros; Kang, Choong-Min; Zhang, Xiao; Zhang, Wei; Byun, Hyang-Min; Schwartz, Joel; Hou, Lifang; Baccarelli, Andrea A

    2015-01-01

    Previous studies have reported epigenetic changes induced by environmental exposures. However, previous investigations did not distinguish 5-methylcytosine (5mC) from a similar oxidative form with opposite functions, 5-hydroxymethylcytosine (5hmC). Here, we measured blood DNA global 5mC and 5hmC by ELISA and used adjusted mixed-effects regression models to evaluate the effects of ambient PM10 and personal PM2.5 and its elemental components—black carbon (BC), aluminum (Al), calcium (Ca), potassium (K), iron (Fe), sulfur (S), silicon (Si), titanium (Ti), and zinc (Zn)—on blood global 5mC and 5hmC levels. The study was conducted in 60 truck drivers and 60 office workers in Beijing, China from The Beijing Truck Driver Air Pollution Study at 2 exams separated by one to 2 weeks. Blood 5hmC level (0.08%) was ∼83-fold lower than 5mC (6.61%). An inter-quartile range (IQR) increase in same-day PM10 was associated with increases in 5hmC of 26.1% in office workers (P = 0.004), 20.2% in truck drivers (P = 0.014), and 21.9% in all participants combined (P < 0.001). PM10 effects on 5hmC were increasingly stronger when averaged over 4, 7, and 14 d preceding assessment (up to 132.6% for the 14-d average in all participants, P < 0.001). PM10 effects were also significant after controlling for multiple testing (family-wise error rate; FWER < 0.05). 5hmC was not correlated with personal measures of PM2.5 and elemental components (FWER > 0.05). 5mC showed no correlations with PM10, PM2.5, and elemental components measures (FWER > 0.05). Our study suggests that exposure to ambient PM10 affects 5hmC over time, but not 5mC. This finding demonstrates the need to differentiate 5hmC and 5mC in environmental studies of DNA methylation. PMID:25970091

  3. Novel Preparation of Nano-Composite CuO-Cr2O3 Using Ctab-Template Method and Efficient for Hydrogenation of Biomass-Derived Furfural

    NASA Astrophysics Data System (ADS)

    Yan, Kai; Wu, Xu; An, Xia; Xie, Xianmei

    2013-02-01

    A simple route to fabricate nano-composite oxides CuO-Cr2O3 using hexadecyltrimethylammonium bromide (CTAB)-templated Cu-Cr hydrotalcite as the precursor is presented. This novel method is based on CTAB-templating effect for mesostructure directing and using the cheap metal nitrate, followed by removal of CTAB. It was indicated that the nano-composite CuO-Cr2O3 was formed during the removal of CTAB. X-ray diffraction (XRD) and transitional electronic microscopy (TEM) revealed nice nano-composite oxides CuO-Cr2O3 were formed with high crystallinity. N2 adsorption and desorption indicated that a high surface area of 170.5 m2/g with a pore size of 2.7 nm of the nano-composite CuO-Cr2O3 was facilely resulted. The as-synthesized nano-composite oxides CuO-Cr2O3 display good catalytic activities for hydrogenation of furfural to furfuryl alcohol, whereas 86% selectivity was achieved at 75% conversion of furfural.

  4. Bacillus sp. strain P38: an efficient producer of L-lactate from cellulosic hydrolysate, with high tolerance for 2-furfural.

    PubMed

    Peng, Lili; Wang, Limin; Che, Chengchuan; Yang, Ge; Yu, Bo; Ma, Yanhe

    2013-12-01

    In this study, efficient polymer-grade L-lactic acid production was achieved with the strain Bacillus sp. P38 by using cellulosic hydrolysate as the sole carbon source. In fed-batch fermentation, 180 g L(-1)L-lactic acid was obtained with a volumetric productivity of 2.4 g L(-1)h(-1) and a yield of 0.96 g g(-1) total reducing sugars. No D-isomer of lactic acid was detected in the broth. Strain P38 tolerated up to 10 g L(-1) 2-furfural, and lactate production was sharply inhibited only when the 2-furfural concentration was higher than 6 g L(-1). Moreover, strain P38 also tolerated high concentrations (>6 g L(-1)) of other fermentation inhibitors in cellulosic hydrolysate, such as vanillin and acetic acid, although it was slightly sensitive to formic acid. The efficient L-lactic acid production, combined with high inhibitor tolerance and efficient pentose utilization, indicate that Bacillus sp. P38 is a promising producer of polymer-grade L-lactic acid from cellulosic biomass.

  5. Metabolomic analysis reveals key metabolites related to the rapid adaptation of Saccharomyce cerevisiae to multiple inhibitors of furfural, acetic acid, and phenol.

    PubMed

    Wang, Xin; Li, Bing-Zhi; Ding, Ming-Zhu; Zhang, Wei-Wen; Yuan, Ying-Jin

    2013-03-01

    During hydrolysis of lignocellulosic biomass, a broad range of inhibitors are generated, which interfere with yeast growth and bioethanol production. In order to improve the strain tolerance to multiple inhibitors--acetic acid, furfural, and phenol (three representative lignocellulose-derived inhibitors) and uncover the underlying tolerant mechanism, an adaptation experiment was performed in which the industrial Saccharomyces cerevisiae was cultivated repeatedly in a medium containing multiple inhibitors. The adaptation occurred quickly, accompanied with distinct increase in growth rate, glucose utilization rate, furfural metabolism rate, and ethanol yield, only after the first transfer. A similar rapid adaptation was also observed for the lab strains of BY4742 and BY4743. The metabolomic analysis was employed to investigate the responses of the industrial S. cereviaise to three inhibitors during the adaptation. The results showed that higher levels of 2-furoic acid, 2, 3-butanediol, intermediates in glycolytic pathway, and amino acids derived from glycolysis, were discovered in the adapted strains, suggesting that enhanced metabolic activity in these pathways may relate to resistance against inhibitors. Additionally, through single-gene knockouts, several genes related to alanine metabolism, GABA shunt, and glycerol metabolism were verified to be crucial for the resistance to multiple inhibitors. This study provides new insights into the tolerance mechanism against multiple inhibitors, and guides for the improvement of tolerant ethanologenic yeast strains for lignocellulose-bioethanol fermentation.

  6. Antifungal susceptibility of Malassezia furfur, Malassezia sympodialis, and Malassezia globosa to azole drugs and amphotericin B evaluated using a broth microdilution method.

    PubMed

    Rojas, Florencia D; Sosa, María de los A; Fernández, Mariana S; Cattana, María E; Córdoba, Susana B; Giusiano, Gustavo E

    2014-08-01

    We studied the in vitro activity of fluconazole (FCZ), ketoconazole (KTZ), miconazole (MCZ), voriconazole (VCZ), itraconazole (ITZ) and amphotericin B (AMB) against the three major pathogenic Malassezia species, M. globosa, M. sympodialis, and M. furfur. Antifungal susceptibilities were determined using the broth microdilution method in accordance with Clinical and Laboratory Standards Institute reference document M27-A3. To support lipid-dependent yeast development, glucose, peptone, ox bile, malt extract, glycerol, and Tween supplements were added to Roswell Park Memorial Institute RPMI 1640 medium. The supplemented medium allowed good growth of all three species studied. The minimal inhibitory concentrations (MICs) were recorded after 72 h of incubation at 32ºC. The three species showed different susceptibility profiles for the drugs tested. Malassezia sympodialis was the most susceptible and M. furfur the least susceptible species. KTZ, ITZ, and VCZ were the most active drugs, showing low variability among isolates of the same species. FCZ, MCZ, and AMB showed high MICs and wide MIC ranges. Differences observed emphasize the need to accurately identify and evaluate antifungal susceptibility of Malassezia species. Further investigations and collaborative studies are essential for correlating in vitro results with clinical outcomes since the existing limited data do not allow definitive conclusions.

  7. Membrane extraction for detoxification of biomass hydrolysates.

    PubMed

    Grzenia, David L; Schell, Daniel J; Wickramasinghe, S Ranil

    2012-05-01

    Membrane extraction was used for the removal of sulfuric acid, acetic acid, 5-hydroxymethyl furfural and furfural from corn stover hydrolyzed with dilute sulfuric acid. Microporous polypropylene hollow fiber membranes were used. The organic extractant consisted of 15% Alamine 336 in: octanol, a 50:50 mixture of oleyl alcohol:octanol or oleyl alcohol. Rapid removal of sulfuric acid, 5-hydroxymethyl and furfural was observed. The rate of acetic acid removal decreased as the pH of the hydrolysate increased. Regeneration of the organic extractant was achieved by back extraction into an aqueous phase containing NaOH and ethanol. A cleaning protocol consisting of flushing the hydrolysate compartment with NaOH and the organic phase compartment with pure organic phase enabled regeneration and reuse of the module. Ethanol yields from hydrolysates detoxified by membrane extraction using 15% Alamine 336 in oleyl alcohol were about 10% higher than those from hydrolysates detoxified using ammonium hydroxide treatment.

  8. Membrane Extraction for Detoxification of Biomass Hydrolysates

    SciTech Connect

    Grzenia, D. L.; Schell, D. J.; Wickramasinghe, S. R.

    2012-05-01

    Membrane extraction was used for the removal of sulfuric acid, acetic acid, 5-hydroxymethyl furfural and furfural from corn stover hydrolyzed with dilute sulfuric acid. Microporous polypropylene hollow fiber membranes were used. The organic extractant consisted of 15% Alamine 336 in: octanol, a 50:50 mixture of oleyl alcohol:octanol or oleyl alcohol. Rapid removal of sulfuric acid, 5-hydroxymethyl and furfural was observed. The rate of acetic acid removal decreased as the pH of the hydrolysate increased. Regeneration of the organic extractant was achieved by back extraction into an aqueous phase containing NaOH and ethanol. A cleaning protocol consisting of flushing the hydrolysate compartment with NaOH and the organic phase compartment with pure organic phase enabled regeneration and reuse of the module. Ethanol yields from hydrolysates detoxified by membrane extraction using 15% Alamine 336 in oleyl alcohol were about 10% higher than those from hydrolysates detoxified using ammonium hydroxide treatment.

  9. Separation of phenols and furfural by pervaporation and reverse osmosis membranes from biomass--superheated steam pyrolysis-derived aqueous solution.

    PubMed

    Sagehashi, Masaki; Nomura, Tsuyoshi; Shishido, Hiromu; Sakoda, Akiyoshi

    2007-07-01

    The separation of valuable chemicals from raw products, where a great number of chemicals coexist, is the key technology in biomass refinery. In this study, the applicability of membrane separation of valuable chemicals from our currently developed portable superheated steam (SHS) biomass pyrolysis process was demonstrated. Phenols (phenol, p-cresol, guaiacol, methyl guaiacol, and ethyl guaiacol), furfural, and acetone were successfully separated by pervaporation using the silicone rubber membrane from model solutions and an actual SHS derived aqueous solution. The solution was also concentrated effectively by reverse osmosis separation using a polyamide membrane. When a high concentration of SHS solution was fed to the pervaporation process, a phase-separated permeate was obtained, which indicated that the reverse osmosis concentration combined with pervaporation separation is useful for the superheated steam process.

  10. Understanding the Mechanism of the Divergent Reactivity of Non-Heteroatom-Stabilized Chromium Carbene Complexes with Furfural Imines: Formation of Benzofurans and Azetines.

    PubMed

    Funes-Ardoiz, Ignacio; González, Jairo; Santamaría, Javier; Sampedro, Diego

    2016-02-19

    The mechanisms of the reaction between non-heteroatom-stabilized alkynyl chromium carbene complexes prepared in situ and furfural imines to yield benzofurans and/or azetines have been explored by means of density functional theory method calculations. The reaction proceeds through a complex cascade of steps triggered by a nucleophilic addition of the imine nitrogen atom. The formation of two benzofuran regioisomers has been explained in terms of competitive nucleophilic attacks to different positions of the carbene complex. Each of these regioisomers can be obtained as the major product depending on the starting materials. The overall sequence could be controlled to yield benzofurans or azetines by adjusting the substituents present in the initial carbene complex. This mechanistic information allowed for the preparation of new benzofurans and azetinylcarbenes in good yields.

  11. Furanic compounds and furfural in different coffee products by headspace liquid-phase micro-extraction followed by gas chromatography-mass spectrometry: survey and effect of brewing procedures.

    PubMed

    Chaichi, Maryam; Ghasemzadeh-Mohammadi, Vahid; Hashemi, Maryam; Mohammadi, Abdorreza

    2015-01-01

    In this study, the levels of furan, 2-methylfuran, 2,5-dimethylfuran, vinyl furan, 2-methoxymethyl-furan and furfural in different coffee products were evaluated. Simultaneous determination of these six furanic compounds was performed by a head space liquid-phase micro-extraction (HS-LPME) method. A total of 67 coffee powder samples were analysed. The effects of boiling and espresso-making procedures on the levels of furanic compounds were investigated. The results showed that different types of coffee samples contained different concentrations of furanic compounds, due to the various processing conditions such as temperature, degree of roasting and fineness of grind. Among the different coffee samples, the highest level of furan (6320 µg kg⁻¹) was detected in ground coffee, while coffee-mix samples showed the lowest furan concentration (10 µg kg⁻¹). Levels in brewed coffees indicated that, except for furfural, brewing by an espresso machine caused significant loss of furanic compounds.

  12. Influence of Solvent on Liquid Phase Hydrodeoxygenation of Furfural-Acetone Condensation Adduct using Ni/Al2O3-ZrO2 Catalysts

    NASA Astrophysics Data System (ADS)

    Ulfa, S. M.; Mahfud, A.; Nabilah, S.; Rahman, M. F.

    2017-02-01

    Influence of water and acidic protic solvent on hydrodeoxygenation (HDO) of the furfural-acetone adduct (FAA) over Ni/Al2O3-ZrO2 (NiAZ) catalysts were investigated. The HDO of FAA was carried out in a batch reactor at 150°C for 8 hours. The NiAZ catalysts were home-made catalysts which were prepared by wet impregnation method with 10 and 20% nickel loading. The HDO reaction of FAA using 10NiAZ in water at 150°C gave alkane and oxygenated hydrocarbons at 31.41% with selectivity over tridecane (C13) in 6.67%. On the other hand, a reaction using acetic acid:water (1:19 v/v) in similar reaction condition gave only oxygenated compounds and hydrocracking product (C8-C10). The formation of tridecane (C13) was proposed by hydrogenation of C=O and C=C followed by decarboxylation without hydrocracking process. The presence of water facilitated decarboxylation mechanism by stabilized dehydrogenated derivatives of FAA.

  13. Sustainable hydrogen production from bio-oil model compounds (meta-xylene) and mixtures (1-butanol, meta-xylene and furfural).

    PubMed

    Bizkarra, K; Barrio, V L; Arias, P L; Cambra, J F

    2016-09-01

    In the present work m-xylene and an equimolecular mixture of m-xylene, 1-butanol and furfural, all of them bio-oil model compounds, were studied in steam reforming (SR) conditions. Three different nickel catalysts, which showed to be active in 1-butanol SR (Ni/Al2O3, Ni/CeO2-Al2O3 and Ni/La2O3-Al2O3), were tested and compared with thermodynamic equilibrium values. Tests were carried out at temperatures from 800 to 600°C at atmospheric pressure with a steam to carbon ratio (S/C) of 5.0. Despite the different bio-oils fed, the amount of moles going through the catalytic bed was kept constant in order to obtain comparable results. After their use, catalysts were characterized by different techniques and those values were correlated with the activity results. All catalysts were deactivated during the SR of the mixture, mainly by coking. The highest hydrogen yields were obtained with Ni/Al2O3 and Ni/CeO2-Al2O3 catalysts in the SR of m-xylene and SR of the mixture, respectively.

  14. Malassezia furfur folliculitis in cancer patients. The need for interaction of microbiologist, surgical pathologist, and clinician in facilitating identification by the clinical microbiology laboratory.

    PubMed

    Sandin, R L; Fang, T T; Hiemenz, J W; Greene, J N; Card, L; Kalik, A; Szakacs, J E

    1993-01-01

    Malassezia furfur (MF) is a lipophilic yeast which can be found as a member of the indigenous microbiota of human skin. In immunocompromised transplant patients, MF can cause a distinctive folliculitis which is a clinical look-alike to Candida folliculitis, the latter of more potentially devastating significance. Recovery of MF in culture is dependent upon the addition to culture media of an exogenous source of fatty acids, such as olive oil. The addition of an extra Sabourauds plate with an olive oil overlay to the routine set of media used to inoculate all skin biopsy specimens in order to detect MF is labor-intensive and not cost-effective. Thus, MF may not be isolated in cases of MF folliculitis unless the clinical microbiology laboratory is put on alert by the clinical suspicions of the attending physician, or by histopathologic findings suggestive of folliculitis revealed by review of surgical pathology slides. The clinical, pathological, and microbiological findings of two cases of MF folliculitis are presented where an interactive approach featuring communication between the microbiologist, the surgical pathologist, and the clinician guided the microbiology laboratory to the isolation and identification of isolates of MF that were clinically-relevant. These cases underscore how a combined approach which features communication between the laboratory and the clinical services always provides superior guidance in the diagnosis and therapy of infectious diseases.

  15. Selective Production of 2-Methylfuran by Gas-Phase Hydrogenation of Furfural on Copper Incorporated by Complexation in Mesoporous Silica Catalysts.

    PubMed

    Jiménez-Gómez, Carmen Pilar; Cecilia, Juan A; Moreno-Tost, Ramón; Maireles-Torres, Pedro

    2017-04-10

    Copper species have been incorporated in mesoporous silica (MS) through complexation with the amine groups of dodecylamine, which was used as a structure-directing agent in the synthesis. A series of Cu/SiO2 catalysts (xCu-MS) with copper loadings (x) from 2.5 to 20 wt % was synthesized and evaluated in the gas-phase hydrogenation of furfural (FUR). The most suitable catalytic performance in terms of 2-methylfuran yield was obtained with an intermediate copper content (10 wt %). This 10Cu-MS catalyst exhibits a 2-methylfuran yield higher than 95 mol % after 5 h time-on-stream (TOS) at a reaction temperature of 210 °C with a H2 /FUR molar ratio of 11.5 and a weight hourly space velocity (WHSV) of 1.5 h(-1) . After 14 h TOS, this catalyst still showed a yield of 80 mol %. In all cases, carbonaceous deposits on the external surface were the cause of the catalyst deactivation, although sintering of the copper particles was observed for higher copper loadings. This intermediate copper loading (10 wt %) offered a suitable balance between resistance to sintering and tendency to form carbonaceous deposits.

  16. Enhancement of photocatalytic degradation of furfural and acetophenone in water media using nano-TiO2-SiO2 deposited on cementitious materials.

    PubMed

    Soltan, Sahar; Jafari, Hoda; Afshar, Shahrara; Zabihi, Omid

    2016-10-01

    In the present study, silicon dioxide (SiO2) nanoparticles were loaded to titanium dioxide (TiO2) nano-particles by sol-gel method to make a high porosity photocatalyst nano-hybrid. These photocatalysts were synthesized using titanium tetrachloride and tetraethyl orthosilicate as titanium and silicon sources, respectively, and characterized by X-ray powder diffraction (XRD) and scanning electron microscope methods. Subsequently, the optimizations of the component and operation conditions were investigated. Then, nano-sized TiO2 and TiO2-SiO2 were supported on concrete bricks by the dip coating process. The photocatalytic activity of nano photocatalysts under UV irradiation was examined by studying the decomposition of aqueous solutions of furfural and acetophenone (10 mg/L) as model of organic pollutants to CO2 and H2O at room temperature. A decrease in the concentration of these pollutants was assayed by using UV-visible absorption, gas chromatography technique, and chemical oxygen demand. The removal of these pollutants from water using the concrete-supported photocatalysts under UV irradiation was performed with a greater efficiency, which does not require an additional separation stage to recover the catalyst. Therefore, it would be applicable to use in industrial wastewater treatment at room temperature and atmospheric pressure within the optimized pH range.

  17. Multiresponse kinetic modelling of Maillard reaction and caramelisation in a heated glucose/wheat flour system.

    PubMed

    Kocadağlı, Tolgahan; Gökmen, Vural

    2016-11-15

    The study describes the kinetics of the formation and degradation of α-dicarbonyl compounds in glucose/wheat flour system heated under low moisture conditions. Changes in the concentrations of glucose, fructose, individual free amino acids, lysine and arginine residues, glucosone, 1-deoxyglucosone, 3-deoxyglucosone, 3,4-dideoxyglucosone, 5-hydroxymethyl-2-furfural, glyoxal, methylglyoxal and diacetyl concentrations were determined to form a multiresponse kinetic model for isomerisation and degradation reactions of glucose. Degradation of Amadori product mainly produced 1-deoxyglucosone. Formation of 3-deoxyglucosone proceeded directly from glucose and also Amadori product degradation. Glyoxal formation was predominant from glucosone while methylglyoxal and diacetyl originated from 1-deoxyglucosone. Formation of 5-hydroxymethyl-2-furfural from fructose was found to be a key step. Multi-response kinetic modelling of Maillard reaction and caramelisation simultaneously indicated quantitatively predominant parallel and consecutive pathways and rate limiting steps by estimating the reaction rate constants.

  18. Biotransformation of Furanic and Phenolic Compounds with Hydrogen Gas Production in a Microbial Electrolysis Cell.

    PubMed

    Zeng, Xiaofei; Borole, Abhijeet P; Pavlostathis, Spyros G

    2015-11-17

    Furanic and phenolic compounds are problematic byproducts resulting from the breakdown of lignocellulosic biomass during biofuel production. The capacity of a microbial electrolysis cell (MEC) to produce hydrogen gas (H2) using a mixture of two furanic (furfural, FF; 5-hydroxymethyl furfural, HMF) and three phenolic (syringic acid, SA; vanillic acid, VA; and 4-hydroxybenzoic acid, HBA) compounds as the substrate in the bioanode was assessed. The rate and extent of biotransformation of the five compounds and efficiency of H2 production, as well as the structure of the anode microbial community, were investigated. The five compounds were completely transformed within 7-day batch runs and their biotransformation rate increased with increasing initial concentration. At an initial concentration of 1200 mg/L (8.7 mM) of the mixture of the five compounds, their biotransformation rate ranged from 0.85 to 2.34 mM/d. The anode Coulombic efficiency was 44-69%, which is comparable to that of wastewater-fed MECs. The H2 yield varied from 0.26 to 0.42 g H2-COD/g COD removed in the anode, and the bioanode volume-normalized H2 production rate was 0.07-0.1 L/L-d. The biotransformation of the five compounds took place via fermentation followed by exoelectrogenesis. The major identified fermentation products that did not transform further were catechol and phenol. Acetate was the direct substrate for exoelectrogenesis. Current and H2 production were inhibited at an initial substrate concentration of 1200 mg/L, resulting in acetate accumulation at a much higher level than that measured in other batch runs conducted with a lower initial concentration of the five compounds. The anode microbial community consisted of exoelectrogens, putative degraders of the five compounds, and syntrophic partners of exoelectrogens. The MEC H2 production demonstrated in this study is an alternative to the currently used process of reforming natural gas to supply H2 needed to upgrade bio-oils to stable

  19. Biotransformation of furanic and phenolic compounds with hydrogen gas production in a microbial electrolysis cell

    DOE PAGES

    Zeng, Xiaofei; Borole, Abhijeet P.; Pavlostathis, Spyros G.

    2015-10-27

    In this study, furanic and phenolic compounds are problematic byproducts resulting from the decomposition of lignocellulosic biomass during biofuel production. This study assessed the capacity of a microbial electrolysis cell (MEC) to produce hydrogen gas (H2) using a mixture of two furanic (furfural, FF; 5-hydroxymethyl furfural, HMF) and three phenolic (syringic acid, SA; vanillic acid, VA; and 4-hydroxybenzoic acid, HBA) compounds as the sole carbon and energy source in the bioanode. The rate and extent of biotransformation of the five compounds, efficiency of H2 production, as well as the anode microbial community structure were investigated. The five compounds were completelymore » transformed within 7-day batch runs and their biotransformation rate increased with increasing initial concentration. At an initial concentration of 1,200 mg/L (8.7 mM) of the mixture of the five compounds, their biotransformation rate ranged from 0.85 to 2.34 mM/d. The anode coulombic efficiency was 44-69%, which is comparable to wastewater-fed MECs. The H2 yield varied from 0.26 to 0.42 g H2-COD/g COD removed in the anode, and the bioanode volume-normalized H2 production rate was 0.07-0.1 L/L-d. The major identified fermentation products that did not transform further were catechol and phenol. Acetate was the direct substrate for exoelectrogenesis. Current and H2 production were inhibited at an initial substrate concentration of 1,200 mg/L, resulting in acetate accumulation at a much higher level than that measured in other batch runs conducted with a lower initial concentration of the five compounds. The anode microbial community consisted of exoelectrogens, putative degraders of the five compounds, and syntrophic partners of exoelectrogens. The H2 production route demonstrated in this study has proven to be an alternative to the currently used process of reforming natural gas to supply H2 needed to upgrade bio-oils to stable hydrocarbon fuels.« less

  20. Biotransformation of furanic and phenolic compounds with hydrogen gas production in a microbial electrolysis cell

    SciTech Connect

    Zeng, Xiaofei; Borole, Abhijeet P.; Pavlostathis, Spyros G.

    2015-10-27

    In this study, furanic and phenolic compounds are problematic byproducts resulting from the decomposition of lignocellulosic biomass during biofuel production. This study assessed the capacity of a microbial electrolysis cell (MEC) to produce hydrogen gas (H2) using a mixture of two furanic (furfural, FF; 5-hydroxymethyl furfural, HMF) and three phenolic (syringic acid, SA; vanillic acid, VA; and 4-hydroxybenzoic acid, HBA) compounds as the sole carbon and energy source in the bioanode. The rate and extent of biotransformation of the five compounds, efficiency of H2 production, as well as the anode microbial community structure were investigated. The five compounds were completely transformed within 7-day batch runs and their biotransformation rate increased with increasing initial concentration. At an initial concentration of 1,200 mg/L (8.7 mM) of the mixture of the five compounds, their biotransformation rate ranged from 0.85 to 2.34 mM/d. The anode coulombic efficiency was 44-69%, which is comparable to wastewater-fed MECs. The H2 yield varied from 0.26 to 0.42 g H2-COD/g COD removed in the anode, and the bioanode volume-normalized H2 production rate was 0.07-0.1 L/L-d. The major identified fermentation products that did not transform further were catechol and phenol. Acetate was the direct substrate for exoelectrogenesis. Current and H2 production were inhibited at an initial substrate concentration of 1,200 mg/L, resulting in acetate accumulation at a much higher level than that measured in other batch runs conducted with a lower initial concentration of the five compounds. The anode microbial community consisted of exoelectrogens, putative degraders of the five compounds, and syntrophic partners of exoelectrogens. The H2 production route demonstrated in this study has proven to be an alternative to the currently used process of reforming natural gas to supply H2 needed to

  1. Improvement on the catalytic performance of Mg-Zr mixed oxides for furfural-acetone aldol condensation by supporting on mesoporous carbons.

    PubMed

    Faba, Laura; Díaz, Eva; Ordóñez, Salvador

    2013-03-01

    A new procedure for improving the performance of the most common catalysts used in aqueous-phase aldol condensation (Mg-Zr mixed oxides) reactions is presented. This reaction is of interest for upgrading carbohydrate feedstocks. The procedure involves supporting Mg-Zr oxides on non-microporous carbonaceous materials, such as carbon nanofibers (CNFs) or high-surface-area graphites (HSAGs), using either incipient wetness or coprecipitation procedures. The use of HSAGs together with the coprecipitation method provides the best performance. Results obtained for the cross-condensation of acetone and furfural at 323 K reveal that the catalyst performance is greatly improved compared to the bulk oxides (96.5 % conversion vs. 81.4 % with the bulk oxide; 87.8 % selectivity for C13 and C8 adducts vs. 76.2 % with the bulk oxide). This difference is even more prominent in terms of rates per catalytically active basic site (four and seven times greater for C8 and C13 adducts, respectively). The improved performance is explained in terms of a more appropriate basic site distribution and by greater interaction of the reactants with the carbon surface. In addition, deactivation behavior of the catalyst is improved by tuning the morphology of the carbonaceous support. An important enhancement of the catalytic stability can be obtained selecting a HSAG with an appropriate pore diameter. With HSAG100 the activity decreased by less than 20 % between successive reaction cycles and the selectivity for the condensation products remained almost unaltered. The decrease is greater than 80 % for the bulk oxides tested at these conditions, with important increases in the selectivity for by-product formation.

  2. A comparative multidimensional LC-MS proteomic analysis reveals mechanisms for furan aldehyde detoxification in Thermoanaerobacter pseudethanolicus 39E

    SciTech Connect

    Clarkson, Sonya M.; Hamilton-Brehm, Scott D.; Giannone, Richard J.; Engle, Nancy L.; Tschaplinski, Timothy J.; Hettich, Robert L.; Elkins, James G.

    2014-12-03

    Background: Chemical and physical pretreatment of lignocellulosic biomass improves substrate reactivity for increased microbial biofuel production, but also restricts growth via the release of furan aldehydes such as furfural and 5-hydroxymethylfurfural (5-HMF). The physiological effects of these inhibitors on thermophilic, fermentative bacteria is important to understand; especially as cellulolytic strains are being developed for consolidated bioprocessing (CBP) of lignocellulosic feedstocks. Identifying mechanisms for detoxification of aldehydes in naturally resistant strains such as Thermoanaerobacter spp. may also enable improvements in candidate CBP microorganisms. Results: T. pseudethanolicus 39E, an anaerobic, saccharolytic thermophile, was found to grow readily in the presence of 30 mM furfural and 20 mM 5-HMF and reduce these aldehydes to their respective alcohols in situ. The proteomes of T. pseudethanolicus 39E grown in the presence or absence of 15 mM furfural were compared to identify upregulated enzymes potentially responsible for the observed reduction. A total of 225 proteins were differentially regulated in response to the 15 mM furfural treatment with 152 upregulated vs. 73 downregulated. Only 86 proteins exhibited a 2-fold change in abundance in either direction. Of these, 53 were upregulated in the presence of furfural and 33 were downregulated. Two oxidoreductases were upregulated at least 2-fold by furfural and were targeted for further investigation: Teth39_1597, encodes a predicted butanol dehydrogenase (BdhA) and Teth39_1598, a predicted aldo/keto reductase (AKR). Both genes were cloned from T. pseudethanolicus 39E, with the respective enzymes overexpressed in E. coli and specific activities determined against a variety of aldehydes. BdhA showed significant activity with all aldehydes tested, including furfural and 5-HMF, using NADPH as the cofactor. AKR also showed significant activity with NADPH

  3. A comparative multidimensional LC-MS proteomic analysis reveals mechanisms for furan aldehyde detoxification in Thermoanaerobacter pseudethanolicus 39E

    DOE PAGES

    Clarkson, Sonya M.; Hamilton-Brehm, Scott D.; Giannone, Richard J.; ...

