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Sample records for 5-hydroxymethyl furfural hmf

  1. Biotransformation of furfural and 5-hydroxymethyl furfural (HMF) by Clostridium acetobutylicum ATCC 824 during butanol fermentation.

    PubMed

    Zhang, Yan; Han, Bei; Ezeji, Thaddeus Chukwuemeka

    2012-02-15

    The ability of fermenting microorganisms to tolerate furan aldehyde inhibitors (furfural and 5-hydroxymethyl furfural (HMF)) will enhance efficient bioconversion of lignocellulosic biomass hydrolysates to fuels and chemicals. The effect of furfural and HMF on butanol production by Clostridium acetobutylicum 824 was investigated. Whereas specific growth rates, μ, of C. acetobutylicum in the presence of furfural and HMF were in the range of 15-85% and 23-78%, respectively, of the uninhibited Control, μ increased by 8-15% and 23-38% following exhaustion of furfural and HMF in the bioreactor. Using high performance liquid chromatography and spectrophotometric assays, batch fermentations revealed that furfural and HMF were converted to furfuryl alcohol and 2,5-bis-hydroxymethylfuran, respectively, with specific conversion rates of 2.13g furfural and 0.50g HMF per g (biomass) per hour, by exponentially growing C. acetobutylicum. Biotransformation of these furans to lesser inhibitory compounds by C. acetobutylicum will probably enhance overall fermentation of lignocellulosic hydrolysates to butanol.

  2. Biotransformation of furfural and 5-hydroxymethyl furfural (HMF) by Clostridium acetobutylicum ATCC 824 during butanol fermentation.

    PubMed

    Zhang, Yan; Han, Bei; Ezeji, Thaddeus Chukwuemeka

    2012-02-15

    The ability of fermenting microorganisms to tolerate furan aldehyde inhibitors (furfural and 5-hydroxymethyl furfural (HMF)) will enhance efficient bioconversion of lignocellulosic biomass hydrolysates to fuels and chemicals. The effect of furfural and HMF on butanol production by Clostridium acetobutylicum 824 was investigated. Whereas specific growth rates, μ, of C. acetobutylicum in the presence of furfural and HMF were in the range of 15-85% and 23-78%, respectively, of the uninhibited Control, μ increased by 8-15% and 23-38% following exhaustion of furfural and HMF in the bioreactor. Using high performance liquid chromatography and spectrophotometric assays, batch fermentations revealed that furfural and HMF were converted to furfuryl alcohol and 2,5-bis-hydroxymethylfuran, respectively, with specific conversion rates of 2.13g furfural and 0.50g HMF per g (biomass) per hour, by exponentially growing C. acetobutylicum. Biotransformation of these furans to lesser inhibitory compounds by C. acetobutylicum will probably enhance overall fermentation of lignocellulosic hydrolysates to butanol. PMID:21925629

  3. Identification and characterization of the furfural and 5-(hydroxymethyl)furfural degradation pathways of Cupriavidus basilensis HMF14

    PubMed Central

    Koopman, Frank; Wierckx, Nick; de Winde, Johannes H.; Ruijssenaars, Harald J.

    2010-01-01

    The toxic fermentation inhibitors in lignocellulosic hydrolysates pose significant problems for the production of second-generation biofuels and biochemicals. Among these inhibitors, 5-(hydroxymethyl)furfural (HMF) and furfural are specifically notorious. In this study, we describe the complete molecular identification and characterization of the pathway by which Cupriavidus basilensis HMF14 metabolizes HMF and furfural. The identification of this pathway enabled the construction of an HMF and furfural-metabolizing Pseudomonas putida. The genetic information obtained furthermore enabled us to predict the HMF and furfural degrading capabilities of sequenced bacterial species that had not previously been connected to furanic aldehyde metabolism. These results pave the way for in situ detoxification of lignocellulosic hydrolysates, which is a major step toward improved efficiency of utilization of lignocellulosic feedstock. PMID:20194784

  4. The protective role of 5-hydroxymethyl-2-furfural (5-HMF) against acute hypobaric hypoxia.

    PubMed

    Li, Ming-Ming; Wu, Li-Ying; Zhao, Tong; Wu, Kui-Wu; Xiong, Lei; Zhu, Ling-Ling; Fan, Ming

    2011-09-01

    Our previous study showed that pretreatment with 5-hydroxymethyl-2-furfural (5-HMF) led to protection against hypoxic injury via a p-ERK-mediated pathway in vitro. Whether the protection of 5-HMF against hypoxia is effective in vivo is unknown. The present study is aimed to verify the role of 5-HMF in acute hypobaric hypoxia using Kunming mice as an in vivo model and further investigate the underlying mechanisms. Mice pretreated with or without 5-HMF for 1 h were exposed to acute hypobaric hypoxic condition for 6 h and then the survival time, the survival rate, the permeability of blood-brain barrier (BBB), the histological analysis in hippocampus and cortex, and the phosphorylation level of mitogen-activated protein kinases (ERK, JNK, and p38) were investigated. The results showed that 5-HMF significantly increased the survival time and the survival rate of mice. Accordingly, pretreatment with 5-HMF markedly attenuated acute hypobaric hypoxia-induced permeability of BBB (P < 0.01). In addition, the cellular damage extent of the hippocampus and the cortex induced by hypoxia for 6 h was also attenuated by pretreatment with 5-HMF, especially in the hippocampus CA1 region. Furthermore, the activation of ERK rather than JNK and p38 was involved in the protection of 5-HMF against acute hypobaric hypoxia. In summary, 5-HMF enhanced the survival capability of mice and decreased acute hypoxic damage to the brain, which may be associated with the effects on BBB and p-ERK. PMID:21494793

  5. 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

  6. 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.

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

    SciTech Connect

    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.

  8. Enhanced Hypoxia-Inducible Factor (HIF)-1α Stability Induced by 5-Hydroxymethyl-2-Furfural (5-HMF) Contributes to Protection against Hypoxia

    PubMed Central

    He, Yun-Ling; Li, Ming-Ming; Wu, Li-Ying; Zhao, Tong; Di, Yao; Huang, Xin; Ding, Xue-Feng; Wu, Kui-Wu; Fan, Ming; Zhu, Ling-Ling

    2014-01-01

    We first reported the role of 5-hydroxymethyl-2-furfural (5-HMF) against hypoxia. Here, we studied the mechanism by using oxygen-dependent degradation domain (ODD)-Luc mice, which are a useful model to probe the stabilization of hypoxia-inducible factor 1α (HIF-1α). Compared with three other compounds that have been reported to have a role in stabilizing HIF-1α, 5-HMF caused stronger bioluminescence, which is indicative of HIF-1α stability in the brain and kidney of ODD-Luc mice. We further demonstrated that the HIF-1α protein accumulated in response to 5-HMF in the brains and kidneys of these mice, as well as in PC12 cells. Additionally, 5-HMF promoted the nuclear translocation of HIF-1α and the transcriptional activity of HIF-1, which was evaluated by detecting vascular endothelial growth factor (VEGF ) mRNA expression. These results suggest that 5-HMF stabilized HIF-1α and increased its activity. Considering the role of proline hydroxylases (PHDs) in negatively regulating HIF-1α stability, we explored whether 5-HMF interacts with the substrates and cofactors of PHDs, such as 2-oxoglutarate (2-OG), Fe2+ and vitamin C (VC), which affects the activity of PHDs. The result revealed that 5-HMF did not interact with Fe2+ or 2-OG but interacted with VC. This interaction was confirmed by subsequent experiments, in which 5-HMF entered into cells and reduced the VC content. The enhanced stability of HIF-1α by 5-HMF was reversed by VC supplementation, and the improved survival of mice caused by 5-HMF under hypoxia was abrogated by VC supplementation. Thus, we demonstrated for the first time that 5-HMF increases HIF-1α stability by reducing the VC content, which mediates the protection against hypoxia. PMID:25333920

  9. Enhanced hypoxia-inducible factor (HIF)-1α stability induced by 5-hydroxymethyl-2-furfural (5-HMF) contributes to protection against hypoxia.

    PubMed

    He, Yun-Ling; Li, Ming-Ming; Wu, Li-Ying; Zhao, Tong; Di, Yao; Huang, Xin; Ding, Xue-Feng; Wu, Kui-Wu; Fan, Ming; Zhu, Ling-Ling

    2014-01-01

    We first reported the role of 5-hydroxymethyl-2-furfural (5-HMF) against hypoxia. Here, we studied the mechanism by using oxygen-dependent degradation domain (ODD)-Luc mice, which are a useful model to probe the stabilization of hypoxia-inducible factor 1α (HIF-1α). Compared with three other compounds that have been reported to have a role in stabilizing HIF-1α, 5-HMF caused stronger bioluminescence, which is indicative of HIF-1α stability in the brain and kidney of ODD-Luc mice. We further demonstrated that the HIF-1α protein accumulated in response to 5-HMF in the brains and kidneys of these mice, as well as in PC12 cells. Additionally, 5-HMF promoted the nuclear translocation of HIF-1α and the transcriptional activity of HIF-1, which was evaluated by detecting vascular endothelial growth factor (VEGF ) mRNA expression. These results suggest that 5-HMF stabilized HIF-1α and increased its activity. Considering the role of proline hydroxylases (PHDs) in negatively regulating HIF-1α stability, we explored whether 5-HMF interacts with the substrates and cofactors of PHDs, such as 2-oxoglutarate (2-OG), Fe(2+) and vitamin C (VC), which affects the activity of PHDs. The result revealed that 5-HMF did not interact with Fe(2+) or 2-OG but interacted with VC. This interaction was confirmed by subsequent experiments, in which 5-HMF entered into cells and reduced the VC content. The enhanced stability of HIF-1α by 5-HMF was reversed by VC supplementation, and the improved survival of mice caused by 5-HMF under hypoxia was abrogated by VC supplementation. Thus, we demonstrated for the first time that 5-HMF increases HIF-1α stability by reducing the VC content, which mediates the protection against hypoxia.

  10. 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.

  11. 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. PMID:26213000

  12. [Binding mechanism of traditional Chinese medicine active component 5-hydroxymethyl-furfural and HSA or BSA].

    PubMed

    Guo, Ming; He, Ling; Lu, Xiao-Wang

    2012-03-01

    A combination of spectral experiment and molecular modeling techniques has been used to characterize the binding mechanism between an active component 5-hydroxymethyl-furfural (5-HMF) of traditional Chinese medicine and human serum albumin (HSA) or bovine serum albumin (BSA). The interaction mechanism of 5-HMF binding with HSA/BSA is analyzed. Although the drug can bind with HSA/BSA to form stable complexes, there are some differences in the bond strength. The values of binding distances (r) are different and low, which indicated the occurrence of energy transfer. The drug had conformational effect on HSA/BSA, which resulted in different changes of hydrophobic environment of the binding domain in HSA/BSA. The 'phase diagram' of fluorescence revealed that the changes on the conformational pattern of proteins have been affected by drug conformed to the "all-or-none" pattern. The interactions between drug and protein influenced by Co(II) were also discussed. Its effects acting on 5-HMF-HSA/BSA interactions are different. The computational modeling method was used to study the interaction between 5-HMF and HSA/BSA. The results of molecular model studies revealed that the binding modes for drug-serum albumin systems are mainly hydrophobic interactions and hydrogen bonding. These results are in accordance with spectral results. The research results have given a better theoretical reference for the study of pharmacological mechanism of 5-hydroxymethyl-furfural.

  13. Indirect competitive ELISA based on monoclonal antibody for the detection of 5-hydroxymethyl-2-furfural in milk, compared with HPLC.

    PubMed

    Guan, Yongguang; Wu, Xinlan; Meng, Hecheng

    2013-08-01

    In this study, a method for rapid detection of 5-hydroxymethyl-2-furfural (HMF) was investigated. Monoclonal antibody (anti-HMF) was prepared and evaluated by an indirect competitive ELISA (ic-ELISA) format. The optimized standard curve was y=-0.2097x+1.0432 [where x is the logarithm (base 10) of the values of the HMF concentration and y is the absorbance of ic-ELISA results tested at 490 nm] and the linear detection range was 0.008 to 32.768 mg/L. The percentage of cross-reactivity of HMF with 5 major furfural derivatives was less than 2.92%. Finally, the established ic-ELISA format was used to test HMF in milk, and compared with the result obtained by HPLC, which produced an error of about 0.3%. Based on the data in this experiment, we concluded that the established ic-ELISA format was reliable with a high specificity.

  14. 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.

  15. 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.

  16. 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.

  17. Selective Aerobic Oxidation of 5-(Hydroxymethyl)furfural to 5-Formyl-2-furancarboxylic Acid in Water.

    PubMed

    Ventura, Maria; Aresta, Michele; Dibenedetto, Angela

    2016-05-23

    A simple, cheap, and selective catalyst based on copper/cerium oxides is described for the oxidation of 5-(hydroxymethyl)furfural (5-HMF) in water. An almost quantitative conversion (99 %) with excellent (90 %) selectivity towards the formation of 5-formyl-2-furancarboxylic acid, a platform molecule for other high value chemicals, is observed. The catalyst does not require any pretreatment or additives, such as bases, to obtain high yield and selectivity in water as solvent and using oxygen as oxidant. When a physical mixture of the oxides is used, low conversion and selectivity are observed. Air can be used instead of oxygen, but a lower conversion rate is observed if the same overall pressure is used, and the selectivity remains high. The catalyst can be recovered almost quantitatively and reused. Deactivation of the catalyst, observed in repeated runs, is due to the deposition of humins on its surface. Upon calcination the catalyst almost completely recovers its activity and selectivity, proving that the catalyst is robust. PMID:27101568

  18. 5-hydroxymethyl-2-furfural prolongs survival and inhibits oxidative stress in a mouse model of forebrain ischemia☆

    PubMed Central

    Ya, Bailiu; Zhang, Lan; Zhang, Li; Li, Yali; Li, Lin

    2012-01-01

    In the present study, we hypothesized that 5-hydroxymethyl-2-furfural could attenuate ischemic brain damage by reducing oxidative injury. Thus, mice were subjected to bilateral common carotid artery occlusion to establish a model of permanent forebrain ischemia. The mice were intraperitoneally injected with 5-hydroxymethyl-2-furfural 30 minutes before ischemia or 5 minutes after ischemia. The survival time of mice injected with 5-hydroxymethyl-2-furfural was longer compared with untreated mice. The mice subjected to ischemia for 30 minutes and reperfusion for 5 minutes were intraperitoneally injected with 5-hydroxymethyl-2-furfural 5 minutes prior to reperfusion, which increased superoxide dismutase content and reduced malondialdehyde content, similar to the effects of Edaravone, a hydroxyl radical scavenger used for the treatment of stroke. These findings indicate that intraperitoneal injection of 5-hydroxymethyl-2-furfural can prolong the survival of mice with permanent forebrain ischemia. This outcome may be mediated by its antioxidative effects. PMID:25624794

  19. 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.