    2014-12-03

    Background: Chemical and physical pretreatment of lignocellulosic biomass improves substrate reactivity for increased microbial biofuel production, but also restricts growth via the release of furan aldehydes such as furfural and 5-hydroxymethylfurfural (5-HMF). The physiological effects of these inhibitors on thermophilic, fermentative bacteria is important to understand; especially as cellulolytic strains are being developed for consolidated bioprocessing (CBP) of lignocellulosic feedstocks. Identifying mechanisms for detoxification of aldehydes in naturally resistant strains such as Thermoanaerobacter spp. may also enable improvements in candidate CBP microorganisms. Results: T. pseudethanolicus 39E, an anaerobic, saccharolytic thermophile, was found to grow readily in the presence of 30more » mM furfural and 20 mM 5-HMF and reduce these aldehydes to their respective alcohols in situ. The proteomes of T. pseudethanolicus 39E grown in the presence or absence of 15 mM furfural were compared to identify upregulated enzymes potentially responsible for the observed reduction. A total of 225 proteins were differentially regulated in response to the 15 mM furfural treatment with 152 upregulated vs. 73 downregulated. Only 86 proteins exhibited a 2-fold change in abundance in either direction. Of these, 53 were upregulated in the presence of furfural and 33 were downregulated. Two oxidoreductases were upregulated at least 2-fold by furfural and were targeted for further investigation: Teth39_1597, encodes a predicted butanol dehydrogenase (BdhA) and Teth39_1598, a predicted aldo/keto reductase (AKR). Both genes were cloned from T. pseudethanolicus 39E, with the respective enzymes overexpressed in E. coli and specific activities determined against a variety of aldehydes. BdhA showed significant activity with all aldehydes tested, including furfural and 5-HMF, using NADPH as the cofactor. AKR also showed significant activity with NADPH, but only with four carbon butyr

  4. Genome and transcriptome analyses reveal that MAPK- and phosphatidylinositol-signaling pathways mediate tolerance to 5-hydroxymethyl-2-furaldehyde for industrial yeast Saccharomyces cerevisiae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The industrial ethanologenic yeast Saccharomyces cerevisiae is a promising biocatalyst for next-generation advanced biofuels applications including lignocellulose-to-ethanol conversion. Here we present the first insight into the genomic background of NRRL Y-12632, a type strain from a worldwide coll...

  5. Antidepressant-Like Effect of Sodium Butyrate is Associated with an Increase in TET1 and in 5-Hydroxymethylation Levels in the Bdnf Gene

    PubMed Central

    Wei, Ya Bin; Melas, Philippe A.; Wegener, Gregers; Mathé, Aleksander A.; Lavebratt, Catharina

    2015-01-01

    Background: Epigenetic drugs like sodium butyrate (NaB) show antidepressant-like effects in preclinical studies, but the exact molecular mechanisms of the antidepressant effects remain unknown. While research using NaB has mainly focused on its role as a histone deacetylase inhibitor (HDACi), there is also evidence that NaB affects DNA methylation. Methods: The purpose of this study was to examine NaB’s putative antidepressant-like efficacy in relation to DNA methylation changes in the prefrontal cortex of an established genetic rat model of depression (the Flinders Sensitive Line [FSL]) and its controls (the Flinders Resistant Line). Results: The FSL rats had lower levels of ten-eleven translocation methylcytosine dioxygenase 1 (TET1), which catalyzes the conversion of DNA methylation to hydroxymethylation. As indicated by the behavioral despair test, chronic administration of NaB had antidepressant-like effects in the FSL and was accompanied by increased levels of TET1. The TET1 upregulation was also associated with an increase of hydroxymethylation and a decrease of methylation in brain-derived neurotrophic factor (Bdnf), a gene associated with neurogenesis and synaptic plasticity. These epigenetic changes were associated with a corresponding BDNF overexpression. Conclusions: Our data support the antidepressant efficacy of HDACis and suggest that their epigenetic effects may also include DNA methylation changes that are mediated by demethylation-facilitating enzymes like TET1. PMID:25618518

  6. Predicted thermochemistry for chemical conversions of 5-hydroxymethylfurfural.

    SciTech Connect

    Assary, R. S.; Redfern, P. C.; Hammond, J. R.; Greeley, J.; Curtiss, L. A.; Northwestern Univ.

    2010-09-10

    The thermochemistry of various chemical transformations of 5-hydroxy methyl furfural (HMF) were investigated using highly accurate Gaussian-4 (G4) theory. The conversion of HMF to nonane through aldol condensation, hydrogenation, and hydrogenolysis reactions was found to be thermodynamically favorable. The hydrogenation reactions involving the keto groups in the nonane reaction sequence were found to be enhanced at low temperatures and high pressures of H{sub 2}. The hydrogenation, selective oxidation, and hydration of HMF were also found to be thermodynamically favorable. Gas phase enthalpies of formation of all the intermediate compounds were calculated at the G4 level of theory and compared against existing experimental data.

  7. Study of the formation mechanisms of some volatile compounds during the aging of sweet fortified wines.

    PubMed

    Cutzach, I; Chatonnet, P; Dubourdieu, D

    1999-07-01

    Sweet fortified wines, traditionally aged under strong oxidation conditions, have a characteristic aroma. An experimental laboratory study investigated the aging of red and white sweet fortified wines under various conditions. The formation of various molecules, previously identified as characteristic of the aroma of this type of wine, was monitored by analysis. The development of these compounds during accelerated aging was affected by oxidation and the color of the wine. Among the molecules studied, sotolon [3-hydroxy-4, 5-dimethyl-2(5H)-furanone] was one of the few molecules present in concentrations above the perception threshold, in both red and white wines. Buildup was strongly affected by the presence of oxygen in white wine subjected to accelerated aging. (Ethoxymethyl)furfural, formed from 5-(hydroxymethyl)furfural, and furfural, derived from sugars, are also involved in the aroma of sweet fortified white wines aged in oxygen-free conditions. The substances most characteristic of accelerated aging of sweet fortified red wines were 5-(hydroxymethyl)furfural, acetylformoin, and hydroxymaltol, the formation of which is affected by oxidation, and dihydromaltol, formed in the absence of oxidation.

  8. Tolerance of the nanocellulose-producing bacterium Gluconacetobacter xylinus to lignocellulose-derived acids and aldehydes.

    PubMed

    Zhang, Shuo; Winestrand, Sandra; Chen, Lin; Li, Dengxin; Jönsson, Leif J; Hong, Feng

    2014-10-08

    Lignocellulosic biomass serves as a potential alternative feedstock for production of bacterial nanocellulose (BNC), a high-value-added product of bacteria such as Gluconacetobacter xylinus. The tolerance of G. xylinus to lignocellulose-derived inhibitors (formic acid, acetic acid, levulinic acid, furfural, and 5-hydroxymethylfurfural) was investigated. Whereas 100 mM formic acid completely suppressed the metabolism of G. xylinus, 250 mM of either acetic acid or levulinic acid still allowed glucose metabolism and BNC production to occur. Complete suppression of glucose utilization and BNC production was observed after inclusion of 20 and 30 mM furfural and 5-hydroxymethylfurfural, respectively. The bacterium oxidized furfural and 5-hydroxymethylfurfural to furoic acid and 5-hydroxymethyl-2-furoic acid, respectively. The highest yields observed were 88% for furoic acid/furfural and 76% for 5-hydroxymethyl-2-furoic acid/5-hydroxymethylfurfural. These results are the first demonstration of the capability of G. xylinus to tolerate lignocellulose-derived inhibitors and to convert furan aldehydes.

  9. Direct enzyme assay evidence confirms aldehyde reductase function of Ydr541cp and Ygl039wp from Saccharomyces cerevisiae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aldehyde reductase gene ARI1 is a recently characterized member of intermediate subfamily under SDR (short-chain dehydrogenase/reductase) superfamily that revealed mechanisms of in situ detoxification of furfural and HMF for tolerance of Saccharomyces cerevisiae. Uncharacterized open reading frames ...

  10. GRE2 from Scheffersomyces stipitis as an aldehyde reductase contributes tolerance to aldehyde inhibitors derived from lignocellulosic biomass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Scheffersomyces (Pichia) stipitis is one of the most promising yeasts for industrial bioethanol production from lignocellulosic biomass. S. stipitis is able to in situ detoxify aldehyde inhibitors [such as furfural and 5-hydroxymethylfurfural (HMF)] to less toxic corresponding alcohols. However, the...

  11. Detoxification of acidic biorefinery waste liquor for production of high value amino acid.

    PubMed

    Christopher, Meera; Anusree, Murali; Mathew, Anil K; Nampoothiri, K Madhavan; Sukumaran, Rajeev Kumar; Pandey, Ashok

    2016-08-01

    The current study evaluates the detoxification of acid pretreatment liquor (APL) using adsorbent (ADS 400 & ADS 800) or ion-exchange (A-27MP & A-72MP) resins and its potential for amino acid production. The APL is generated as a by-product from the pretreatment of lignocellulosic biomass and is rich monomeric sugars as well as sugar degradation products (fermentation inhibitors) such as furfural and hydroxymethyl furfural (HMF). Of the four resins compared, ADS 800 removed approximately 85% and 60% of furfural and HMF, respectively. ADS 800 could be reused for up to six cycles after regeneration without losing its adsorption properties. The study was further extended by assessing the fermentability of detoxified APL for l-lysine production using wild and mutant strains of Corynebacterium glutamicum. The detoxified APL was superior to APL for l-lysine production.

  12. Evolutionarily engineered ethanologenic yeast detoxifies lignocellulosic biomass conversion inhibitors by reprogrammed pathways.

    PubMed

    Liu, Z Lewis; Ma, Menggen; Song, Mingzhou

    2009-09-01

    Lignocellulosic biomass conversion inhibitors, furfural and HMF, inhibit microbial growth and interfere with subsequent fermentation of ethanol, posing significant challenges for a sustainable cellulosic ethanol conversion industry. Numerous yeast genes were found to be associated with the inhibitor tolerance. However, limited knowledge is available about mechanisms of the tolerance and the detoxification of the biomass conversion inhibitors. Using a robust standard for absolute mRNA quantification assay and a recently developed tolerant ethanologenic yeast Saccharomyces cerevisiae NRRL Y-50049, we investigate pathway-based transcription profiles relevant to the yeast tolerance and the inhibitor detoxification. Under the synergistic inhibitory challenges by furfural and HMF, Y-50049 was able to withstand the inhibitor stress, in situ detoxify furfural and HMF, and produce ethanol, while its parental control Y-12632 failed to function till 65 h after incubation. The tolerant strain Y-50049 displayed enriched genetic background with significantly higher abundant of transcripts for at least 16 genes than a non-tolerant parental strain Y-12632. The enhanced expression of ZWF1 appeared to drive glucose metabolism in favor of pentose phosphate pathway over glycolysis at earlier steps of glucose metabolisms. Cofactor NAD(P)H generation steps were likely accelerated by enzymes encoded by ZWF1, GND1, GND2, TDH1, and ALD4. NAD(P)H-dependent aldehyde reductions including conversion of furfural and HMF, in return, provided sufficient NAD(P)(+) for NAD(P)H regeneration in the yeast detoxification pathways. Enriched genetic background and a well maintained redox balance through reprogrammed expression responses of Y-50049 were accountable for the acquired tolerance and detoxification of furfural to furan methanol and HMF to furan dimethanol. We present significant gene interactions and regulatory networks involved in NAD(P)H regenerations and functional aldehyde reductions under

  13. Enhancing the stability of copper chromite catalysts for the selective hydrogenation of furfural with ALD overcoating (II) – Comparison between TiO2 and Al2O3 overcoatings

    SciTech Connect

    Zhang, Hongbo; Canlas, Christian; Kropf, A. Jeremy; Elam, Jeffrey W.; Dumesic, James A; Marshall, Christopher L.

    2015-01-01

    TiO2 atomic layer deposition (ALD) overcoatings were applied to copper chromite catalysts to increase the stability for 2-furfuraldehyde (“furfural”) hydrogenation. After overcoating, about 75% activity was preserved compared to neat copper chromite: much higher activity than an alumina ALD overcoated catalyst with a similar number of ALD cycles. The effects of ALD TiO2 on the active Cu nanoparticles were studied extensively using both in-situ TPR/isothermal-oxidation and in-situ furfural hydrogenation via Cu XAFS. The redox properties of Cu were modified only slightly by the TiO2 ALD overcoat. However, a subtle electronic interaction was observed between the TiO2 ALD layers and the Cu nanoparticles. With calcination at 500 °C the interaction between the TiO2 overcoat and the underlying catalyst is strong enough to inhibit migration and site blocking by chromite, but is sufficiently weaker than the interaction between the Al2O3 overcoat and copper chromite that it does not strongly inhibit the catalytic activity of the copper nanoparticles.

  14. Mechanism research on cellulose pyrolysis by Py-GC/MS and subsequent density functional theory studies.

    PubMed

    Wang, Shurong; Guo, Xiujuan; Liang, Tao; Zhou, Yan; Luo, Zhongyang

    2012-01-01

    The mechanism of fast pyrolysis of cellulose has been studied by using an analytical pyrolyzer coupled with a gas chromatography-mass spectrometry set-up (Py-GC/MS). The results showed that the main products comprised pyrans such as levoglucosan and levoglucosenone, furans such as furfural and 5-hydroxymethyl furfural, and linear small molecular chemicals such as acetaldehyde and 1-hydroxy-2-propanone. The compositions of products from fast pyrolysis of cellubiose and glucose were similar to that from cellulose, but with higher furan contents and lower pyran contents. Based on the experimental results, density functional theory (DFT) studies were carried out to deduce the pyrolysis mechanism of cellulose. The results showed the formation of 5-hydroxymethyl furfural from d-glucopyranose unit to be easier than the formation of levoglucosan, in agreement with the experimental results. The deduced mechanism of reaction pathways in cellulose pyrolysis provides insight into the pyrolysis behavior of cellulose and allows modification of previously proposed related mechanisms.

  15. Anti-arthritic active fraction of Capparis spinosa L. fruits and its chemical constituents.

    PubMed

    Feng, Xiaolu; Lu, Jincai; Xin, Hailiang; Zhang, Lei; Wang, Yuliang; Tang, Kexuan

    2011-03-01

    The aim of this study was to ascertain the anti-arthritic active fraction of Capparis spinosa L. (Capparidaceae) fruits and its chemical constituents. The adjuvant arthritic rat model was developed to evaluate the anti-arthritic effects of different fractions of ethanol extraction from C. spinosa L. The fraction eluted by ethanol-water (50:50, v/v) had the most significant anti-arthritic activity. The chemical constituents of this fraction were therefore studied; seven known compounds were isolated and identified as: P-hydroxy benzoic acid; 5-(hydroxymethyl) furfural; bis(5-formylfurfuryl) ether; daucosterol; α-D-fructofuranosides methyl; uracil; and stachydrine.

  16. Manothermosonication of foods and food-resembling systems: effect on nutrient content and nonenzymatic browning.

    PubMed

    Vercet, A; Burgos, J; López-Buesa, P

    2001-01-01

    The effect of manothermosonication (MTS), an emergent technology for food preservation, on thiamin, riboflavin, carotenoids, and ascorbic acid was evaluated in milk and orange juice. The effect of both heat treatment and MTS on several compounds produced in nonenzymatic browning in model systems was also studied. MTS does not affect significantly the nutrient content studied. However, it changes the behavior of nonenzymatic browning. No formation of 5-(hydroxymethyl)-2-furfuraldehyde (HMF) was detected in fruit juice model systems after heat and MTS treatments at the experimental conditions used. In a milk-resembling system, free HMF formation by MTS is higher compared to that by heat treatment. As the MTS temperature increases, free HMF production by both treatments equaled on another. For bound HMF the production rate is lower by MTS than by heat treatment under the experimental conditions used. Formation kinetics of brown pigments and that of fluorescent compounds are different for both treatments. Fluorescence and brown pigment production are faster in MTS.

  17. Development of a novel ultrasound-assisted alkali pretreatment strategy for the production of bioethanol and xylanases from chili post harvest residue.

    PubMed

    Sindhu, Raveendran; Binod, Parameswaran; Mathew, Anil Kuruvilla; Abraham, Amith; Gnansounou, Edgard; Ummalyma, Sabeela Beevi; Thomas, Leya; Pandey, Ashok

    2017-03-04

    A novel ultrasound-assisted alkali pretreatment strategy was developed which could effectively remove lignin and hemicelluloses and improve the sugar yield from chili post harvest residue. Operational parameters that affect the pretreatment efficiency were studied and optimized. Inhibitor analysis of the hydrolyzate revealed that major fermentation inhibitors like furfural, 5-hydroxymethyl furfural as well as organic acids like citric acid, succinic acid and propionic acid were absent. Hence fermentation can be carried out without detoxification of the hydrolyzate. Changes in structural properties of the biomass were studied in relation to the pretreatment process using Scanning Electron Microscopy (SEM) and the changes in chemical composition were also monitored. The biomass pretreated with the optimized novel method could yield 0.428g/g of reducing sugars upon enzymatic hydrolysis. The hydrolyzate obtained by this novel pretreatment strategy was found to be suitable for bioethanol and xylanase production.

  18. First report about pharmaceutical properties and phytochemicals analysis of Rosa abyssinica R. Br. ex Lindl. (Rosaceae).

    PubMed

    Moustafa, Mahmoud Fawzy; Alrumman, Sulaiman Abdullah

    2015-11-01

    In vitro antimicrobial efficacy of seven solvent extracts from leaves and hips of Saudi Arabian weed Rosa abyssinica against a variety of human pathogenic bacteria and Candida species have been evaluated using well diffusion methods. Phytochemicals present in the leaves and hips of Rosa abyssinica has been characterized using Gas Chromatogram Mass spectrometry analysis. The extracts comparative efficacy against tested microbes gained from the fresh and dry leaves exhibited more prominent activity than fresh and dry hips. The methanol, chloroform, petroleum ether, acetone and diethyl ether extracts have a greater lethal effect on pathogenic microbes than hot water extracts, while cold-water extracts showed no activity. Twenty-four phytochemicals have been characterized from ethanol extract of the leaves of Rosa abyssinica and fifteen from hips by GC-MS. The major compounds detected in the leaves were squalene (38.21%), ethane, 1,1-diethoxy- (9.65%), β-D-glucopyranose, 1,6-anhydro- (8.55%), furfural (5.50%) and 2-furancarboxaldehyde 5-(hydroxymethyl)- (5.19%). The major compounds in the hips were 2-furancarboxaldehyde 5-(hydroxymethyl)- (51.27%), β-D-glucopyranose, 1,6-anhydro- (8.18%), 4H-pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl- (7.42%), 2,5-furandione, dihydro-3-methylene- (6.79%) and furfural (5.99%). Current findings indicate that extract from leaves and hips of Rosa abyssinica and the bioactive components present could be used as pharmaceutical agents.

  19. Pyrolysis of table sugar.

    PubMed

    Bulut, Adnan; Karagöz, Selhan

    2013-01-01

    Table sugars were pyrolyzed at different temperatures (300, 400, and 500°C) in a fixed-bed reactor. The effect of pyrolysis temperature on yields of liquid, solid, and gaseous products was investigated. As expected the yield of liquid products gradually increased and the yield of solid products gradually decreased when the pyrolysis temperature was raised. The yield of liquid products was greatest (52 wt%) at 500°C. The composition of bio-oils extracted with diethyl ether was identified by means of gas chromatography mass spectrometry (GC-MS), nuclear magnetic resonance ((1)H-NMR), and Fourier transform infrared spectroscopy (FTIR). The following compounds were observed in bio-oils produced from the pyrolysis of table sugar at 500°C: 1,4:3,6-dianhydro- α -d-glucopyranose, 5-(hydroxymethyl) furfural, 5-acetoxymethyl-2-furaldehyde, and cyclotetradecane liquid product. The relative concentration of 5-(hydroxymethyl) furfural was the highest in bio-oils obtained from pyrolysis of table sugars at 500°C.

  20. Behavior of selected hydrolyzed and dehydrated products during hydrothermal carbonization of biomass.

    PubMed

    Reza, M Toufiq; Wirth, Benjamin; Lüder, Ulf; Werner, Maja

    2014-10-01

    In this study, effects of reaction temperature and reaction time on both solid hydrochar and HTC process liquid products were studied for hydrothermal carbonization (HTC) of cellulose, wheat straw, and poplar. A novel slurry sampling system was designed and used with an 18.6L Parr reactor for 0-480 min in 200, 230, and 260 °C. Sugars (sucrose, glucose, and fructose), HMF, and furfural were found maximum in lower HTC temperature and time. However, they degrade following first order degradation kinetics. Activation energies of total sugars (glucose, fructose, sucrose, and xylose), furfural, and HMF for straw and poplar were 95-127, 130-135, and 74-90 kJ mol(-1), respectively and individuals were lower for HTC of cellulose than others. Organic acids (acetic acid, formic acid, and lactic acid) and phenolic compounds (phenol, catechol, and guaiacol) were increasing with higher HTC severity.

  1. GRE2 from Scheffersomyces stipitis as an aldehyde reductase contributes tolerance to aldehyde inhibitors derived from lignocellulosic biomass.

    PubMed

    Wang, Xu; Ma, Menggen; Liu, Z Lewis; Xiang, Quanju; Li, Xi; Liu, Na; Zhang, Xiaoping

    2016-08-01

    Scheffersomyces (Pichia) stipitis is one of the most promising yeasts for industrial bioethanol production from lignocellulosic biomass. S. stipitis is able to in situ detoxify aldehyde inhibitors (such as furfural and 5-hydroxymethylfurfural (HMF)) to less toxic corresponding alcohols. However, the reduction enzymes involved in this reaction remain largely unknown. In this study, we reported that an uncharacterized open reading frame PICST_72153 (putative GRE2) from S. stipitis was highly induced in response to furfural and HMF stresses. Overexpression of this gene in Saccharomyces cerevisiae improved yeast tolerance to furfural and HMF. GRE2 was identified as an aldehyde reductase which can reduce furfural to FM with either NADH or NADPH as the co-factor and reduce HMF to FDM with NADPH as the co-factor. This enzyme can also reduce multiple aldehydes to their corresponding alcohols. Amino acid sequence analysis indicated that it is a member of the subclass "intermediate" of the short-chain dehydrogenase/reductase (SDR) superfamily. Although GRE2 from S. stipitis is similar to GRE2 from S. cerevisiae in a three-dimensional structure, some differences were predicted. GRE2 from S. stipitis forms loops at D133-E137 and T143-N145 locations with two α-helices at E154-K157 and E252-A254 locations, different GRE2 from S. cerevisiae with an α-helix at D133-E137 and a β-sheet at T143-N145 locations, and two loops at E154-K157 and E252-A254 locations. This research provided guidelines for the study of other SDR enzymes from S. stipitis and other yeasts on tolerant mechanisms to aldehyde inhibitors derived from lignocellulosic biomass.

  2. Superheated steam pyrolysis of biomass elemental components and Sugi (Japanese cedar) for fuels and chemicals.

    PubMed

    Sagehashi, Masaki; Miyasaka, Noritaka; Shishido, Hiromu; Sakoda, Akiyoshi

    2006-07-01

    To develop a novel noncatalytic biomass refinery process that can be used as a portable process, superheated steam pyrolysis was investigated to produce both carbonized solid fuels and chemicals using a large-scale reactor. Individual biomass components and native biomass (Sugi, Japanese cedar) were pyrolyzed. Between 150 and 400 degrees C, the vaporizing fractions of cellulose, xylan, and kraft lignin were summarized using a numerical model. Cellulose was converted to glycolaldehyde, furfural, 5-hydroxymethyl furfural and levoglucosan, whereas xylan was converted to glycolaldehyde, furfural, and acetic acid. Kraft lignin produced a slight yield of phenol and guaiacol. The total vaporization fraction of Sugi and its vaporizing rate were explained sufficiently using a numerical model based on the weighted average of the vaporizing properties of the individual components. However, the yields of phenol, guaiacol, and acetic acid were underestimated, while the yields of furfurals and levoglucosan were overestimated. Possible synergetic effects among chemicals in the superheated steam pyrolysis of native biomass were also discussed.

  3. Molecular sieve adsorbents and membranes for applications in the production of renewable fuels and chemicals

    NASA Astrophysics Data System (ADS)

    Ranjan, Rajiv

    Metal organic frameworks (MOF), a new class of porous materials, have emerged as promising candidate for gas storage, separation membrane and chemical sensors. We used secondary growth method to grow microporous metal organic framework (MMOF) films on porous alumina supports. Examination of the film using SEM and XRD showed that the crystals were well inter-grown and preferentially oriented. Gas permeation study showed that membranes were defect free and moderate selectivity was achieved for H2/N2 gas pairs. The next project had to do with ethanol production from lignocellulosic biomass as an alternate energy source. However, toxic inhibitors produced from the hydrolysis of biomass decrease ethanol yield during the fermentation process. We demonstrated the use of zeolites for the pretreatment of hydrolyzate in order to remove inhibitors like 5-Hydroxymethylfurfuraldehyde (HMF) and furfural from aqueous solution. Zeolites exhibit preferential adsorption of the inhibitors and in effect improve the ethanol yield during fermentation. Ideal Adsorbed Solution Theory (IAST) was also used to predict adsorption isotherms for HMF-furfural mixtures using single component adsorption data. We also studied production of HMF, a potential substitute as a building block for plastic and chemical production, from renewable biomass resources. Catalytic dehydration of fructose for HMF production faces problems like low conversion and yield. Dimethyl sulfoxide (DMSO) can be used as the solvent as well as the catalyst resulting in high HMF yield. We studied a reaction-separation system for this dehydration reaction where the product (HMF) could be recovered by selective adsorption on solid adsorbents from the reaction mixture.

  4. Study of Influence of Heat Treatment on Cyclic Properties of L21HMF Cast Steel

    NASA Astrophysics Data System (ADS)

    Mroziński, Stanisław; Golański, Grzegorz

    2016-07-01

    This work presents the results of studies of CrMoV cast steel after long-term service and after regenerative heat treatment (RHT). The cast steel was investigated in the conditions of static and changeable load. The tests were carried out at room temperature and 550 °C. The fatigue lifetime curves were determined and described using the Basquin-Manson-Coffin relationship. It has been shown that the cast steel after RHT is characterized by smaller range of plastic strain and bigger range of stress amplitude, with the same value of total strain, compared with the cast steel after service. For the cast steel after RHT, the observed fatigue properties were different in comparison with the cast steel after service at small and large strains. At room temperature (20 °C) and at elevated temperature (550 °C), there is an increase in the life of samples of the cast steel after RHT in comparison with the samples of the cast steel after service only in the area of large strains ( ɛ ac > 1.2%). For small strains ɛ ac < 0.50%, the life of the cast steel after RHT at the examined temperatures is shorter than that of the cast steel after service. The paper shows that regardless of an explicit improvement in the strength properties (the static and cyclic ones), as a result of the performed RHT, a complete improvement in the fatigue properties of the cast steel does not occur.

  5. Predicting Success at Marine Security Guard (MSG) School Utilizing the Headquarters Master File (HMF)

    DTIC Science & Technology

    1993-03-01

    omander or HQM assessing the probability of success That any varticula Marine would have at the school. Examples were jiven detailing how to do this...Electronics Schools," CRC 362-Vol.1, Center for Naval Analyses, Arlington, Virginia, October 1978. Shelton, David L., "The Marine Security Guard Program...34 vol.74, no.6, p.73- 7 7, Marine Corps Gazette, Quantico, Virginia, June 1990. 108 Shelton, David L., ’"Thoughts on The MSG roqr.," no.6, p.15-i

  6. Synthesis of terephthalic acid via Diels-Alder reactions with ethylene and oxidized variants of 5-hydroxymethylfurfural.

    PubMed

    Pacheco, Joshua J; Davis, Mark E

    2014-06-10

    Terephthalic acid (PTA), a monomer in the synthesis of polyethylene terephthalate (PET), is obtained by the oxidation of petroleum-derived p-xylene. There is significant interest in the synthesis of renewable, biomass-derived PTA. Here, routes to PTA starting from oxidized products of 5-hydroxymethylfurfural (HMF) that can be produced from biomass are reported. These routes involve Diels-Alder reactions with ethylene and avoid the hydrogenation of HMF to 2,5-dimethylfuran. Oxidized derivatives of HMF are reacted with ethylene over solid Lewis acid catalysts that do not contain strong Brønsted acids to synthesize intermediates of PTA and its equally important diester, dimethyl terephthalate (DMT). The partially oxidized HMF, 5-(hydroxymethyl)furoic acid (HMFA), is reacted with high pressure ethylene over a pure-silica molecular sieve containing framework tin (Sn-Beta) to produce the Diels-Alder dehydration product, 4-(hydroxymethyl)benzoic acid (HMBA), with 31% selectivity at 61% HMFA conversion after 6 h at 190 °C. If HMFA is protected with methanol to form methyl 5-(methoxymethyl)furan-2-carboxylate (MMFC), MMFC can react with ethylene in the presence of Sn-Beta for 2 h to produce methyl 4-(methoxymethyl)benzenecarboxylate (MMBC) with 46% selectivity at 28% MMFC conversion or in the presence of a pure-silica molecular sieve containing framework zirconium (Zr-Beta) for 6 h to produce MMBC with 81% selectivity at 26% MMFC conversion. HMBA and MMBC can then be oxidized to produce PTA and DMT, respectively. When Lewis acid containing mesoporous silica (MCM-41) and amorphous silica, or Brønsted acid containing zeolites (Al-Beta), are used as catalysts, a significant decrease in selectivity/yield of the Diels-Alder dehydration product is observed.

  7. Microbial biodiesel production from oil palm biomass hydrolysate using marine Rhodococcus sp. YHY01.

    PubMed

    Bhatia, Shashi Kant; Kim, Junyoung; Song, Hun-Seok; Kim, Hyun Joong; Jeon, Jong-Min; Sathiyanarayanan, Ganesan; Yoon, Jeong-Jun; Park, Kyungmoon; Kim, Yun-Gon; Yang, Yung-Hun

    2017-02-20

    The effect of various biomass derived inhibitors (i.e. furfural, hydroxymethylfurfural (HMF), vanillin, 4-hydroxy benzaldehyde (4-HB) and acetate) was investigated for fatty acid accumulation in Rhodococcus sp. YHY 01. Rhodococcus sp. YHY01 was able to utilize acetate, vanillin, and 4-HB for biomass production and fatty acid accumulation. The IC50 value for furfural (3.1mM), HMF (3.2mM), vanillin (2.0mM), 4-HB (2.7mM) and acetate (3.7mM) was calculated. HMF and vanillin affect fatty acid composition and increase saturated fatty acid content. Rhodococcus sp. YHY 01 cultured with empty fruit bunch hydrolysate (EFBH) as the main carbon source resulted in enhanced biomass (20%) and fatty acid productivity (37%), in compression to glucose as a carbon source. Overall, this study showed the beneficial effects of inhibitory molecules on growth and fatty acid production, and support the idea of biomass hydrolysate utilization for biodiesel production by avoiding complex efforts to remove inhibitory compounds.

  8. [Analysis of volatile components in Qingshanlvshui tea using solid-phase microextraction/accelerated solvent extraction-gas chromatography-mass spectrometry].

    PubMed

    Zhan, Jiafen; Lu, Sheming; Meng, Zhaoyu; Xiang, Nengjun; Cao, Qiu'e; Miao, Mingming

    2008-05-01

    The volatile components of Qingshanlvshui Tea were extracted using solid phase micro-extraction (SPME) and accelerated solvent extraction (ASE), and then were identified by gas chromatography-mass spectrometry (GC-MS). It showed that ninety-one compounds were identified, including forty-nine by SPME, fifty-six by ASE, and fourteen by both of them. The main constituents were beta-myrcene, 3,5,5-trimethyl-1,5-heptadiene, L-limonene, alpha-ocimene, beta-ocimene, beta-pinene, 2-methylbenzaldehyde, 5-(hydroxymethyl)-2-furfural. Both SPME and ASE have their advantages. SPME is excellent at simplicity, rapidity, solvent-free, high enrichment, low detection limit, environment friendly etc. ASE has characteristics of time and solvent saving, automation, simplicity, as well as high efficiency.

  9. Quality Evaluation of Polar and Active Components in Crude and Processed Fructus Corni by Quantitative Analysis of Multicomponents with Single Marker.

    PubMed

    Jiang, Yuhong; Chen, Hui; Wang, Liling; Zou, Jing; Zheng, Xiao; Liu, Zhihui

    2016-01-01

    Objective. To develop a quantitative analysis of multicomponents by single-marker (QAMS) method for the simultaneous determination of polar active components in Fructus Corni. Methods. Loganin was selected as the internal reference, and the relative correction factors (RCFs) of gallic acid, 5-hydroxymethyl-2-furfural, morroniside, sweroside, cornin, 7α-O-methylmorroniside, 7β-O-methylmorroniside, 7α-O-ethylmorroniside, 7β-O-ethylmorroniside, and cornuside were established. The contents of multicomponents were then calculated based on their RCFs, respectively. Contents of the 11 components were also calculated by external standard method and compared with those of the QAMS method. Results. The contents of the 11 components in 21 crude and 10 processed Fructus Corni products were measured. No significant difference was found in the quantitative results of the QAMS and external standard methods. Conclusion. QAMS could serve as an accurate and convenient method in determining the polar and active components in Fructus Corni and its processed products.

  10. Chromatographic Evaluation and Characterization of Components of Gentian Root Extract Used as Food Additives.

    PubMed

    Amakura, Yoshiaki; Yoshimura, Morio; Morimoto, Sara; Yoshida, Takashi; Tada, Atsuko; Ito, Yusai; Yamazaki, Takeshi; Sugimoto, Naoki; Akiyama, Hiroshi

    2016-01-01

    Gentian root extract is used as a bitter food additive in Japan. We investigated the constituents of this extract to acquire the chemical data needed for standardized specifications. Fourteen known compounds were isolated in addition to a mixture of gentisin and isogentisin: anofinic acid, 2-methoxyanofinic acid, furan-2-carboxylic acid, 5-hydroxymethyl-2-furfural, 2,3-dihydroxybenzoic acid, isovitexin, gentiopicroside, loganic acid, sweroside, vanillic acid, gentisin 7-O-primeveroside, isogentisin 3-O-primeveroside, 6'-O-glucosylgentiopicroside, and swertiajaposide D. Moreover, a new compound, loganic acid 7-(2'-hydroxy-3'-O-β-D-glucopyranosyl)benzoate (1), was also isolated. HPLC was used to analyze gentiopicroside and amarogentin, defined as the main constituents of gentian root extract in the List of Existing Food Additives in Japan.

  11. Acid-catalyzed conversion of mono- and poly-sugars into platform chemicals: effects of molecular structure of sugar substrate.

    PubMed

    Hu, Xun; Wu, Liping; Wang, Yi; Song, Yao; Mourant, Daniel; Gunawan, Richard; Gholizadeh, Mortaza; Li, Chun-Zhu

    2013-04-01

    Hydrolysis/pyrolysis of lignocellulosic biomass always produces a mixture of sugars with distinct structures as intermediates or products. This study tried to elucidate the effects of molecular structure of sugars on their acid-catalyzed conversions in ethanol/water. Location of carbonyl group in sugars (fructose versus glucose) and steric configuration of hydroxyl groups (glucose versus galactose) significantly affected yields of levulinic acid/ester (fructose>glucose>galactose). The dehydration of fructose to 5-(hydroxymethyl)furfural produces much less soluble polymer than that from glucose and galactose, which results in high yields of levulinic acid/ester from fructose. Anhydrate sugar such as levoglucosan tends to undergo the undesirable decomposition to form less levulinic acid/ester. Catalytic behaviors of the poly-sugars (sucrose, maltose, raffinose, β-cyclodextrins) were determined much by their basic units. However, their big molecular sizes create the steric hindrance that significantly affects their followed conversion over solid acid catalyst.

  12. Effect of inhibitors formed during wheat straw pretreatment on ethanol fermentation by Pichia stipitis.

    PubMed

    Bellido, Carolina; Bolado, Silvia; Coca, Mónica; Lucas, Susana; González-Benito, Gerardo; García-Cubero, María Teresa

    2011-12-01

    The inhibitory effect of the main inhibitors (acetic acid, furfural and 5-hydroxymethylfurfural) formed during steam explosion of wheat straw was studied through ethanol fermentations of model substrates and hydrolysates from wheat straw by Pichia stipitis. Experimental results showed that an increase in acetic acid concentration led to a reduction in ethanol productivity and complete inhibition was observed at 3.5 g/L. Furfural produced a delay on sugar consumption rates with increasing concentration and HMF did not exert a significant effect. Fermentations of the whole slurry from steam exploded wheat straw were completely inhibited by a synergistic effect due to the presence of 1.5 g/L acetic acid, 0.15 g/L furfural and 0.05 g/L HMF together with solid fraction. When using only the solid fraction from steam explosion, hydrolysates presented 0.5 g/L of acetic acid, whose fermentations have submitted promising results, providing an ethanol yield of 0.45 g ethanol/g sugars and the final ethanol concentration reached was 12.2 g/L (10.9 g ethanol/100 g DM).

  13. Co-Utilization of Glucose and Xylose for Enhanced Lignocellulosic Ethanol Production with Reverse Membrane Bioreactors

    PubMed Central

    Ishola, Mofoluwake M.; Ylitervo, Päivi; Taherzadeh, Mohammad J.

    2015-01-01

    Integrated permeate channel (IPC) flat sheet membranes were examined for use as a reverse membrane bioreactor (rMBR) for lignocellulosic ethanol production. The fermenting organism, Saccharomyces cerevisiae (T0936), a genetically-modified strain with the ability to ferment xylose, was used inside the rMBR. The rMBR was evaluated for simultaneous glucose and xylose utilization as well as in situ detoxification of furfural and hydroxylmethyl furfural (HMF). The synthetic medium was investigated, after which the pretreated wheat straw was used as a xylose-rich lignocellulosic substrate. The IPC membrane panels were successfully used as the rMBR during the batch fermentations, which lasted for up to eight days without fouling. With the rMBR, complete glucose and xylose utilization, resulting in 86% of the theoretical ethanol yield, was observed with the synthetic medium. Its application with the pretreated wheat straw resulted in complete glucose consumption and 87% xylose utilization; a final ethanol concentration of 30.3 g/L was obtained, which corresponds to 83% of the theoretical yield. Moreover, complete in situ detoxification of furfural and HMF was obtained within 36 h and 60 h, respectively, with the rMBR. The use of the rMBR is a promising technology for large-scale lignocellulosic ethanol production, since it facilitates the co-utilization of glucose and xylose; moreover, the technology would also allow the reuse of the yeast for several batches. PMID:26633530

  14. Bioactive compounds and antioxidant potential in tomato pastes as affected by hot and cold break process.

    PubMed

    Kelebek, Hasim; Selli, Serkan; Kadiroğlu, Pınar; Kola, Osman; Kesen, Songul; Uçar, Burçak; Çetiner, Başak

    2017-04-01

    The effects of hot and cold break industrial tomato paste production steps on phenolic compounds, carotenoids, organic acids, hydroxy methyl furfural (HMF) and other quality parameters of tomato pastes were investigated in this study. Phenolic compounds, carotenoids, organic acids, and HMF analyses were performed with LC-DAD-ESI-MS/MS and LC-DAD-RID was used for the sugar analyses. Furthermore, the antioxidant capacities of tomato pastes were assessed via the DPPH and ABTS methods. The increase of phenol acids at the processing steps of cold break production method was higher than the hot break production method. According to PCA analyses, phenolic acids characterized cold break tomato pastes while hot break tomato pastes were characterized by flavanols and flavanones. The total amount of organic acids decreased with processing and the loss of organic acids was lower in cold break pastes. Heating and evaporation were determined as the most important processing steps in which the amount of different quality parameters change.

  15. Microwave assisted conversion of microcrystalline cellulose into value added chemicals using dilute acid catalyst.

    PubMed

    Ching, Teck Wei; Haritos, Victoria; Tanksale, Akshat

    2017-02-10

    One of the grand challenges of this century is to transition fuels and chemicals production derived from fossil feedstocks to renewable feedstocks such as cellulosic biomass. Here we describe fast microwave conversion of microcrystalline cellulose (MCC) in water, with dilute acid catalyst to produce valuable platform chemicals. Single 10min microwave assisted treatment was able to convert >60% of MCC, with >50mol% yield of desirable products such as glucose, HMF, furfural and levulinic acid. Recycling of residual MCC with make-up fresh MCC resulted in an overall conversion of >93% after 5 cycles while maintaining >60% conversion in each cycle. Addition of isopropanol (70%v/v) as a co-solvent increased the yields of HMF and levulinic acid. This work shows for the first time proof of concept for complete conversion of recalcitrant microcrystalline cellulose in mild conditions of low temperature, dilute acid and short residence time using energy efficient microwave technology.

  16. Scale-up of diluted sulfuric acid hydrolysis for producing sugarcane bagasse hemicellulosic hydrolysate (SBHH).

    PubMed

    Rodrigues, Rita de Cássia L B; Rocha, George J M; Rodrigues, Durval; Filho, Hélcio J I; Felipe, Maria das Graças A; Pessoa, Adalberto

    2010-02-01

    Sugarcane bagasse was pretreated with diluted sulfuric acid to obtain sugarcane bagasse hemicellulosic hydrolysate (SBHH). Experiments were conducted in laboratory and semi-pilot reactors to optimize the xylose recovery and to reduce the generation of sugar degradation products, as furfural and 5-hydroxymethylfurfural (HMF). The hydrolysis scale-up procedure was based on the H-Factor, that combines temperature and residence time and employs the Arrhenius equation to model the sulfuric acid concentration (100 mg(acid)/g(dm)) and activation energy (109 kJ/mol). This procedure allowed the mathematical estimation of the results through simulation of the conditions prevailing in the reactors with different designs. The SBHH obtained from different reactors but under the same H-Factor of 5.45+/-0.15 reached similar xylose yield (approximately 74%) and low concentration of sugar degradation products, as furfural (0.082 g/L) and HMF (0.0071 g/L). Also, the highest lignin degradation products (phenolic compounds) were rho-coumarilic acid (0.15 g/L) followed by ferulic acid (0.12 g/L) and gallic acid (0.035 g/L). The highest concentration of ions referred to S (3433.6 mg/L), Fe (554.4 mg/L), K (103.9 mg/L). The H-Factor could be used without dramatically altering the xylose and HMF/furfural levels. Therefore, we could assume that H-Factor was directly useful in the scale-up of the hemicellulosic hydrolysate production.

  17. Adaptation and transcriptome analysis of Aureobasidium pullulans in corncob hydrolysate for increased inhibitor tolerance to malic acid production.

    PubMed

    Zou, Xiang; Wang, Yongkang; Tu, Guangwei; Zan, Zhanquan; Wu, Xiaoyan

    2015-01-01

    Malic acid is a dicarboxylic acid widely used in the food industry, and is also a potential C4 platform chemical. Corncob is a low-cost renewable feedstock from agricultural industry. However, side-reaction products (furfural, 5-hydroxymethylfurfural (HMF), formic acid, and acetic acid) that severely hinder fermentation are formed during corncob pretreatment. The process for producing malic acid from a hydrolysate of corncob was investigated with a polymalic acid (PMA)-producing Aureobasidium pullulans strain. Under the optimal hydrolysate sugar concentration 110 g/L, A. pullulans was further adapted in an aerobic fibrous bed bioreactor (AFBB) by gradually increasing the sugar concentration of hydrolysate. After nine batches of fermentation, the production and productivity of malic acid reached 38.6 g/L and 0.4 g/L h, respectively, which was higher than that in the first batch (27.6 g/L and 0.29 g/L h, respectively). The adapted strain could grow under the stress of 0.5 g/L furfural, 3 g/L HMF, 2g/L acetic acid, and 0.5 g/L formic acid, whereas the wild type did not. Transcriptome analysis revealed that the differentially expressed genes were related to carbohydrate transport and metabolism, lipid transport and metabolism, signal transduction mechanism, redox metabolism, and energy production and conversion under 0.5 g/L furfural and 3 g/L HMF stress conditions. In total, 42 genes in the adapted strain were upregulated by 15-fold or more, and qRT-PCR also confirmed that the expression levels of key genes (i.e. SIR, GSS, CYS, and GSR) involved in sulfur assimilation pathway were upregulated by over 10-fold in adapted strain for cellular protection against oxidative stress.

  18. Adaptation and Transcriptome Analysis of Aureobasidium pullulans in Corncob Hydrolysate for Increased Inhibitor Tolerance to Malic Acid Production

    PubMed Central

    Zou, Xiang; Wang, Yongkang; Tu, Guangwei; Zan, Zhanquan; Wu, Xiaoyan

    2015-01-01

    Malic acid is a dicarboxylic acid widely used in the food industry, and is also a potential C4 platform chemical. Corncob is a low-cost renewable feedstock from agricultural industry. However, side-reaction products (furfural, 5-hydroxymethylfurfural (HMF), formic acid, and acetic acid) that severely hinder fermentation are formed during corncob pretreatment. The process for producing malic acid from a hydrolysate of corncob was investigated with a polymalic acid (PMA)-producing Aureobasidium pullulans strain. Under the optimal hydrolysate sugar concentration 110 g/L, A. pullulans was further adapted in an aerobic fibrous bed bioreactor (AFBB) by gradually increasing the sugar concentration of hydrolysate. After nine batches of fermentation, the production and productivity of malic acid reached 38.6 g/L and 0.4 g/L h, respectively, which was higher than that in the first batch (27.6 g/L and 0.29 g/L h, respectively). The adapted strain could grow under the stress of 0.5 g/L furfural, 3 g/L HMF, 2g/L acetic acid, and 0.5 g/L formic acid, whereas the wild type did not. Transcriptome analysis revealed that the differentially expressed genes were related to carbohydrate transport and metabolism, lipid transport and metabolism, signal transduction mechanism, redox metabolism, and energy production and conversion under 0.5 g/L furfural and 3 g/L HMF stress conditions. In total, 42 genes in the adapted strain were upregulated by 15-fold or more, and qRT-PCR also confirmed that the expression levels of key genes (i.e. SIR, GSS, CYS, and GSR) involved in sulfur assimilation pathway were upregulated by over 10-fold in adapted strain for cellular protection against oxidative stress. PMID:25793624

  19. Decomposition of cellulose by ultrasonic welding in water

    NASA Astrophysics Data System (ADS)

    Nomura, Shinfuku; Miyagawa, Seiya; Mukasa, Shinobu; Toyota, Hiromichi

    2016-07-01

    The use of ultrasonic welding in water to decompose cellulose placed in water was examined experimentally. Filter paper was used as the decomposition material with a horn-type transducer 19.5 kHz adopted as the ultrasonic welding power source. The frictional heat at the point where the surface of the tip of the ultrasonic horn contacts the filter paper decomposes the cellulose in the filter paper into 5-hydroxymethylfurfural (5-HMF), furfural, and oligosaccharide through hydrolysis and thermolysis that occurs in the welding process.

  20. Evaluation of carbohydrates and lignocellulosic biomass from different wood species as raw material for the synthesis of 5-bromomethyfurfural.

    PubMed

    Bredihhin, Aleksei; Mäeorg, Uno; Vares, Lauri

    2013-06-28

    The influence of different parameters on the conversion of carbohydrates and biomass into the potential biofuel intermediate 5-bromomethylfurfural (BMF) has been studied. Our optimized conditions avoid the use of lithium salt additives, making this method cheaper and environmentally more benign compared to previously reported methods. Different wood species and their potential as a raw material in BMF and furfural production have also been evaluated. In addition, we report a very simple and efficient procedure for conversion of 5-hydroxymethylfurfural (HMF) into BMF or 5-chloromethylfurfural (CMF).

  1. Biorefineries based on coffee cut-stems and sugarcane bagasse: furan-based compounds and alkanes as interesting products.

    PubMed

    Aristizábal M, Valentina; Gómez P, Álvaro; Cardona A, Carlos A

    2015-11-01

    This work presents a techno-economic and environmental assessment for a biorefinery based on sugarcane bagasse (SCB), and coffee cut-stems (CCS). Five scenarios were evaluated at different levels, conversion pathways, feedstock distribution, and technologies to produce ethanol, octane, nonane, furfural, and hydroxymethylfurfural (HMF). These scenarios were compared between each other according to raw material, economic, and environmental characteristics. A single objective function combining the Net Present Value and the Potential Environmental Impact was used through the Analytic Hierarchy Process approach to understand and select the best configurations for SCB and CCS cases. The results showed that the configuration with the best economic and environmental performance for SCB and CCS is the one that considers ethanol, furfural, and octane production (scenario 1). The global economic margin was 62.3% and 61.6% for SCB and CCS respectively. The results have shown the potential of these types of biomass to produce fuels and platform products.

  2. Degradation kinetics of the main carbohydrates in birch wood during hot water extraction in a batch reactor at elevated temperatures.

    PubMed

    Borrega, Marc; Nieminen, Kaarlo; Sixta, Herbert

    2011-11-01

    Hot water extraction of wood at elevated temperatures may be a suitable method to produce hemicellulose-lean pulps and to recover xylan-derived products from the water extract. In this study, water extractions of birch wood were conducted at temperatures between 180 and 240 °C in a batch reactor. Xylan was extensively removed, whereas cellulose was partly degraded only at temperatures above 180 °C. Under severe extraction conditions, acetic acid content in the water extract was higher than the corresponding amount of acetyl groups in wood. In addition to oligo- and monosaccharides, considerable amounts of furfural and 5-hydroxymethylfurfural (HMF) were recovered from the extracts. After reaching a maximum, the furfural yield remained constant with increasing extraction time. This maximum slightly decreased with increasing extraction temperature, suggesting the preferential formation of secondary degradation products from xylose. Kinetic models fitting experimental data are proposed to explain degradation and conversion reactions of xylan and glucan.

  3. Production of ethanol and furfural from corn stover

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Corn stover has potential for economical production of biofuels and value-added chemicals. The conversion of corn stover to sugars involves pretreatment and enzymatic hydrolysis. We have optimized hydrothermal, dilute H2SO4 and dilute H3PO4 pretreatments of corn stover for enzymatic saccharificati...

  4. Development of corn silk as a biocarrier for Zymomonas mobilis biofilms in ethanol production from rice straw.

    PubMed

    Todhanakasem, Tatsaporn; Tiwari, Rashmi; Thanonkeo, Pornthap

    2016-01-01

    Z. mobilis cell immobilization has been proposed as an effective means of improving ethanol production. In this work, polystyrene and corn silk were used as biofilm developmental matrices for Z. mobilis ethanol production with rice straw hydrolysate as a substrate. Rice straw was hydrolyzed by dilute sulfuric acid (H2SO4) and enzymatic hydrolysis. The final hydrolysate contained furfural (271.95 ± 76.30 ppm), 5-hydroxymethyl furfural (0.07 ± 0.00 ppm), vanillin (1.81 ± 0.00 ppm), syringaldehyde (5.07 ± 0.83 ppm), 4-hydroxybenzaldehyde (4-HB) (2.39 ± 1.20 ppm) and acetic acid (0.26 ± 0.08%). Bacterial attachment or biofilm formation of Z. mobilis strain TISTR 551 on polystyrene and delignified corn silk carrier provided significant ethanol yields. Results showed up to 0.40 ± 0.15 g ethanol produced/g glucose consumed when Z. mobilis was immobilized on a polystyrene carrier and 0.51 ± 0.13 g ethanol produced/g glucose consumed when immobilized on delignified corn silk carrier under batch fermentation by Z. mobilis TISTR 551 biofilm. The higher ethanol yield from immobilized, rather than free living, Z. mobilis could possibly be explained by a higher cell density, better control of anaerobic conditions and higher toxic tolerance of Z. mobilis biofilms over free cells.

  5. Unorthodox methods for enhancing solvent production in solventogenic Clostridium species.

    PubMed

    Ujor, Victor; Okonkwo, Christopher; Ezeji, Thaddeus Chukwuemeka

    2016-02-01

    While production of biofuels from renewable resources is currently receiving increased attention globally, concerns on availability and sustainability of cheap substrates for their production are growing as well. Lignocellulose-derived sugars (LDS) remain underutilized and merit consideration as a key feedstock. Among other obstacles such as low yield and low solvent titer, mitigation of stresses stemming from lignocellulose-derived microbial inhibitory compounds (LDMICs) that severely impair cell growth and solvent production is a major area of research interest. In addition to attempts at developing LDMIC-tolerant strains via metabolic engineering to enhance utilization of LDS, unconventional approaches that elicit different metabolic perturbations in microorganisms to relieve solvent- and LDMIC-mediated stresses have been explored to increase solvent production from LDS. In this review, the impacts of metabolic perturbations including medium supplementation with glycerol; furfural and 5-hydroxymethyl furfural; allopurinol, an inhibitor of xanthine dehydrogenase; calcium (Ca(2+)) and zinc (Zn(2+)) ions); and artificial electron carriers, methyl viologen and neutral red, on butanol production are discussed. Although these approaches have brought about considerable increases in butanol production, both from LDS and defined glucose-based media, the modes of action for most of these perturbations have yet to be fully characterized. Better understanding of these mechanisms would likely inform development of LDMIC-tolerant, butanol-overproducing strains, as well as possible combinatorial application of these approaches for enhanced butanol production. Hence, delineating the underlying mechanisms of these perturbations deserves further attention.

  6. Development and validation of a fast high pressure liquid chromatography method for the analysis of lignocellulosic biomass hydrolysis and fermentation products.

    PubMed

    Scarlata, Christopher J; Hyman, Deborah A

    2010-04-02

    A simple, precise, and accurate 10-min high pressure liquid chromatography (HPLC) method was developed and validated for the analysis of organic acids, alcohols, and furans from processing biomass into renewable fuels. The method uses an H(+) form cation-exchange resin stationary phase that has a five-fold shorter analysis time versus that in the traditional method. The new method was used for the analysis of acetic acid, ethanol, 5-hydroxymethyl furfural, and furfural. Results were compared with a legacy method that has historically has been used to analyze the same compounds but with a 55 min run time. Linearity was acceptable on the new method with r(2)>0.999 for all compounds using refractive index detection. Limits of detection were between 0.003 and 0.03 g/L and limits of quantification were between 0.1 and 0.01 g/L. The relative standard deviations for precision were less than 0.4% and recoveries ranged from 92% to 114% for all compounds.

  7. Tolerance of S. cerevisiae and Z. mobilis to inhibitors produced during dilute acid hydrolysis of soybean meal.

    PubMed

    Lujan-Rhenals, Deivis E; Morawicki, Rubén O; Ricke, Steven C

    2014-01-01

    The objective of this research was to determine the minimum inhibitory concentration of 5-hydroxymethyl furfural, furfural, and acetic acid on Saccharomyces cerevisiae (NRRL Y-2233) and Zymomonas mobilis subspecies mobilis (NRRL B-4286) in both detoxified hydrolyzed soybean meal and synthetic YM broth spiked with the three compounds. Soybean meal was hydrolyzed with dilute sulfuric acid (0.0, 0.5, 1.25, and 2.0% wt v(-1)) at three temperatures (105, 120, and 135°C) and three durations (15, 30, and 45 min) followed by detoxification with activated carbon. Of all the combinations, only the treatments obtained at 135°C, 2.0% H2SO4, and 45 min and the one at 135°C, 1.25% H2SO4, and 45 min showed inhibition in the growth of the tested microorganisms. Spiked YM broths showed inhibition for the highest levels of inhibitors, either applied individually or in combination.

  8. Ethanol fermentation by xylose-assimilating Saccharomyces cerevisiae using sugars in a rice straw liquid hydrolysate concentrated by nanofiltration.

    PubMed

    Sasaki, Kengo; Sasaki, Daisuke; Sakihama, Yuri; Teramura, Hiroshi; Yamada, Ryosuke; Hasunuma, Tomohisa; Ogino, Chiaki; Kondo, Akihiko

    2013-11-01

    Concentrating sugars using membrane separation, followed by ethanol fermentation by recombinant xylose-assimilating Saccharomyces cerevisiae, is an attractive technology. Three nanofiltration membranes (NTR-729HF, NTR-7250, and ESNA3) were effective in concentrating glucose, fructose, and sucrose from dilute molasses solution and no permeation of sucrose. The separation factors of acetate, formate, furfural, and 5-hydroxymethyl furfural, which were produced by dilute acid pretreatment of rice straw, over glucose after passage through these three membranes were 3.37-11.22, 4.71-20.27, 4.32-16.45, and 4.05-16.84, respectively, at pH 5.0, an applied pressure of 1.5 or 2.0 MPa, and 25 °C. The separation factors of these fermentation inhibitors over xylose were infinite, as there was no permeation of xylose. Ethanol production from approximately two-times concentrated liquid hydrolysate using recombinant S. cerevisiae was double (5.34-6.44 g L(-1)) that compared with fermentation of liquid hydrolysate before membrane separation (2.75 g L(-1)).

  9. Inhibitory effects of furan derivatives and phenolic compounds on dark hydrogen fermentation.

    PubMed

    Lin, Richen; Cheng, Jun; Ding, Lingkan; Song, Wenlu; Zhou, Junhu; Cen, Kefa

    2015-11-01

    The inhibitory effects of furan derivatives [i.e. furfural and 5-hydroxymethylfurfural (5-HMF)] and phenolic compounds (i.e. vanillin and syringaldehyde) on dark hydrogen fermentation from glucose were comparatively evaluated. Phenolic compounds exhibited stronger inhibition on hydrogen production and glucose consumption than furan derivatives under the same 15mM concentration. Furan derivatives were completely degraded after 72h fermentation, while over 55% of phenolic compounds remained unconverted after 108h fermentation. The inhibition coefficients of vanillin (14.05) and syringaldehyde (11.21) were higher than those of 5-HMF (4.35) and furfural (0.64). Vanillin exhibited the maximum decrease of hydrogen yield (17%). The consumed reducing power by inhibitors reduction from R-CHO to RCH2OH was a possible reason contributed to the decreased hydrogen yield. Vanillin exhibited the maximum delay of peak times of hydrogen production rate and glucose consumption. Soluble metabolites and carbon conversion efficiency decreased with inhibitors addition, which were consistent with hydrogen production.

  10. Acid hydrolysis of Curcuma longa residue for ethanol and lactic acid fermentation.

    PubMed

    Nguyen, Cuong Mai; Nguyen, Thanh Ngoc; Choi, Gyung Ja; Choi, Yong Ho; Jang, Kyoung Soo; Park, Youn-Je; Kim, Jin-Cheol

    2014-01-01

    This research examines the acid hydrolysis of Curcuma longa waste, to obtain the hydrolysate containing lactic acid and ethanol fermentative sugars. A central composite design for describing regression equations of variables was used. The selected optimum condition was 4.91% sulphuric acid, 122.68°C and 50 min using the desirability function under the following conditions: the maximum reducing sugar (RS) yield is within the limited range of the 5-hydroxymethylfurfural (HMF) and furfural concentrations. Under the condition, the obtained solution contained 144 g RS/L, 0.79 g furfural/L and 2.59 g HMF/L and was directly fermented without a detoxification step. The maximum product concentration, average productivity, RS conversion and product yield were 115.36 g/L, 2.88 g/L/h, 89.43% and 64% for L-lactic acid; 113.92 g/L, 2.59 g/L/h, 88.31% and 63.29% for D-lactic acid; and 55.03 g/L, 1.38 g/L/h, 42.66 and 30.57%, respectively, for ethanol using a 7-L jar fermenter.

  11. Oil production by oleaginous yeasts using the hydrolysate from pretreatment of wheat straw with dilute sulfuric acid.