  20. 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...

  1. Reporter gene mutation in the livers of gpt delta mice treated with 5-(hydroxymethyl)-2-furfural, a contaminant of various foods.

    PubMed

    Matsushita, Kohei; Ishii, Yuji; Kijima, Aki; Jin, Meilan; Takasu, Shinji; Kuroda, Ken; Kodama, Yukio; Ogawa, Kumiko; Umemura, Takashi

    2012-01-01

    A major product formed during the Maillard reaction is 5-(hydroxymethyl)-2-furfural (HMF), which is present in various foods and beverages such as honey and fruit juice. HMF was shown to be a hepatocarcinogen in female mice using long-term bioassays. Although HMF is not a mutagen in conventional in vitro mutation assays, 5-sulfoxymethylfurfural (SMF), a reactive metabolite of HMF produced following sulfotransferase conjugation, does show mutagenicity. Thus, HMF-induced hepatocarcinogenesis likely involves genotoxic mechanisms. To clarify the mechanisms underlying HMF-induced hepatocarcinogenesis, female B6C3F(1) gpt delta mice were given HMF at carcinogenic doses (188 or 375 mg/kg b.w.) by gavage for 5 days per week for 4 weeks. This treatment produced no significant differences in mutant frequencies (MFs) of gpt and red/gam (Spi(-)) genes among the groups. These results suggest that genotoxicity does not contribute to HMF-induced hepatocarcinogenesis. Parameters related to cell proliferation, such as proliferation cell nuclear antigen-labeling index and Cyclin D1 and E1 mRNA expression, exhibited no significant changes in the livers of HMF-treated groups. In view of the lack of carcinogenicity in rats, HMF may be considered to be a weak carcinogen. These results help us to understand the underlying mechanisms of action of HMF carcinogenesis. PMID:23038016

  2. Organocatalytic upgrading of furfural and 5-hydroxymethyl furfural to C10 and C12 furoins with quantitative yield and atom-efficiency.

    PubMed

    Zang, Hongjun; Chen, Eugene Y X

    2015-03-30

    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.

  3. 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

  4. 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.

  5. Spectroscopic and molecular modeling methods to investigate the interaction between 5-Hydroxymethyl-2-furfural and calf thymus DNA using ethidium bromide as a probe.

    PubMed

    Zhu, Jinhua; Chen, Lanlan; Dong, Yingying; Li, Jiazhong; Liu, Xiuhua

    2014-04-24

    In this work, the interaction of 5-Hydroxymethyl-2-furfural (5-HMF) with calf thymus DNA (ctDNA) under simulated physiological conditions (Tris-HCl buffer of pH 7.40), was explored by UV absorption spectroscopy, fluorescence spectroscopy and molecular modeling method, using ethidium bromide (EB) as a fluorescence probe of DNA. The fluorescence quenching mechanism of EB-ctDNA by 5-HMF was confirmed to be a static quenching, which derived from the formation of a new complex. The binding constants of 5-HMF with DNA in the presence of EB were calculated to be 2.17×10(3), 4.24×10(3) and 6.95×10(3) L mol(-1) at 300, 305 and 310 K, respectively. The calculated thermodynamic parameters, enthalpy change ΔH and entropy change ΔS, suggested that both hydrophobic interactions and hydrogen bonds played a predominant role in the binding of 5-HMF to DNA. According to the UV absorption spectroscopy and melting temperature (Tm) curve results, the binding mode of 5-HMF with DNA was indicative of a non-intercalative binding, which was supposed to be a groove binding. The molecular modeling results showed that 5-HMF could bind into the hydrophobic region of ctDNA and supported the conclusions obtained from the above experiments.

  6. Sulfonated graphene oxide as effective catalyst for conversion of 5-(hydroxymethyl)-2-furfural into biofuels.

    PubMed

    Antunes, Margarida M; Russo, Patrícia A; Wiper, Paul V; Veiga, Jacinto M; Pillinger, Martyn; Mafra, Luís; Evtuguin, Dmitry V; Pinna, Nicola; Valente, Anabela A

    2014-03-01

    The acid-catalyzed reaction of 5-(hydroxymethyl)-2-furfural with ethanol is a promising route to produce biofuels or fuel additives within the carbohydrate platform; specifically, this reaction may give 5-ethoxymethylfurfural, 5-(ethoxymethyl)furfural diethylacetal, and/or ethyl levulinate (bioEs). It is shown that sulfonated, partially reduced graphene oxide (S-RGO) exhibits a more superior catalytic performance for the production of bioEs than several other acid catalysts, which include sulfonated carbons and the commercial acid resin Amberlyst-15, which has a much higher sulfonic acid content and stronger acidity. This was attributed to the cooperative effects of the sulfonic acid groups and other types of acid sites (e.g., carboxylic acids), and to the enhanced accessibility to the active sites as a result of the 2D structure. Moreover, the acidic functionalities bonded to the S-RGO surface were more stable under the catalytic reaction conditions than those of the other solids tested, which allowed its efficient reuse.

  7. [Rapid screening and quality evaluation for the harmful substance 5-hydroxymethyl furfural in commercially available traditional Chinese medicine injection using LC-MS/MS method].

    PubMed

    Zang, Qing-ce; He, Jing-jing; Bai, Jin-fa; Zheng, Ya-jie; Zhang, Rui-ping; Li, Tie-gang; Wang, Zhong-hua; He, Jiu-ming; Abliz, Zeper

    2013-11-01

    To screen the harmful substance 5-hydroxymethyl furfural content in commercially available traditional Chinese medicine injection which are commonly used, and to preliminarily evaluate the quality of these injections, 5-hydroxymethyl furfural was taken as an index. The contents of 5-hydroxymethyl furfural in 56 samples which consist of 23 kinds of traditional Chinese medicine injections and glucose injection were determined using LC-MS/MS, and 5-hydroxymethyl furfural was detected in 52 of these samples. The minimal content was 0.0038 microg x L(-1) and the maximum content was 1420 microg x mL(-1). The contents of 5-hydroxymethyl furfural were significantly different in traditional Chinese medicine injection which came from different kinds, manufacturers or batches. The results showed the quality difference of commercially available traditional Chinese medicine injection is significant taking 5-hydroxymethyl furfural content as assessment index. More attention should be paid to the safety of 5-hydroxymethyl furfural in traditional Chinese medicine injection, and unified limitation standard should be set to improve medication safety of traditional Chinese medicine injection.

  8. Selective conversion of cotton cellulose to glucose and 5-hydroxymethyl furfural with SO4(2-)/MxOy solid superacid catalyst.

    PubMed

    Yang, Fang; Li, Yang; Zhang, Qian; Sun, Xiaofeng; Fan, Hongxian; Xu, Nian; Li, Gang

    2015-10-20

    This paper presented a mild hydrothermal process for degradation of cotton cellulose with solid superacid catalyst and selective conversion of cotton cellulose to glucose and 5-hydroxymethyl furfural (HMF). Five kinds of solid superacid catalyst such as SO4(2-)/SnO2, SO4(2-)/TiO2, SO4(2-)/ZrO2, SO4(2-)/Fe2O3 and SO4(2-)/Al2O3 were prepared by impregnation method. The BET surface area of catalyst SO4(2-)/SnO2 was up to 118.8m(2)g(-1) when impregnation was performed with 1molL(-1) H2SO4 of impregnating solution at 550°C calcination temperature for 3h. It made the hydrothermal temperature of cellulose degradation decrease to 190°C successfully and suppressed the side reaction. The NH3-TPD profile of SO4(2-)/SnO2 indicated there was a wide region of stronger acid sites on the catalyst surface. The depolymerization of cotton cellulose obtained 11.0% yield and 22.0% selectivity of HMF and 26.8% yield and 53.4% selectivity of glucose, respectively. The regeneration and reuse of solid superacid catalyst were also discussed in this paper. PMID:26256154

  9. Effect of Sodium Chloride on α-Dicarbonyl Compound and 5-Hydroxymethyl-2-furfural Formations from Glucose under Caramelization Conditions: A Multiresponse Kinetic Modeling Approach.

    PubMed

    Kocadağlı, Tolgahan; Gökmen, Vural

    2016-08-17

    This study aimed to investigate the kinetics of α-dicarbonyl compound formation in glucose and glucose-sodium chloride mixture during heating under caramelization conditions. Changes in the concentrations of glucose, fructose, glucosone, 1-deoxyglucosone, 3-deoxyglucosone, 3,4-dideoxyglucosone, 5-hydroxymethyl-2-furfural (HMF), glyoxal, methylglyoxal, and diacetyl were determined. A comprehensive reaction network was built, and the multiresponse model was compared to the experimentally observed data. Interconversion between glucose and fructose became 2.5 times faster in the presence of NaCl at 180 and 200 °C. The effect of NaCl on the rate constants of α-dicarbonyl compound formation varied across the precursor and the compound itself and temperature. A decrease in rate constants of 3-deoxyglucosone and 1-deoxyglucosone formations by the presence of NaCl was observed. HMF formation was revealed to be mainly via isomerization to fructose and dehydration over cyclic intermediates, and the rate constants increase 4-fold in the presence of NaCl.

  10. Selective conversion of cotton cellulose to glucose and 5-hydroxymethyl furfural with SO4(2-)/MxOy solid superacid catalyst.

    PubMed

    Yang, Fang; Li, Yang; Zhang, Qian; Sun, Xiaofeng; Fan, Hongxian; Xu, Nian; Li, Gang

    2015-10-20

    This paper presented a mild hydrothermal process for degradation of cotton cellulose with solid superacid catalyst and selective conversion of cotton cellulose to glucose and 5-hydroxymethyl furfural (HMF). Five kinds of solid superacid catalyst such as SO4(2-)/SnO2, SO4(2-)/TiO2, SO4(2-)/ZrO2, SO4(2-)/Fe2O3 and SO4(2-)/Al2O3 were prepared by impregnation method. The BET surface area of catalyst SO4(2-)/SnO2 was up to 118.8m(2)g(-1) when impregnation was performed with 1molL(-1) H2SO4 of impregnating solution at 550°C calcination temperature for 3h. It made the hydrothermal temperature of cellulose degradation decrease to 190°C successfully and suppressed the side reaction. The NH3-TPD profile of SO4(2-)/SnO2 indicated there was a wide region of stronger acid sites on the catalyst surface. The depolymerization of cotton cellulose obtained 11.0% yield and 22.0% selectivity of HMF and 26.8% yield and 53.4% selectivity of glucose, respectively. The regeneration and reuse of solid superacid catalyst were also discussed in this paper.

  11. Effect of Sodium Chloride on α-Dicarbonyl Compound and 5-Hydroxymethyl-2-furfural Formations from Glucose under Caramelization Conditions: A Multiresponse Kinetic Modeling Approach.

    PubMed

    Kocadağlı, Tolgahan; Gökmen, Vural

    2016-08-17

    This study aimed to investigate the kinetics of α-dicarbonyl compound formation in glucose and glucose-sodium chloride mixture during heating under caramelization conditions. Changes in the concentrations of glucose, fructose, glucosone, 1-deoxyglucosone, 3-deoxyglucosone, 3,4-dideoxyglucosone, 5-hydroxymethyl-2-furfural (HMF), glyoxal, methylglyoxal, and diacetyl were determined. A comprehensive reaction network was built, and the multiresponse model was compared to the experimentally observed data. Interconversion between glucose and fructose became 2.5 times faster in the presence of NaCl at 180 and 200 °C. The effect of NaCl on the rate constants of α-dicarbonyl compound formation varied across the precursor and the compound itself and temperature. A decrease in rate constants of 3-deoxyglucosone and 1-deoxyglucosone formations by the presence of NaCl was observed. HMF formation was revealed to be mainly via isomerization to fructose and dehydration over cyclic intermediates, and the rate constants increase 4-fold in the presence of NaCl. PMID:27477785

  12. 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.

  13. 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. PMID:25045144

  14. 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.

  15. 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.

  16. 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.

  17. 5-(Chloromethyl)furfural is the New HMF: Functionally Equivalent But More Practical in Terms of its Production From Biomass.

    PubMed

    Mascal, Mark

    2015-10-26

    5-(Chloromethyl)furfural (CMF) is a disruptive innovation in the biorefinery. Chemically, it is at least as versatile as the well-known HMF but, unlike HMF, it is accessible in high yield directly from cellulosic biomass due to its lipophilicity and stability under acidic conditions, which facilitate isolation. It has a rich derivative chemistry that includes biofuels, renewable polymers, specialty chemicals, and value-added agrochemical and pharmaceutical products.

  18. 5-(Chloromethyl)furfural is the New HMF: Functionally Equivalent But More Practical in Terms of its Production From Biomass.

    PubMed

    Mascal, Mark

    2015-10-26

    5-(Chloromethyl)furfural (CMF) is a disruptive innovation in the biorefinery. Chemically, it is at least as versatile as the well-known HMF but, unlike HMF, it is accessible in high yield directly from cellulosic biomass due to its lipophilicity and stability under acidic conditions, which facilitate isolation. It has a rich derivative chemistry that includes biofuels, renewable polymers, specialty chemicals, and value-added agrochemical and pharmaceutical products. PMID:26373463

  19. Quantification of glucose, xylose, arabinose, furfural, and HMF in corncob hydrolysate by HPLC-PDA-ELSD.

    PubMed

    Liu, Xuejun; Ai, Ning; Zhang, Haiyan; Lu, Meizhen; Ji, Dengxiang; Yu, Fengwen; Ji, Jianbing

    2012-05-15

    Lignocellulose and other carbohydrates are being studied extensively as potential renewable carbon sources for liquid biofuels and other valuable chemicals. In the present study, a simple, sensitive, selective, and reliable HPLC method using a photodiode array (PDA) detector and an evaporative light scattering detector (ELSD) was developed for the simultaneous determination of important sugars (D(+)-cellobiose, glucose, xylose, and arabinose), furfural and 5-hydroxymethylfurfural (5-HMF) in lignocellulose hydrolysate. The analysis was carried out on an Aminex HPX-87H column (250 mm × 4.6 mm, 5 μm particle size). Ultra-pure water with 0.00035 M H(2)SO(4) was used as the mobile phase with a flow rate of 0.6 mL/min. The temperature of the ELSD drift tube was kept at 50 °C, the carrier gas pressure was 350 kPa, and the gain was set at 7. Furfural and 5-HMF were quantified on a PDA detector at 275 nm and 284 nm, respectively. The sugar concentrations were determined by ELSD. This method was validated for accuracy and precision. The regression equation revealed a good linear relationship (r(2) = 0.9986 ± 0.0012) within the test ranges. The method showed good reproducibility for the quantification of six analytes in corncob hydrolysate, with intra- and inter-day variations less than 1.12%. This method is also convenient because it allows the rapid analysis of the primary products of biomass hydrolysis and carbohydrate degradation. PMID:22516168

  20. The protective role of 5-HMF against hypoxic injury.

    PubMed

    Li, Ming-Ming; Wu, Li-Ying; Zhao, Tong; Xiong, Lei; Huang, Xin; Liu, Zhao-Hui; Fan, Xue-Lai; Xiao, Cheng-Rong; Gao, Yue; Ma, Yun-Bao; Chen, Ji-Jun; Zhu, Ling-Ling; Fan, Ming

    2011-05-01

    In an attempt to find new types of anti-hypoxic agents from herbs, we identified 5-hydroxymethyl-2-furfural (5-HMF) as a natural agent that fulfills the criterion. 5-HMF, the final product of carbohydrate metabolism, has favorable biological effects such as anti-oxidant activity and inhibiting sickling of red blood cells. The role of 5-HMF in hypoxia, however, is not yet. Our pilot results showed that pretreatment with 5-HMF markedly increased both the survival time and the survival rate of mice under hypoxic stress. The present study was aimed to further investigate the protective role of 5-HMF and the underlying mechanisms in hypoxic injury using ECV304 cells as an in vitro model. ECV304 cells pretreated with or without 5-HMF for 1 h were exposed to hypoxic condition (0.3% O(2)) for 24 h and then cell apoptosis, necrosis, the changes of mitochondrial membrane potential (MMP) and the expressions of phosphorylation- extracellular signal-regulated kinase (p-ERK) were investigated. Pretreatment with 5-HMF markedly attenuated hypoxia-induced cell necrosis and apoptosis at late stage (p < 0.01). Furthermore, pretreatment with 5-HMF rescued both the decline of the MMP and the increase of p-ERK protein under hypoxia. In a word, these results indicated that 5-HMF had protective effects against hypoxic injury in ECV304 cells, and its effects on MMP and p-ERK may be involved in the mechanism. PMID:21057989

  1. Novel pathways to 2,5-dimethylfuran via biomass-derived 5-(chloromethyl)furfural.

    PubMed

    Dutta, Saikat; Mascal, Mark

    2014-11-01

    2,5-Dimethylfuran (DMF) is one of the most actively pursued biomass-derived chemicals due to the fact that it can serve both as a biofuel and an intermediate for drop-in terephthalate polymers. DMF can be accessed via catalytic hydrogenation of 5-(hydroxymethyl)furfural (HMF), but the difficult accessibility of HMF from cellulosic biomass is a major impediment to the commercial development of such a process. Alternatively, 5-(chloromethyl)furfural (CMF) is freely accessible in high yield directly from raw biomass and is shown here to be efficiently reduced to DMF under mild conditions via simple derivatives (aldimine, acetal).

  2. Short communication: determination of potential 5-hydroxymethyl-2-furaldehyde and 2-furaldehyde compounds in follow-on milks and infant formulas using the high-performance liquid chromatography method.

    PubMed

    Er Demirhan, B; Demirhan, B; Sönmez, C; Torul, H; Tamer, U; Yentür, G

    2015-02-01

    The aim of present study was to determine the levels of potential 5-hydroxymethyl-2-furaldehyde (HMF) and 2-furaldehyde (F) in 109 baby food samples (60 follow-on milks, 49 cereal- and milk-based infant formulas) obtained from different markets in Ankara (Turkey). Potential HMF and F compounds were determined by HPLC. Mean levels (± standard error) of HMF and F of follow-on milk samples were found to be 237.85±18.25 and 9.44±0.39 µg/100mL, respectively. Regarding the infant formulas, mean levels of HMF and F were found to be 905.41±91.94 and 13.22±1.21 µg/100g. As a result, potential HMF was determined in all of the samples; potential F was determined in all the samples except 1. The mean levels of potential HMF and F of infant formulas were higher than mean levels of potential HMF and F of follow-on milks. In addition, HMF and F values of some samples with an imminent expiration date were found to be higher than HMF and F values of the other samples. At present, no limits have been established in the Turkish Food Codex (TFC) for furfural compounds concentrations in infant formula and milks. Establishing limits related to these compounds would be important for protecting the quality of infant foods.

  3. 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

  4. 5-HMF prevents against oxidative injury via APE/Ref-1.

    PubMed

    Zhang, J-H; Di, Y; Wu, L-Y; He, Y-L; Zhao, T; Huang, X; Ding, X-F; Wu, K-W; Fan, M; Zhu, L-L

    2015-01-01

    Oxidative injury is involved in many diseases, including ischemic and neurodegenerative diseases. Antioxidant drugs can be used to relieve the oxidative injury caused by these diseases; however, there are very few antioxidant drugs available for clinical use. In this study, we found that 5-(hydroxymethyl)-2-furfural (5-HMF) protects against the oxidative damage induced by cerebral ischemia in rats or by hydrogen peroxide (H2O2) in PC12 cells. We demonstrated that 5-HMF performs this function via apurinic/apyrimidinic endonuclease/redox factor-1 (APE/Ref-1). APE/Ref-1 is a multifunctional protein involved in oxidative DNA damage repair through the base excision repair (BER) pathway and in the regulation of the DNA-binding activity of several transcription factors. The current study focused on the role of APE/Ref-1 in the antioxidative properties of 5-HMF. The results show that 5-HMF inhibited the reduction of APE/Ref-1 protein level caused by cerebral ischemia-reperfusion injury in rats or H2O2 treatment in PC12 cells. Treatment with an APE/Ref-1 inhibitor blocked 5-HMF-induced protection, suggesting that APE/Ref-1's DNA repair function contributes to antioxidation. In conclusion, this study suggests that APE/Ref-1 may be a potential target for antioxidant drugs.

  5. 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 )

  6. Biorefining: heterogeneously catalyzed reactions of carbohydrates for the production of furfural and hydroxymethylfurfural.

    PubMed

    Karinen, Reetta; Vilonen, Kati; Niemelä, Marita

    2011-08-22

    Furfurals are important intermediates in the chemical industry. They are typically produced by homogeneous catalysis in aqueous solutions. However, heterogeneously catalyzed processes would be beneficial in view of the principles of green chemistry: the elimination of homogeneous mineral acids makes the reaction mixtures less corrosive, produces less waste, and facilitates easy separation and recovery of the catalyst. Finding an active and stable water-tolerant solid acid catalyst still poses a challenge for the production of furfural (furan-2-carbaldehyde) and 5-(hydroxymethyl)-2-furaldehyde (HMF). Furfural is produced in the dehydration of xylose, and HMF is formed from glucose and fructose in the presence of an acidic catalyst. Bases are not active in dehydration reaction but do catalyze the isomerization of monosaccharides, which is favorable when using glucose as a raw material. In addition to the desired dehydration of monosaccharides, many undesired side reactions take place, reducing the selectivity and deactivating the catalyst. In addition, the catalyst properties play an important role in the selectivity. In this Review, catalytic conversion approaches are summarized, focusing on the heterogeneously catalyzed formation of furfural. The attractiveness of catalytic concepts is evaluated, keeping in mind productivity, sustainability, and environmental footprint. PMID:21728248

  7. 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.

  8. 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.

  9. 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.

  10. 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. PMID:27475406

  11. 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

  12. Isolation and characterization of Cupriavidus basilensis HMF14 for biological removal of inhibitors from lignocellulosic hydrolysate

    PubMed Central

    Wierckx, Nick; Koopman, Frank; Bandounas, Luaine; De Winde, Johannes H.; Ruijssenaars, Harald J.

    2010-01-01

    Summary The formation of toxic fermentation inhibitors such as furfural and 5‐hydroxy‐2‐methylfurfural (HMF) during acid (pre‐)treatment of lignocellulose, calls for the efficient removal of these compounds. Lignocellulosic hydrolysates can be efficiently detoxified biologically with microorganisms that specifically metabolize the fermentation inhibitors while preserving the sugars for subsequent use by the fermentation host. The bacterium Cupriavidus basilensis HMF14 was isolated from enrichment cultures with HMF as the sole carbon source and was found to metabolize many of the toxic constituents of lignocellulosic hydrolysate including furfural, HMF, acetate, formate and a host of aromatic compounds. Remarkably, this microorganism does not grow on the most abundant sugars in lignocellulosic hydrolysates: glucose, xylose and arabinose. In addition, C. basilensis HMF14 can produce polyhydroxyalkanoates. Cultivation of C. basilensis HMF14 on wheat straw hydrolysate resulted in the complete removal of furfural, HMF, acetate and formate, leaving the sugar fraction intact. This unique substrate profile makes C. basilensis HMF14 extremely well suited for biological removal of inhibitors from lignocellulosic hydrolysates prior to their use as fermentation feedstock. PMID:21255332

  13. Nematicidal activity of 5-hydroxymethyl-2-furoic acid against plant-parasitic nematodes.

    PubMed

    Kimura, Yasuo; Tani, Satoko; Hayashi, Asami; Ohtani, Kouhei; Fujioka, Shozo; Kawano, Tsuyoshi; Shimada, Atsumi

    2007-01-01

    A nematicide, 5-hydroxymethyl-2-furoic acid (1), was isolated from cultures of the fungus Aspergillus sp. and its structure was identified by spectroscopic analysis. Compound 1 showed effective nematicidal activities against the pine wood nematode Bursaphelenchus xylophilus and the free-living nematode Caenorhabditis elegans without inhibitory activity against plant growth, but 1 did not show any effective nematicidal activity against Pratylenchus penetrans. PMID:17542490

  14. Short communication: Amino trap column improves the separation of methylimidazoles, 5-hydroxymethyl-2-furaldehyde, and sugars in Maillard reaction.

    PubMed

    Xu, Xian-Bing; Liu, Ding-Bo; Yu, Shu-Juan; Zhao, Zhen-Gang; Yu, Pei

    2014-11-01

    A simultaneous analysis of methylimidazoles, reducing sugars, and 5-hydroxymethyl-2-furaldehyde in the Maillard reaction was improved by use of an amino trap column. Analysis was carried out by using high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) coupled with an amino trap column. The amino trap column was a useful tool to improve the separation of methylimidazoles, reducing sugars, and 5-hydroxymethyl-2-furaldehyde. This technique is useful for simultaneous analysis of methylimidazoles, reducing sugars, and 5-hydroxymethyl-2-furaldehyde in risk assessment for dairy products.

  15. Biphasic catalytic conversion of fructose by continuous hydrogenation of HMF over a hydrophobic ruthenium catalyst.

    PubMed

    Yang, Yanliang; Du, Zhongtian; Ma, Jiping; Lu, Fang; Zhang, Junjie; Xu, Jie

    2014-05-01

    The production of chemicals directly from sugars is an important step in biomass conversion. Herein, tetrahydro-2,5-furandimethanol (THFDM), obtained from fructose, is formed by using a combination of acid and hydrophobic Ru/SiO2 in a water/cyclohexane biphasic system. Two key factors enable the high selectivity towards THFDM: modifying the hydrogenation catalyst so that it has hydrophobic properties, and the continuous hydrogenation of generated 5-(hydroxymethyl)furfural in the cyclohexane phase. Moreover, the selectivity towards THFDM is found to depend strongly on the acid catalyst used. PMID:24644062

  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. [Effects of furfural and 5-hydroxymethylfurfural on succinic acid production by Escherichia coli].

    PubMed

    Wang, Dan; Wang, Honghui; Wang, Jing; Wang, Nan; Zhang, Jie; Xing, Jianmin

    2013-10-01

    Succinic acid production by fermentation from biomass, especially the lignocellulosic hydrolysate, is an alternative to chemical synthesis. Many studies report the inhibition of cell growth and succinic acid production from lignocellulosic hydrolysate, hardly is known about the actual kinetic and mechanism of the inhibition of individual factors. In this study, we studied inhibition effects of furfurals and 5-hydroxymethylfurfural (5-HMF) on cell growth and succinic acid production of engineered E. coli. Cell growth and succinic acid titer were severely inhibited by furfural and HMF with both concentrations higher than 0.8 g/L. Cell growth was totally inhibited when the concentration of furfural was above 6.4 g/L, or the concentration of HMF was above 12.8 g/L. At the concentration of maximum toleration, which was 3.2 g/L, furfural decreased the cell mass by 77.8% and the succinic acid titer by 36.1%. HMF decreased the cell mass by 13.6% and the succinic acid titer by 18.3%. Activity measurements of key enzymes revealed that phosphoenolpyruvate carboxylase, malate dehydrogenase, fumarate reductase all were inhibited by furfural and HMF. This study gave a quantitative view to the succinic acid production under the inhibition of lignocellulose degradation products and will help overcome the difficulties of the lignocellulosic hydrolysate fermentation.

  18. 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...

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

    DOEpatents

    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.