    PubMed

    Yu, Xiaochen; Zheng, Yubin; Dorgan, Kathleen M; Chen, Shulin

    2011-05-01

    This paper explores the use of the hydrolysate from the dilute sulfuric acid pretreatment of wheat straw for microbial oil production. The resulting hydrolysate was composed of pentoses (24.3g/L) and hexoses (4.9 g/L), along with some other degradation products, such as acetic acid, furfural, and hydroxymethylfurfural (HMF). Five oleaginous yeast strains, Cryptococcus curvatus, Rhodotorula glutinis, Rhodosporidium toruloides, Lipomyces starkeyi, and Yarrowia lipolytica, were evaluated by using this hydrolysate as substrates. The results showed that all of these strains could use the detoxified hydrolysate to produce lipids while except R. toruloides non-detoxified hydrolysate could also be used for the growth of all of the selective yeast strains. C. curvatus showed the highest lipid concentrations in medium on both the detoxified (4.2g/L) and non-detoxified (5.8 g/L) hydrolysates. And the inhibitory effect studies on C. curvatus indicated HMF had insignificant impacts at a concentration of up to 3g/L while furfural inhibited cell growth and lipid content by 72.0% and 62.0% at 1g/L, respectively. Our work demonstrates that lipid production is a promising alternative to utilize hemicellulosic sugars obtained during pretreatment of lignocellulosic materials.

  12. Alcoholic fermentation of Saccharomyces cerevisiae, Pichia stipitis and Zymomonas mobilis in the presence of inhibitory compounds and seawater.

    PubMed

    Gonçalves, Fabiano Avelino; dos Santos, Everaldo Silvino; de Macedo, Gorete Ribeiro

    2015-06-01

    Production of cellulosic ethanol and holocellulosic ethanol from vegetable or microbial biomass starts with a hydrolysate containing compounds which may produce negative effects in the enzymatic hydrolysis and fermentation stages due to the need of pretreatment of the materials. In this way, the simultaneous presence of hydroxymethylfurfural (HMF), furfural, acetic acid, levulinic acid, and formic acid in different concentrations was tested in the fermentation using Saccharomyces cerevisiae, Pichia stipitis, and Zymomonas mobilis. The substitution of freshwater by seawater in the culture medium was also analyzed. Thus, inhibitory effects were stronger in the fermentation using P. stipitis, followed by Z. mobilis and S. cerevisiae. Formic acid and acetic acid presented more significant effects among the inhibitory compounds, followed by HMF, furfural and levulinic acid. Fermentation performed in culture medium with seawater showed promising results, especially in the ethanol yield using S. cerevisiae (0.50 g ethanol/g glucose) and Z. mobilis (0.49 g ethanol/g glucose). Whereas the production of cellulosic ethanol and holocellulosic ethanol are in early stages of development on an industrial scale, and that the availability and use of freshwater may cause socio-environmental problems for expansion of ethanol production, the use of seawater appears as an alternative to mitigate this problem.

  13. Improvement of ethanol productivity and energy efficiency by degradation of inhibitors using recombinant Zymomonas mobilis (pHW20a-fdh).

    PubMed

    Dong, Hong-Wei; Fan, Li-Qiang; Luo, Zichen; Zhong, Jian-Jiang; Ryu, Dewey D Y; Bao, Jie

    2013-09-01

    Toxic compounds, such as formic acid, furfural, and hydroxymethylfurfural (HMF) generated during pretreatment of corn stover (CS) at high temperature and low pH, inhibit growth of Zymomonas mobilis and lower the conversion efficiency of CS to biofuel and other products. The inhibition of toxic compounds is considered as one of the major technical barriers in the lignocellulose bioconversion. In order to detoxify and/or degrade these toxic compounds by the model ethanologenic strain Z. mobilis itself in situ the fermentation medium, we constructed a recombinant Z. mobilis ZM4 (pHW20a-fdh) strain that is capable of degrading toxic inhibitor, formate. This is accomplished by cloning heterologous formate dehydrogenase gene (fdh) from Saccharomyces cerevisiae and by coupling this reaction of NADH regeneration reaction system with furfural and HMF degradation in the recombinant Z. mobilis strain. The NADH regeneration reaction also improved both the energy efficiency and cell physiological activity of the recombinant organism, which were definitely confirmed by the improved cell growth, ethanol yield, and ethanol productivity during fermentation with CS hydrolysate.

  14. Improvement of the fermentability of oxalic acid hydrolysates by detoxification using electrodialysis and adsorption.

    PubMed

    Jeong, So-Yeon; Trinh, Ly Thi Phi; Lee, Hong-Joo; Lee, Jae-Won

    2014-01-01

    A two-step detoxification process consisting of electrodialysis and adsorption was performed to improve the fermentability of oxalic acid hydrolysates. The constituents of the hydrolysate differed significantly between mixed hardwood and softwood. Acetic acid and furfural concentrations were high in the mixed hardwood, whereas 5-hydroxymethylfurfural (HMF) concentration was relatively low compared with that of the mixed softwood. The removal efficiency of acetic acid reached 100% by electrodialysis (ED) process in both hydrolysates, while those of furfural and HMF showed very low, due to non-ionizable properties. Most of the remaining inhibitors were removed by XAD-4 resin. In the mixed hardwood hydrolysate without removal of the inhibitors, ethanol fermentation was not completed. Meanwhile, both ED-treated hydrolysates successfully produced ethanol with 0.08 and 0.15 g/Lh ethanol productivity, respectively. The maximum ethanol productivity was attained after fermentation with 0.27 and 0.35 g/Lh of detoxified hydrolysates, which were treated by ED, followed by XAD-4 resin.

  15. Superelectrophilic activation of 5-hydroxymethylfurfural and 2,5-diformylfuran: organic synthesis based on biomass-derived products.

    PubMed

    Ryabukhin, Dmitry S; Zakusilo, Dmitry N; Kompanets, Mikhail O; A Tarakanov, Anton; Boyarskaya, Irina A; Artamonova, Tatiana O; Khohodorkovskiy, Mikhail A; Opeida, Iosyp O; Vasilyev, Aleksander V

    2016-01-01

    The reaction of 5-hydroxymethylfurfural (5-HMF) with arenes in superacidic trifluoromethanesulfonic acid (triflic acid, TfOH) as the solvent at room temperature for 1-24 h gives rise to 5-arylmethylfurfurals (yields of 17-91%) and 2-arylmethyl-5-(diarylmethyl)furans (yields of 10-37%). The formation of these two types of reaction products depends on the nucleophilicity of the arene. The same reactions under the action of acidic zeolites H-USY in high pressure tubes at 130 °C for 1 h result in the formation of only 5-arylmethylfurfurals (yields of 45-79%). 2,5-Diformylfuran (2,5-DFF) in the reaction with arenes under the action of AlBr3 at room temperature for 1 h leads to 5-(diarylmethyl)furfurals (yields of 51-90%). The reactive protonated species of 5-HMF and 2,5-DFF were characterized by NMR spectroscopy in TfOH and studied by DFT calculations. These reactions show possibilities of organic synthesis based on biomass-derived 5-HMF and 2,5-DFF.

  16. Superelectrophilic activation of 5-hydroxymethylfurfural and 2,5-diformylfuran: organic synthesis based on biomass-derived products

    PubMed Central

    Ryabukhin, Dmitry S; Zakusilo, Dmitry N; Kompanets, Mikhail O; A.Tarakanov, Anton; Boyarskaya, Irina A; Artamonova, Tatiana O; Khohodorkovskiy, Mikhail A; Opeida, Iosyp O

    2016-01-01

    Summary The reaction of 5-hydroxymethylfurfural (5-HMF) with arenes in superacidic trifluoromethanesulfonic acid (triflic acid, TfOH) as the solvent at room temperature for 1–24 h gives rise to 5-arylmethylfurfurals (yields of 17–91%) and 2-arylmethyl-5-(diarylmethyl)furans (yields of 10–37%). The formation of these two types of reaction products depends on the nucleophilicity of the arene. The same reactions under the action of acidic zeolites H-USY in high pressure tubes at 130 °C for 1 h result in the formation of only 5-arylmethylfurfurals (yields of 45–79%). 2,5-Diformylfuran (2,5-DFF) in the reaction with arenes under the action of AlBr3 at room temperature for 1 h leads to 5-(diarylmethyl)furfurals (yields of 51–90%). The reactive protonated species of 5-HMF and 2,5-DFF were characterized by NMR spectroscopy in TfOH and studied by DFT calculations. These reactions show possibilities of organic synthesis based on biomass-derived 5-HMF and 2,5-DFF. PMID:27829919

  17. [Effect of byproducts in lignocellulose hydrolysates on ethanol fermentation by Issatchenkia orientalis].

    PubMed

    Wang, Fengqin; Liu, Yaqiong; Zhang, Rui; Wang, Yuanyuan; Xie, Hui; Song, Andong

    2014-05-01

    Byproducts in lignocellulose hydrolysates, namely sodium formate (1 to 5 g/L), sodium acetic (2.5 to 8.0 g/L), furfural (0.2-2 g/L), 5-hydroxymethylfurfural (5-HMF, 1 to 1.0 g/L) or vanillin (0.5 to 2 g/L) were used to evaluate their effects on ethanol fermentation by Issatchenkia orientalis HN-1 using single factor test and the response surface central composite experiment. Results showed that most of the byproducts had no obvious inhibition on the production of ethanol, except for the addition of 2 g/L vanillin or 1 g/L of 5-HMF, which reduced the ethanol production by 20.38% and 11.2%, respectively. However, high concentration of some byproducts in lignocellulose hydrolysates, such as sodium formate (1 to 5 g/L), sodium acetic (2.5 to 8.0 g/L), furfural (0.2 to 2 g/L) and vanillin (0.5 to 2 g/L) inhibited the growth of I. orientalis HN-1 significantly. Compared with the control, the dry cell weight of I. orientalis HN-1 decreased by 25.04% to 37.02%, 28.83% to 43.82%, 20.06% to 37.60% and 26.39% to 52.64%, respectively, when the above components were added into the fermentation broth and the fermentation lasted for 36 h. No significant interaction effect of the various inhibitors (sodium formate, sodium acetic, furfural and vanillin) except for vanillin single factor on the ethanol production was observed based on the central composite experiments. The concentrations of byproducts in most lignocellulose hydrolysates were below the initial inhibition concentration on ethanol production by Issatchenkia orientalis HN-1, which indicated that Issatchenkia orientalis HN-1 can be used for ethanol production from lignocellulose hydrolysates.

  18. Connecting Lignin-Degradation Pathway with Pre-Treatment Inhibitor Sensitivity of Cupriavidus necator

    SciTech Connect

    Wang, W.; Yang, S.; Hunsinger, G. B.; Pienkos, P. T.; Johnson, D. K.

    2014-05-27

    In order to produce lignocellulosic biofuels economically, the complete release of monomers from the plant cell wall components, cellulose, hemicellulose, and lignin, through pre-treatment and hydrolysis (both enzymatic and chemical), and the efficient utilization of these monomers as carbon sources, is crucial. In addition, the identification and development of robust microbial biofuel production strains that can tolerate the toxic compounds generated during pre-treatment and hydrolysis is also essential. In this work, Cupriavidus necator was selected due to its capabilities for utilizing lignin monomers and producing polyhydroxylbutyrate (PHB), a bioplastic as well as an advanced biofuel intermediate. We characterized the growth kinetics of C. necator in pre-treated corn stover slurry as well as individually in the pre-sence of 11 potentially toxic compounds in the saccharified slurry. We found that C. necator was sensitive to the saccharified slurry produced from dilute acid pre-treated corn stover. Five out of 11 compounds within the slurry were characterized as toxic to C. necator, namely ammonium acetate, furfural, hydroxymethylfurfural (HMF), benzoic acid, and p-coumaric acid. Aldehydes (e.g., furfural and HMF) were more toxic than the acetate and the lignin degradation products benzoic acid and p-coumaric acid; furfural was identified as the most toxic compound. Although toxic to C. necator at high concentration, ammonium acetate, benzoic acid, and p-coumaric acid could be utilized by C. necator with a stimulating effect on C. necator growth. Consequently, the lignin degradation pathway of C. necator was reconstructed based on genomic information and literature. The efficient conversion of intermediate catechol to downstream products of cis,cis-muconate or 2-hydroxymuconate-6-semialdehyde may help improve the robustness of C. necator to benzoic acid and p-coumaric acid as well as improve PHB productivity.

  19. Microwave-assisted chemical pre-treatment of waste sorghum leaves: Process optimization and development of an intelligent model for determination of volatile compound fractions.

    PubMed

    Rorke, Daneal C S; Suinyuy, Terence N; Gueguim Kana, E B

    2017-01-01

    This study reports the profiling of volatile compounds generated during microwave-assisted chemical pre-treatment of sorghum leaves. Compounds including acetic acid (0-186.26ng/g SL), furfural (0-240.80ng/g SL), 5-hydroxymethylfurfural (HMF) (0-19.20ng/g SL) and phenol (0-7.76ng/g SL) were detected. The reducing sugar production was optimized. An intelligent model based on Artificial Neural Networks (ANNs) was developed and validated to predict a profile of 21 volatile compounds under novel pre-treatment conditions. This model gave R(2)-values of up to 0.93. Knowledge extraction revealed furfural and phenol exhibited high sensitivity to acid- and alkali concentration and S:L ratio, while phenol showed high sensitivity to microwave duration and intensity. Furthermore, furfural production was majorly dependent on acid concentration and fit a dosage-response relationship model with a 2.5% HCl threshold. Significant non-linearities were observed between pre-treatment conditions and the profile of various compounds. This tool reduces analytical costs through virtual analytical instrumentation, improving process economics.

  20. Glucose and Fructose to Platform Chemicals: Understanding the Thermodynamic Landscapes of Acid-Catalysed Reactions Using High-Level ab Initio Methods

    SciTech Connect

    Assary, Rajeev S.; Kim, Taijin; Low, John; Greeley, Jeffrey P.; Curtiss, Larry A.

    2012-12-28

    Molecular level understanding of acid-catalysed conversion of sugar molecules to platform chemicals such as hydroxy-methyl furfural (HMF), furfuryl alcohol (FAL), and levulinic acid (LA) is essential for efficient biomass conversion. In this paper, the high-level G4MP2 method along with the SMD solvation model is employed to understand detailed reaction energetics of the acid-catalysed decomposition of glucose and fructose to HMF. Based on protonation free energies of various hydroxyl groups of the sugar molecule, the relative reactivity of gluco-pyranose, fructo-pyranose and fructo-furanose are predicted. Calculations suggest that, in addition to the protonated intermediates, a solvent assisted dehydration of one of the fructo-furanosyl intermediates is a competing mechanism, indicating the possibility of multiple reaction pathways for fructose to HMF conversion in aqueous acidic medium. Two reaction pathways were explored to understand the thermodynamics of glucose to HMF; the first one is initiated by the protonation of a C2–OH group and the second one through an enolate intermediate involving acyclic intermediates. Additionally, a pathway is proposed for the formation of furfuryl alcohol from glucose initiated by the protonation of a C2–OH position, which includes a C–C bond cleavage, and the formation of formic acid. The detailed free energy landscapes predicted in this study can be used as benchmarks for further exploring the sugar decomposition reactions, prediction of possible intermediates, and finally designing improved catalysts for biomass conversion chemistry in the future.

  1. Bioprospecting thermotolerant ethanologenic yeasts for simultaneous saccharification and fermentation from diverse environments.

    PubMed

    Choudhary, Jairam; Singh, Surender; Nain, Lata

    2017-03-01

    Lignocellulosic biomass, a promising renewable energy source, can be used for the production of second generation bioethanol. Simultaneous saccharification and fermentation (SSF), the process which alleviates the problem of separate hydrolysis and fermentation (SHF), requires thermotolerant ethanologenic yeast for bioethanol production. Therefore, ten yeast strains isolated from diverse sources, belonging to various genera like Saccharomyces, Candida, Pichia and Wickerhamomyces were evaluated for their thermotolerance, sugar utilization pattern, inhibitor tolerance and ethanol production potential with glucose, xylose and alkali pretreated paddy straw. All the tested strains were found to be thermotolerant, capable of significant growth at 40°C. Candida tropicalis Y6 was capable of utilizing a wide range of sugars as compared with other yeast isolates. Strains of Candida showed better inhibitor tolerance as compared to Saccharomyces and Pichia strains and exhibited only 5.1-18.8% and 4.7-7.9% reduction in growth with furfural and 5-hydroxymethyl furfural, respectively. Saccharomyces cerevisiae JRC6, isolated from distillery waste, produced ethanol with 88.3% and 89.1% theoretical efficiency at 40°C and 42°C, respectively, from glucose. This strain also produced significantly higher amount of ethanol (3.8 g/L) with better fermentation efficiency (87.9%) from alkali pretreated paddy straw at 40°C, as compared with the other yeast strains. Therefore, S. cerevisiae JRC6, based on its ability to ferment sugars at a higher temperature, can be a promising candidate for production of ethanol from lignocellulosic biomass via SSF process.

  2. Imaging flow cytometry for automated detection of hypoxia-induced erythrocyte shape change in sickle cell disease.

    PubMed

    van Beers, Eduard J; Samsel, Leigh; Mendelsohn, Laurel; Saiyed, Rehan; Fertrin, Kleber Y; Brantner, Christine A; Daniels, Mathew P; Nichols, James; McCoy, J Philip; Kato, Gregory J

    2014-06-01

    In preclinical and early phase pharmacologic trials in sickle cell disease, the percentage of sickled erythrocytes after deoxygenation, an ex vivo functional sickling assay, has been used as a measure of a patient's disease outcome. We developed a new sickle imaging flow cytometry assay (SIFCA) and investigated its application. To perform the SIFCA, peripheral blood was diluted, deoxygenated (2% oxygen) for 2 hr, fixed, and analyzed using imaging flow cytometry. We developed a software algorithm that correctly classified investigator tagged "sickled" and "normal" erythrocyte morphology with a sensitivity of 100% and a specificity of 99.1%. The percentage of sickled cells as measured by SIFCA correlated strongly with the percentage of sickle cell anemia blood in experimentally admixed samples (R = 0.98, P ≤ 0.001), negatively with fetal hemoglobin (HbF) levels (R = -0.558, P = 0.027), negatively with pH (R = -0.688, P = 0.026), negatively with pretreatment with the antisickling agent, Aes-103 (5-hydroxymethyl-2-furfural) (R = -0.766, P = 0.002), and positively with the presence of long intracellular fibers as visualized by transmission electron microscopy (R = 0.799, P = 0.002). This study shows proof of principle that the automated, operator-independent SIFCA is associated with predictable physiologic and clinical parameters and is altered by the putative antisickling agent, Aes-103. SIFCA is a new method that may be useful in sickle cell drug development.

  3. Yeast metabolic state identification using micro-fiber optics spectroscopy

    NASA Astrophysics Data System (ADS)

    Silva, J. S.; Castro, C. C.; Vicente, A. A.; Tafulo, P.; Jorge, P. A. S.; Martins, R. C.

    2011-05-01

    Saccharomyces cerevisiae morphology is known to be dependent on the cell physiological state and environmental conditions. On their environment, wild yeasts tend to form complex colonies architectures, such as stress response and pseudohyphal filaments morphologies, far away from the ones found inside bioreactors, where the regular cell cycle is observed under controlled conditions (e.g. budding and flocculating colonies). In this work we explore the feasibility of using micro-fiber optics spectroscopy to classify Saccharomyces cerevisiae S288C colony structures in YPD media, under different growth conditions, such as: i) no alcohol; ii) 1 % (v/v) Ethanol; iii) 1 % (v/v) 1-butanol; iv) 1 % (v/v) Isopropanol; v) 1 % (v/v) Tert-Amyl alcohol (2 Methyl-2-butanol); vi) 0,2 % (v/v) 2-Furaldehyde; vii) 5 % (w/v) 5 (Hydroxymethyl)-furfural; and viii) 1 % (w/v) (-)-Adenosine3', 5'cyclic monophosphate. The microscopy system includes a hyperspectral camera apparatus and a micro fiber (sustained by micro manipulator) optics system for spectroscopy. Results show that micro fiber optics system spectroscopy has the potential for yeasts metabolic state identification once the spectral signatures of colonies differs from each others. This technique associated with others physico-chemical information can benefit the creation of an information system capable of providing extremely detailed information about yeast metabolic state that will aid both scientists and engineers to study and develop new biotechnological products.

  4. Generation of Maillard compounds from inulin during the thermal processing of Agave tequilana Weber Var. azul.

    PubMed

    Mancilla-Margalli, Norma A; López, Mercedes G

    2002-02-13

    During the cooking process of Agave tequilana Weber var. azul to produce tequila, besides the hydrolysis of inulin to generate fermentable sugars, many volatiles, mainly Maillard compounds, are produced, most of which may have a significant impact on the overall flavor of tequila. Exudates (agave juice) from a tequila company were collected periodically, and color, Brix, fructose concentration, and reducing sugars were determined as inulin breakdown took place. Maillard compounds were obtained by extraction with CH(2)Cl(2), and the extracts were analyzed by GC-MS. Increments in color, Brix, and reducing sugars were observed as a function of time, but a decrease in fructose concentration was found. Many Maillard compounds were identified in the exudates, including furans, pyrans, aldehydes, and nitrogen and sulfur compounds. The most abundant Maillard compounds were methyl-2-furoate, 2,3-dihydroxy-3,5-dihydro-6-methyl-4(H)-pyran-4-one, and 5-(hydroxymethyl)furfural. In addition, a series of short- and long-chain fatty acids was also found. A large number of the volatiles in A. tequilana Weber var. azul were also detected in tequila extracts, and most of these have been reported as a powerful odorants, responsible for the unique tequila flavor.

  5. Protective Effect of Salicornia europaea Extracts on High Salt Intake-Induced Vascular Dysfunction and Hypertension

    PubMed Central

    Panth, Nisha; Park, Sin-Hee; Kim, Hyun Jung; Kim, Deuk-Hoi; Oak, Min-Ho

    2016-01-01

    High salt intake causes and aggravates arterial hypertension and vascular dysfunction. We investigated the effect of Salicornia europaea extracts (SE) on vascular function and blood pressure. SE constituents were analyzed using high performance liquid chromatography, and SE’s effect on vascular function was evaluated in isolated porcine coronary arteries. SE’s vascular protective effect was also evaluated in vivo using normotensive and spontaneous hypertensive rats (SHRs). SE mainly contained sodium chloride (55.6%), 5-(hydroxymethyl)furfural, p-coumaric acid, and trans-ferulic acid. High sodium (160 mmol/L) induced vascular dysfunction; however, SE containing the same quantity of sodium did not cause vascular dysfunction. Among the compounds in SE, trans-ferulic acid accounts for the vascular protective effect. Normotensive rats fed a high-salt diet showed significantly increased systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP), which decreased significantly in the SE-treated groups. In SHRs, high edible salt intake significantly increased SBP, DBP, and MAP, but SE intake was associated with a significantly lower MAP. Thus, SE did not induce vascular dysfunction, and trans-ferulic acid might be at least partly responsible for the vasoprotective effect of SE. Taken together, SE could be used as an alternative to purified salt to prevent and ameliorate hypertension. PMID:27455235

  6. Phytochemistry, antioxidant capacity, total phenolic content and anti-inflammatory activity of Hibiscus sabdariffa leaves.

    PubMed

    Zhen, Jing; Villani, Thomas S; Guo, Yue; Qi, Yadong; Chin, Kit; Pan, Min-Hsiung; Ho, Chi-Tang; Simon, James E; Wu, Qingli

    2016-01-01

    A liquid chromatography-mass spectrometry method was developed for the simultaneous separation, and determination of natural compounds including phenolic acids and flavonoids in the leaves of Hibiscus sabdariffa. By analyzing the UV and MS data, and comparison with authenticated standards, 10 polyphenols including neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid, quercetin, kaempferol and their glycosides were identified together with 5-(hydroxymethyl)furfural. Major constituents in the leaves of 25 different populations from worldwide accessions were quantified and compared with each other. The total phenolic content of each accession was determined using Folin-Ciocalteu assay, ranging from 18.98 ± 2.7 to 29.9 ± 0.5 mg GAE/g. Their in vitro antioxidant activities were measured by ABTS radical cation decolorization assay, varying from 17.5 to 152.5 ± 18.8 μmol Trolox/g. After the treatment of H. sabdariffa leaf extract, the reduction of LPS-induced NO production dose-dependently in RAW 264.7 cell indicates the extract's potential anti-inflammatory activity.

  7. Evaluation of antioxidant activity, colour and some nutritional characteristics of pomegranate (Punica granatum L.) juice and its sour concentrate processed by conventional evaporation.

    PubMed

    Orak, H Hülya

    2009-01-01

    In this study the antioxidant activity, colour and some nutritional characteristics of pomegranate juice (PJ) and its traditional sour concentrate (CPJ), produced in Denizli, Turkey, were analysed. The total anthocyanin content of PJ was found to be 492.9 mg/l but it was not determined in CPJ. The total phenolics were also found to be 3,246 and 9,870 microg/ml in PJ and CPJ, respectively. The antioxidant activity (percentage of inhibition of on peroxidation in linoleic acid system) of CPJ was determined to be higher (85.91%) than that of PJ (79.06%). During the concentration process, the reducing sugars, glucose and fructose level of CPJ showed an increase to 46.46%, 23.89%, and 22.53%, respectively. In CPJ the amounts of sodium, iron, zinc, copper and lead were found lower than those of PJ. On the other hand, potassium and magnesium mineral contents increased during concentration. Among the various elements, cadmium, mercury, manganese, cobalt and boron were also analysed for determination of metallic contamination, but they were not found in PJ juice and CPJ. 5-Hydroxymethyl furfural was determined to be at a significant level in CPJ as a result of the heat process.

  8. Identification of H₂O₂ as a major antimicrobial component in coffee.

    PubMed

    Mueller, Ulla; Sauer, Tanja; Weigel, Ingrid; Pichner, Rohtraud; Pischetsrieder, Monika

    2011-05-01

    Coffee shows distinct antimicrobial activity against several bacterial genera. The present study investigated molecular mechanisms and active ingredients mediating the antimicrobial effect of coffee. Depending on concentration, roasted, but not raw coffee brew inhibited the growth of Escherichia coli and Listeria innocua. Several coffee ingredients with known antibacterial properties were tested for their contribution to the observed effect. In natural concentration, caffeine, ferulic acid and a mixture of all test compounds showed very weak, but significant activity, whereas trigonelline, 5-(hydroxymethyl)furfural, chlorogenic acid, nicotinic acid, caffeic acid, and methylglyoxal were not active. Antimicrobial activity, however, was completely abolished by addition of catalase indicating that H(2)O(2) is a major antimicrobial coffee component. In accordance with this assumption, bacterial counts during 16 h of incubation were inversely related to the H(2)O(2) concentration in the incubation solution. Pure H(2)O(2) showed slightly weaker activity. The H(2)O(2) dependent antimicrobial activity of coffee could be mimicked by a reaction mixture of d-ribose and l-lysine (30 min 120 °C) indicating that H(2)O(2) is generated in the coffee brew by Maillard reaction products. Identification of H(2)O(2) as major antimicrobial coffee component is important to evaluate the application of coffee or coffee extracts as natural preservatives.

  9. Enzymatic saccharification of dilute acid pretreated eucalyptus chips for fermentable sugar production.

    PubMed

    Wei, Weiqi; Wu, Shubin; Liu, Liguo

    2012-04-01

    Dilute sulfuric acid was used to pretreat eucalyptus chips prior to enzymatic hydrolysis. After both pretreatment and enzymatic hydrolysis processes. Attention is paid to sugar recovery. The maximum total sugars yield (combined xylose and glucose, 47.69g/100g raw material, representing 82% of total sugars in the eucalyptus biomass) was obtained at 160°C, 0.75% acid concentration and 10min residence time, which is consider to be the best reasonable conditions for the dilute acid pretreatment of eucalyptus, corresponding concentrations of acetic acid, HMF, and furfural in the prehydrolysate were about 2.01g/L, 0.13g/L and 1.37g/L, respectively. Under this optimal pretreatment condition, the acid-insoluble lignin recovery in the insoluble solid resulting from enzymatic hydrolysis, was 22.7g/100g raw material, representing 80% of acid-insoluble lignin in the eucalyptus biomass.

  10. Expression of a heat-stable NADPH-dependent alcohol dehydrogenase in Caldicellulosiruptor bescii results in furan aldehyde detoxification

    DOE PAGES

    Chung, Daehwan; Verbeke, Tobin J.; Cross, Karissa L.; ...

    2015-07-22

    Compounds such as furfural and 5-hydroxymethylfurfural (5-HMF) are generated through the dehydration of xylose and glucose, respectively, during dilute-acid pretreatment of lignocellulosic biomass and are also potent microbial growth and fermentation inhibitors. The enzymatic reduction of these furan aldehydes to their corresponding, and less toxic, alcohols is an engineering approach that has been successfully implemented in both Saccharomyces cerevisiae and ethanologenicEscherichia coli, but has not yet been investigated in thermophiles relevant to biofuel production through consolidated bioprocessing (CBP). Developing CBP-relevant biocatalysts that are either naturally resistant to such inhibitors, or are amenable to engineered resistance, is therefore, an important componentmore » in making biofuels production from lignocellulosic biomass feasible.« less

  11. Expression of a heat-stable NADPH-dependent alcohol dehydrogenase in Caldicellulosiruptor bescii results in furan aldehyde detoxification

    SciTech Connect

    Chung, Daehwan; Verbeke, Tobin J.; Cross, Karissa L.; Westpheling, Janet; Elkins, James G.

    2015-07-22

    Compounds such as furfural and 5-hydroxymethylfurfural (5-HMF) are generated through the dehydration of xylose and glucose, respectively, during dilute-acid pretreatment of lignocellulosic biomass and are also potent microbial growth and fermentation inhibitors. The enzymatic reduction of these furan aldehydes to their corresponding, and less toxic, alcohols is an engineering approach that has been successfully implemented in both Saccharomyces cerevisiae and ethanologenicEscherichia coli, but has not yet been investigated in thermophiles relevant to biofuel production through consolidated bioprocessing (CBP). Developing CBP-relevant biocatalysts that are either naturally resistant to such inhibitors, or are amenable to engineered resistance, is therefore, an important component in making biofuels production from lignocellulosic biomass feasible.