  20. 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

  1. Roles of the Yap1 transcription factor and antioxidants in Saccharomyces cerevisiae's tolerance to furfural and 5-hydroxymethylfurfural, which function as thiol-reactive electrophiles generating oxidative stress.

    PubMed

    Kim, Daehee; Hahn, Ji-Sook

    2013-08-01

    Development of the tolerance of Saccharomyces cerevisiae strains to furfural and 5-hydroxymethylfurfural (HMF) is an important issue for cellulosic ethanol production. Although furfural and HMF are known to induce oxidative stress, the underlying mechanisms are largely unknown. In this study, we show that both furfural and HMF act as thiol-reactive electrophiles, thus directly activating the Yap1 transcription factor via the H2O2-independent pathway, depleting cellular glutathione (GSH) levels, and accumulating reactive oxygen species in Saccharomyces cerevisiae. However, furfural showed higher reactivity than did HMF toward GSH in vitro and in vivo. In line with such toxic mechanisms, overexpression of YAP1(C620F), a constitutively active mutant of YAP1, and Yap1 target genes encoding catalases (CTA1 and CTT1) increased tolerance to furfural and HMF. However, increasing GSH levels by overexpression of genes for GSH biosynthesis (GSH1 and GLR1) or by the exogenous addition of GSH to the culture medium enhanced tolerance to furfural but not to HMF.

  2. Roles of the Yap1 transcription factor and antioxidants in Saccharomyces cerevisiae's tolerance to furfural and 5-hydroxymethylfurfural, which function as thiol-reactive electrophiles generating oxidative stress.

    PubMed

    Kim, Daehee; Hahn, Ji-Sook

    2013-08-01

    Development of the tolerance of Saccharomyces cerevisiae strains to furfural and 5-hydroxymethylfurfural (HMF) is an important issue for cellulosic ethanol production. Although furfural and HMF are known to induce oxidative stress, the underlying mechanisms are largely unknown. In this study, we show that both furfural and HMF act as thiol-reactive electrophiles, thus directly activating the Yap1 transcription factor via the H2O2-independent pathway, depleting cellular glutathione (GSH) levels, and accumulating reactive oxygen species in Saccharomyces cerevisiae. However, furfural showed higher reactivity than did HMF toward GSH in vitro and in vivo. In line with such toxic mechanisms, overexpression of YAP1(C620F), a constitutively active mutant of YAP1, and Yap1 target genes encoding catalases (CTA1 and CTT1) increased tolerance to furfural and HMF. However, increasing GSH levels by overexpression of genes for GSH biosynthesis (GSH1 and GLR1) or by the exogenous addition of GSH to the culture medium enhanced tolerance to furfural but not to HMF. PMID:23793623

  3. Identification, purification and characterization of furfural transforming enzymes from Clostridium beijerinckii NCIMB 8052.

    PubMed

    Zhang, Yan; Ujor, Victor; Wick, Macdonald; Ezeji, Thaddeus Chukwuemeka

    2015-06-01

    Generation of microbial inhibitory compounds such as furfural and 5-hydroxymethylfurfural (HMF) is a formidable roadblock to fermentation of lignocellulose-derived sugars to butanol. Bioabatement offers a cost effective strategy to circumvent this challenge. Although Clostridium beijerinckii NCIMB 8052 can transform 2-3 g/L of furfural and HMF to their less toxic alcohols, higher concentrations present in biomass hydrolysates are intractable to microbial transformation. To delineate the mechanism by which C. beijerinckii detoxifies furfural and HMF, an aldo/keto reductase (AKR) and a short-chain dehydrogenase/reductase (SDR) found to be over-expressed in furfural-challenged cultures of C. beijerinckii were cloned and over-expressed in Escherichia coli Rosetta-gami™ B(DE3)pLysS, and purified by histidine tag-assisted immobilized metal affinity chromatography. Protein gel analysis showed that the molecular weights of purified AKR and SDR are close to the predicted values of 37 kDa and 27 kDa, respectively. While AKR has apparent Km and Vmax values of 32.4 mM and 254.2 mM s(-1) respectively, using furfural as substrate, SDR showed lower Km (26.4 mM) and Vmax (22.6 mM s(-1)) values on the same substrate. However, AKR showed 7.1-fold higher specific activity on furfural than SDR. Further, both AKR and SDR were found to be active on HMF, benzaldehyde, and butyraldehyde. Both enzymes require NADPH as a cofactor for aldehydes reduction. Based on these results, it is proposed that AKR and SDR are involved in the biotransformation of furfural and HMF by C. beijerinckii.

  4. Furfural and hydroxymethylfurfural tolerance in Escherichia coli ΔacrR regulatory mutants.

    PubMed

    Luhe, Annette Lin; Lim, Chan Yuen; Gerken, Henri; Wu, Jinchuan; Zhao, Hua

    2015-01-01

    The presence of the highly toxic furfural and hydroxymethylfurfural (HMF) in the hydrolysate of lignocellulosic biomass prompted the investigation of the Escherichia coli ΔacrR regulatory mutant for higher tolerance to these compounds, to facilitate the production of biofuels and biochemicals, and further biocatalytic conversions. In comparison with the parental strain, the regulatory mutant with the upregulated efflux pump AcrAB-TolC produced moderately better growth and higher tolerance to concentrations of furfural and HMF between 1 and 2 g L(-1) .

  5. 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 ...

  6. Biomass conversion inhibitors furfural and 5-hydroxymethylfurfural induce formation of messenger RNP granules and attenuate translation activity in Saccharomyces cerevisiae.

    PubMed

    Iwaki, Aya; Kawai, Takao; Yamamoto, Yosuke; Izawa, Shingo

    2013-03-01

    Various forms of stress can cause an attenuation of bulk translation activity and the accumulation of nontranslating mRNAs into cytoplasmic messenger RNP (mRNP) granules termed processing bodies (P-bodies) and stress granules (SGs) in eukaryotic cells. Furfural and 5-hydroxymethylfurfural (HMF), derived from lignocellulosic biomass, inhibit yeast growth and fermentation as stressors. Since there is no report regarding their effects on the formation of cytoplasmic mRNP granules, here we investigated whether furfural and HMF cause the assembly of yeast P-bodies and SGs accompanied by translational repression. We found that furfural and HMF cause the attenuation of bulk translation activity and the assembly of cytoplasmic mRNP granules in Saccharomyces cerevisiae. Notably, a combination of furfural and HMF induced the remarkable repression of translation initiation and SG formation. These findings provide new information about the physiological effects of furfural and HMF on yeast cells, and also suggest the potential usefulness of cytoplasmic mRNP granules as a warning sign or index of the deterioration of cellular physiological status in the fermentation of lignocellulosic hydrolysates.

  7. Removal and recovery of furfural, 5-hydroxymethylfurfural, and acetic acid from aqueous solutions using a soluble polyelectrolyte.

    PubMed

    Carter, Brian; Gilcrease, Patrick C; Menkhaus, Todd J

    2011-09-01

    In the cellulosic ethanol process, furfural, 5-hydroxymethylfurfural (HMF), and acetic acid are formed during the high temperature acidic pretreatment step needed to convert biomass into fermentable sugars. These compounds can inhibit cellulase enzymes and fermentation organisms at relatively low concentrations (≥ 1 g/L). Effective removal of these inhibitory compounds would allow the use of more severe pretreatment conditions to improve sugar yields and lead to more efficient fermentations; if recovered and purified, they could also be sold as valuable by-products. This study investigated the separation of aldhehydes (furfural and HMF) and organic acid (acetic acid) inhibitory compounds from simple aqueous solutions by using polyethyleneimene (PEI), a soluble cationic polyelectrolyte. PEI added to simple solutions of each inhibitor at a ratio of 1 mol of functional group to 1 mol inhibitor removed up to 89.1, 58.6, and 81.5 wt% of acetic acid, HMF, and furfural, respectively. Furfural and HMF were recovered after removal by washing the polyelectrolyte/inhibitor complex with dilute sulfuric acid solution. Recoveries up to 81.0 and 97.0 wt% were achieved for furfural and HMF, respectively. The interaction between PEI and acetic acid was easily disrupted by the addition of chloride ions, sulfate ions, or hydroxide ions. The use of soluble polymers for the removal and recovery of inhibitory compounds from biomass slurries is a promising approach to enhance the efficiency and economics of an envisioned biorefinery.

  8. 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.

  9. 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.

  10. 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.

  11. Direct Observation of Self-Organized Water-Containing Structures in the Liquid Phase and Their Influence on 5-(Hydroxymethyl)furfural Formation in Ionic Liquids.

    PubMed

    Kashin, Alexey S; Galkin, Konstantin I; Khokhlova, Elena A; Ananikov, Valentine P

    2016-02-01

    Water-containing organic solutions are widespread reaction media in organic synthesis and catalysis. This type of multicomponent liquid system has a number of unique properties because of the tendency for water to self-organize in mixtures with other liquids. The characterization of these water domains is a challenging task because of their soft and dynamic nature. In the present study, the morphology and dynamics of micrometer- and nanometer-scale water-containing compartments in ionic liquids were directly observed by electron microscopy. A variety of morphologies, including isolated droplets, dense structures, aggregates, and 2D meshworks, have been experimentally detected and studied. Using the developed method, the impact of water on the acid-catalyzed biomass conversion reaction was studied at the microscopic level. The process that produced nanostructured domains in solution led to better yields and higher selectivities compared with reactions involving the bulk system. PMID:26754786

  12. Synthesis of furfural from xylose, xylan, and biomass using AlCl3·6H2O in biphasic media via xylose isomerization to xylulose.

    PubMed

    Yang, Yu; Hu, Chang-Wei; Abu-Omar, Mahdi M

    2012-02-13

    Furfural was prepared in high yields (75 %) from the reaction of xylose in a water-tetrahydrofuran biphasic medium containing AlCl(3)·6H2O and NaCl under microwave heating at 140 °C. The reaction profile revealed the formation of xylulose as an intermediate en route to the dehydration product (furfural). The reaction under these conditions reached completion in 45 min. The aqueous phase containing AlCl(3)·6H(2)O and NaCl could be recycled multiple times (>5) without any loss of activity or selectivity for furfural. Extension of this biphasic reaction system to include xylan as the starting material afforded furfural in 64 % yield. The use of corn stover, pinewood, switchgrass, and poplar gave furfural in 55, 38, 56, and 64 % yield, respectively, at 160 °C. Even though AlCl(3)·6H(2)O did not affect the conversion of crystalline cellulose, moderate yields of the by-product 5-hydroxymethylfurfural (HMF) were noted. The highest HMF yield of 42 % was obtained from pinewood. The coproduction of HMF and furfural from biomass was attributed to the weakening of the cellulose network in the biomass, as a result of hemicellulose hydrolysis. The multifunctional capacity of AlCl(3)·6H(2)O (hemicellulose hydrolysis, xylose isomerization, and xylulose dehydration) in combination with its ease of recyclability make it an attractive candidate/catalyst for the selective synthesis of furfural from various biomass feedstocks.

  13. Kinetic mechanism of an aldehyde reductase of Saccharomyces cerevisiae that relieves toxicity of furfural and 5-hydroxymethylfurfural

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An effective means of relieving the toxicity of furan aldehydes, furfural (FFA) and 5-hydroxymethylfurfural (HMF), on fermenting organisms is essential for achieving efficient fermentation of lignocellulosic biomass to ethanol and other products. Ari1p, an aldehyde reductase from Saccharomyces cerev...

  14. Conversion of corn stalk into furfural using a novel heterogeneous strong acid catalyst in γ-valerolactone.

    PubMed

    Xu, Zhiping; Li, Wenzhi; Du, Zhijie; Wu, Hao; Jameel, Hasan; Chang, Hou-Min; Ma, Longlong

    2015-12-01

    A novel solid acid catalyst was prepared by the copolymerization of p-toluenesulfonic acid and paraformaldehyde and then characterized by FT-IR, TG/DTG, HRTEM and N2-BET. Furfural was successfully produced by the dehydration of xylose and xylan using the novel catalyst in γ-valerolactone. This investigation focused on effects of various reaction conditions including solvent, acid catalyst, reaction temperature, residence time, water concentration, xylose loading and catalyst dosage on the dehydration of xylose to furfural. It was found that the solid catalyst displayed extremely high activity for furfural production. 80.4% furfural yield with 98.8% xylose conversion was achieved at 170°C for 10 min. The catalyst could be recycled at least five times without significant loss of activity. Furthermore, 83.5% furfural yield and 19.5% HMF yield were obtained from raw corn stalk under more severe conditions (190°C for 100 min).

  15. 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...

  16. One-Pot Conversion of Carbohydrates into Furan Derivatives via Furfural and 5-Hydroxylmethylfurfural as Intermediates.

    PubMed

    Liu, Bing; Zhang, Zehui

    2016-08-23

    Recently, there has been growing interest in the transformation of renewable biomass into value-added fuels and chemicals. The catalytic conversion of naturally abundant carbohydrates can generate two-important furan chemicals: 5-hydroxymethylfurfural (HMF) from C6 carbohydrates and furfural from C5 carbohydrates. Both HMF and furfural have received great interest as precursors in the synthesis of commodity chemicals and liquid fuels. In recent years, a trend has emerged to integrate sequential catalytic processes involving multistep reactions for the direct one-pot transformation of carbohydrates into the aimed fuels and chemicals. One-pot reactions have remarkably unique and environmentally friendly benefits, including the fact that isolation and purification of intermediate compounds can be avoided. Herein, the present article aims to review recent advances in the one-pot conversion of carbohydrates into furan derivatives via furfural and HMF as intermediates. Special attention will be paid to the catalytic systems, mechanistic insight, reaction pathways, and catalyst stability. It is expected that this review will guide researchers to develop effective catalytic systems for the one-pot transformation of carbohydrates into furan derivatives. PMID:27396713

  17. One-Pot Conversion of Carbohydrates into Furan Derivatives via Furfural and 5-Hydroxylmethylfurfural as Intermediates.

    PubMed

    Liu, Bing; Zhang, Zehui

    2016-08-23

    Recently, there has been growing interest in the transformation of renewable biomass into value-added fuels and chemicals. The catalytic conversion of naturally abundant carbohydrates can generate two-important furan chemicals: 5-hydroxymethylfurfural (HMF) from C6 carbohydrates and furfural from C5 carbohydrates. Both HMF and furfural have received great interest as precursors in the synthesis of commodity chemicals and liquid fuels. In recent years, a trend has emerged to integrate sequential catalytic processes involving multistep reactions for the direct one-pot transformation of carbohydrates into the aimed fuels and chemicals. One-pot reactions have remarkably unique and environmentally friendly benefits, including the fact that isolation and purification of intermediate compounds can be avoided. Herein, the present article aims to review recent advances in the one-pot conversion of carbohydrates into furan derivatives via furfural and HMF as intermediates. Special attention will be paid to the catalytic systems, mechanistic insight, reaction pathways, and catalyst stability. It is expected that this review will guide researchers to develop effective catalytic systems for the one-pot transformation of carbohydrates into furan derivatives.

  18. 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.

  19. 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. PMID:25590423

  20. One-pot conversions of raffinose into furfural derivatives and sugar alcohols by using heterogeneous catalysts.

    PubMed

    Dabral, Saumya; Nishimura, Shun; Ebitani, Kohki

    2014-01-01

    Inedible and/or waste biomass reserves are being strongly focused upon as a suitable new energy and chemical source. Raffinose, which is an indigestible trisaccharide composed of glucose, galactose, and fructose, is found abundantly in beet molasses, sugar cane, and seeds of many leguminous plants. Herein, we demonstrate the one-pot synthesis of furan derivatives and sugar alcohols from raffinose by using heterogeneous acid, base, and/or metal-supported catalysts. The combination of Amberlyst-15 and hydrotalcite (HT) showed a high activity (37% yield) for 5-hydroxymethyl-2-furaldehyde (HMF) through continuous hydrolysis, isomerization, and dehydration reactions. In addition, the use of a hydrotalcite-supported ruthenium catalyst (Ru/HT) successfully afforded 2,5-diformylfuran (DFF, 27% yield) from HMF produced by raffinose, directly. Moreover, the hydrogenation of hexoses obtained by raffinose hydrolysis into sugar alcohols (galactitol, mannitol, sorbitol) was also achieved in a high yield (91%) with Amberlyst-15 and Ru/HT catalysts. Thus, we suggest that raffinose has great potential for the synthesis of important industrial intermediates under mild reaction conditions.

  1. Vitamin B1 de novo synthesis in the human malaria parasite Plasmodium falciparum depends on external provision of 4-amino-5-hydroxymethyl-2-methylpyrimidine.

    PubMed

    Wrenger, Carsten; Eschbach, Marie-Luise; Müller, Ingrid B; Laun, Nathan P; Begley, Tadhg P; Walter, Rolf D

    2006-01-01

    Vitamin B1 (thiamine) is an essential cofactor for several key enzymes of carbohydrate metabolism. Mammals have to salvage this crucial nutrient from their diet to complement their deficiency of de novo synthesis. In contrast, bacteria, fungi, plants and, as reported here, Plasmodium falciparum, possess a vitamin B1 biosynthesis pathway. The plasmodial pathway identified consists of the three vitamin B1 biosynthetic enzymes 5-(2-hydroxy-ethyl)-4-methylthiazole (THZ) kinase (ThiM), 4-amino-5-hydroxymethyl-2-methylpyrimidine (HMP)/HMP-P kinase (ThiD) and thiamine phosphate synthase (ThiE). Recombinant PfThiM and PfThiD proteins were biochemically characterised, revealing K(m)app values of 68 microM for THZ and 12 microM for HMP. Furthermore, the ability of PfThiE for generating vitamin B1 was analysed by a complementation assay with thiE-negative E. coli mutants. All three enzymes are expressed throughout the developmental blood stages, as shown by Northern blotting, which indicates the presence of the vitamin B1 biosynthesis enzymes. However, cultivation of the parasite in minimal medium showed a dependency on the provision of HMP or thiamine. These results demonstrate that the human malaria parasite P. falciparum possesses active vitamin B1 biosynthesis, which depends on external provision of thiamine precursors. PMID:16497163

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

    NASA Astrophysics Data System (ADS)

    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 106Hz . 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.

  3. 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.

  4. 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).

  5. 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.

  6. 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. PMID:26565240

  7. 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.

  8. On-line purity monitoring in high-speed counter-current chromatography: application of HSCCC-HPLC-DAD for the preparation of 5-HMF, neomangiferin and mangiferin from Anemarrhena asphodeloides Bunge.

    PubMed

    Zhou, Tingting; Zhu, Zhenyu; Wang, Chen; Fan, Guorong; Peng, Jinyong; Chai, Yifeng; Wu, Yutian

    2007-05-01

    An efficient on-line purity monitoring strategy based on on-line coupling of high-speed counter-current chromatography (HSCCC) with high-performance liquid chromatography-diode array detection (HPLC-DAD) was successfully applied for the first time to the isolation and purification of 5-hydroxymethyl-furancarboxaldehyde (5-HMF), mangiferin and neomangiferin from the Chinese medicinal plant Anemarrhena asphodeloides Bunge, a plant used in the traditional Chinese medicine. The introduction of on-line purity monitoring in HSCCC has greatly improved the efficiency of this technique by overcoming the drawbacks of post-purification sample handling in HSCCC isolation. The effluent from the outlet of HSCCC was split into two parts, and one was collected, while the other was introduced directly through a switch valve into a HPLC-DAD system for purity monitoring. Using this method the desired fractions with high purities could be collected. From 600 mg partially purified extract, 165.6 mg neomangiferin and 292.8 mg mangiferin with purities of 98.9 and 99.5%, respectively, were obtained with a two-phase solvent system composed of n-butanol-water (1:1, v/v) by increasing the flow-rate of the mobile phase stepwise from 1.0 to 2.2 ml min(-1) after 210 min. A 17.1mg 5-HMF with purity of 96.6% was also isolated for the first time.

  9. 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%.

  10. Studies of the Raman spectra of cyclic and acyclic molecules: Combination and prediction spectrum methods

    NASA Astrophysics Data System (ADS)

    Kim, Taejin; Assary, Rajeev S.; Marshall, Christopher L.; Gosztola, David J.; Curtiss, Larry A.; Stair, Peter C.

    2012-04-01

    A combination of Raman spectroscopy and density functional methods was employed to investigate the spectral features of selected molecules: furfural, 5-hydroxymethyl furfural (HMF), methanol, acetone, acetic acid, and levulinic acid. The computed spectra and measured spectra are in excellent agreement, consistent with previous studies. Using the combination and prediction spectrum method (CPSM), we were able to predict the important spectral features of two platform chemicals, HMF and levulinic acid. The results have shown that CPSM is a useful alternative method for predicting vibrational spectra of complex molecules in the biomass transformation process.

  11. Studies of the Raman Spectra of Cyclic and Acyclic Molecules: Combination and Prediction Spectrum Methods

    SciTech Connect

    Kim, Taijin; Assary, Rajeev S.; Marshall, Christopher L.; Gosztola, David J.; Curtiss, Larry A.; Stair, Peter C.

    2012-04-02

    A combination of Raman spectroscopy and density functional methods was employed to investigate the spectral features of selected molecules: furfural, 5-hydroxymethyl furfural (HMF), methanol, acetone, acetic acid, and levulinic acid. The computed spectra and measured spectra are in excellent agreement, consistent with previous studies. Using the combination and prediction spectrum method (CPSM), we were able to predict the important spectral features of two platform chemicals, HMF and levulinic acid.The results have shown that CPSM is a useful alternative method for predicting vibrational spectra of complex molecules in the biomass transformation process.

  12. Furfural production using ionic liquids: A review.

    PubMed

    Peleteiro, Susana; Rivas, Sandra; Alonso, José Luis; Santos, Valentín; Parajó, Juan Carlos

    2016-02-01

    Furfural, a platform chemical with a bright future, is commercially obtained by acidic processing of xylan-containing biomass in aqueous media. Ionic liquids (ILs) can be employed in processed for furfural manufacture as additives, as catalysts and/or as reaction media. Depending on the IL utilized, externally added catalysts (usually, Lewis acids, Brönsted acids and/or solid acid catalysts) can be necessary to achieve high reaction yields. Oppositely, acidic ionic liquids (AILs) can perform as both solvents and catalysts, enabling the direct conversion of suitable substrates (pentoses, pentosans or xylan-containing biomass) into furfural. Operating in IL-containing media, the furfural yields can be improved when the product is continuously removed along the reaction (for example, by stripping or extraction), to avoid unwanted side-reactions leading to furfural consumption. These topics are reviewed, as well as the major challenges involved in the large scale utilization of ILs for furfural production.

  13. 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.

  14. 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.

  15. Aerosol Chemistry of Furfural and Sugars

    NASA Astrophysics Data System (ADS)

    Srithawirat, T.; Brimblecombe, P.

    2008-12-01

    Furfural and sugars (as levoglucosan equivalent) are derived from biomass burning and contribute to aerosol composition. This study examined the potential of furfural and levoglucosan to be tracers of biomass burning. Furfural is likely to be oxidized quickly so comparison with levoglucosan may give a sense of the age of the aerosols in forest fire smoke. However, few furfural emissions are available for biomass combustion. Furfural and sugars were determined in coarse aerosols (>2.4μm aerodynamic diameter) and fine aerosols (<2.4μm aerodynamic diameter) collected in 24 hour periods during different seasons in the United Kingdom and PM10 collected from Thailand and Malaysia including haze episodes. Also total suspended particulate matter (TSP) samples were collected from Taiwan. Furfural and sugars dominated in fine fractions, especially in the UK autumn. Sugars were found at 5.96-18.37 nmol m-3 in fine mode and 1.36-5.75 nmol m-3 in coarse mode aerosols in the UK. Furfural was found at 0.18-0.91 nmol m-3 and 0.05-0.51 nmol m-3 respectively in the same aerosols. Sugars were a dominant contributor to aerosol derived from biomass burning. Sugars and furfural were about 10 and 20 times higher during haze episodes in Malaysia. Laboratory experimental simulation suggested furfural is more rapid destroyed by UV and sunlight than levoglucosan.

  16. First identification of primary nanoparticles in the aggregation of HMF.

    PubMed

    Zhang, Mu; Yang, Hong; Liu, Yinong; Sun, Xudong; Zhang, Dongke; Xue, Dongfeng

    2012-01-01

    5-Hydroxymethylfurfural [HMF] is an important intermediate compound for fine chemicals. It is often obtained via hydrothermal treatment of biomass-derived carbohydrates, such as fructose, glucose and sucrose. This study investigates the formation of carbonaceous spheres from HMF created by dehydration of fructose under hydrothermal conditions. The carbonaceous spheres, ranging between 0.4 and 10 μm in diameter, have granulated morphologies both on the surface and in the interior. The residual solution is found to contain a massive number of primary nanoparticles. The chemical structure of the carbonaceous spheres was characterised by means of FTIR and NMR spectroscopies. Based on these observations, a mechanism involving the formation and aggregation of the nanoparticles is proposed. This mechanism differs considerably from the conventional understanding in the open literature. PMID:22221552

  17. First identification of primary nanoparticles in the aggregation of HMF

    NASA Astrophysics Data System (ADS)

    Zhang, Mu; Yang, Hong; Liu, Yinong; Sun, Xudong; Zhang, Dongke; Xue, Dongfeng

    2012-01-01

    5-Hydroxymethylfurfural [HMF] is an important intermediate compound for fine chemicals. It is often obtained via hydrothermal treatment of biomass-derived carbohydrates, such as fructose, glucose and sucrose. This study investigates the formation of carbonaceous spheres from HMF created by dehydration of fructose under hydrothermal conditions. The carbonaceous spheres, ranging between 0.4 and 10 μm in diameter, have granulated morphologies both on the surface and in the interior. The residual solution is found to contain a massive number of primary nanoparticles. The chemical structure of the carbonaceous spheres was characterised by means of FTIR and NMR spectroscopies. Based on these observations, a mechanism involving the formation and aggregation of the nanoparticles is proposed. This mechanism differs considerably from the conventional understanding in the open literature.

  18. 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.

  19. Aerobic oxidation of hydroxymethylfurfural and furfural by using heterogeneous Cox Oy -N@C catalysts.

    PubMed

    Deng, Jin; Song, Hai-Jie; Cui, Min-Shu; Du, Yi-Ping; Fu, Yao

    2014-12-01

    2,5-Furandicarboxylic acid (FDCA) is considered to be a promising replacement for terephthalic acid since they share similar structures and properties. In contrast to FDCA, 2,5-furandicarboxylic acid methyl (FDCAM) has properties that allow it to be easily purified. In this work, we reported an oxidative esterification of 5-hydroxymethylfurfural (HMF) and furfural to prepare corresponding esters over Cox Oy -N@C catalysts using O2 as benign oxidant. High yield and selectivity of FDCAM and methyl 2-furoate were obtained under optimized conditions. Factors which influenced the product distribution were examined thoroughly. The Cox Oy -N@C catalysts were recycled five times and no significant loss of activity was detected. Characterization of the catalysts could explain such phenomena. Using XPS and TGA, we made a thorough investigation of the effects of ligand and pyrolysis temperature on catalyst activity.

  20. 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.

  1. Transcriptome profiling of Zymomonas mobilis under furfural stress.

    PubMed

    He, Ming-xiong; Wu, Bo; Shui, Zong-xia; Hu, Qi-chun; Wang, Wen-guo; Tan, Fu-rong; Tang, Xiao-yu; Zhu, Qi-li; Pan, Ke; Li, Qing; Su, Xiao-hong

    2012-07-01

    Furfural from lignocellulosic hydrolysates is the prevalent inhibitor to microorganisms during cellulosic ethanol production, but the molecular mechanisms of tolerance to this inhibitor in Zymomonas mobilis are still unclear. In this study, genome-wide transcriptional responses to furfural were investigated in Z. mobilis using microarray analysis. We found that 433 genes were differentially expressed in response to furfural. Furfural up- or down-regulated genes related to cell wall/membrane biogenesis, metabolism, and transcription. However, furfural has a subtle negative effect on Entner-Doudoroff pathway mRNAs. Our results revealed that furfural had effects on multiple aspects of cellular metabolism at the transcriptional level and that membrane might play important roles in response to furfural. This research has provided insights into the molecular response to furfural in Z. mobilis, and it will be helpful to construct more furfural-resistant strains for cellulosic ethanol production.