  12. Nutritional and physicochemical characteristic of commercial Spanish citrus juices.

    PubMed

    Alvarez, J; Pastoriza, S; Alonso-Olalla, R; Delgado-Andrade, C; Rufián-Henares, J A

    2014-12-01

    Citrus juices are perceived as healthy foods by consumers due to their richness in antioxidant compounds. Despite the large number of papers about the antioxidant activity of citrus juices, less is known about the relationship with physicochemical properties. This paper shows that the overall antioxidant activity of citrus juices is underestimated with the standard methodologies, being up to 10-times higher with the GAR method (including an in vitro gastrointestinal digestion). 70% of the antioxidant activity was found in the soluble fraction and citrus juices contributed up to 12% of the overall antioxidant intake within the Spanish diet. Physicochemical parameters, such as colour, fluorescence, 5-hydroxymethylfurfural and furfural contents, were correlated with nutritional parameters in some samples. The intake of HMF was negligible from commercial citrus juices and was absent in freshly squeezed ones. Finally, a mathematical model is developed to classify juices depending on their nature or storage conditions.

  13. High temperature dilute acid pretreatment of coastal Bermuda grass for enzymatic hydrolysis.

    PubMed

    Redding, Arthur P; Wang, Ziyu; Keshwani, Deepak R; Cheng, Jay J

    2011-01-01

    Dilute sulfuric acid was used to pretreat coastal Bermuda grass at high temperature prior to enzymatic hydrolysis. After both pretreatment and enzymatic hydrolysis processes, the highest yield of total sugars (combined xylose and glucose) was 97% of the theoretical value. The prehydrolyzate liquor was analyzed for inhibitory compounds (furfural, hydroxymethylfurfural (HMF)) in order to assess potential risk for inhibition during the following fermentation. Accounting for the formation of the inhibitory compounds, a pretreatment with 1.2% acid at 140 °C for 30 min with a total sugar yield of 94% of the theoretical value may be more favorable for fermentation. From this study, it can be concluded that dilute sulfuric acid pretreatment can be successfully applied to coastal Bermuda grass to achieve high yields of monomeric glucose and xylose with acceptable levels of inhibitory compound formation.

  14. Modeling the production of sugar and byproducts from acid bisulfite pretreatment and enzymatic hydrolysis of Douglas-fir.

    PubMed

    Liu, Yalan; Wang, Jinwu; Wolcott, Michael

    2017-01-01

    The aim of this work was to investigate the kinetics of multiple chemicals in acid bisulfite pretreatment and the relationship between total sugar yields and pretreatment factors (temperature and time). The results showed Saeman model accurately fitted the pretreatment process. According to this kinetic model, a maximum hemicellulose hydrolysis yield was achieved at a treatment time of 75min with a temperature of 145°C. Meantime, the concentrations of acetic acid, hydroxymethylfurfural (HMF), and furfural were 1.54, 0.60, and 1.15gL(-1), respectively. Also, a Lorentzian function described the relationship between total sugar yield and pretreatment factors: temperature and time. The regression parameters from this mathematical fitting have accurately reflected the maximum total sugar yield and the optimal treatment conditions were determined to be 145°C and 110min.

  15. Acetic acid-assisted hydrothermal fractionation of empty fruit bunches for high hemicellulosic sugar recovery with low byproducts.

    PubMed

    Kim, Dong Young; Um, Byung Hwan; Oh, Kyeong Keun

    2015-07-01

    Xylose, mannose, and galactose (xmg) recovery from empty fruit bunches using acetic acid-assisted hydrothermal (AAH) fractionation method was investigated. Acetic acid has been demonstrated to be effective in xmg recovery in comparison with the liquid hot-water (LHW) fractionation. The maximum xmg recovery yield (50.7 %) from the empty fruit bunch (EFB) was obtained using AAH fractionation at optimum conditions (6.9 wt.% acetic acid at 170 °C and for 18 min); whereas, only 16.2 % of xmg recovery was obtained from the LHW fractionation at the same reaction conditions (170 °C and 18 min). Releasing out the glucose from EFB was kept at low level (<1.0 %) through all tested conditions and consequently negligible 5-HMF and formic acid were analyzed in the hydrolyzate. The production of furfural was also resulted with extremely low level (1.0 g/L).

  16. Evaluation of the antioxidant capacity, furan compounds and cytoprotective/cytotoxic effects upon Caco-2 cells of commercial Colombian coffee.

    PubMed

    Bedoya-Ramírez, Daniel; Cilla, Antonio; Contreras-Calderón, José; Alegría-Torán, Amparo

    2017-03-15

    Antioxidant capacity (AC), total phenolics (TPs), furan compounds (HMF and furfural F) and cytoprotective/cytotoxic effects upon Caco-2 cells (MTT, cell cycle and reactive oxygen species (ROS)) were evaluated in Colombian coffee (2 ground and 4 soluble samples). The AC (ABTS and FRAP), TPs and HMF ranged between 124-722, 95-802μmoles Trolox/g, 21-100mg gallic acid/g and 69-2900mg/kg, respectively. Pretreatment of cells for 24h with lyophilized coffee infusions at the highest dose without cytotoxic effects (500μg/mL) significantly prevented the decrease in cell viability compared to control stress with H2O2 (5mM/2h), recovering viability to values between 34% and 45% and restoring the control values without stress induction in the G1 phase of cell cycle. After exposure to stress, four extracts decreased ROS values significantly to 22.5-24.9%. The coffee samples exerted a cytoprotective effect against oxidative stress, with improvement in cell viability and a reduction of intracellular ROS.

  17. Tunable and selective conversion of 5-HMF to 2,5-furandimethanol and 2,5-dimethylfuran over copper-doped porous metal oxides.

    PubMed

    Kumalaputri, Angela J; Bottari, Giovanni; Erne, Petra M; Heeres, Hero J; Barta, Katalin

    2014-08-01

    Tunable and selective hydrogenation of the platform chemical 5-hydroxymethylfurfural into valuable C6 building blocks and liquid fuel additives is achieved with copper-doped porous metal oxides in ethanol. A new catalyst composition with improved hydrogenation/hydrogenolysis activity is obtained by introducing small amounts of ruthenium dopant into the previously reported Cu(0.59) Mg2.34 Al1.00 structure. At a mild reaction temperature (100 °C), 2,5-furandimethanol is obtained with excellent selectivity up to >99%. Higher reaction temperatures (220 °C) favor selective deoxygenation to 2,5-dimethylfuran and minor product 2,5-dimethyltetrahydrofuran with a combined yield as high as 81%. Notably, these high product yields are maintained at a substrate concentration up to 10 wt% and a low catalyst loading. The influence of different alcohol solvents on product selectivity is explored. Furthermore, reaction intermediates formed at different reaction temperatures are identified. The composition of these product mixtures provides mechanistic insight into the nature of the reduction pathways that influence product selectivity. The catalysts are characterized by elemental analysis, TEM, and BET techniques before and after the reaction. Catalyst recycling experiments are conducted in batch and in a continuous-flow setup.

  18. Hydrothermal processing and enzymatic hydrolysis of sorghum bagasse for fermentable carbohydrates production.

    PubMed

    Dogaris, Ioannis; Karapati, Sofia; Mamma, Diomi; Kalogeris, Emmanuel; Kekos, Dimitris

    2009-12-01

    Untreated and hydrothermally treated sorghum bagasse (SB) was hydrolyzed to simple sugars by the synergistic action of cellulases and hemicellulases produced by the fungi Fusarium oxysporum and Neurospora crassa. Synergism between the two lignocellulolytic systems was maximized with the application of higher fraction of N. crassa enzymes. Hydrothermolysis of SB was studied at a wide range of treatment times and temperatures. At intense pretreatment conditions (210 degrees C for 20 min; logR(0)=4.54), the residual hemicellulose percentage was 17.45%, while formation of inhibitory products, 5-hydromethyl-furfural (HMF), furfural, acetic and formic acid, (0.21, 0.51, 3.36 and 1.80 g/l, respectively) remained in acceptable levels. Maximum conversion of cellulose and total polysaccharides of the untreated SB were 23.18% and 18.79%, respectively. Combining hydrothermal treatment and enzymatic hydrolysis of released oligosaccharides and insoluble solids resulted in improvement of cellulose (approximately 15% increase) and total polysaccharides (two fold) hydrolysis compared to that of untreated SB.

  19. Onsite bio-detoxification of steam-exploded corn stover for cellulosic ethanol production.

    PubMed

    Yu, Yanling; Feng, Yujie; Xu, Chen; Liu, Jia; Li, Dongmei

    2011-04-01

    In the process of ethanol production from steam-exploded corn stover (SECS), a cellulose-degradation strain of Aspergillus nidulans (FLZ10) was investigated whether it could remove the inhibitors released from steam exploded pretreatment , and thereby be used for biological detoxification on Saccharomycescerevisiae. The results showed that FLZ10 removed 75.2% formic acid, 53.6% acetic acid, and 100% hydroxymethyl furfural (5-HMF) and furfural from the hydrolysate washed from SECS after 72h cultivation. A cellulase activity of 0.49 IU/ml was simultaneously produced while the biological detoxification occurred. An ethanol yield of 0.45 g/g on glucose was obtained in the hydrolysate biodetoxified by FLZ10. The glucose consumption rate of FLZ10 was much lower than that of S. cerevisiae, thereby it had little competition with S. cerevisiae on glucose consumption. Based on SECS to ethanol mass balance analysis, with the onsite bio-detoxification, fermentation using S. cerevisiae effectively converted monomeric glucose with 94.4% ethanol yield.

  20. Separate hydrolysis and fermentation (SHF) of Prosopis juliflora, a woody substrate, for the production of cellulosic ethanol by Saccharomyces cerevisiae and Pichia stipitis-NCIM 3498.

    PubMed

    Gupta, Rishi; Sharma, Krishna Kant; Kuhad, Ramesh Chander

    2009-02-01

    Prosopis juliflora (Mesquite) is a raw material for long-term sustainable production of cellulosics ethanol. In this study, we used acid pretreatment, delignification and enzymatic hydrolysis to evaluate the pretreatment to produce more sugar, to be fermented to ethanol. Dilute H(2)SO(4) (3.0%,v/v) treatment resulted in hydrolysis of hemicelluloses from lignocellulosic complex to pentose sugars along with other byproducts such as furfural, hydroxymethyl furfural (HMF), phenolics and acetic acid. The acid pretreated substrate was delignified to the extent of 93.2% by the combined action of sodium sulphite (5.0%,w/v) and sodium chlorite (3.0%,w/v). The remaining cellulosic residue was enzymatically hydrolyzed in 0.05 M citrate phosphate buffer (pH 5.0) using 3.0 U of filter paper cellulase (FPase) and 9.0 U of beta-glucosidase per mL of citrate phosphate buffer. The maximum enzymatic saccharification of cellulosic material (82.8%) was achieved after 28 h incubation at 50 degrees C. The fermentation of both acid and enzymatic hydrolysates, containing 18.24 g/L and 37.47 g/L sugars, with Pichia stipitis and Saccharomyces cerevisiae produced 7.13 g/L and 18.52 g/L of ethanol with corresponding yield of 0.39 g/g and 0.49 g/g, respectively.

  1. Evolutionary engineering of Saccharomyces cerevisiae for enhanced tolerance to hydrolysates of lignocellulosic biomass.

    PubMed

    Almario, María P; Reyes, Luis H; Kao, Katy C

    2013-10-01

    Lignocellulosic biomass has become an important feedstock to mitigate current ethical and economical concerns related to the bio-based production of fuels and chemicals. During the pre-treatment and hydrolysis of the lignocellulosic biomass, a complex mixture of sugars and inhibitors are formed. The inhibitors interfere with microbial growth and product yields. This study uses an adaptive laboratory evolution method called visualizing evolution in real-time (VERT) to uncover the molecular mechanisms associated with tolerance to hydrolysates of lignocellulosic biomass in Saccharomyces cerevisiae. VERT enables a more rational scheme for isolating adaptive mutants for characterization and molecular analyses. Subsequent growth kinetic analyses of the mutants in individual and combinations of common inhibitors present in hydrolysates (acetic acid, furfural, and hydroxymethylfurfural) showed differential levels of resistance to different inhibitors, with enhanced growth rates up to 57%, 12%, 22%, and 24% in hydrolysates, acetic acid, HMF and furfural, respectively. Interestingly, some of the adaptive mutants exhibited reduced fitness in the presence of individual inhibitors, but showed enhanced fitness in the presence of combinations of inhibitors compared to the parental strains. Transcriptomic analysis revealed different mechanisms for resistance to hydrolysates and a potential cross adaptation between oxidative stress and hydrolysates tolerance in several of the mutants.

  2. Biomass Conversion Strategies and the Renewable Production of Hydrogen using Heterogeneous Metal Catalysts

    NASA Astrophysics Data System (ADS)

    Carrasquillo-Flores, Ronald

    Biomass is a renewable carbon source that can be processed into fuels and chemicals in a biorefinery. However, there are a number of challenges that need to be overcome for biomass utilization to be viable. The work presented herein aims to address two existing challenges in biomass processing schemes, namely the efficient utilization of all fractions of lignocellulosic biomass and the renewable production of the hydrogen necessary to reduce the oxygen functionalities native in biomass. First, lignin was depolymerized to produce a renewable phenolic solvent mixture. Biphasic reactions with this solvent and aqueous solution of glucose or xylose produce 5-hydroxymethylfurfural (HMF) and furfural, respectively, at high yields. HMF and furfuryl alcohol could also be upgraded into levulinic acid at high yields. The yields are due to the capacity of the solvent to partition these molecules and prevent their degradation. Second, propyl guaiacol, a component of the phenolic solvent, was used for biphasic reactions where ball milled biomass substrates were used. These substrates are converted to furfural and HMF at high yields due to the partition of these molecules into the solvent and the on-demand production of glucose and xylose from the substrate, minimizing the formation of humins. A study of the water-gas shift reaction over Pt-based catalysts was conducted. Alloying Pt with Re was found to increase the catalytic activity and microkinetic modeling revealed Pt is a good representation of the active site and Re acts as a promoter slightly destabilizing CO binding. A study on formic acid decomposition over Au catalysts was performed. Experiments, density functional theory and microkinetic modeling results indicate the reaction proceeds completely on highly undercoordinated Au atoms with any high coordination atom being largely inert. Motivated by the results on Au catalysts, the metal-support interaction was investigated for the reverse water-gas shift reaction. Using a

  3. Furfural and ethanol production from corn stover by dilute phosphoric acid pretreatment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lignocellulosic biomass is the most abundant carbohydrate source in the world and has potential for economical production of biofuels, especially ethanol. However, its composition is an obstacle for the production of ethanol by the conventional ethanol producing yeast Saccharomyces cerevisiae as it...

  4. A new resistance source of aldehyde reductase functions from Scheffersomyces stipitis against biomass fermentation inhibitor furfural

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aldehyde inhibitory compounds derived from lignocellulosic biomass pretreatment are a major class of toxic chemicals that interfere with microbial growth and subsequent fermentation for advanced biofuels production. This study identified five uncharacterized putative genes of Scheffersomyces stipiti...

  5. Acid-catalyzed furfurly alcohol polymerization : characterizations of molecular structure and thermodynamic properties.

    SciTech Connect

    Kim, T.; Assary, R. S.; Marshall, C. L.; Gosztola, D. J.; Curtiss, L. A.; Stair, P. C.

    2011-01-01

    The liquid-phase polymerization of furfuryl alcohol catalyzed by sulfuric acid catalysts and the identities of molecular intermediates were investigated by using Raman spectroscopy and density functional theory calculation. At room temperature, with an acid catalyst, a vigorous furfuryl alcohol polymerization reaction was observed, whereas even at a high water concentration, furfuryl alcohol was very stable in the absence of an acid catalyst. Theoretical studies were carried out to investigate the thermodynamics of protonation of furfuryl alcohol, initiation of polymerization, and formation of conjugated dienes and diketonic species by using the B3LYP level of theory. A strong aliphatic C=C band observed in the calculated and measured Raman spectra provided crucial evidence to understand the polymerization reaction mechanism. It is confirmed that the formation of a conjugated diene structure rather than a diketone structure is involved in the furfuryl alcohol polymerization reaction.

  6. Heptamethoxyflavone, a citrus flavonoid, suppresses inflammatory osteoclastogenesis and alveolar bone resorption.

    PubMed

    Matsumoto, Chiho; Inoue, Hiroki; Tominari, Tsukasa; Watanabe, Kenta; Hirata, Michiko; Miyaura, Chisato; Inada, Masaki

    2015-01-01

    We examined the effects of heptamethoxyflavone (HMF), a citrus flavonoid on inflammatory bone resorption. HMF suppressed the osteoclast formation and PGE2 production induced by IL-1. In mouse calvarial organ cultures, HMF attenuated the bone resorption elicited by LPS. HMF suppressed bone resorption in the mandibular alveolar bone. HMF may protect against inflammatory bone loss such as periodontal disease.

  7. Renewable liquid fuels from catalytic reforming of biomass-derived oxygenated hydrocarbons

    NASA Astrophysics Data System (ADS)

    Barrett, Christopher J.

    Diminishing fossil fuel reserves and growing concerns about global warming require the development of sustainable sources of energy. Fuels for use in the transportation sector must have specific physical properties that allow for efficient distribution, storage, and combustion; these requirements are currently fulfilled by petroleum-derived liquid fuels. The focus of this work has been the development of two new biofuels that have the potential to become widely used transportation fuels from carbohydrate intermediates. Our first biofuel has cetane numbers ranging from 63 to 97 and is comprised of C7 to C15 straight chain alkanes. These alkanes can be blended with diesel like fuels or with P-series biofuel. Production involves a solid base catalyzed aldol condensation with mixed Mg-Al-oxide between furfural or 5-hydroxymethylfurfural (HMF) and acetone, followed by hydrogenation over Pd/Al2O3, and finally hydrogenation/dehydration over Pt/SiO2-Al2O3. Water was the solvent for all process steps, except for the hydrogenation/dehydration stage where hexadecane was co-fed to spontaneously separate out all alkane products and eliminate the need for energy intensive distillation. A later optimization identified Pd/MgO-ZrO2 as a hydrothermally stable bifunctional catalyst to replace Pd/Al2O3 and the hydrothermally unstable Mg-Al-oxide catalysts along with optimizing process parameters, such as temperature and molar ratios of reactants to maximize yields to heavier alkanes. Our second biofuel involved creating an improved process to produce HMF through the acid-catalyzed dehydration of fructose in a biphasic reactor. Additionally, we developed a technique to further convert HMF into 2,5-dimethylfuran (DMF) by hydrogenolysis of C-O bonds over a copper-ruthenium catalyst. DMF has many properties that make it a superior blending agent to ethanol: it has a high research octane number at 119, a 40% higher energy density than ethanol, 20 K higher boiling point, and is insoluble in

  8. Quantification of furanic derivatives in fortified wines by a highly sensitive and ultrafast analytical strategy based on digitally controlled microextraction by packed sorbent combined with ultrahigh pressure liquid chromatography.

    PubMed

    Perestrelo, Rosa; Silva, Catarina L; Câmara, José S

    2015-02-13

    An improved, reliable and powerful analytical strategy based on digitally controlled microextraction by packed sorbent (MEPS) combined with ultrahigh pressure liquid chromatography (UHPLC) was validated for the simultaneous identification and quantification of major furanic derivatives, namely 5-hydroxymethyl-2-furaldehyde (5HMF), 5-methyl-2-furaldehyde (5MF), 2-furaldehyde (2F) and 2-furyl methyl ketone (2FMK), in fortified wines. To enhance the extraction efficiency of the target furanic derivates, several influencing extraction parameters, such as number of loading cycles, nature of elution solvent and elution volume, were evaluated and optimized. In addition the ability of different MEPS sorbent materials, namely C2, C8, C18, SIL, M1, R-AX, R-CX and PGC, were also tested. The optimal analytical conditions involved loading 3×200 μL of wine samples through a C8 sorbent in a MEPS syringe placed in the semi-automatic eVolH syringe followed by elution using 200 μL MeOH:H2O (95:5, v/v). The furanic derivates separation was achieved using a CORTECS UPLC(®) C18 analytical column in an ultrafast chromatographic run (within 4 min). The method performance was assessed for dry/medium dry (D/MD) and sweet/medium sweet (S/MS) model wines in terms of selectivity, linearity, limit of detection (LOD), limit of quantitation (LOQ), accuracy, precision and matrix effect, using model wine matrix-matched calibration. Good linearity was obtained with a regression coefficient (r(2)) higher than 0.992. A good precision was attained (RSD<5%) and low LODs were achieved for D/MD (4.5-129.3 ng L(-1)) and S/MS (6.9-285.2 ng L(-1)) model wines. The quantification limits (LOQ) for D/MD model wines ranged from 14.9 to 431.0 ng L(-1), whereas for S/MS model wines range from 23.1 to 950.5 ng L(-1). The method also afforded satisfactory results in terms of accuracy, ranging from 74 to 97% for D/MD wines and between 84 and 99% for S/MS wines. The MEPS(C8)/UHPLC-PDA analytical strategy was

  9. Manned Mars mission health maintenance facility

    NASA Technical Reports Server (NTRS)

    Degioanni, Joseph C.

    1986-01-01

    The Health Maintenance Facility (HMF) requirements which enable/enhance manned Mars missions (MMMs) are addressed. It does not attempt to resolve any issues that may affect the feasibility of any given element in the HMF. Reference is made to current work being conducted in the design of the space station HMF. The HMF requirements are discussed within the context of two distinctly different scenarios: HMF as part of the Mars surface infrastructure, and HMF as part of the nine months translation from low Earth orbit to Mars orbit. Requirements for an HMF are provided, and a concept of HMF is shown.

  10. Ultra-trace analysis of furanic compounds in transformer/rectifier oils with water extraction and high-performance liquid chromatography.

    PubMed

    Lin, Monica; Lin, Kham; Lin, Amanda; Gras, Ronda; Luong, Jim

    2016-07-01

    A novel approach for the determination of parts-per-billion level of 5-hydroxymethyl-2-furaldehyde, furfuryl alcohol, furfural, 2-furyl methyl ketone, and 5-methylfurfural in transformer or rectifier oils has been successfully innovated and implemented. Various extraction methods including solid-phase extraction, liquid-liquid extraction using methanol, acetonitrile, and water were studied. Water was by far the most efficient solvent for use as an extraction medium. Separation of the analytes was conducted using a 4.6 mm × 250 mm × 3.5 μm Agilent Zorbax column while detection and quantitation were conducted with a variable wavelength UV detector. Detection limits of all furans were at 1 ppb v/v with linear ranges range from 5 to 1000 ppb v/v with correlation coefficients of 0.997 or better. A relative standard deviation of at most 2.4% at 1000 ppb v/v and 7.3% at 5 ppb v/v and a recovery from 43% to 90% depending on the analyte monitored were obtained. The method was purposely designed to be environmental friendly with water as an extraction medium. Also, the method uses 80% water and 20% acetonitrile with a mere 0.2 mL/min of acetonitrile in an acetonitrile/water mixture as mobile phase. The analytical technique has been demonstrated to be highly reliable with low cost of ownership, suitable for deployment in quality control labs or in regions where available analytical resources and solvents are difficult to procure.

  11. Structural basis for the potent antisickling effect of a novel class of five-membered heterocyclic aldehydic compounds.

    PubMed

    Safo, Martin K; Abdulmalik, Osheiza; Danso-Danquah, Richmond; Burnett, James C; Nokuri, Samuel; Joshi, Gajanan S; Musayev, Faik N; Asakura, Toshio; Abraham, Donald J

    2004-09-09

    Naturally occurring five-membered heterocyclic aldehydes, including 5-hydroxymethyl-2-furfural, increase the oxygen affinity of hemoglobin (Hb) and strongly inhibit the sickling of homozygous sickle red blood (SS) cells. X-ray studies of Hb complexed with these compounds indicate that they form Schiff base adducts in a symmetrical fashion with the N-terminal alphaVal1 nitrogens of Hb. Interestingly, two cocrystal types were isolated during crystallization experiments with deoxygenated Hb (deoxyHb): one crystal type was composed of the low-affinity or tense (T) state Hb quaternary structure; the other crystal type was composed of high-affinity or relaxed state Hb (with a R2 quaternary structure). The R2 crystal appears to be formed as a result of the aldehydes binding to fully or partially ligated Hb in the deoxyHb solution. Repeated attempts to crystallize the compounds with liganded Hb failed, except on rare occasions when very few R state crystals were obtained. Oxygen equilibrium, high performance liquid chromatography (HPLC), antisickling, and X-ray studies suggest that the examined heterocyclic aldehydes may be acting to prevent polymerization of sickle hemoglobin (HbS) by binding to and stabilizing liganded Hb in the form of R2 and/or various relaxed state Hbs, as well as binding to and destabilizing unliganded T state Hb. The proposed mechanism may provide a general model for the antisickling effects of aldehyde containing small molecules that bind to N-terminal alphaVal1 nitrogens of Hb. The examined compounds also represent a new class of potentially therapeutic agents for treating sickle cell disease (SCD).

  12. Comparative biochemical analysis after steam pretreatment of lignocellulosic agricultural waste biomass from Williams Cavendish banana plant (Triploid Musa AAA group).

    PubMed

    Kamdem, Irénée; Jacquet, Nicolas; Tiappi, Florian Mathias; Hiligsmann, Serge; Vanderghem, Caroline; Richel, Aurore; Jacques, Philippe; Thonart, Philippe

    2015-11-01

    The accessibility of fermentable substrates to enzymes is a limiting factor for the efficient bioconversion of agricultural wastes in the context of sustainable development. This paper presents the results of a biochemical analysis performed on six combined morphological parts of Williams Cavendish Lignocellulosic Biomass (WCLB) after steam cracking (SC) and steam explosion (SE) pretreatments. Solid (S) and liquid (L) fractions (Fs) obtained from SC pretreatment performed at 180°C (SLFSC180) and 210°C (SLFSC210) generated, after diluted acid hydrolysis, the highest proportions of neutral sugar (NS) contents, specifically 52.82 ± 3.51 and 49.78 ± 1.39%w/w WCLB dry matter (DM), respectively. The highest proportions of glucose were found in SFSC210 (53.56 ± 1.33%w/w DM) and SFSC180 (44.47 ± 0.00%w/w DM), while the lowest was found in unpretreated WCLB (22.70 ± 0.71%w/w DM). Total NS content assessed in each LF immediately after SC and SE pretreatments was less than 2%w/w of the LF DM, thus revealing minor acid autohydrolysis consequently leading to minor NS production during the steam pretreatment. WCLB subjected to SC at 210 °C (SC210) generated up to 2.7-fold bioaccessible glucan and xylan. SC and SE pretreatments showed potential for the deconstruction of WCLB (delignification, depolymerization, decrystallization and deacetylation), enhancing its enzymatic hydrolysis. The concentrations of enzymatic inhibitors, such as 2-furfuraldehyde and 5-(hydroxymethyl)furfural from LFSC210, were the highest (41 and 21 µg ml(-1), respectively). This study shows that steam pretreatments in general and SC210 in particular are required for efficient bioconversion of WCLB. Yet, biotransformation through biochemical processes (e.g., anaerobic digestion) must be performed to assess the efficiency of these pretreatments.

  13. Bioprospecting of thermo- and osmo-tolerant fungi from mango pulp-peel compost for bioethanol production.

    PubMed

    Dandi, N D; Dandi, B N; Chaudhari, A B

    2013-04-01

    The persistent edaphic stress on microbial succession due to dynamic changes during composting was explored for selection of multi-stress tolerant microbe(s) desirable for ethanol production. A total of 23 strains were isolated from mango compost using four successive enrichments in YP broth (g l(-1)): glucose, 100; 150; 250 with ethanol (40) and cycloheximide (0.4) at 40 °C, pH 6.0. Based on multi-gene ribotyping, 14 yeasts (61 %) of Saccharomycetaceae, 2 filamentous fungi (8.6 %) and 7 bacteria (30.4 %) were obtained. Phenetic and phylogenetic analysis of the 14 yeasts revealed 64.3 % tolerant to 500 g l(-1) glucose, growth at 45 °C and resemblance to Candida sp. (14.3 %), Kluyveromyces marxianus (35.7 %), Pichia kudriavzevii (21.4 %) and Saccharomyces cerevisiae (28.6 %). Assessment of the 14 yeasts in glucose fermentation medium (pH 4.5 at 40 °C) showed ethanol productivity of ≥92 % by 12 yeasts with theoretical yields of 90-97 %. Fermentation of molasses (150 g l(-1) glucose equivalent) by P. kudriavzevii D1C at 40 °C resulted in 73.70 ± 0.02 g l(-1) ethanol and productivity of 4.91 ± 0.01 g l(-1) h(-1). Assessment of P. kudriavzevii D1C revealed multi-stress tolerance towards 5-hydroxymethyl furfural, ethanol (20 %, v/v), high gravity and H2O2 (0.3 M) indicating suitability for ethanol production using high gravity molasses and pre-treated lignocellulosic biomass fermentation.

  14. Identification of hydroxycinnamic acid-maillard reaction products in low-moisture baking model systems.

    PubMed

    Jiang, Deshou; Chiaro, Christopher; Maddali, Pranav; Prabhu, K Sandeep; Peterson, Devin G

    2009-11-11

    The chemistry and fate of hydroxycinnamic acids (ferulic, p-coumeric, caffeic, sinapic, and cinnamic acid) in a glucose/glycine simulated baking model (10% moisture at 200 degrees C for 15 min) were investigated. Liquid chromatography-mass spectrometry analysis of glucose/glycine and glucose/glycine/hydroxycinnamic acid model systems confirmed the phenolics reacted with Maillard intermediates; two main reaction product adducts were reported. On the basis of isotopomeric analysis, LC-MS, and NMR spectroscopy, structures of two ferulic acid-Maillard reaction products were identified as 6-(4-hydroxy-3-methoxyphenyl)-5-(hydroxymethyl)-8-oxabicyclo[3.2.1]oct-3-en-2-one (adduct I) and 2-(6-(furan-2-yl)-7-(4-hydroxy-3-methoxyphenyl)-1-methyl-3-oxo-2,5-diazabicyclo[2.2.2]oct-5-en-2-yl)acetic acid (adduct II). In addition, a pyrazinone-type Maillard product, 2-(5-(furan-2-yl)-6-methyl-2-oxopyrazin-1(2H)-yl) acetic acid (IIa), was identified as an intermediate for reaction product adduct II, whereas 3-deoxy-2-hexosulose was identified as an intermediate of adduct I. Both adducts I and II were suggested to be generated by pericyclic reaction mechanisms. Quantitative gas chromatography (GC) analysis and liquid chromatography (LC) also indicated that the addition of ferulic acid to a glucose/glycine model significantly reduced the generation of select Maillard-type aroma compounds, such as furfurals, methylpyrazines, 2-acetylfuran, 2-acetylpyridine, 2-acetylpyrrole, and cyclotene as well as inhibited color development in these Maillard models. In addition, adducts I and II suppressed the bacterial lipopolysaccharide (LPS)-mediated expression of two prototypical pro-inflammatory genes, inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2, in an in vitro murine macrophage model; ferulic acid reported negligible activity.