  2. 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.

  3. Phospholipase activity in Malassezia furfur pathogenic strains.

    PubMed

    Riciputo, R M; Oliveri, S; Micali, G; Sapuppo, A

    1996-01-01

    The lipophilic dimorphic yeast Malassezia furfur is a common skin commensal and the aetiological agent of pityriasis versicolor. A source of lipids is essential for its growth, and there are already demonstrations of in vitro lipase and lipoxygenase production. In eight wild strains, isolated from patients with pityriasis versicolor, we showed a phospholipase activity using a medium containing egg yolk emulsion as the only source of lipids; in this medium M. furfur grows and produces a phospholipase zone. Adding manganese sulphate, an unspecific inhibitor of phospholipase activity, M. furfur does not grow, because the lipophilic fungus cannot utilize the egg yolk as a source of fatty acids. Adding Tween 60 to the same medium, M. furfur also grows in presence of manganese sulphate.

  4. 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. PMID:24106213

  5. 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.

  6. Effect of hydroxymethylfurfural (HMF) on mortality of artificially reared honey bee larvae (Apis mellifera carnica).

    PubMed

    Krainer, Sophie; Brodschneider, Robert; Vollmann, Jutta; Crailsheim, Karl; Riessberger-Gallé, Ulrike

    2016-03-01

    Hydroxymethylfurfural (HMF) is a heat-formed, acid-catalyzed contaminant of sugar syrups, which find their way into honey bee feeding. As HMF was noted to be toxic to adult honey bees, we investigated the toxicity of HMF towards larvae. Therefore we exposed artificially reared larvae to a chronic HMF intoxication over 6 days using 6 different concentrations (5, 50, 750, 5000, 7500 and 10,000 ppm) and a control. The mortality was assessed from day 2 to day 7 (d7) and on day 22 (d22). Concentrations ranging from 5 to 750 ppm HMF did not show any influence on larval or pupal mortality compared to controls (p > 0.05; Kaplan-Meier analysis). Concentrations of 7500 ppm or higher caused a larval mortality of 100%. An experimental LC50 of 4280 ppm (d7) and 2424 ppm (d22) was determined. The calculated LD50 was 778 µg HMF per larva on d7 and 441 µg HMF on d22. Additionally, we exposed adult honey bees to high concentrations of HMF to compare the mortality to the results from larvae. On d7 larvae are much more sensitive against HMF than adult honey bees after 6 days of feeding. However, on d22 after emergence adults show a lower LC50, which indicates a higher sensitivity than larvae. As toxicity of HMF against honey bees is a function of time and concentration, our results indicate that HMF in supplemental food will probably not cause great brood losses. Yet sublethal effects might decrease fitness of the colony. PMID:26590927

  7. Production of furfural from pentosan-rich biomass: analysis of process parameters during simultaneous furfural stripping.

    PubMed

    Agirrezabal-Telleria, I; Gandarias, I; Arias, P L

    2013-09-01

    Among the furan-based compounds, furfural (FUR) shows interesting properties as building-block or industrial solvent. It is produced from pentosan-rich biomass via xylose cyclodehydration. The current FUR production makes use of homogeneous catalysts and excessive amounts of steam. The development of greener furfural production and separation techniques implies the use of heterogeneous catalysts and innovative separation processes. This work deals with the conversion of corncobs as xylose source to be dehydrated to furfural. The results reveal differences between the use of direct corncob hydrolysis and dehydration to furfural and the prehydrolysis and dehydration procedures. Moreover, this work focuses on an economical analysis of the main process parameters during N2-stripping and its economical comparison to the current steam-stripping process. The results show a considerable reduction of the annual utility costs due to use of recyclable nitrogen and the reduction of the furfural purification stages. PMID:23810948

  8. Production of furfural from pentosan-rich biomass: analysis of process parameters during simultaneous furfural stripping.

    PubMed

    Agirrezabal-Telleria, I; Gandarias, I; Arias, P L

    2013-09-01

    Among the furan-based compounds, furfural (FUR) shows interesting properties as building-block or industrial solvent. It is produced from pentosan-rich biomass via xylose cyclodehydration. The current FUR production makes use of homogeneous catalysts and excessive amounts of steam. The development of greener furfural production and separation techniques implies the use of heterogeneous catalysts and innovative separation processes. This work deals with the conversion of corncobs as xylose source to be dehydrated to furfural. The results reveal differences between the use of direct corncob hydrolysis and dehydration to furfural and the prehydrolysis and dehydration procedures. Moreover, this work focuses on an economical analysis of the main process parameters during N2-stripping and its economical comparison to the current steam-stripping process. The results show a considerable reduction of the annual utility costs due to use of recyclable nitrogen and the reduction of the furfural purification stages.

  9. 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.

  10. 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.

  11. In vitro susceptibility of Malassezia furfur.

    PubMed

    Schmidt, A; Rühl-Hörster, B

    1996-04-01

    Malassezia (M.) furfur is an anthropophilic fungus with complex growth requirements. Apart from its physiological appearance on human skin it is the causative agent of several skin disorders. A method for in vitro antifungal susceptibility testing of M. furfur in a microtiter plate assay has been developed. Read-out was performed colorimetrically in modified Leeming-Notman medium after incubation with alamarBlue. Twenty-two strains of M. furfur were tested, minimum inhibitory concentrations (MICs) were determined for climbazole, piroctone-olamine, selenium disulfide, zinc pyrithione. These substances are of common use in topical therapy of M. furfur-associated skin conditions. For climbazole, the range of MICs was between < 0.03 and 2 micrograms/ml with an empirical median mean of 0.03 micrograms/ml. For piroctoneolamine the range of MICs was between 16 and 64 micrograms/ml (mean = 64 micrograms/ml), for selenium disulfide between 2 and 64 micrograms/ml (mean = 8 micrograms/ml), and for zinc pyrithione between 0.12 and 8 micrograms/ml (mean = 1 micrograms/ml). These data indicate the high in vitro activity of climbazole against M. furfur, followed by zinc pyrithione. Selenium disulfide and piroctone-olamine were less active. PMID:8740097

  12. 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. PMID:24423522

  13. 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. PMID:27146565

  14. Mechanistic insights into the decomposition of fructose to hydroxy methyl furfural in neutral and acidic environments using high-level quantum chemical methods.

    SciTech Connect

    Assary, R. S.; Redfern, P. C.; Greeley, J.; Curtiss, L. A.

    2011-03-28

    Efficient catalytic chemical transformation of fructose to hydroxy methyl furfural (HMF) is one of the key steps for attaining industrial level conversion of biomass to useful chemicals. We report an investigation of the reaction mechanisms for the decomposition of fructose to HMF in both neutral and acidic environments at the Gaussian-4 level of theory including calculation of enthalpies, free energies, and effective solvation interactions. In neutral water solvent, the transformation of fructose to HMF involves a four step reaction sequence with four transition states. The effective activation energy relative to fructose in neutral water at 298 K is very large, about 74 kcal/mol, so that transformation in neutral media around this temperature is unlikely. In contrast, the computed potential energy surface is much more favorable for the transformation in acidic media at 498 K, as the effective activation barrier is about 39 kcal/mol. The transformation in acidic media is a much more complex mechanism involving dehydration and hydrogen transfer steps, which are more favorable when protonated intermediates are involved.

  15. Mechanistic insights into the decomposition of fructose to hydroxy methyl furfural in neutral and acidic environments using high-level quantum chemical methods.

    PubMed

    Assary, Rajeev S; Redfern, Paul C; Greeley, Jeffrey; Curtiss, Larry A

    2011-04-21

    Efficient catalytic chemical transformation of fructose to hydroxy methyl furfural (HMF) is one of the key steps for attaining industrial level conversion of biomass to useful chemicals. We report an investigation of the reaction mechanisms for the decomposition of fructose to HMF in both neutral and acidic environments at the Gaussian-4 level of theory including calculation of enthalpies, free energies, and effective solvation interactions. In neutral water solvent, the transformation of fructose to HMF involves a four step reaction sequence with four transition states. The effective activation energy relative to fructose in neutral water at 298 K is very large, about 74 kcal/mol, so that transformation in neutral media around this temperature is unlikely. In contrast, the computed potential energy surface is much more favorable for the transformation in acidic media at 498 K, as the effective activation barrier is about 39 kcal/mol. The transformation in acidic media is a much more complex mechanism involving dehydration and hydrogen transfer steps, which are more favorable when protonated intermediates are involved. PMID:21443225

  16. Mechanistic Insights into the Decomposition of Fructose to Hydroxy Methyl Furfural in Neutral and Acidic Environments Using High-Level Quantum Chemical Methods

    SciTech Connect

    Assary, Rajeev S.; Redfern, Paul C.; Greeley, Jeffrey P.; Curtiss, Larry A.

    2011-04-21

    Efficient catalytic chemical transformation of fructose to hydroxy methyl furfural (HMF) is one of the key steps for attaining industrial level conversion of biomass to useful chemicals. We report an investigation of the reaction mechanisms for the decomposition of fructose to HMF in both neutral and acidic environments at the Gaussian-4 level of theory including calculation of enthalpies, free energies, and effective solvation interactions. In neutral water solvent, the transformation of fructose to HMF involves a four step reaction sequence with four transition states. The effective activation energy relative to fructose in neutral water at 298 K is very large, about 74 kcal/mol, so that transformation in neutral media around this temperature is unlikely. In contrast, the computed potential energy surface is much more favorable for the transformation in acidic media at 498 K, as the effective activation barrier is about 39 kcal/mol. The transformation in acidic media is a much more complex mechanism involving dehydration and hydrogen transfer steps, which are more favorable when protonated intermediates are involved.

  17. Mechanistic Insights into the Decomposition of Fructose to Hydroxy Methyl Furfural in Neutral and Acidic Environments Using High-Level Quantum Chemical Methods

    SciTech Connect

    Assary, Rajeev S.; Redfern, Paul C.; Greeley, Jeffrey; Curtiss, Larry A.

    2011-03-28

    Efficient catalytic chemical transformation of fructose to hydroxy methyl furfural (HMF) is one of the key steps for attaining industrial level conversion of biomass to useful chemicals. We report an investigation of the reaction mechanisms for the decomposition of fructose to HMF in both neutral and acidic environments at the Gaussian-4 level of theory including calculation of enthalpies, free energies, and effective solvation interactions. In neutral water solvent, the transformation of fructose to HMF involves a four step reaction sequence with four transition states. The effective activation energy relative to fructose in neutral water at 298 K is very large, about 74 kcal/mol, so that transformation in neutral media around this temperature is unlikely. In contrast, the computed potential energy surface is much more favorable for the transformation in acidic media at 498 K, as the effective activation barrier is about 39 kcal/mol. The transformation in acidic media is a much more complex mechanism involving dehydration and hydrogen transfer steps, which are more favorable when protonated intermediates are involved.

  18. Diffusion of air (1); furfural (2)

    NASA Astrophysics Data System (ADS)

    Winkelmann, J.

    This document is part of Subvolume A `Gases in Gases, Liquids and their Mixtures' of Volume 15 `Diffusion in Gases, Liquids and Electrolytes' of Landolt-Börnstein Group IV `Physical Chemistry'. It is part of the chapter of the chapter `Diffusion in Pure Gases' and contains data on diffusion of (1) air; (2) furfural

  19. 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.

  20. Furfural production by 'acidic steam stripping' of lignocellulose.

    PubMed

    van Buijtenen, Jeroen; Lange, Jean-Paul; Espinosa Alonso, Leticia; Spiering, Wouter; Polmans, Rob F; Haan, Rene J

    2013-11-01

    Furfural and acetic acid are produced with approximately 60 and 90 mol % yield, respectively, upon stripping bagasse with a gaseous stream of HCl/steam and condensing the effluent to water/furfural/acetic acid. The reaction kinetics is 1(st)  order in furfural and 0.5(th)  order in HCl. A process concept with full recycling of the reaction effluents is proposed to reduce the energy demand to <10 tonsteam  tonfurfural (-1) and facilitate the product recovery through a simple liquid/liquid separation of the condensate into a water-rich and a furfural-rich phase.

  1. Caloric curves fitted by polytropic distributions in the HMF model

    NASA Astrophysics Data System (ADS)

    Campa, Alessandro; Chavanis, Pierre-Henri

    2013-04-01

    We perform direct numerical simulations of the Hamiltonian mean field (HMF) model starting from non-magnetized initial conditions with a velocity distribution that is (i) Gaussian; (ii) semi-elliptical, and (iii) waterbag. Below a critical energy E c , depending on the initial condition, this distribution is Vlasov dynamically unstable. The system undergoes a process of violent relaxation and quickly reaches a quasi-stationary state (QSS). We find that the distribution function of this QSS can be conveniently fitted by a polytrope with index (i) n = 2; (ii) n = 1; and (iii) n = 1/2. Using the values of these indices, we are able to determine the physical caloric curve T kin ( E) and explain the negative kinetic specific heat region C kin = dE/ d T kin < 0 observed in the numerical simulations. At low energies, we find that the system has a "core-halo" structure. The core corresponds to the pure polytrope discussed above but it is now surrounded by a halo of particles. In case (iii), we recover the "uniform" core-halo structure previously found by Pakter and Levin [Phys. Rev. Lett. 106, 200603 (2011)]. We also consider unsteady initial conditions with magnetization M 0 = 1 and isotropic waterbag velocity distribution and report the complex dynamics of the system creating phase space holes and dense filaments. We show that the kinetic caloric curve is approximately constant, corresponding to a polytrope with index n 0 ≃ 3.56 (we also mention the presence of an unexpected hump). Finally, we consider the collisional evolution of an initially Vlasov stable distribution, and show that the time-evolving distribution function f( θ,v,t) can be fitted by a sequence of polytropic distributions with a time-dependent index n( t) both in the non-magnetized and magnetized regimes. These numerical results show that polytropic distributions (also called Tsallis distributions) provide in many cases a good fit of the QSSs. They may even be the rule rather than the exception

  2. Phosphorylated mesoporous carbon as effective catalyst for the selective fructose dehydration to HMF

    SciTech Connect

    Villa, Alberto; Schiavoni, Marco; Fulvio, Pasquale F; Mahurin, Shannon Mark; Dai, Sheng; Mayes, Richard T; Veith, Gabriel M; Prati, Laura

    2013-01-01

    Phosphorylated mesoporous carbons (PMCs) have been synthesized using an already reported one pot methodology. These materials have been applied as acidic catalysts in the dehydration of fructose to hydroxymethylfurfural (HMF). PMCs showed better selectivity to HMF compared to sulfonated carbon catalyst (SC) despite lower activity. The concentration of P-O groups correlates to the activity/selectivity of the catalysts; the higher the P-O concentration the higher the activity. However, the higher the P-O content the lower the selectivity to HMF. Indeed a lower concentration of the P-O groups (and even the acidic groups) minimized the degradation of HMF to levulinic acid and the formation of by-products, such as humines. Stability tests showed that these systems deactivate due to the formation of humines, water insoluble by-products derived from the dehydration of fructose, blocking the active site of the catalyst. Increasing the amount of P-O groups, higher amount of humines are formed; therefore carbons containing lower amount of phosphorylated groups, such as P/N-0.25, are less prone to deactivation. Keywords: Phosphorylated mesoporous carbons; fructose dehydration; HMF

  3. [Furfural degradation by filamentous fungus Amorphotheca resinae ZN1].

    PubMed

    Wang, Xiaofeng; Zhang, Jian; Xin, Xiujuan; Bao, Jie

    2012-09-01

    Some degradation products from lignocellulose pretreatment strongly inhibit the activities of cellulolytic enzymes and ethanol fermentation strains, thus the efficient removal of the inhibitor substances ("detoxification") is the inevitable step for the biotransformation processes. In this study, the biological detoxification of furfural by a newly isolated fungus, Amorphotheca resinae ZN1, was studied and the metabolic pathways of furfural degradation was analyzed. The metabolic pathway of furfural degradation in A. resinae ZN1 was described as follows: first, furfural was quickly converted into the low toxic furfuryl alcohol; then the furfuryl alcohol was gradually converted into furfural again but under the low concentration under aerobic condition, which was not lethal to the growth of the fungi; furfural continued to be oxidized to furoic acid by A. resinae ZN1. It is likely that furoic acid was further degraded in the TCA cycle to complete the biological degradation of furfural. The present study provided the important experimental basis for speeding up the biodetoxification of furfural by A. resinae ZN1 and the rate-limiting step in the lignocellulose biotransformation to ethanol.

  4. Biodegradation of furfural by Bacillus subtilis strain DS3.

    PubMed

    Zheng, Dan; Bao, Jianguo; Lu, Jueming; Lv, Quanxi

    2015-07-01

    An aerobic bacterial strain DS3, capable of growing on furfural as sole carbon source, was isolated from actived sludge of wastewater treatment plant in a diosgenin factory after enrichment. Based on morphological physiological tests as well as 16SrDNA sequence and Biolog analyses it was identified as Bacillus subtilis. The study revealed that strain DS3 utilized furfural, as analyzed by high-performance liquid chromatography (HPLC). Under following conditions: pH 8.0, temperature 35 degrees C, 150 rpm and 10% inoculum, strain DS3 showed 31.2% furfural degradation. Furthermore, DS3 strain was found to tolerate furfural concentration as high as 6000 mg(-1). The ability of Bacillus subtilis strain DS3 to degrade furfural has been demonstrated for the first time in the present study.

  5. Biodegradation of furfural by Bacillus subtilis strain DS3.

    PubMed

    Zheng, Dan; Bao, Jianguo; Lu, Jueming; Lv, Quanxi

    2015-07-01

    An aerobic bacterial strain DS3, capable of growing on furfural as sole carbon source, was isolated from actived sludge of wastewater treatment plant in a diosgenin factory after enrichment. Based on morphological physiological tests as well as 16SrDNA sequence and Biolog analyses it was identified as Bacillus subtilis. The study revealed that strain DS3 utilized furfural, as analyzed by high-performance liquid chromatography (HPLC). Under following conditions: pH 8.0, temperature 35 degrees C, 150 rpm and 10% inoculum, strain DS3 showed 31.2% furfural degradation. Furthermore, DS3 strain was found to tolerate furfural concentration as high as 6000 mg(-1). The ability of Bacillus subtilis strain DS3 to degrade furfural has been demonstrated for the first time in the present study. PMID:26387346

  6. 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.

  7. 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.

  8. Stereochemistry of furfural reduction by a Saccharomyces cerevisiae aldehyde reductase that contributes to in situ furfural detoxification.

    PubMed

    Bowman, Michael J; Jordan, Douglas B; Vermillion, Karl E; Braker, Jay D; Moon, Jaewoong; Liu, Z Lewis

    2010-08-01

    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 yeast, particularly when the carbon source is acid-treated lignocellulose, which contains furfural at a relatively high concentration. NADPH is Ari1p's best known hydride donor. Here we report the stereochemistry of the hydride transfer step, determined by using (4R)-[4-(2)H]NADPD and (4S)-[4-(2)H]NADPD and unlabeled furfural in Ari1p-catalyzed reactions and following the deuterium atom into products 2-furanmethanol or NADP(+). Analysis of the products demonstrates unambiguously that Ari1p directs hydride transfer from the si face of NADPH to the re face of furfural. The singular orientation of substrates enables construction of a model of the Michaelis complex in the Ari1p active site. The model reveals hydrophobic residues near the furfural binding site that, upon mutation, may increase specificity for furfural and enhance enzyme performance. Using (4S)-[4-(2)H]NADPD and NADPH as substrates, primary deuterium kinetic isotope effects of 2.2 and 2.5 were determined for the steady-state parameters k(cat)(NADPH) and k(cat)/K(m)(NADPH), respectively, indicating that hydride transfer is partially rate limiting to catalysis.

  9. 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.

  10. Microwave spectroscopy of furfural in vibrationally excited states

    NASA Astrophysics Data System (ADS)

    Motiyenko, R. A.; Alekseev, E. A.; Dyubko, S. F.

    2007-07-01

    The results of microwave spectrum investigation of the excited vibrational states of furfural in the frequency range between 49 and 149 GHz are reported. In total 15 excited vibrational states (9 for trans-furfural and 6 for cis-furfural) were assigned and analyzed. Six of the 15 investigated states were assigned for the first time. Accurate values of rigid rotor and quartic centrifugal distortion constants of asymmetric top Hamiltonian have been determined for 13 excited states. Also for some states several sextic and octic level constants were needed in order to fit the data within experimental accuracy. The vt = 3 and vs = 1, va = 1 states of trans-furfural were found to be strongly perturbed and only rotational transitions with low Ka values can be reliably identified in this study.

  11. [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. PMID:15538815

  12. 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.

  13. 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.

  14. 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.

  15. Large scale preparation of positively supercoiled DNA using the archaeal histone HMf.

    PubMed

    LaMarr, W A; Sandman, K M; Reeve, J N; Dedon, P C

    1997-04-15

    A technique to prepare relatively large quantities (>/=100 microg) of highly positively supercoiled DNA is reported. This uses a recombinant archaeal histone (rHMfB) to introduce toroidal supercoils, and an inexpensive chicken blood extract to relax unrestrained superhelical tension. Preparation of positively supercoiled pUC19 DNA molecules, >50% of which have linking number changes ranging from+8 to+17, is demonstrated. Advantages include the high degree of positive supercoiling that can be achieved, control over the extent of supercoiling, easy production of relatively large quantities of supercoiled DNA, and low cost.

  16. 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.

  17. HMF sectors since 1926: Comparison of two ground-based data sets

    NASA Astrophysics Data System (ADS)

    Hiltula, T.; Mursula, K.

    In this paper, we compare two recent long-term data sets of daily HMF sector polarities since 1926 based on ground-based geomagnetic measurements: the combined data set by Echer and Svalgaard [Echer, E., Svalgaard, L. Asymmetry in the Rosenberg-Coleman effect around solar minimum revealed by wavelet analysis of the interplanetary magnetic field polarity data (1927-2002). Geophys. Res. Lett. 31, 12808, 2004] (ES data set) and a three-station data set derived by Vennerstroem et al. [Vennerstroem, S., Zieger, B., Friis-Christensen, E. An improved method of inferring interplanetary sector structure, 1905-present. J. Geophys. Res. 106 (15), 16011-16020, 2001] (VZF data set). The Rosenberg-Coleman rule is consistently valid in the ES data during the last 80 years, but fails in the VZF data set in the early cycles. There is a clear bias (T sector dominance) in the VZF data that is not observed in satellite measurements collected in the OMNI-2 data set, or in the ES data. Also, there is a difference on the success rates between the two sectors in the VZF data. Therefore, we conclude that the ES data set is more reliable, especially in cycles 16-18, in reproducing the HMF sector structure. Both data sets reproduce the southward shift of the heliospheric current sheet during the OMNI-2 interval. However, only the more reliable ES data set depicts this systematically also during the early cycles 16-18.

  18. 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. PMID:19086900

  19. [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.

  20. 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.

  1. [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. PMID:26964338

  2. Release of acetic acid and furfural from cork products.

    PubMed

    Salthammer, T; Fuhrmann, F

    2000-06-01

    Cork samples were exposed to different temperatures and volatile ingredients were analyzed using gas chromatography/mass spectrometry (GC/MS). Thermal treatment at 180 degrees C yielded considerable amounts of furfural and acetic acid. In accordance with previous investigations it was concluded that both compounds are produced under thermal stress from degradation of polyoses.

  3. PREFACE: 20th International Conference on the Application of High Magnetic Fields in Semiconductor Physics (HMF-20)

    NASA Astrophysics Data System (ADS)

    Faugeras, Clément; Orlita, Milan; Piot, Benjamin; Potemski, Marek

    2013-08-01

    The 20th International Conference on 'High Magnetic Fields in Semiconductor Physics' (HMF-20) was held on 22-27 July 2012, in Chamonix Mont Blanc, France, as a satellite meeting to the 31st International Conference on the Physics of Semiconductors. HMF-20 followed a series of biennial conferences, initiated by Gottfried Landwehr, in Wurzburg, Germany, in 1972. Primarily focused on 'semiconductors' and 'magnetic fields', the main topics of the conference have evolved with time and are now dominated by current themes related to the physics of low dimensional systems in conjunction with the application of magnetic fields. The list of HMF-20 topics included: quantum Hall effect phenomena, graphene and carbon nanotubes, quantum wells, dots and wires, bulk semiconductors, topological insulators and organic conductors, magneto-transport and magneto-spectroscopy, electron correlations and magnetic field driven phases, spin-dependent phenomena and non-equilibrium effects, as well as novel phenomena and new techniques in high magnetic fields. The HMF-20 conference gathered 200 participants from 23 different countries. It was organized by the Laboratoire National des Champs Magnétiques Intenses, Grenoble, France, and greatly sponsored by the European High Magnetic Field Laboratory under the EC-FP7 framework. The 21st edition of the HMF conference series will take place during the summer of 2014 in Florida, USA. We thank the participants who, through their presentations, convivial discussions, and the papers presented here, contributed to the success of HMF-20 and advancements in the physics related to the applications of high magnetic fields. Clément Faugeras, Milan Orlita, Benjamin Piot and Marek Potemski Laboratoire National des Champs Magnétiques Intenses CNRS/UJF/UPS/INSA, Grenoble France

  4. Cupriavidus necator JMP134 rapidly reduces furfural with a Zn-dependent alcohol dehydrogenase.

    PubMed

    Li, Qunrui; Metthew Lam, L K; Xun, Luying

    2011-11-01

    Ethanol is a renewable biofuel, and it can be produced from lignocellulosic biomass. The biomass is usually converted to hydrolysates that consist of sugar and sugar derivatives, such as furfural. Yeast ferments sugar to ethanol, but furfural higher than 3 mM is inhibitory. It can take several days for yeast cells to reduce furfural to non-inhibitory furfuryl alcohol before producing ethanol. Bioreduction of furfural to furfuryl alcohol before fermentation may relieve yeast from furfural toxicity. We observed that Cupriavidus necator JMP134, a strict aerobe, rapidly reduced 17 mM furfural to less than 3 mM within 14 min with cell turbidity of 1.0 at 600 nm at 50°C. The rapid reduction consumed ethanol. The "furfural reductase" (FurX) was purified, and it oxidized ethanol to acetaldehyde and reduced furfural to furfuryl alcohol with NAD(+) as the cofactor. The protein was identified with mass spectrometry fingerprinting to be a hypothetical protein belonging to Zn-dependent alcohol dehydrogenase family. The furX-inactivation mutant of C. necator JMP134 lost the ability to rapidly reduce furfural, and Escherichia coli producing recombinant FurX gained the ability. Thus, an alcohol dehydrogenase enabled bacteria to rapidly reduce furfural with ethanol as the reducing power.

  5. Temporal quantitative proteomics of Saccharomyces cerevisiae in response to a nonlethal concentration of furfural.

    PubMed

    Lin, Feng-Ming; Tan, Ying; Yuan, Ying-Jin

    2009-12-01

    Furfural, one of the main inhibitory compounds in lignocellulosic hydrolytes, inhibits the growth and ethanol production rate of yeast. To get a global view of the dynamic expression pattern of proteins in Saccharomyces cerevisiae during the fermentation with the introduction of 8 g/L furfural, the protein samples were taken before the addition of furfural, during the initial phase of furfural conversion and immediately after the conversion of furfural for comparative proteomic analysis with iTRAQ on a LC-ESI-MS/MS instrument. A comparison of the temporal expression pattern of 107 proteins related to protein synthesis between the reference cultures and the furfural-treated cultures showed that a temporal downregulation of these proteins was retarded after the addition of furfural. The expression levels of 20 enzymes in glucose fermentation and 5 enzymes in the tricarboxylic acid cycle were reduced by furfural, with notably delayed temporal downregulations of Glk1p, Tdh1p, Eno1p and Aco1p, which is correlated to the reduced ethanol formation rate and glucose consumption rate by 66.7 and 60.4%, respectively. In the presence of furfural, proteins catalyzing the upper part of the super pathway of sulfur amino acid biosynthesis were repressed at all time points, which is related to the inhibited growth of furfural-treated yeast. The expressions of 18 proteins related to stress response showed increased trends, including several highly induced heat shock proteins and proteins related to cellular signaling pathways.