  15. Content of metals and metabolites in honey originated from the vicinity of industrial town Košice (eastern Slovakia).

    PubMed

    Kováčik, Jozef; Grúz, Jiří; Biba, Ondřej; Hedbavny, Josef

    2016-03-01

    Composition of three types of honey (mixed forest honey and monofloral-black locust and rapeseed honeys) originated from the vicinity of an industrial town (Košice, Slovak Republic) was compared. Higher content of minerals including toxic metals in forest honey (1358.6 ng Ni/g, 85.6 ng Pb/g, and 52.4 ng Cd/g) than in rapeseed and black locust honeys confirmed that botanical origin rather than the distance for eventual source of pollution (steel factory) affects metal deposition. Benzoic acid derivatives were typically more accumulated in forest but cinnamic acid derivatives and some flavonoids in rapeseed honey (in free and/or glycoside-bound fraction). In terms of quantity, p-hydroxybenzoic and p-coumaric acids were mainly abundant. Total phenols, thiols, and proteins were abundant in forest honey. Some metals and phenols contributed to separation of honeys based on principal component analysis (PCA). Native amount of 5-(hydroxymethyl)furfural was not related to honey type (~11 μg/g) and was elevated after strong acid hydrolysis (200-350 μg/g) but it did not interfere with the assay of phenols by Folin-Ciocalteu reagent. This is the first report of metals and metabolites in the same study, and data are discussed with available literature. We conclude that black locust (acacia) honey is the most suitable for daily use and that central European monofloral honeys contain lower amounts of toxic metals in comparison with other geographical regions.

  16. Comparison of a Powdered, Acidified Liquid, and Non-Acidified Liquid Human Milk Fortifier on Clinical Outcomes in Premature Infants

    PubMed Central

    Thoene, Melissa; Lyden, Elizabeth; Weishaar, Kara; Elliott, Elizabeth; Wu, Ruomei; White, Katelyn; Timm, Hayley; Anderson-Berry, Ann

    2016-01-01

    We previously compared infant outcomes between a powdered human milk fortifier (P-HMF) vs. acidified liquid HMF (AL-HMF). A non-acidified liquid HMF (NAL-HMF) is now commercially available. The purpose of this study is to compare growth and outcomes of premature infants receiving P-HMF, AL-HMF or NAL-HMF. An Institutional Review Board (IRB) approved retrospective chart review compared infant outcomes (born < 2000 g) who received one of three HMF. Growth, enteral nutrition, laboratory and demographic data were compared. 120 infants were included (P-HMF = 46, AL-HMF = 23, NAL-HMF = 51). AL-HMF infants grew slower in g/day (median 23.66 vs. P-HMF 31.27, NAL-HMF 31.74 (p < 0.05)) and in g/kg/day, median 10.59 vs. 15.37, 14.03 (p < 0.0001). AL-HMF vs. NAL-HMF infants were smaller at 36 weeks gestational age (median 2046 vs. 2404 g, p < 0.05). However AL-HMF infants received more daily calories (p = 0.21) and protein (p < 0.0001), mean 129 cal/kg, 4.2 g protein/kg vs. P-HMF 117 cal/kg, 3.7 g protein/kg , NAL-HMF 120 cal/kg, 4.0 g protein/kg. AL-HMF infants exhibited lower carbon dioxide levels after day of life 14 and 30 (p < 0.0001, p = 0.0038). Three AL-HMF infants (13%) developed necrotizing enterocolitis (NEC) vs. no infants in the remaining groups (p = 0.0056). A NAL-HMF is the most optimal choice for premature human milk-fed infants in a high acuity neonatal intensive care unit (NICU). PMID:27472359

  17. Comparison of a Powdered, Acidified Liquid, and Non-Acidified Liquid Human Milk Fortifier on Clinical Outcomes in Premature Infants.

    PubMed

    Thoene, Melissa; Lyden, Elizabeth; Weishaar, Kara; Elliott, Elizabeth; Wu, Ruomei; White, Katelyn; Timm, Hayley; Anderson-Berry, Ann

    2016-07-26

    We previously compared infant outcomes between a powdered human milk fortifier (P-HMF) vs. acidified liquid HMF (AL-HMF). A non-acidified liquid HMF (NAL-HMF) is now commercially available. The purpose of this study is to compare growth and outcomes of premature infants receiving P-HMF, AL-HMF or NAL-HMF. An Institutional Review Board (IRB) approved retrospective chart review compared infant outcomes (born < 2000 g) who received one of three HMF. Growth, enteral nutrition, laboratory and demographic data were compared. 120 infants were included (P-HMF = 46, AL-HMF = 23, NAL-HMF = 51). AL-HMF infants grew slower in g/day (median 23.66 vs. P-HMF 31.27, NAL-HMF 31.74 (p < 0.05)) and in g/kg/day, median 10.59 vs. 15.37, 14.03 (p < 0.0001). AL-HMF vs. NAL-HMF infants were smaller at 36 weeks gestational age (median 2046 vs. 2404 g, p < 0.05). However AL-HMF infants received more daily calories (p = 0.21) and protein (p < 0.0001), mean 129 cal/kg, 4.2 g protein/kg vs. P-HMF 117 cal/kg, 3.7 g protein/kg , NAL-HMF 120 cal/kg, 4.0 g protein/kg. AL-HMF infants exhibited lower carbon dioxide levels after day of life 14 and 30 (p < 0.0001, p = 0.0038). Three AL-HMF infants (13%) developed necrotizing enterocolitis (NEC) vs. no infants in the remaining groups (p = 0.0056). A NAL-HMF is the most optimal choice for premature human milk-fed infants in a high acuity neonatal intensive care unit (NICU).

  18. Inhibitory Effect of Furanic and Phenolic Compounds on Exoelectrogenesis in a Microbial Electrolysis Cell Bioanode

    SciTech Connect

    Zeng, Xiaofei; Borole, Abhijeet P.; Pavlostathis, Spyros G.

    2016-09-09

    Furanic and phenolic compounds are 20 lignocellulose-derived compounds known to inhibit to H2- and ethanol- producing microorganisms in dark fermentation. Bioelectrochemical conversion of furanic and phenolic compounds to electricity or H2 has recently been demonstrated as a productive method to use these compounds. However, potential inhibitory effect of furanic and phenolic compounds on exoelectrogenesis in bioelectrochemical systems is not well understood. This study systematically investigated the inhibitory effect of furfural (FF), 5-hydroxymethylfurfural (HMF), syringic acid (SA), vanillic acid (VA), and 4-hydroxybenzoic acid (HBA) on exoelectrogenesis in the bioanode of a microbial electrolysis cell. A mixture of these five compounds at an increasing initial total concentration from 0.8 to 8.0 g/L resulted in current decrease up to 91%. The observed inhibition primarily affected exoelectrogenesis, instead of non-exoelectrogenic biotransformation pathways (e.g., fermentation) of the five compounds. Furthermore, the parent compounds at a high concentration, as opposed to their biotransformation products, were responsible for the observed inhibition. Tests with individual compounds show that all five parent compounds contributed to the observed inhibition by the mixture. The IC50 (concentration resulting in 50% current decrease) was estimated as 2.7 g/L for FF, 3.0 g/L for HMF, 1.9 g/L for SA, 2.1 g/L for VA and 2.0 g/L for HBA. Nevertheless, these compounds below their non-inhibitory concentrations jointly resulted in significant inhibition as a mixture. Catechol and phenol, which were persistent biotransformation products of the mixture, inhibited exoelectrogens at high concentrations, but to a lesser extent than the parent compounds. Recovery of exoelectrogenesis from inhibition by all compounds was observed, except for catechol, which resulted in irreversible inhibition. The reversibility of inhibition, as well as the observed difference in recovery rates

  19. Antibacterial activity of bee honey and its therapeutic usefulness against Escherichia coli O157:H7 and Salmonella typhimurium infection.

    PubMed

    Badawy, O F H; Shafii, S S A; Tharwat, E E; Kamal, A M

    2004-12-01

    The authors studied the effect of storage period and heat on the physical and chemical properties of honey and proceeded to study the antibacterial effect of honey on Escherichia coli and Salmonella typhimurium. In samples of honey (Egyptian clover honey) that were heat-treated and stored over a long period of time, water content decreased, hydroxymethyl furfural (HMF) was produced and increased in concentration, and enzyme activity decreased. Colour, measured in optical density, was markedly affected in honey samples stored over long periods of time, as was the refractive index, but electrical conductivity remained unaffected by storage or heating. Similarly, the storage period had no effect on pH value. To study the therapeutic effect of honey on E.coli and S. typhimurium, 25 isolates of E. coil O157:H7 (18.5%) and 49 isolates of S. typhimurium (36.2%) were isolated from 135 samples taken from children and calves (30 stool samples from children and 105 samples from calf organs and faecal swabs). Most E. coli O157:H7 and S. typhimurium isolates were highly resistant to most antibiotic discs. In vitro, the antibacterial effect of honey was more pronounced on E. coil O157:H7 than on S. typhimurium. Water content, pH value, HMF and the presence of H2O, all played an important role in the potency of olover honey as an antibacterial agent. In vivo, mice were used as a model for studying the parenteral usefulness of honey as an antibacterial agent against both pathogens. The antibacterial activity of honey that had been stored over a long period of time decreased and high concentrations of honey proved more effective as antibacterial agents. In this study there was lower mortality among mice treated with honey but the parenteral application of honey and its therapeutic properties require further investigation.

  20. Reversion and dehydration reactions of glucose during the dilute sulfuric acid hydrolysis of cellulose

    SciTech Connect

    Helm, R.F.

    1987-01-01

    The inaccessibility of all glycosidic bonds necessitates industrial conversion schemes which employ a dilute acid catalyst at high temperatures. Process conditions also promote further reactions of glucose via the reversion and dehydration pathways. Quantitative determination of the yields of the major reversion and dehydration products is important for understanding and predicting the amounts of these materials expected under envisioned industrial operating conditions. Microcrystalline cellulose (Avicel) was hydrolyzed with sulfuric acid (0.0-1.25 wt.%), at high temperatures (160-250/sup 0/C), and at a 3:1 liquid-to-solid ratio. The hydrolysis was monitored by evaluating the amount of cellulose remaining and the yields of glucose, solid humin, levulinic acid, formic acid, hydroxymethylfurfural (HMF), and reversion products as a function of the aforementioned reaction conditions. Analysis of the reversion products required the development of a technique for the quantitation of trace carbohydrates in complex mixtures and led to the development of a reduction/permethylation gas chromatographic procedure. Cellulose hydrolysis followed pseudo-homogeneous first-order kinetics. Glucose yield was adequately described as consecutive first-order reactions. Anhydrosugars formed via reversion followed equilibrium reaction kinetics whereas the disaccharides did not. Total reversion product yields approached 10% at 250/sup 0/C. Quantitative determination of the major dehydration products provided important information concerning the destruction of glucose. HMF was produced in up to 12% yields based on the theoretical amount of glucose available, and furfural was detected in up to 5% yields. A carbon mass balance based on the determined product yields revealed that approximately 90% of all carbon was accounted for at maximum glucose yields.

  1. Do furanic and phenolic compounds of lignocellulosic and algae biomass hydrolyzate inhibit anaerobic mixed cultures? A comprehensive review.

    PubMed

    Monlau, F; Sambusiti, C; Barakat, A; Quéméneur, M; Trably, E; Steyer, J-P; Carrère, H

    2014-01-01

    Nowadays there is a growing interest on the use of both lignocellulosic and algae biomass to produce biofuels (i.e. biohydrogen, ethanol and methane), as future alternatives to fossil fuels. In this purpose, thermal and thermo-chemical pretreatments have been widely investigated to overcome the natural physico-chemical barriers of such biomass and to enhance biofuel production from lignocellulosic residues and, more recently, marine biomass (i.e. macro and microalgae). However, the pretreatment technologies lead not only to the conversion of carbohydrate polymers (ie cellulose, hemicelluloses, starch, agar) to soluble monomeric sugar (ie glucose, xylose, arabinose, galactose), but also the generation of various by-products (i.e. furfural and 5-HMF). In the case of lignocellulosic residues, part of the lignin can also be degraded in lignin derived by-products, mainly composed of phenolic compounds. Although the negative impact of such by-products on ethanol production has been widely described in literature, studies on their impact on biohydrogen and methane production operated with mixed cultures are still very limited. This review aims to summarise and discuss literature data on the impact of pre-treatment by-products on H2-producing dark fermentation and anaerobic digestion processes when using mixed cultures as inoculum. As a summary, furanic (5-HMF, furfural) and phenolic compounds were found to be stronger inhibitors of the microbial dark fermentation than the full anaerobic digestion process. Such observations can be explained by differences in process parameters: anaerobic digestion is performed with more complex mixed cultures, lower substrate/inoculum and by-products/inoculum ratios and longer batch incubation times than dark fermentation. Finally, it has been reported that, during dark fermentation process, the presence of by-products could lead to a metabolic shift from H2-producing pathways (i.e. acetate and butyrate) to non-H2-producing pathways (i

  2. Inhibition of growth of Zymomonas mobilis by model compounds found in lignocellulosic hydrolysates

    PubMed Central

    2013-01-01

    Background During the pretreatment of biomass feedstocks and subsequent conditioning prior to saccharification, many toxic compounds are produced or introduced which inhibit microbial growth and in many cases, production of ethanol. An understanding of the toxic effects of compounds found in hydrolysate is critical to improving sugar utilization and ethanol yields in the fermentation process. In this study, we established a useful tool for surveying hydrolysate toxicity by measuring growth rates in the presence of toxic compounds, and examined the effects of selected model inhibitors of aldehydes, organic and inorganic acids (along with various cations), and alcohols on growth of Zymomonas mobilis 8b (a ZM4 derivative) using glucose or xylose as the carbon source. Results Toxicity strongly correlated to hydrophobicity in Z. mobilis, which has been observed in Escherichia coli and Saccharomyces cerevisiae for aldehydes and with some exceptions, organic acids. We observed Z. mobilis 8b to be more tolerant to organic acids than previously reported, although the carbon source and growth conditions play a role in tolerance. Growth in xylose was profoundly inhibited by monocarboxylic organic acids compared to growth in glucose, whereas dicarboxylic acids demonstrated little or no effects on growth rate in either substrate. Furthermore, cations can be ranked in order of their toxicity, Ca++ > > Na+ > NH4+ > K+. HMF (5-hydroxymethylfurfural), furfural and acetate, which were observed to contribute to inhibition of Z. mobilis growth in dilute acid pretreated corn stover hydrolysate, do not interact in a synergistic manner in combination. We provide further evidence that Z. mobilis 8b is capable of converting the aldehydes furfural, vanillin, 4-hydroxybenzaldehyde and to some extent syringaldehyde to their alcohol forms (furfuryl, vanillyl, 4-hydroxybenzyl and syringyl alcohol) during fermentation. Conclusions Several key findings in this report provide a

  3. Sulfite pretreatment (SPORL) for robust enzymatic saccharification of spruce and red pine.

    PubMed

    Zhu, J Y; Pan, X J; Wang, G S; Gleisner, R

    2009-04-01

    This study established a novel process using sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) for robust and efficient bioconversion of softwoods. The process consists of sulfite treatment of wood chips under acidic conditions followed by mechanical size reduction using disk refining. The results indicated that after the SPORL pretreatment of spruce chips with 8-10% bisulfite and 1.8-3.7% sulfuric acid on oven dry (od) wood at 180 degrees C for 30 min, more than 90% cellulose conversion of substrate was achieved with enzyme loading of about 14.6 FPU cellulase plus 22.5 CBU beta-glucosidase per gram of od substrate after 48 h hydrolysis. Glucose yield from enzymatic hydrolysis of the substrate per 100 g of untreated od spruce wood (glucan content 43%) was about 37 g (excluding the dissolved glucose during pretreatment). Hemicellulose removal was found to be as critical as lignin sulfonation for cellulose conversion in the SPORL process. Pretreatment altered the wood chips, which reduced electric energy consumption for size reduction to about 19 Wh/kg od untreated wood, or about 19 g glucose/Wh electricity. Furthermore, the SPORL produced low amounts of fermentation inhibitors, hydroxymethyl furfural (HMF) and furfural, of about 5 and 1 mg/g of untreated od wood, respectively. In addition, similar results were achieved when the SPORL was applied to red pine. By building on the mature sulfite pulping and disk refining technologies already practiced in the pulp and paper industry, the SPORL has very few technological barriers and risks for commercialization.

  4. Effect of pretreatment severity on the conversion of barley straw to fermentable substrates and the release of inhibitory compounds.

    PubMed

    Panagiotopoulos, I A; Bakker, R R; de Vrije, T; Koukios, E G

    2011-12-01

    The production of fermentable substrates from barley straw under various process conditions was studied. Pretreatment included chemical pretreatment with dilute-acid followed by enzymatic hydrolysis; the pretreatment conditions were expressed in a combined severity factor, CS, which ranged in the present study from -1.6 to 1.1. Considering the production of fermentable sugars and the release of inhibitory compounds, the optimal pretreatment conditions were 170°C, 0% sulfuric acid and 60 min, corresponding to CS -0.4. Under these conditions, 21.4 g glucose/L, 8.5 g xylose/L, and 0.5 g arabinose/L were produced, while 0.1g HMF/L, 0.4 g furfural/L, 0.0 g levulinic acid/L, 0.0 g formic acid/L, and 2.1g acetic acid/L were released. The ratio of Σ sugars/Σ inhibitors proved to be a good tool for evaluating the suitability of a hydrolysate for fermentation purposes.

  5. Effect of acid hydrolysis and fungal biotreatment on agro-industrial wastes for obtainment of free sugars for bioethanol production

    PubMed Central

    El-Tayeb, T.S.; Abdelhafez, A.A.; Ali, S.H.; Ramadan, E.M.

    2012-01-01

    This study was designed to evaluate selected chemical and microbiological treatments for the conversion of certain local agro-industrial wastes (rice straw, corn stalks, sawdust, sugar beet waste and sugarcane bagasse) to ethanol. The chemical composition of these feedstocks was determined. Conversion of wastes to free sugars by acid hydrolysis varied from one treatment to another. In single-stage dilute acid hydrolysis, increasing acid concentration from 1 % (v/v) to 5 % (v/v) decreased the conversion percentage of almost all treated agro-industrial wastes. Lower conversion percentages for some treatments were obtained when increasing the residence time from 90 to 120 min. The two-stage dilute acid hydrolysis by phosphoric acid (1.0 % v/v) followed by sulphuric acid (1.0 % v/v) resulted in the highest conversion percentage (41.3 % w/w) on treated sugar beet waste. This treatment when neutralized, amended with some nutrients and inoculated with baker’s yeast, achieved the highest ethanol concentration (1.0 % v/v). Formation of furfural and hydroxymethylfurfural (HMF) were functions of type of acid hydrolysis, acid concentration, residence time and feedstock type. The highest bioconversion of 5 % wastes (37.8 % w/w) was recorded on sugar beet waste by Trichoderma viride EMCC 107. This treatment when followed by baker’s yeast fermentation, 0.41 % (v/v) ethanol and 8.2 % (v/w) conversion coefficient were obtained. PMID:24031984

  6. Effect of modified atmosphere packaging on the shelf life of lal peda.

    PubMed

    Jha, Alok; Kumar, Arvind; Jain, Parul; Gautam, Anuj Kumar; Rasane, Prasad

    2015-02-01

    Lal peda is a traditional dairy-based sweet, popular in the Indian subcontinent, but it has a poor shelf life. The lal peda samples were packed in polyethylene bags filled with 3 different gaseous compositions (Air, 70 % N2: 30 % CO2 and 98 % N2) and stored at 10 °C. The shelf life was evaluated on the basis of changes in the microbial status of the product such as total plate count, yeast and molds and coliform counts and also the physico-chemical changes such as hydroxy methyl furfural (HMF), thiobarbituric acid (TBA) and free fatty acid (FFA). The microbial spoilage and the indices of chemical changes increased in all the samples with the progression of storage period. The samples packed with air showed significantly higher chemical deterioration and microbial spoilage as compared to the other two combinations. The results showed that samples packed with 70 % N2: 30 % CO2 combination had better shelf stability as compared to the samples packed under air and 98 % N2.

  7. Sodium borohydride removes aldehyde inhibitors for enhancing biohydrogen fermentation.

    PubMed

    Lin, Richen; Cheng, Jun; Ding, Lingkan; Song, Wenlu; Zhou, Junhu; Cen, Kefa

    2015-12-01

    To enhance biohydrogen production from glucose and xylose in the presence of aldehyde inhibitors, reducing agent (i.e., sodium borohydride) was in situ added for effective detoxification. The detoxification efficiencies of furfural (96.7%) and 5-hydroxymethylfurfural (5-HMF, 91.7%) with 30mM NaBH4 were much higher than those of vanillin (77.3%) and syringaldehyde (69.3%). Biohydrogen fermentation was completely inhibited without detoxification, probably because of the consumption of nicotinamide adenine dinucleotide (NADH) by inhibitors reduction (R-CHO+2NADH→R-CH2OH+2NAD(+)). Addition of 30mM NaBH4 provided the reducing power necessary for inhibitors reduction (4R-CHO+NaBH4+2H2O→4R-CH2OH+NaBO2). The recovered reducing power in fermentation resulted in 99.3% recovery of the hydrogen yield and 64.6% recovery of peak production rate. Metabolite production and carbon conversion after detoxification significantly increased to 63.7mM and 81.9%, respectively.

  8. Efficient fractionation of spruce by SO(2)-ethanol-water treatment: closed mass balances for carbohydrates and sulfur.

    PubMed

    Iakovlev, Mikhail; van Heiningen, Adriaan

    2012-08-01

    SO(2)-ethanol-water (SEW) lignocellulosic fractionation has the potential to overcome the present techno-economic barriers that hinder the commercial implementation of renewable transportation fuel production. In this study, SEW fractionation of spruce wood chips is examined for its ability to separate the main wood components, hemicelluloses, lignin, and cellulose, and the potential to recover SO(2) and ethanol from the spent fractionation liquid. Therefore, overall sulfur and carbohydrate mass balances are established. 95-97 % of the charged SO(2) remains in the liquid and can be fully recovered by distillation. During fractionation, hemicelluloses and lignin are effectively dissolved, whereas cellulose is preserved in the solid (fibre) phase. Hemicelluloses are hydrolysed, producing up to 50 % monomeric sugars, whereas dehydration and oxidation of carbohydrates are insignificant. The latter is proven by the closed carbohydrate material balances as well as by the near absence of corresponding by-products (furfural, hydroxymethylfurfural (HMF) and aldonic acids). In addition, acid methanolysis/GC and acid hydrolysis/high performance anion exchange chromatography (HPAEC) methods for the carbohydrate determination are compared.

  9. Development of a high-throughput method to evaluate the impact of inhibitory compounds from lignocellulosic hydrolysates on the growth of Zymomonas mobilis.

    PubMed

    Franden, Mary Ann; Pienkos, Philip T; Zhang, Min

    2009-12-01

    Overcoming the effects of hydrolysate toxicity towards ethanologens is a key technical barrier in the biochemical conversion process for biomass feedstocks to ethanol. Despite its importance, the complexity of the hydrolysate toxicity phenomena and the lack of systematic studies, analysis and tools surrounding this issue have blocked a full understanding of relationships involving toxic compounds in hydrolysates and their effects on ethanologen growth and fermentation. In this study, we developed a quantitative, high-throughput biological growth assay using an automated turbidometer to obtain detailed inhibitory kinetics for individual compounds present in lignocellulosic biomass hydrolysate. Information about prolonged lag time and final cell densities can also be obtained. The effects of furfural, hydroxymethylfurfural (HMF), acetate and ethanol on growth rate and final cell densities of Zymomonas mobilis 8b on glucose are presented. This method was also shown to be of value in toxicity studies of hydrolysate itself, despite the highly colored nature of this material. Using this approach, we can generate comprehensive inhibitory profiles with many individual compounds and develop models that predict and examine toxic effects in the complex mixture of hydrolysates, leading to the development of improved pretreatment and conditioning processes as well as fermentation organisms.

  10. High added-value products from the hydrothermal carbonisation of olive stones.

    PubMed

    Borrero-López, A M; Fierro, V; Jeder, A; Ouederni, A; Masson, E; Celzard, A

    2016-11-21

    Olive stones (OS) were submitted to hydrothermal carbonisation (HTC) in order to evaluate the possibility of producing high added-value products, mainly furfural (FU) and 5-hydroxymethylfurfural (5-HMF) on one hand and hydrochars and carbons on the other hand. Temperature (160-240 °C), residence time (1-8 h), initial pH (1-5.5) and liquid/solid ratio (4-48 w/w) were systematically varied in order to study the main products and to optimise FU production. FU production yield up to 19.9 %, based on the hemicellulose content, was obtained. Other minor, but valuable, compounds such as 5-methylfurfural (5-MF) and some phenolic compounds were also produced. The hydrochar was carbonised at 900 °C, and the resultant carbon material was highly ultramicroporous with a peak of pore size distribution centred on 0.5 nm and a surface area as high as 1065 m(2) g(-1), typical of most carbon molecular sieves.

  11. 3-Hydroxy-4,5-dimethyl-2(5H)-furanone: a key odorant of the typical aroma of oxidative aged Port wine.

    PubMed

    Silva Ferreira, A C; Barbe, Jean-Christophe; Bertrand, Alain

    2003-07-16

    Application of aroma extract dilution analysis (AEDA) on organic extracts from Port wines barrel-aged over 40 years revealed 5 odor-active compounds corresponding to descriptors used to qualify the characteristic old wine aroma. One of the compounds, described as "nutty" and "spicy-like", and present in at least 9 dilutions above the others, was perceived as particularly important. The compound responsible for this flavor was identified as 3-hydroxy-4,5-dimethyl-2(5H)-furanone (sotolon). The levels ranged from 5 to 958 microg/L for wines between 1 and 60 years old. It was also observed that during oxidative aging the concentration of this compound increased with time according to a linear trend (r > 0.95). Although the presence of 2-ketobutyric acid was verified, the constant rate of formation of sotolon with aging and its high correlation with sugar derivates (HMF, furfural) suggests other mechanisms, different from those reported for other wines. The flavor threshold of sotolon was evaluated in Port wine at 19 microg/L. Sensorial tests provided valuable information concerning sotolon impact on Port wine aroma. Samples supplemented with this substance were consistently ranked as older. In view of these results it can be expected that sotolon plays a pre-eminent role in the characteristic old Port wine aroma.

  12. New insights into non-enzymatic glycation of human serum albumin biopolymer: A study to unveil its impaired structure and function.

    PubMed

    Raghav, Alok; Ahmad, Jamal; Alam, Khursheed; Khan, Asad U

    2017-03-18

    Albumin glycation and subsequent formation of advanced glycation end products (AGEs) correlate with diabetes and associated complications. Human Serum Albumin (HSA) was modified with d-glucose for a 40day period under sterile conditions at 37°C. Modified samples along with native HSA (unmodified) were analyzed for impairment in biochemical characteristics ((fructosamine, carbonyl, thiol, lysine, arginine, hydroxymethyl furfural [HMF] content), electrochemical (electrical conductance), simulated gastric fluid assay, simulated intestinal fluid assay, spectroscopic properties (UV, fluorescence), optical (surface contact angle) and fluid dynamics (viscosity and Stokes radius). Impairment in drug binding capacity of glycosylated-HSA was assessed with molecular docking experiment using metformin. UV-absorbance and fluorescence measurement were performed for drug bound glycated and native-HSA. Extensively modified HSA has been used to study its relevance in diabetes mellitus. Glucose modified-HSA resulted in AGEs formation. It suggests deleterious impairment in biochemical, electrochemical, spectroscopic, optical and fluidity properties of HSA at high concentrations of glucose. The results of the present study can be useful to understand the phenomenon of proteins damage in hyperglycemic conditions.

  13. Improvement in HPLC separation of acetic acid and levulinic acid in the profiling of biomass hydrolysate.

    PubMed

    Xie, Rui; Tu, Maobing; Wu, Yonnie; Adhikari, Sushil

    2011-04-01

    5-Hydroxymethylfurfural (HMF) and furfural could be separated by the Aminex HPX-87H column chromatography, however, the separation and quantification of acetic acid and levulinic acid in biomass hydrolysate have been difficult with this method. In present study, the HPLC separation of acetic acid and levulinic acid on Aminex HPX-87H column has been investigated by varying column temperature, flow rate, and sulfuric acid content in the mobile phase. The column temperature was found critical in resolving acetic acid and levulinic acid. The resolution for two acids increased dramatically from 0.42 to 1.86 when the column temperature was lowered from 60 to 30 °C. So did the capacity factors for levulinic acid that was increased from 1.20 to 1.44 as the column temperature dropped. The optimum column temperature for the separation was found at 45 °C. Variation in flow rate and sulfuric acid concentration improved not as much as the column temperature did.

  14. Evolution of the Maillard Reaction in Glutamine or Arginine-Dextrinomaltose Model Systems

    PubMed Central

    Pastoriza, Silvia; Rufián-Henares, José Ángel; García-Villanova, Belén; Guerra-Hernández, Eduardo

    2016-01-01

    Enteral formulas are foods designed for medical uses to feed patients who are unable to eat normally. They are prepared by mixing proteins, amino acids, carbohydrates and fats and submitted to sterilization. During thermal treatment, the Maillard reaction takes place through the reaction of animo acids with reducing sugars. Thus, although glutamine and arginine are usually added to improve the nutritional value of enteral formulas, their final concentration may vary. Thus, in the present paper the early, intermediate, and advanced states of the Maillard reaction were studied in model systems by measuring loss of free amino acids through the decrease of fluorescence intensity with o-phtaldialdehyde (OPA), 5-Hydroximethylfurfural (HMF), furfural, glucosylisomaltol, fluorescence, and absorbance at 420 nm. The systems were prepared by mixing glutamine or arginine with dextrinomaltose (similar ingredients to those used in special enteral formula), and heated at 100 °C, 120 °C and 140 °C for 0 to 30 min. The recorded changes in the concentration of furanic compounds was only useful for longer heating times of high temperatures, while absorbance and fluorescence measurements were useful in all the assayed conditions. In addition, easiness and sensitivity of absorbance and fluorescence make them useful techniques that could be implemented as indicators for monitoring the manufacture of special enteral formulas. Glucosylisomaltol is a useful indicator to monitor the manufacture of glutamine-enriched enteral formulas. PMID:28231180

  15. Evaluation of beer deterioration by gas chromatography-mass spectrometry/multivariate analysis: a rapid tool for assessing beer composition.

    PubMed

    Rodrigues, João A; Barros, António S; Carvalho, Beatriz; Brandão, Tiago; Gil, Ana M; Ferreira, António C Silva

    2011-02-18

    Beer stability is a major concern for the brewing industry, as beer characteristics may be subject to significant changes during storage. This paper describes a novel non-targeted methodology for monitoring the chemical changes occurring in a lager beer exposed to accelerated aging (induced by thermal treatment: 18 days at 45 °C), using gas chromatography-mass spectrometry in tandem with multivariate analysis (GC-MS/MVA). Optimization of the chromatographic run was performed, achieving a threefold reduction of the chromatographic time. Although losing optimum resolution, rapid GC runs showed similar chromatographic profiles and semi-quantitative ability to characterize volatile compounds. To evaluate the variations on the global volatile signature (chromatographic profile and m/z pattern of fragmentation in each scan) of beer during thermal deterioration, a non-supervised multivariate analysis method, Principal Component Analysis (PCA), was applied to the GC-MS data. This methodology allowed not only the rapid identification of the degree of deterioration affecting beer, but also the identification of specific compounds of relevance to the thermal deterioration process of beer, both well established markers such as 5-hydroxymethylfufural (5-HMF), furfural and diethyl succinate, as well as other compounds, to our knowledge, newly correlated to beer aging.

  16. Lactic Acid Production from Pretreated Hydrolysates of Corn Stover by a Newly Developed Bacillus coagulans Strain

    PubMed Central

    Jiang, Ting; Qiao, Hui; Zheng, Zhaojuan; Chu, Qiulu; Li, Xin; Yong, Qiang; Ouyang, Jia

    2016-01-01

    An inhibitor-tolerance strain, Bacillus coagulans GKN316, was developed through atmospheric and room temperature plasma (ARTP) mutation and evolution experiment in condensed dilute-acid hydrolysate (CDH) of corn stover. The fermentabilities of other hydrolysates with B. coagulans GKN316 and the parental strain B. coagulans NL01 were assessed. When using condensed acid-catalyzed steam-exploded hydrolysate (CASEH), condensed acid-catalyzed liquid hot water hydrolysate (CALH) and condensed acid-catalyzed sulfite hydrolysate (CASH) as substrates, the concentration of lactic acid reached 45.39, 16.83, and 18.71 g/L by B. coagulans GKN316, respectively. But for B. coagulans NL01, only CASEH could be directly fermented to produce 15.47 g/L lactic acid. The individual inhibitory effect of furfural, 5-hydroxymethylfurfural (HMF), vanillin, syringaldehyde and p-hydroxybenzaldehyde (pHBal) on xylose utilization by B. coagulans GKN316 was also studied. The strain B. coagulans GKN316 could effectively convert these toxic inhibitors to the less toxic corresponding alcohols in situ. These results suggested that B. coagulans GKN316 was well suited to production of lactic acid from undetoxified lignocellulosic hydrolysates. PMID:26863012

  17. Acid-catalyzed hydrothermal severity on the fractionation of agricultural residues for xylose-rich hydrolyzates.

    PubMed

    Lee, Ji Ye; Ryu, Hyun Jin; Oh, Kyeong Keun

    2013-03-01

    The objective of this work was to investigate the feasibility of acid-catalyzed hydrothermal fractionation for maximum solubilization of the hemicellulosic portion of three agricultural residues. The fractionation conditions converted into combined severity factor (CS) in the range of 1.2-2.9. The highest hemicellulose yield of 87.88% was achieved when barley straw was fractionated at a CS of 2.19. However, the maximum glucose release of 15.29% was achieved for the case of rice straw. The maximum productions of various by-products were observed with the fractionation of rape straw: 0.88 g/L of 5-hydroxymethylfurfural (5-HMF), 2.16 g/L of furfural, 0.44 g/L of levulinic acid, 1.59 g/L of formic acid, and 3.06 g/L of acetic acid. The highest selectivities, a criterion for evaluating the fractionation of 21.55 for fractionated solid and 7.48 for liquid hydrolyzate were obtained from barley straw.

  18. Identifying inhibitory compounds in lignocellulosic biomass hydrolysates using an exometabolomics approach

    PubMed Central

    2014-01-01

    Background Inhibitors are formed that reduce the fermentation performance of fermenting yeast during the pretreatment process of lignocellulosic biomass. An exometabolomics approach was applied to systematically identify inhibitors in lignocellulosic biomass hydrolysates. Results We studied the composition and fermentability of 24 different biomass hydrolysates. To create diversity, the 24 hydrolysates were prepared from six different biomass types, namely sugar cane bagasse, corn stover, wheat straw, barley straw, willow wood chips and oak sawdust, and with four different pretreatment methods, i.e. dilute acid, mild alkaline, alkaline/peracetic acid and concentrated acid. Their composition and that of fermentation samples generated with these hydrolysates were analyzed with two GC-MS methods. Either ethyl acetate extraction or ethyl chloroformate derivatization was used before conducting GC-MS to prevent sugars are overloaded in the chromatograms, which obscure the detection of less abundant compounds. Using multivariate PLS-2CV and nPLS-2CV data analysis models, potential inhibitors were identified through establishing relationship between fermentability and composition of the hydrolysates. These identified compounds were tested for their effects on the growth of the model yeast, Saccharomyces. cerevisiae CEN.PK 113-7D, confirming that the majority of the identified compounds were indeed inhibitors. Conclusion Inhibitory compounds in lignocellulosic biomass hydrolysates were successfully identified using a non-targeted systematic approach: metabolomics. The identified inhibitors include both known ones, such as furfural, HMF and vanillin, and novel inhibitors, namely sorbic acid and phenylacetaldehyde. PMID:24655423

  19. Lactic Acid Production from Pretreated Hydrolysates of Corn Stover by a Newly Developed Bacillus coagulans Strain.

    PubMed

    Jiang, Ting; Qiao, Hui; Zheng, Zhaojuan; Chu, Qiulu; Li, Xin; Yong, Qiang; Ouyang, Jia

    2016-01-01

    An inhibitor-tolerance strain, Bacillus coagulans GKN316, was developed through atmospheric and room temperature plasma (ARTP) mutation and evolution experiment in condensed dilute-acid hydrolysate (CDH) of corn stover. The fermentabilities of other hydrolysates with B. coagulans GKN316 and the parental strain B. coagulans NL01 were assessed. When using condensed acid-catalyzed steam-exploded hydrolysate (CASEH), condensed acid-catalyzed liquid hot water hydrolysate (CALH) and condensed acid-catalyzed sulfite hydrolysate (CASH) as substrates, the concentration of lactic acid reached 45.39, 16.83, and 18.71 g/L by B. coagulans GKN316, respectively. But for B. coagulans NL01, only CASEH could be directly fermented to produce 15.47 g/L lactic acid. The individual inhibitory effect of furfural, 5-hydroxymethylfurfural (HMF), vanillin, syringaldehyde and p-hydroxybenzaldehyde (pHBal) on xylose utilization by B. coagulans GKN316 was also studied. The strain B. coagulans GKN316 could effectively convert these toxic inhibitors to the less toxic corresponding alcohols in situ. These results suggested that B. coagulans GKN316 was well suited to production of lactic acid from undetoxified lignocellulosic hydrolysates.

  20. Answering the Space Medicine Challenge

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The development of the Space Station Health Maintenance Facility (HMF) is featured. The HMF will provide necessary inflight medical care, including prevention, diagnosis, treatment, and care during transport if the patient must be evacuated from Space Station.

  1. Inhibitory Effect of Furanic and Phenolic Compounds on Exoelectrogenesis in a Microbial Electrolysis Cell Bioanode

    DOE PAGES

    Zeng, Xiaofei; Borole, Abhijeet P.; Pavlostathis, Spyros G.

    2016-09-09

    Furanic and phenolic compounds are 20 lignocellulose-derived compounds known to inhibit to H2- and ethanol- producing microorganisms in dark fermentation. Bioelectrochemical conversion of furanic and phenolic compounds to electricity or H2 has recently been demonstrated as a productive method to use these compounds. However, potential inhibitory effect of furanic and phenolic compounds on exoelectrogenesis in bioelectrochemical systems is not well understood. This study systematically investigated the inhibitory effect of furfural (FF), 5-hydroxymethylfurfural (HMF), syringic acid (SA), vanillic acid (VA), and 4-hydroxybenzoic acid (HBA) on exoelectrogenesis in the bioanode of a microbial electrolysis cell. A mixture of these five compounds atmore » an increasing initial total concentration from 0.8 to 8.0 g/L resulted in current decrease up to 91%. The observed inhibition primarily affected exoelectrogenesis, instead of non-exoelectrogenic biotransformation pathways (e.g., fermentation) of the five compounds. Furthermore, the parent compounds at a high concentration, as opposed to their biotransformation products, were responsible for the observed inhibition. Tests with individual compounds show that all five parent compounds contributed to the observed inhibition by the mixture. The IC50 (concentration resulting in 50% current decrease) was estimated as 2.7 g/L for FF, 3.0 g/L for HMF, 1.9 g/L for SA, 2.1 g/L for VA and 2.0 g/L for HBA. Nevertheless, these compounds below their non-inhibitory concentrations jointly resulted in significant inhibition as a mixture. Catechol and phenol, which were persistent biotransformation products of the mixture, inhibited exoelectrogens at high concentrations, but to a lesser extent than the parent compounds. Recovery of exoelectrogenesis from inhibition by all compounds was observed, except for catechol, which resulted in irreversible inhibition. The reversibility of inhibition, as well as the observed difference in recovery

  2. Leaching of radionuclides from furfural-based polymers used to solidify reactor compartments and components disposed of in the Arctic Kara Sea

    SciTech Connect

    HEISER,J.H.; SIVINTSEV,Y.; ALEXANDROV,V.P.; DYER,R.S.

    1999-09-01

    Within the course of operating its nuclear navy, the former Soviet Union (FSU) disposed of reactor vessels and spent nuclear fuel (SNF) in three fjords on the east coast of Novaya Zemlya and in the open Kara Sea within the Novaya Zemlya Trough during the period 1965 to 1988. The dumping consisted of 16 reactors, six of which contained SNF and one special container that held ca. 60% of the damaged SNF and the screening assembly from the No. 2 reactor of the atomic icebreaker Lenin. At the time, the FSU considered dumping of decommissioned nuclear submarines with damaged cores in the bays of and near by the Novaya Zemlya archipelago in the Arctic Kara Sea to be acceptable. To provide an additional level of safety, a group of Russian scientists embarked upon a course of research to develop a solidification agent that would provide an ecologically safe barrier. The barrier material would prevent direct contact of seawater with the SNF and the resultant leaching and release of radionuclides. The solidification agent was to be introduced by flooding the reactors vessels and inner cavities. Once introduced the agent would harden and form an impermeable barrier. This report describes the sample preparation of several ``Furfurol'' compositions and their leach testing using cesium 137 as tracer.

  3. Factors affecting alcohol fermentation of wood acid hydrolysate

    SciTech Connect

    Azhar, A.F.; Bery, M.K.; Colcord, A.R.; Roberts, R.S.; Corbitt, G.V.

    1981-01-01

    The inhibitory effects of ethanol and furfural on the growth of Saccharomyces cerevisiae and ethanol production, at different glucose and furfural concentrations, were examined. The data collected during the fermentation of glucose with no furfural present in the medium fitted the model system proposed by Aiba et al. Furfural disappeared rapidly from the medium at the early stages of fermentation, followed by a constant rate which continued throughout the experiment. The initial furfural concentration of 3 g/L decreased the cell multiplication and the fermentation rate to 59 and 33%, respectively. The furfural concentration in this medium reached 60% of its initial value after 27.5 h.

  4. Synthesis and evaluation of novel analogues of vitamin B6 as reactivators of tabun and paraoxon inhibited acetylcholinesterase.

    PubMed

    Gaso-Sokac, Dajana; Katalinić, Maja; Kovarik, Zrinka; Busić, Valentina; Kovac, Spomenka

    2010-09-06

    A series of novel pyridinium oximes was prepared by reactions of quaternization of pyridoxal oxime with substituted phenacyl bromides in acetone at room temperature. The structures of compounds were determined according to the data obtained by IR spectroscopy, mass spectrometry, (1)H and (13)C nuclear magnetic resonance spectroscopy as well as by elemental analysis. We tested pyridoxal oxime (1) and five prepared oximes in 1mM concentration as reactivators of human erythrocytes acetylcholinesterase (AChE) inhibited by organophosphorus compounds tabun and paraoxon: 1-phenacyl-3-hydroxy-4-hydroxyiminomethyl-5-hydroxymethyl-2-methylpyridinium bromide (2), 1-(4'-chlorophenacyl)-3-hydroxy-4-hydroxyiminomethyl-5-hydroxymethyl-2-methylpyridinium bromide (3), 1-(4'-fluorophenacyl)-3-hydroxy-4-hydroxyiminomethyl-5-hydroxymethyl-2-methylpyridinium bromide (4), 3-hydroxy-4-hydroxyiminomethyl-5-hydroxymethyl-2-methyl-1-(4'-methylphenacyl)pyridinium bromide (5), 3-hydroxy-4-hydroxyiminomethyl-5-hydroxymethyl-2-methyl-1-(4'-methoxyphenacyl)pyridinium bromide (6). However, tested oximes were not efficient in reactivation of either tabun or paraoxon inhibited AChE. The maximum restored enzyme activity in 24h was below 25%. Therefore, this class of compounds cannot be considered as potential improvement in a search for new and more efficient antidotes against OP poisoning.

  5. Chlorogenic acid increased 5-hydroxymethylfurfural formation when heating fructose alone or with aspartic acid at two pH levels.

    PubMed

    Zhang, Zhenhua; Zou, Yueyu; Wu, Taigang; Huang, Caihuan; Pei, Kehan; Zhang, Guangwen; Lin, Xiaohua; Bai, Weibin; Ou, Shiyi

    2016-01-01

    Chlorogenic acid (CGA) is a phenolic acid that ubiquitously exists in fruits. This work aims to investigate whether and how CGA influences HMF formation during heating fructose alone, or with an amino acid. The results showed that that CGA increased 5-hydroxymethylfurfural (HMF) formation. At pH 5.5 and 7.0, the addition of 5.0 μmol/ml CGA increased HMF formation by 49.4% and 25.2%, respectively when heating fructose alone, and by 9.0% and 16.7%, respectively when heating fructose with aspartic acid. CGA significantly increased HMF formation by promoting 3-deoxosone formation, and its conversion to HMF by inhibiting HMF elimination, especially in the Maillard reaction system. A comparison of the catalytic capacity of CGA with its six analogous compounds showed that both its di-hydroxyphenyl and carboxyl groups function in increasing HMF formation.

  6. Evaluation of Anti-HIV-1 Mutagenic Nucleoside Analogues*

    PubMed Central

    Vivet-Boudou, Valérie; Isel, Catherine; El Safadi, Yazan; Smyth, Redmond P.; Laumond, Géraldine; Moog, Christiane; Paillart, Jean-Christophe; Marquet, Roland

    2015-01-01

    Because of their high mutation rates, RNA viruses and retroviruses replicate close to the threshold of viability. Their existence as quasi-species has pioneered the concept of “lethal mutagenesis” that prompted us to synthesize pyrimidine nucleoside analogues with antiviral activity in cell culture consistent with an accumulation of deleterious mutations in the HIV-1 genome. However, testing all potentially mutagenic compounds in cell-based assays is tedious and costly. Here, we describe two simple in vitro biophysical/biochemical assays that allow prediction of the mutagenic potential of deoxyribonucleoside analogues. The first assay compares the thermal stabilities of matched and mismatched base pairs in DNA duplexes containing or not the nucleoside analogues as follows. A promising candidate should display a small destabilization of the matched base pair compared with the natural nucleoside and the smallest gap possible between the stabilities of the matched and mismatched base pairs. From this assay, we predicted that two of our compounds, 5-hydroxymethyl-2′-deoxyuridine and 5-hydroxymethyl-2′-deoxycytidine, should be mutagenic. The second in vitro reverse transcription assay assesses DNA synthesis opposite nucleoside analogues inserted into a template strand and subsequent extension of the newly synthesized base pairs. Once again, only 5-hydroxymethyl-2′-deoxyuridine and 5-hydroxymethyl-2′-deoxycytidine are predicted to be efficient mutagens. The predictive potential of our fast and easy first line screens was confirmed by detailed analysis of the mutation spectrum induced by the compounds in cell culture because only compounds 5-hydroxymethyl-2′-deoxyuridine and 5-hydroxymethyl-2′-deoxycytidine were found to increase the mutation frequency by 3.1- and 3.4-fold, respectively. PMID:25398876

  7. Experimental and theoretical study on a new copper(II) complex derived from pyridoxal hydrochloride and 1,2-diaminocyclohexane

    NASA Astrophysics Data System (ADS)

    Mandal, Senjuti; Sikdar, Yeasin; Sanyal, Ria; Goswami, Sanchita

    2017-01-01

    In this work, guided by a pyridoxal derived Schiff base ligand, H2PydChda [5-Hydroxymethyl-4-({2-[5-hydroxymethyl-2-methylpyridin-3-hydroxy-4-ylethylene)-amino]-cyclohexylimino}-methyl)-2-methylpyridin-3-ol], a new copper(II) complex, [Cu(PydChda-2H+)]2·4ClO4·2H2O was constructed and structurally characterized by single crystal X-ray diffraction study. DFT calculations further substantiate the experimental features. Additionally, experiments were performed to demonstrate the accessibility to any enzymatic activity and the complex provides positive response for phosphatase activity towards 4-NPP substrate.

  8. Determination of 5-hydroxymethylfurfural in honey, using headspace-solid-phase microextraction coupled with a polyoxometalate-coated piezoelectric quartz crystal.

    PubMed

    Veríssimo, Marta I S; Gamelas, José A F; Evtuguin, Dmitry V; Gomes, M Teresa S R

    2017-04-01

    High concentrations of 5-hydroxymethylfurfural (HMF) in honey provide an indication of overheating under inappropriate storage conditions or aging. Conventional methods for determining HMF are cumbersome and require expensive equipment or hazardous reagents. Hence the aim of this study was to propose a new analytical tool for HMF determination in honey, using a low cost acoustic wave sensor. Volatile organic compounds (VOCs) of honey samples were extracted, using the solid phase microextraction (SPME) technique, and HMF was quantified, using a piezoelectric quartz crystal with gold electrodes coated with a layer of decamolybdodivanado phosphoric acid, sensitive to HMF. The reliability of the proposed method was confirmed after comparing the results of HMF quantification with those obtained by the conventional spectrophotometric White method, and no statistical differences were found (α=0.05).

  9. Formation and reduction of 5-hydroxymethylfurfural at frying temperature in model system as a function of amino acid and sugar composition.

    PubMed

    Kavousi, Parviz; Mirhosseini, Hamed; Ghazali, Hasanah; Ariffin, Abdul Azis

    2015-09-01

    5-Hydroxymethylfurfural (HMF) is formed during heat treatment of carbohydrate-containing foods, especially in a deep-fat frying process. This study aimed to investigate the effect of amino acids on the formation and reduction of HMF from glucose, fructose and sucrose at frying temperature in model systems containing binary mixtures of an amino acid and a sugar in equal concentrations (0.3M). The results revealed that the formation of HMF from sugars accelerated in the presence of acidic amino acids (i.e. glutamic and aspartic acids). Conversely, the presence of basic amino acids (i.e. lysine, arginine and histidine) led to reduced concentrations of HMF to non-detectable levels in model systems. The results showed that both pH and heating time significantly affected the formation of HMF from fructose in the presence of glutamic acid. In this regard, a higher amount of HMF was formed at lower pH.

  10. Acidic resin-catalysed conversion of fructose into furan derivatives in low boiling point solvents.

    PubMed

    Zhu, Hong; Cao, Quan; Li, Chunhu; Mu, Xindong

    2011-09-27

    Conversion of fructose into furan derivatives 5-hydroxymethylfurfural (HMF) and 5-methoxymethylfurfural (MMF) is performed in tetrahydrofuran (THF) and methanol-organic solvent systems, catalysed by an acidic resin Amberlyst-15. The melted fructose can be converted into HMF on the surface of the solid resin catalyst in the presence of THF as an extracting phase, which is a good solvent for HMF and other by-products. The solid resin catalyst can be reused eleven times without losing its catalytic ability, with an average HMF yield of approximately 50%. Upon the addition of methanol, the generated HMF can further react with methanol to form MMF, and the total yield of HMF and MMF could be promoted to 65%. GC-MS analysis confirms the formation of a small amount of methyl levulinate in methanolorganic solvent system.

  11. Critical Influence of 5-Hydroxymethylfurfural Aging and Decomposition on the Utility of Biomass Conversion in Organic Synthesis.

    PubMed

    Galkin, Konstantin I; Krivodaeva, Elena A; Romashov, Leonid V; Zalesskiy, Sergey S; Kachala, Vadim V; Burykina, Julia V; Ananikov, Valentine P

    2016-07-11

    Spectral studies revealed the presence of a specific arrangement of 5-hydroxymethylfurfural (5-HMF) molecules in solution as a result of a hydrogen-bonding network, and this arrangement readily facilitates the aging of 5-HMF. Deterioration of the quality of this platform chemical limits its practical applications, especially in synthesis/pharma areas. The model drug Ranitidine (Zantac®) was synthesized with only 15 % yield starting from 5-HMF which was isolated and stored as an oil after a biomass conversion process. In contrast, a much higher yield of 65 % was obtained by using 5-HMF isolated in crystalline state from an optimized biomass conversion process. The molecular mechanisms responsible for 5-HMF decomposition in solution were established by NMR and ESI-MS studies. A highly selective synthesis of a 5-HMF derivative from glucose was achieved using a protecting group at O(6) position.

  12. NASA Associate Administrator for Space Flight Rothenberg addresses guests at ribbon cutting for the

    NASA Technical Reports Server (NTRS)

    2000-01-01

    NASA Associate Administrator for Space Flight Joseph Rothenberg addresses attendees at a ribbon cutting for the new Checkout and Launch Control System (CLCS) at the Hypergolic Maintenance Facility (HMF). The CLCS was declared operational in a ribbon cutting ceremony earlier. The new control room will be used to process the Orbital Maneuvering System pods and Forward Reaction Control System modules at the HMF. This hardware is removed from Space Shuttle orbiters and routinely taken to the HMF for checkout and servicing.

  13. Center Director Bridges addresses guests at ribbon cutting for the new Checkout & Launch Control

    NASA Technical Reports Server (NTRS)

    2000-01-01

    KSC Director Roy Bridges addresses attendees at a ribbon cutting for the new Checkout and Launch Control System (CLCS) at the Hypergolic Maintenance Facility (HMF). The CLCS was declared operational in a ribbon cutting ceremony earlier. The new control room will be used to process the Orbital Maneuvering System pods and Forward Reaction Control System modules at the HMF. This hardware is removed from Space Shuttle orbiters and routinely taken to the HMF for checkout and servicing.

  14. Dehydration of highly concentrated solutions of fructose to 5-hydroxymethylfurfural in a cheap and sustainable choline chloride/carbon dioxide system.

    PubMed

    Liu, Fei; Barrault, Joël; De Oliveira Vigier, Karine; Jérôme, François

    2012-07-01

    Fête DES sciences: The dehydration of fructose and inulin to HMF is conveniently performed in a cheap and sustainable choline chloride/CO(2) deep eutectic solvent (DES) system. The medium is capable of converting high contents of fructose (>100 wt %) without affecting the yield of HMF (up to 72 %). The purity of the recovered HMF is >98%, and the reaction medium can be recycled.

  15. Nanoconfinement Effects in Catalysis

    SciTech Connect

    Kung, Harold H.

    2016-09-19

    neighboring Sn-O-Si bond. The resulting acidic silanol is active in epoxide ring opening and acetalization reactions. The open structure of the Sn center makes it accessible to larger molecules, including cellobiose which can be converted to 5-(hydroxymethyl)-furfural. The third structure is a support planted with functional group pairing of a known separation distance. Using a precursor molecule that contains a hydrolysable silyl ester bond, and making use of known chemistry to convert silanol groups into amino/pyridyl and phosphinyl groups, silica surfaces with carboxylic acid/silanol, carboxylic acid/amine, carboxylic acid/pyridine, and carboxylic acid/phosphine pairs can be constructed. The amino groups paired with carboxylic acid on such a surface is more active in the Henry reaction of 4-nitobenzaldehyde with nitromethane.

  16. Growth and Tolerance of Preterm Infants Fed a New Extensively Hydrolyzed Liquid Human Milk Fortifier

    PubMed Central

    Kim, Jae H.; Chan, Gary; Schanler, Richard; Groh-Wargo, Sharon; Bloom, Barry; Dimmit, Reed; Williams, Larry; Baggs, Geraldine; Barrett-Reis, Bridget

    2015-01-01

    ABSTRACT Objectives: This study was a comparison of growth and tolerance in premature infants fed either standard powdered human milk fortifier (HMF) or a newly formulated concentrated liquid that contained extensively hydrolyzed protein. Methods: This was an unblinded randomized controlled multicenter noninferiority study on preterm infants receiving human milk (HM) supplemented with 2 randomly assigned HMFs, either concentrated liquid HMF containing extensively hydrolyzed protein (LE-HMF) or a powdered intact protein HMF (PI-HMF) as the control. The study population consisted of preterm infants ≤33 weeks who were enterally fed HM. Infants were studied from the first day of HM fortification until day 29 or hospital discharge, whichever came first. Results: A total of 147 preterm infants were enrolled. Noninferiority was observed in weight gain reported in the intent-to-treat (ITT) analysis was 18.2 and 17.5 g · kg−1 · day−1 for the LE-HMF and PI-HMF groups, respectively. In an a priori defined subgroup of strict protocol followers (n = 75), the infants fed LE-HMF achieved greater weight over time than those fed PI-HMF (P = 0.036). The LE-HMF group achieved greater linear growth over time compared to the PI-HMF (P = 0.029). The protein intake from fortified HM was significantly higher in the LE-HMF group compared with the PI-HMF group (3.9 vs 3.3 g · kg−1 · day−1, P < 0.0001). Both fortifiers were well tolerated with no significant differences in overall morbidity. Conclusions: Both fortifiers showed excellent weight gain (grams per kilograms per day), tolerance, and low incidence of morbidity outcomes with the infants who were strict protocol followers fed LE-HMF having improved growth during the study. These data point to the safety and suitability of this new concentrated liquid HMF (LE-HMF) in preterm infants. Growth with this fortifier closely matches the recent recommendations for a weight gain of >18 g · kg−1 · day−1. PMID

  17. Novel Simulated moving bed technologies

    SciTech Connect

    Purdue University

    2003-12-30

    Cellulose and hemicellulose from plants and other biomass can be hydrolyzed to produce sugars (i.e. glucose and xylose). Once these sugars are separated from other impurities, they can serve as feedstock in fermentation to produce ethanol (as fuels), lactic acid, or other valuable chemicals. The need for producing fuels and chemicals from renewable biomass has become abundantly clear over the last decade. However, the cost of producing fermentable sugars from biomass hydrolyzate using existing technology is relatively high and has been a major obstacle. The objective of this project is to develop an efficient and economical simulated moving bed (SMB) process to recover fermentable sugars from biomass hydrolyzate. Sulfuric acid can hydrolyze the cellulose and hemicellulose in biomass to sugars, but this process can generate byproducts such as acetic acid, and can lead to further degradation of the xylose to furfural and glucose to hydroxymethyl furfural (HMF). Also, lignin and other compounds in the biomass will degrade to various phenolic compounds. If the concentrations of these compounds exceed certain threshold levels, they will be toxic to the downstream fermentation, and will severely limit the usefulness of the derived sugars. Standard post-hydrolysis processing involves neutralization of sulfuric acid, usually with lime (calcium hydroxide). A study by Wooley et al.showed that the limed hydrolyzate gave a low ethanol yield in fermentation test (20% of theoretical yield compared to 77% of theoretical yield from fermentation of pure sugars). They showed that instead of adding lime, an ion exclusion chromatography process could be used to remove acids, as well as to isolate the sugars from the biomass hydrolyzate. In this project, we investigated the feasibility of developing an economical SMB process based on (1) a polymeric adsorbent, Dowex99, which was used by Wooley et al., (2) a second polymeric adsorbent, poly-4-vinyl pyridine (or PVP in short, Reilly

  18. Effects of TET2 mutations on DNA methylation in chronic myelomonocytic leukemia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    TET2 enzymatically converts 5-methyl-cytosine to 5-hydroxymethyl-cytosine, possibly leading to loss of DNA methylation. TET2 mutations are common in myeloid leukemia and were proposed to contribute to leukemogenesis through DNA methylation. To expand on this concept, we studied chronic myelomonocyti...

  19. Compounds Released from Biomass Deconstruction: Understanding Their Effect on Cellulose Enzyme Hydrolysis and Their Biological Activity

    NASA Astrophysics Data System (ADS)

    Djioleu, Angele Mezindjou

    The effect of compounds produced during biomass pretreatment on cellulolytic enzyme was investigated. Liquid prehydrolyzates were prepared by pretreating switchgrass using 24 combinations of temperature, time, and sulfuric acid concentration based on a full factorial design. Temperature was varied from 140°C to 180°C; time ranged from 10 to 40 min; and the sulfuric acid concentrations were 0.5% or 1% (v/v). Identified products in the prehydrolyzates included xylose, glucose, hydroxymethylfurfural (HMF), furfural, acetic acid, formic acid, and phenolic compounds at concentration ranging from 0 to 21.4 g/L. Pretreatment conditions significantly affected the concentrations of compounds detected in prehydrolyzates. When assayed in the presence of switchgrass prehydrolyzates against model substrates, activities of cellulase, betaglucosidase, and exoglucanase, were significantly reduced by at least 16%, 31.8%, and 57.8%, respectively, as compared to the control. A strong positive correlation between inhibition of betaglucosidase and concentration of glucose, acetic acid, and furans in prehydrolyzate was established. Exoglucanase inhibition correlated with the presence of phenolic compounds and acetic acid. The prehydrolyzate, prepared at 160°C, 30 min, and 1% acid, was fractionated by centrifugal partition chromatography (CPC) into six fractions; the inhibition effect of these fractions on betaglucosidase and exoglucanase was determined. The initial hydrolysis rate of cellobiose by betaglucosidase was significantly reduced by the CPC sugar-rich fraction; however, exoglucanase was deactivated by the CPC phenolic-rich fraction. Finally, biological activities of water-extracted compounds from sweetgum bark and their effect on cellulase was investigated. It was determined that 12% of solid content of the bark extract could be accounted by phenolic compounds with gallic acid identified as the most concentrated phytochemical. Sweetgum bark extract inhibited Staphylococcus

  20. Simultaneously improving xylose fermentation and tolerance to lignocellulosic inhibitors through evolutionary engineering of recombinant Saccharomyces cerevisiae harbouring xylose isomerase

    PubMed Central

    2014-01-01

    Background Yeasts tolerant to toxic inhibitors from steam-pretreated lignocellulose with xylose co-fermentation capability represent an appealing approach for 2nd generation ethanol production. Whereas rational engineering, mutagenesis and evolutionary engineering are established techniques for either improved xylose utilisation or enhancing yeast tolerance, this report focuses on the simultaneous enhancement of these attributes through mutagenesis and evolutionary engineering of Saccharomyces cerevisiae harbouring xylose isomerase in anoxic chemostat culture using non-detoxified pretreatment liquor from triticale straw. Results Following ethyl methanesulfonate (EMS) mutagenesis, Saccharomyces cerevisiae strain D5A+ (ATCC 200062 strain platform), harbouring the xylose isomerase (XI) gene for pentose co-fermentation was grown in anoxic chemostat culture for 100 generations at a dilution rate of 0.10 h-1 in a medium consisting of 60% (v/v) non-detoxified hydrolysate liquor from steam-pretreated triticale straw, supplemented with 20 g/L xylose as carbon source. In semi-aerobic batch cultures in the same medium, the isolated strain D5A+H exhibited a slightly lower maximum specific growth rate (μmax = 0.12 ± 0.01 h-1) than strain TMB3400, with no ethanol production observed by the latter strain. Strain D5A+H also exhibited a shorter lag phase (4 h vs. 30 h) and complete removal of HMF, furfural and acetic acid from the fermentation broth within 24 h, reaching an ethanol concentration of 1.54 g/L at a yield (Yp/s) of 0.06 g/g xylose and a specific productivity of 2.08 g/gh. Evolutionary engineering profoundly affected the yeast metabolism, given that parental strain D5A+ exhibited an oxidative metabolism on xylose prior to strain development. Conclusions Physiological adaptations confirm improvements in the resistance to and conversion of inhibitors from pretreatment liquor with simultaneous enhancement of xylose to ethanol fermentation. These data

  1. Improving a recombinant Zymomonas mobilis strain 8b through continuous adaptation on dilute acid pretreated corn stover hydrolysate

    SciTech Connect

    Mohagheghi, Ali; Linger, Jeffrey G.; Yang, Shihui; Smith, Holly; Dowe, Nancy; Zhang, Min; Pienkos, Philip T.

    2015-03-31

    Complete conversion of the major sugars of biomass including both the C5 and C6 sugars is critical for biofuel production processes. Several inhibitory compounds like acetate, hydroxymethylfurfural (HMF), and furfural are produced from the biomass pretreatment process leading to ‘hydrolysate toxicity,’ a major problem for microorganisms to achieve complete sugar utilization. Therefore, development of more robust microorganisms to utilize the sugars released from biomass under toxic environment is critical. In this study, we use continuous culture methodologies to evolve and adapt the ethanologenic bacterium Zymomonas mobilis to improve its ethanol productivity using corn stover hydrolysate. The results are the following: A turbidostat was used to adapt the Z. mobilis strain 8b in the pretreated corn stover liquor. The adaptation was initiated using pure sugar (glucose and xylose) followed by feeding neutralized liquor at different dilution rates. Once the turbidostat reached 60% liquor content, the cells began washing out and the adaptation was stopped. Several ‘sub-strains’ were isolated, and one of them, SS3 (sub-strain 3), had 59% higher xylose utilization than the parent strain 8b when evaluated on 55% neutralized PCS (pretreated corn stover) liquor. Using saccharified PCS slurry generated by enzymatic hydrolysis from 25% solids loading, SS3 generated an ethanol yield of 75.5% compared to 64% for parent strain 8b. Furthermore, the total xylose utilization was 57.7% for SS3 versus 27.4% for strain 8b. To determine the underlying genotypes in these new sub-strains, we conducted genomic resequencing and identified numerous single-nucleotide mutations (SNPs) that had arisen in SS3. We further performed quantitative reverse transcription PCR (qRT-PCR) on genes potentially affected by these SNPs and identified significant down-regulation of two genes, ZMO0153 and ZMO0776, in SS3 suggesting potential genetic mechanisms behind SS3

  2. Improving a recombinant Zymomonas mobilis strain 8b through continuous adaptation on dilute acid pretreated corn stover hydrolysate

    DOE PAGES

    Mohagheghi, Ali; Linger, Jeffrey G.; Yang, Shihui; ...

    2015-03-31

    Complete conversion of the major sugars of biomass including both the C5 and C6 sugars is critical for biofuel production processes. Several inhibitory compounds like acetate, hydroxymethylfurfural (HMF), and furfural are produced from the biomass pretreatment process leading to ‘hydrolysate toxicity,’ a major problem for microorganisms to achieve complete sugar utilization. Therefore, development of more robust microorganisms to utilize the sugars released from biomass under toxic environment is critical. In this study, we use continuous culture methodologies to evolve and adapt the ethanologenic bacterium Zymomonas mobilis to improve its ethanol productivity using corn stover hydrolysate. The results are the following:more » A turbidostat was used to adapt the Z. mobilis strain 8b in the pretreated corn stover liquor. The adaptation was initiated using pure sugar (glucose and xylose) followed by feeding neutralized liquor at different dilution rates. Once the turbidostat reached 60% liquor content, the cells began washing out and the adaptation was stopped. Several ‘sub-strains’ were isolated, and one of them, SS3 (sub-strain 3), had 59% higher xylose utilization than the parent strain 8b when evaluated on 55% neutralized PCS (pretreated corn stover) liquor. Using saccharified PCS slurry generated by enzymatic hydrolysis from 25% solids loading, SS3 generated an ethanol yield of 75.5% compared to 64% for parent strain 8b. Furthermore, the total xylose utilization was 57.7% for SS3 versus 27.4% for strain 8b. To determine the underlying genotypes in these new sub-strains, we conducted genomic resequencing and identified numerous single-nucleotide mutations (SNPs) that had arisen in SS3. We further performed quantitative reverse transcription PCR (qRT-PCR) on genes potentially affected by these SNPs and identified significant down-regulation of two genes, ZMO0153 and ZMO0776, in SS3 suggesting potential genetic mechanisms behind SS3’s improved

  3. Two New Native β-Glucosidases from Clavispora NRRL Y-50464 Confer Its Dual Function as Cellobiose Fermenting Ethanologenic Yeast

    PubMed Central

    Wang, Xu; Liu, Z. Lewis; Weber, Scott A.; Zhang, Xiaoping

    2016-01-01

    Yeast strain Clavispora NRRL Y-50464 is able to produce cellulosic ethanol from lignocellulosic materials without addition of external β-glucosidase by simultaneous saccharification and fermentation. A β-glucosidase BGL1 protein from this strain was recently reported supporting its cellobiose utilization capability. Here, we report two additional new β-glucosidase genes encoding enzymes designated as BGL2 and BGL3 from strain NRRL Y-50464. Quantitative gene expression was analyzed and the gene function of BGL2 and BGL3 was confirmed by heterologous expression using cellobiose as a sole carbon source. Each gene was cloned and partially purified protein obtained separately for direct enzyme assay using varied substrates. Both proteins showed the highest specific activity at pH 5 and relatively strong affinity with a Km of 0.08 and 0.18 mM for BGL2 and BGL3, respectively. The optimum temperature was found to be 50°C for BGL2 and 55°C for BGL3. Both proteins were able to hydrolyze 1,4 oligosaccharides evaluated in this study. They also showed a strong resistance to glucose product inhibition with a Ki of 61.97 and 38.33 mM for BGL2 and BGL3, respectively. While BGL3 was sensitive showing a significantly reduced activity to 4% ethanol, BGL2 demonstrated tolerance to ethanol. Its activity was enhanced in the presence of ethanol but reduced at concentrations greater than 16%. The presence of the fermentation inhibitors furfural and HMF did not affect the enzyme activity. Our results suggest that a β-glucosidase gene family exists in Clavispora NRRL Y-50464 with at least three members in this group that validate its cellobiose hydrolysis functions for lower-cost cellulosic ethanol production. Results of this study confirmed the cellobiose hydrolysis function of strain NRRL Y-50464, and further supported this dual functional yeast as a candidate for lower-cost cellulosic ethanol production and next-generation biocatalyst development in potential industrial

  4. Xylitol production from xylose mother liquor: a novel strategy that combines the use of recombinant Bacillus subtilis and Candida maltosa

    PubMed Central

    2011-01-01

    Background Xylose mother liquor has high concentrations of xylose (35%-40%) as well as other sugars such as L-arabinose (10%-15%), galactose (8%-10%), glucose (8%-10%), and other minor sugars. Due to the complexity of this mother liquor, further isolation of xylose by simple method is not possible. In China, more than 50,000 metric tons of xylose mother liquor was produced in 2009, and the management of sugars like xylose that present in the low-cost liquor is a problem. Results We designed a novel strategy in which Bacillus subtilis and Candida maltosa were combined and used to convert xylose in this mother liquor to xylitol, a product of higher value. First, the xylose mother liquor was detoxified with the yeast C. maltosa to remove furfural and 5-hydromethylfurfural (HMF), which are inhibitors of B. subtilis growth. The glucose present in the mother liquor was also depleted by this yeast, which was an added advantage because glucose causes carbon catabolite repression in B. subtilis. This detoxification treatment resulted in an inhibitor-free mother liquor, and the C. maltosa cells could be reused as biocatalysts at a later stage to reduce xylose to xylitol. In the second step, a recombinant B. subtilis strain with a disrupted xylose isomerase gene was constructed. The detoxified xylose mother liquor was used as the medium for recombinant B. subtilis cultivation, and this led to L-arabinose depletion and xylose enrichment of the medium. In the third step, the xylose was further reduced to xylitol by C. maltosa cells, and crystallized xylitol was obtained from this yeast transformation medium. C. maltosa transformation of the xylose-enriched medium resulted in xylitol with 4.25 g L-1·h-1 volumetric productivity and 0.85 g xylitol/g xylose specific productivity. Conclusion In this study, we developed a biological method for the purification of xylose from xylose mother liquor and subsequent preparation of xylitol by C. maltosa-mediated biohydrogenation of xylose

  5. Mini-rack testbed evaluation

    NASA Technical Reports Server (NTRS)

    Gosbee, John; Stegmann, Barbara; Guess, Terrell M.

    1991-01-01

    The goal was to characterize the Health Maintenance Facility (HMF)-like mini-racks and drawers onboard the KC-135 as a test bed for the Space Station Freedom HMF racks. An additional goal was to evaluate the attachments, mounting points, and inner drawer assemblies of the mini-racks for various medical equipment and supplies. Results and recommendations are given.

  6. Shielding of the Geomagnetic Field Alters Actin Assembly and Inhibits Cell Motility in Human Neuroblastoma Cells

    PubMed Central

    Mo, Wei-Chuan; Zhang, Zi-Jian; Wang, Dong-Liang; Liu, Ying; Bartlett, Perry F.; He, Rong-Qiao

    2016-01-01

    Accumulating evidence has shown that absence of the geomagnetic field (GMF), the so-called hypomagnetic field (HMF) environment, alters the biological functions in seemingly non-magnetosensitive cells and organisms, which indicates that the GMF could be sensed by non-iron-rich and non-photo-sensing cells. The underlying mechanisms of the HMF effects on those cells are closely related to their GMF sensation but remain poorly understood so far. Previously, we found that the HMF represses expressions of genes associated with cell migration and cytoskeleton assembly in human neuroblastoma cells (SH-SY5Y cell line). Here, we measured the HMF-induced changes on cell morphology, adhesion, motility and actin cytoskeleton in SH-SY5Y cells. The HMF inhibited cell adhesion and migration accompanied with a reduction in cellular F-actin amount. Moreover, following exposure to the HMF, the number of cell processes was reduced and cells were smaller in size and more round in shape. Furthermore, disordered kinetics of actin assembly in vitro were observed during exposure to the HMF, as evidenced by the presence of granule and meshed products. These results indicate that elimination of the GMF affects assembly of the motility-related actin cytoskeleton, and suggest that F-actin is a target of HMF exposure and probably a mediator of GMF sensation. PMID:27029216

  7. Strength of Cu-28 wt%Ag composite solidified under high magnetic field followed by cold drawing

    NASA Astrophysics Data System (ADS)

    Zhao, Congcong; Zuo, Xiaowei; Wang, Engang; Han, Ke

    2017-03-01

    Cu-Ag composite is one of the best conductors for high-field magnets. Increasing its strength is crucial for designing newer high-field magnets. Cu-28 wt%Ag samples were solidified with and without a 12-T high magnetic field (HMF), and then cold-drawn. We investigated the influence of HMF on microstructure, hardness and strength of Cu-Ag samples both before and after cold-drawing. The introduction of external HMF during solidification increased both the dendrite arm spacing and the dissolved Ag in Cu, and it reduced the spacing between both the Ag precipitates in proeutectic Cu and the eutectic lamellae. The transversal microstructure after cold-drawing inherited the network solidification structure, but at a refined scale. The Cu dendrite spacing in the 12-T HMF samples at all deformation strain was larger than that without HMF. HMF slightly increased the intensity of <111> fiber texture of Cu, which strengthened proeutectic Cu at the level of 3.5 deformation strain. In samples deformed to strain of 3.5, refined Ag precipitation spacing, increased Ag solubility in Cu matrix, and refined eutectic lamellar spacing by 12-T HMF increased the strength by 5% in the sample compared with that without HMF.

  8. Emticicia aquatica sp. nov., a species of the family Cytophagaceae isolated from fresh water.

    PubMed

    Joung, Yochan; Seo, Mi-Ae; Kang, Heeyoung; Kim, Haneul; Ahn, Tae-Seok; Cho, Jang-Cheon; Joh, Kiseong

    2015-12-01

    A Gram-staining-negative, non-gliding, orange-pigmented bacterial strain, designated HMF2925T, was isolated from fresh water in Korea. The phylogenetic tree based on 16S rRNA gene sequences showed that strain HMF2925T formed a distinct lineage within the genus Emticicia. Strain HMF2925T was closely related to Emticicia oligotrophica DSM 17448T (95.5 %) and Emticicia ginsengisoli Gsoil 085T (94.1 %). The major fatty acids of strain HMF2925T were summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c), iso-C15 : 0, C16 : 1ω5c and C16 : 0.The major polar lipids of strain HMF2925T were phosphatidylethanolamine, phosphatidylinositol, diphosphatidylglycerol, phosphatidylglycerol, an unidentified glycolipid, two unidentified amino lipids and three unidentified polar lipids. The DNA G+C content of strain HMF2925T was 36.5 mol%. On the basis of the evidence presented in this study, strain HMF2925T represents a novel species of the genus Emticicia, for which the name Emticicia aquatica sp. nov. is proposed. The type strain is HMF2925T ( = KCTC 42574T = CECT 8858T).

  9. Polymorphic Transformation in Mixtures of High- and Low-Melting Fractions of Milk Fat

    SciTech Connect

    Cisneros,A.; Mazzanti, G.; Campos, R.; Marangoni, A.

    2006-01-01

    The kinetics of crystallization of high-melting fraction (HMF) and a mixture of 40% HMF and 60% low-melting fraction (LMF) of milk fat were studied at 5 C by time-resolved in-situ synchrotron X-ray diffraction. HMF crystallized in the {alpha} polymorph, had a longer lifetime than the ones previously reported in pure milk fat, and was almost completely solid. The HMF/LMF mixture crystallized initially in the {alpha} form and transformed into the {beta}' polymorph, with a solid fat content much lower than that of HMF. The polymorphic change was therefore attributed to a delayed sudden formation of {beta}' mixed crystals from the uncrystallized melt. These findings are important for the food industry and as fundamental knowledge to improve our understanding of the origin of the macroscopic physical properties of solid milk fat fractions used in many manufacturing processes.

  10. Synergy of Lewis and Brønsted acids on catalytic hydrothermal decomposition of carbohydrates and corncob acid hydrolysis residues to 5-hydroxymethylfurfural

    PubMed Central

    Wang, Chao; Zhang, Liming; Zhou, Tian; Chen, Jiachuan; Xu, Feng

    2017-01-01

    5-hydroxymethylfurfural (HMF) is an important platform molecule in the synthesis of various chemicals and materials. Herein, we reported a simple and effective dehydration of glucose-based carbohydrates to HMF in a biphasic system containing cyclopentyl methyl ether as the organic phase and AlCl3 with minute amounts of HCl as co-catalysts. The results showed that the mixed catalysts had a positive synergistic catalytic effect on glucose conversion to HMF compared with single AlCl3 or HCl catalyst. For glucose, the highest HMF yield of 54.5% was achieved at 175 °C for 20 min. More importantly, the optimal catalytic system was so efficient that it achieved one of the highest reported yields of HMF (30.5%) directly from corncob acid hydrolysis residues. Thus, the catalytic system can become a promising route for effective utilization of biomass in future biorefineries. PMID:28084456

  11. 5-Hydroxy-7-Methoxyflavone Triggers Mitochondrial-Associated Cell Death via Reactive Oxygen Species Signaling in Human Colon Carcinoma Cells

    PubMed Central

    Paul, Souren; Jakhar, Rekha; Han, Jaehong; Kang, Sun Chul

    2016-01-01

    Plant-derived compounds are an important source of clinically useful anti-cancer agents. Chrysin, a biologically active flavone found in many plants, has limited usage for cancer chemotherapeutics due to its poor oral bioavailability. 5-Hydroxy-7-methoxyflavone (HMF), an active natural chrysin derivative found in various plant sources, is known to modulate several biological activities. However, the mechanism underlying HMF-induced apoptotic cell death in human colorectal carcinoma cells in vitro is still unknown. Herein, HMF was shown to be capable of inducing cytotoxicity in HCT-116 cells and induced cell death in a dose-dependent manner. Treatment of HCT-116 cells with HMF caused DNA damage and triggered mitochondrial membrane perturbation accompanied by Cyt c release, down-regulation of Bcl-2, activation of BID and Bax, and caspase-3-mediated apoptosis. These results show that ROS generation by HMF was the crucial mediator behind ER stress induction, resulting in intracellular Ca2+ release, JNK phosphorylation, and activation of the mitochondrial apoptosis pathway. Furthermore, time course study also reveals that HMF treatment leads to increase in mitochondrial and cytosolic ROS generation and decrease in antioxidant enzymes expression. Temporal upregulation of IRE1-α expression and JNK phosphorylation was noticed after HMF treatment. These results were further confirmed by pre-treatment with the ROS scavenger N-acetyl-l-cysteine (NAC), which completely reversed the effects of HMF treatment by preventing lipid peroxidation, followed by abolishment of JNK phosphorylation and attenuation of apoptogenic marker proteins. These results emphasize that ROS generation by HMF treatment regulates the mitochondrial-mediated apoptotic signaling pathway in HCT-116 cells, demonstrating HMF as a promising pro-oxidant therapeutic candidate for targeting colorectal cancer. PMID:27116119

  12. A study of different indicators of Maillard reaction with whey proteins and different carbohydrates under adverse storage conditions.

    PubMed

    Leiva, Graciela E; Naranjo, Gabriela B; Malec, Laura S

    2017-01-15

    This study examined different indicators of each stage of Maillard reaction under adverse storage conditions in a system with whey proteins and lactose or glucose. The analysis of lysine loss by the o-phthaldialdehyde method can be considered a good indicator of the early stage, showing considerable differences in reactivity when systems with mono and disaccharides were analyzed. Capillary electrophoresis proved to be a sensitive method for evaluating the extent of glycosylation of the native proteins, providing valuable information when the loss of lysine was not significant. The estimation of the Amadori compound from the determination of total 5-hydroxymethyl-2-furfuraldehyde would have correlate well with reactive lysine content if the advanced stages of the reaction had not been reached. For assessing the occurrence of the intermediate and final stages, the measurement of free 5-hydroxymethyl-2-furfuraldehyde and color, proved not to be suitable for storage conditions.

  13. Synthesis of 1,3,3-trinitroazetidine

    DOEpatents

    Hiskey, M.A.; Coburn, M.D.

    1994-08-09

    A process of preparing 1,3,3-trinitroazetidine includes forming a 5-hydroxymethyl-5-nitro-1-alkyltetrahydro-1,3-oxazine, e.g., reacting a 1,3,5-trialkyl hexahydrotriazine and tris(hydroxymethyl)nitromethane, ring opening said 5-hydroxymethyl-5-nitro-1-alkyltetrahydro-1,3-oxazine to form a 3-alkylamino-2-hydroxymethyl-2-nitro-1-propanol salt, ring closing said 3-alkylamino-2-hydroxymethyl-2-nitro-1-propanol salt to form a 3-hydroxymethyl-3-nitro-1-alkylazetidine salt, nitrating said 3-hydroxymethyl-3-nitro-1-alkylazetidine salt to form a 1-alkyl-3,3-dinitroazetidine, and converting said 1-alkyl-3,3-dinitroazetidine into 1,3,3-trinitroazetidine is disclosed. 1 fig.

  14. Synthesis of 1,3,3-trinitroazetidine

    DOEpatents

    Hiskey, Michael A.; Coburn, Michael D.

    1994-01-01

    A process of preparing 1,3,3-trinitroazetidine including forming a 5-hydroxymethyl-5-nitro-1-alkyltetrahydro-1,3-oxazine, e.g., reacting a 1,3,5-trialkyl hexahydrotriazine and tris(hydroxymethyl)nitromethane, ring opening said 5-hydroxymethyl-5-nitro-1-alkyltetrahydro-1,3-oxazine to form a 3-alkylamino-2-hydroxymethyl-2-nitro-1-propanol salt, ring closing said 3-alkylamino-2-hydroxymethyl-2-nitro-1-propanol salt to form a 3-hydroxymethyl-3-nitro-1-alkylazetidine salt, nitrating said 3-hydroxymethyl-3-nitro-1-alkylazetidine salt to form a 1-alkyl-3,3-dinitroazetidine, and converting said 1-alkyl-3,3-dinitroazetidine into 1,3,3-trinitroazetidine is disclosed.

  15. Drug-excipient compatibility testing-Identification and characterization of degradation products of phenylephrine in several pharmaceutical formulations against the common cold.

    PubMed

    Douša, Michal; Gibala, Petr; Havlíček, Jaroslav; Plaček, Lukáš; Tkadlecová, Marcela; Břicháč, Jiří

    2011-07-15

    Different pharmaceutical preparations against the common cold containing phenylephrine (PHE) and saccharose were studied. New impurities were discovered in these preparations after exposure using isocratic ion-pair chromatography separation on a C18 column. LC-MS and NMR techniques were employed to identify and to fully characterize these new compounds. The products were identified as 1-[5-(hydroxymethyl)-2-furyl]-2-methyl-1,2,3,4-tetrahydroisochinolin-4,8-diol and 1-[5-(hydroxymethyl)-2-furyl]-2-methyl-1,2,3,4-tetrahydroisochinolin-4,6-diol. Identification of these degradation products allowed to understand and to confirm their formation mechanism. The developed HPLC method separates of all known impurities and impurities originated from PHE as well.

  16. Characterisation of tequila according to their major volatile composition using multilayer perceptron neural networks.

    PubMed

    Ceballos-Magaña, Silvia G; de Pablos, Fernando; Jurado, José Marcos; Martín, María Jesús; Alcázar, Ángela; Muñiz-Valencia, Roberto; Gonzalo-Lumbreras, Raquel; Izquierdo-Hornillos, Roberto

    2013-02-15

    Differentiation of silver, gold, aged and extra-aged tequila using 1-propanol, ethyl acetate, 2-methyl-1-propanol, 3-methyl-1-butanol and 2-methyl-1-butanol and furan derivatives like 5-(hydroxymethyl)-2-furaldehyde and 2-furaldehyde has been carried out. The content of 1-propanol, ethyl acetate, 2-methyl-1-propanol, 3-methyl-1-butanol and 2-methyl-1-butanol was determined by means of head space solid phase microextraction gas chromatography mass-spectrometry. 5-(Hydroxymethyl)-2-furaldehyde and 2-furaldehyde were determined by high performance liquid chromatography with diode array detection. Kruskal-Wallis test was used to highlight significant differences between types of tequila. Principal component analysis was applied as visualisation technique. Linear discriminant analysis and multilayer perceptron artificial neural networks were used to construct classification models. The best classification performance was obtained when multilayer perceptron model was applied.

  17. One-pot conversion of disaccharide into 5-hydroxymethylfurfural catalyzed by imidazole ionic liquid

    PubMed Central

    Qu, Yongshui; Li, Li; Wei, Quanyuan; Huang, Chongpin; Oleskowicz-Popiel, Piotr; Xu, Jian

    2016-01-01

    Conversion of carbohydrate into 5-hydroxymethylfurfural (5- HMF), a versatile, key renewable platform compound is regarded as an important transformation in biomass-derived carbohydrate chemistry. A variety of ILs, not only acidic but also alkaline ILs, were synthesized and used as catalyst in the production of 5-HMF from disaccharide. Several factors including reaction temperature, IL dosage, solvent and reaction time,were found to influence the yield of 5-HMF from cellobiose. Of the ILs tested, hydroxy-functionalized ionic liquid (IL), 1-hydroxyethyl-3-methylimidazolium tetrafluoroborate ([AEMIM]BF4) showed the highest catalytic activity and selectivity. 5-HMF yield of 68.71% from sucrose was obtained after 6 hrs at 160 °C. At the same condition with cellobiose as substrate, 5-HMF yield was 24.73%. In addition, 5-HMF also exhibited good stablity in this reaction system. Moreover, a kinetic analysis was carried out in both acidic and alkaline IL-catalyzed system, suggesting main side reaction in the conversion of fructose catalyzed by acidic and alkaline IL was polymerization of fructose and 5-HMF degradation, respectively. PMID:27181523

  18. The Heliospheric Magnetic Field

    NASA Astrophysics Data System (ADS)

    Owens, Mathew J.; Forsyth, Robert J.

    2013-12-01

    The heliospheric magnetic field (HMF) is the extension of the coronal magnetic field carried out into the solar system by the solar wind. It is the means by which the Sun interacts with planetary magnetospheres and channels charged particles propagating through the heliosphere. As the HMF remains rooted at the solar photosphere as the Sun rotates, the large-scale HMF traces out an Archimedean spiral. This pattern is distorted by the interaction of fast and slow solar wind streams, as well as the interplanetary manifestations of transient solar eruptions called coronal mass ejections. On the smaller scale, the HMF exhibits an array of waves, discontinuities, and turbulence, which give hints to the solar wind formation process. This review aims to summarise observations and theory of the small- and large-scale structure of the HMF. Solar-cycle and cycle-to-cycle evolution of the HMF is discussed in terms of recent spacecraft observations and pre-spaceage proxies for the HMF in geomagnetic and galactic cosmic ray records.

  19. Using Flow Cytometry to Evaluate the Stress Physiological Response of the Yeast Saccharomyces carlsbergensis ATCC 6269 to the Presence of 5-Hydroxymethylfurfural During Ethanol Fermentations.

    PubMed

    Lopes da Silva, Teresa; Baptista, Cátia; Reis, Alberto; Passarinho, Paula C

    2017-03-01

    Lignocellulosic materials have been considered low-cost effective substrates for bioethanol production. However, lignocellulosic pretreatment releases toxic compounds such as 5-hydroxymethylfurfural (HMF) that is known to inhibit the yeast growth and ethanol production. In this work, flow cytometry was used to monitor the physiological response of the yeast Saccharomyces carlsbergensis ATCC 6269 in the presence of different initial HMF concentrations within the range of 0-15 g/L, in terms of cell membrane integrity, potential, and intracellular lipids. It was observed that the HMF presence affected more significantly the yeast growth than the ethanol production. At 15 g/L HMF, the yeast growth and fermentation ability were completely inhibited. The cell membrane integrity and potential decreased as the initial HMF concentration increased. At the end of the fermentation process with 10 g/L HMF, the yeast culture contained 45 % of cells with depolarized plasma membrane, 52 % of cells with permeabilized plasma membrane, and 53 % of cells with increasing reactive oxygen species (ROS) levels. Using the Nile Red stain, it was observed that intracellular polar lipids were more affected by the initial HMF concentration than the neutral lipids, probably due to the extensive membrane damage.

  20. A new bipyrrole and some phenolic constituents in prunes (Prunus domestica L.) and their oxygen radical absorbance capacity (ORAC).

    PubMed

    Kayano, Shin-ichi; Kikuzaki, Hiroe; Ikami, Takao; Suzuki, Tomoo; Mitani, Takahiko; Nakatani, Nobuji

    2004-04-01

    Isolation and structural elucidation of prune constituents were performed and total 10 compounds were determined by NMR and MS analyses. A novel compound was identified to be 2-(5-hydroxymethyl-2',5'-dioxo-2',3',4',5'-tetrahydro-1'H-1,3'-bipyrrole)carbaldehyde, and 7 phenolic compounds were isolated from prunes for the first time. In addition, antioxidant activity of them was evaluated on the basis of the oxygen radical absorbance capacity (ORAC).