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

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

    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.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. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr06752a

  7. 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.

  8. Decarboxylation of furfural on Pd(111): Ab initio molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Xue, Wenhua; Dang, Hongli; Shields, Darwin; Liu, Yingdi; Jentoft, Friederike; Resasco, Daniel; Wang, Sanwu

    2013-03-01

    Furfural conversion over metal catalysts plays an important role in the studies of biomass-derived feedstocks. We report ab initio molecular dynamics simulations for the decarboxylation process of furfural on the palladium surface at finite temperatures. We observed and analyzed the atomic-scale dynamics of furfural on the Pd(111) surface and the fluctuations of the bondlengths between the atoms in furfural. We found that the dominant bonding structure is the parallel structure in which the furfural plane, while slightly distorted, is parallel to the Pd surface. Analysis of the bondlength fluctuations indicates that the C-H bond is the aldehyde group of a furfural molecule is likely to be broken first, while the C =O bond has a tendency to be isolated as CO. Our results show that the reaction of decarbonylation dominates, consistent with the experimental measurements. Supported by DOE (DE-SC0004600). Simulations and calculations were performed on XSEDE's and NERSC's supercomputers.

  9. Ab initio study on the dynamics of furfural at the liquid-solid interfaces

    NASA Astrophysics Data System (ADS)

    Dang, Hongli; Xue, Wenhua; Shields, Darwin; Liu, Yingdi; Jentoft, Friederike; Resasco, Daniel; Wang, Sanwu

    2013-03-01

    Catalytic biomass conversion sometimes occurs at the liquid-solid interfaces. We report ab initio molecular dynamics simulations at finite temperatures for the catalytic reactions involving furfural at the water-Pd and water-Cu interfaces. We found that, during the dynamic process, the furan ring of furfural prefers to be parallel to the Pd surface and the aldehyde group tends to be away from the Pd surface. On the other hand, at the water-Cu(111) interface, furfural prefers to be tilted to the Cu surface while the aldehyde group is bonded to the surface. In both cases, interaction of liquid water and furfural is identified. The difference of dynamic process of furfural at the two interfaces suggests different catalytic reaction mechanisms for the conversion of furfural, consistent with the experimental investigations. Supported by DOE (DE-SC0004600). Simulations and calculations were performed on XSED's and NERSC's supercomputers

  10. In vivo detoxification of furfural during lipid production by the oleaginous yeast Trichosporon fermentans.

    PubMed

    Huang, Chao; Wu, Hong; Smith, Thomas J; Liu, Zong-Jun; Lou, Wen-Yong; Zong, Min-Hua

    2012-09-01

    In vivo detoxification of furfural by the oleaginous yeast, Trichosporon fermentans, under lipid-producing (i.e., nitrogen-limited) conditions was evaluated for the first time. During the initial fermentation phase, furfural was rapidly reduced to furfuryl alcohol, which is more toxic to T. fermentans than furfural. Furfuryl alcohol was subsequently oxidized to furoic acid which has low toxicity to T. fermentans and is the end product of the in vivo detoxification of furfural in this organism. These observations explain how T. fermentans can grow and accumulate lipids in medium containing furfural. They also indicate that strategies to minimize the transient production of furfuryl alcohol could further improve the capacity of the strain to produce lipids from furfural-containing lignocellulosic hydrolysates.

  11. 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.

  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. PMID:25214353

  13. Effect of fortification with human milk fortifier (HMF) and other fortifying agents on the osmolality of preterm breast milk.

    PubMed

    Agarwal, Ramesh; Singal, Ashwani; Aggarwal, Rajiv; Deorari, Ashok K; Paul, Vinod K

    2004-01-01

    This study was conducted to test the effect of fortification with human milk fortifier (HMF), low birth weight (LBW) formula and coconut oil, initially and upon subsequent storage, on the osmolality of preterm breast milk. Milk samples (n = 48) were collected from mothers (n = 25) delivered at 34 pounds weeks and fortified with HMF (Lactodex-HMF), LBW formula (Lactodex-LBW) and edible coconut oil. Osmolality was measured before and after fortification and after 6 hours,.The gestation and birth weight (median) was 31 (range 29-32) weeks and 1198 (range 716-1478) grams. The median (range) postnatal age at testing was 15 days (range 3-60 days). There was a significant increase in osmolality of breast milk (302.3 +/- l.82) after addition of HMF (392.9 +/- 3.01) and LBW formula (390.5 +/- 2.4). There was no change in osmolality with addition of coconut oil (304 +/- 1.6). There was no further change in the osmolality after 6 hours of storage at 4 degrees C. PMID:14767087

  14. A study of surface enhanced Raman scattering for furfural adsorbed on silver surface

    NASA Astrophysics Data System (ADS)

    Jia, Ting-jian; Li, Peng-wei; Shang, Zhi-guo; Zhang, Ling; He, Ting-chao; Mo, Yu-jun

    2008-02-01

    The normal Raman spectrum (NRS) and the surface enhanced Raman scattering (SERS) spectrum of furfural in silver colloid were recorded and analyzed in this paper. The assignment of these bands to furfural molecules was performed by density functional theory (DFT) calculation. The data of the SERS by comparing with the one of NRS show that furfural molecules are adsorbed on the silver surface via the nonbonding electrons of the carbonyl oxygen.

  15. Organocatalytic Conversion of Cellulose into a Platform Chemical†

    PubMed Central

    Caes, Benjamin R.; Palte, Michael J.

    2014-01-01

    The search for a source of fuels and chemicals that is both abundant and renewable has become of paramount importance. The polysaccharide cellulose meets both criteria, and methods have been developed for its transformation into the platform chemical 5-(hydroxymethyl)furfural (HMF). These methods employ harsh reaction conditions or toxic heavy metal catalysts, deterring large-scale implementation. Here, we describe a low-temperature, one-pot route that uses ortho-carboxyl-substituted phenylboronic acids as organocatalysts in conjunction with hydrated magnesium chloride and mineral acids to convert cellulose and cellulose-rich municipal waste to HMF in yields comparable to processes that use toxic heavy metal catalysts. Isotopic labeling studies indicate that the key aldose-to-ketose transformation occurs via an enediol intermediate. The route, which also allows for facile catalyst recovery and recycling, provides a green prototype for cellulose conversion. PMID:24596655

  16. Genome-wide mapping of furfural tolerance genes in Escherichia coli.

    PubMed

    Glebes, Tirzah Y; Sandoval, Nicholas R; Reeder, Philippa J; Schilling, Katherine D; Zhang, Min; Gill, Ryan T

    2014-01-01

    Advances in genomics have improved the ability to map complex genotype-to-phenotype relationships, like those required for engineering chemical tolerance. Here, we have applied the multiSCale Analysis of Library Enrichments (SCALEs; Lynch et al. (2007) Nat. Method.) approach to map, in parallel, the effect of increased dosage for >10(5) different fragments of the Escherichia coli genome onto furfural tolerance (furfural is a key toxin of lignocellulosic hydrolysate). Only 268 of >4,000 E. coli genes (∼ 6%) were enriched after growth selections in the presence of furfural. Several of the enriched genes were cloned and tested individually for their effect on furfural tolerance. Overexpression of thyA, lpcA, or groESL individually increased growth in the presence of furfural. Overexpression of lpcA, but not groESL or thyA, resulted in increased furfural reduction rate, a previously identified mechanism underlying furfural tolerance. We additionally show that plasmid-based expression of functional LpcA or GroESL is required to confer furfural tolerance. This study identifies new furfural tolerant genes, which can be applied in future strain design efforts focused on the production of fuels and chemicals from lignocellulosic hydrolysate.

  17. Genome-Wide Mapping of Furfural Tolerance Genes in Escherichia coli

    PubMed Central

    Glebes, Tirzah Y.; Sandoval, Nicholas R.; Reeder, Philippa J.; Schilling, Katherine D.; Zhang, Min; Gill, Ryan T.

    2014-01-01

    Advances in genomics have improved the ability to map complex genotype-to-phenotype relationships, like those required for engineering chemical tolerance. Here, we have applied the multiSCale Analysis of Library Enrichments (SCALEs; Lynch et al. (2007) Nat. Method.) approach to map, in parallel, the effect of increased dosage for >105 different fragments of the Escherichia coli genome onto furfural tolerance (furfural is a key toxin of lignocellulosic hydrolysate). Only 268 of >4,000 E. coli genes (∼6%) were enriched after growth selections in the presence of furfural. Several of the enriched genes were cloned and tested individually for their effect on furfural tolerance. Overexpression of thyA, lpcA, or groESL individually increased growth in the presence of furfural. Overexpression of lpcA, but not groESL or thyA, resulted in increased furfural reduction rate, a previously identified mechanism underlying furfural tolerance. We additionally show that plasmid-based expression of functional LpcA or GroESL is required to confer furfural tolerance. This study identifies new furfural tolerant genes, which can be applied in future strain design efforts focused on the production of fuels and chemicals from lignocellulosic hydrolysate. PMID:24489935

  18. Antioxidants in heat-processed koji and the production mechanisms.

    PubMed

    Okutsu, Kayu; Yoshizaki, Yumiko; Ikeda, Natsumi; Kusano, Tatsuro; Hashimoto, Fumio; Takamine, Kazunori

    2015-11-15

    We previously developed antioxidative heat-processed (HP)-koji via two-step heating (55 °C/2days → 75 °C/3 days) of white-koji. In this study, we isolated antioxidants in HP-koji and investigated their formation mechanisms. The antioxidants were identified to be 5-hydroxymethyl furfural (HMF) and 5-(α-D-glucopyranosyloxymethyl)-2-furfural (GMF) based on nuclear magnetic resonance spectral analysis. HMF and GMF were not present in intact koji, but were formed by heating at 75 °C. As production of these antioxidants was more effective by two-step heating than by constant heating at 55 °C or 75 °C, we presumed that the antioxidant precursors are derived enzymatically at 55°C and that the antioxidants are formed subsequently by thermal reaction at 75 °C. The heating assay of saccharide solutions revealed glucose and isomaltose as HMF and GMF precursors, respectively, and thus the novel finding of GMF formation from isomaltose. Finally, HMF and GMF were effectively formed by two-step heating from glucose and isomaltose present in koji.

  19. 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.

  20. 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

  1. Furfural formation from the pre-hydrolysis liquor of a hardwood kraft-based dissolving pulp production process.

    PubMed

    Liu, Haitang; Hu, Huiren; Jahan, M Sarwar; Ni, Yonghao

    2013-03-01

    This study aimed to produce furfural from the PHL. Results showed best furfural yield of 32.8% and the furfural selectivity of 37.7% in the monophase system (170 °C, 100 min), while they were 60.1% and 69.8%, respectively in the biphase system. The lower furfural selectivity in the monophase system was explained by more side reactions, such as fragmentation, condensation reactions, resinification and others. Model compounds such as: xylose, furfural, syringaldehyde, were used to confirm/identify these side reactions. The addition of dilute sulfuric acid/acetic acid in the system under the same conditions decreased the recovery of furfural. The addition of syringaldehyde into the PHL also led to a decrease in the furfural yield, supporting the conclusion that lignin structures in the PHL may also be involved in the side reactions, thus decreasing the furfural yield.

  2. Furfural and its biochar improve the general properties of a saline soil

    NASA Astrophysics Data System (ADS)

    Wu, Y.; Xu, G.; Shao, H. B.

    2014-07-01

    Organic materials (e.g., furfural residue) are generally believed to improve the physical and chemical properties of saline soils with low fertility. Recently, biochar has been received more attention as a possible measure to improve the carbon balance and improve soil quality in some degraded soils. However, little is known about their different amelioration of a sandy saline soil. In this study, 56 d incubation experiment was conducted to evaluate the influence of furfural and its biochar on the properties of saline soil. The results showed that both furfural and biochar greatly reduced pH, increased soil organic carbon (SOC) content and cation exchange capacity (CEC), and enhanced the available phosphorus (P) in the soil. Furfural is more efficient than biochar in reducing pH: 5% furfural lowered the soil pH by 0.5-0.8 (soil pH: 8.3-8.6), while 5% biochar decreased by 0.25-0.4 due to the loss of acidity in pyrolysis process. With respect to available P, furfural addition at a rate of 5% increased available P content by 4-6 times in comparison to 2-5 times with biochar application. In reducing soil exchangeable sodium percentage (ESP), biochar is slightly superior to furfural because soil ESP reduced by 51% and 43% with 5% furfural and 5% biochar at the end of incubation. In addition, no significant differences were observed between furfural and biochar about their capacity to retain N, P in leaching solution and to increase CEC in soil. These facts may be caused by the relatively short incubation time. In general, furfural and biochar exhibited a different effect depending on the property: furfural was more effective in decreasing pH and increasing available P, whereas biochar played a more important role in increasing SOC and reducing ESP of saline soil.

  3. Detoxification of furfural in Corynebacterium glutamicum under aerobic and anaerobic conditions.

    PubMed

    Tsuge, Yota; Hori, Yoshimi; Kudou, Motonori; Ishii, Jun; Hasunuma, Tomohisa; Kondo, Akihiko

    2014-10-01

    The toxic fermentation inhibitors in lignocellulosic hydrolysates raise serious problems for the microbial production of fuels and chemicals. Furfural is considered to be one of the most toxic compounds among these inhibitors. Here, we describe the detoxification of furfural in Corynebacterium glutamicum ATCC13032 under both aerobic and anaerobic conditions. Under aerobic culture conditions, furfuryl alcohol and 2-furoic acid were produced as detoxification products of furfural. The ratio of the products varied depending on the initial furfural concentration. Neither furfuryl alcohol nor 2-furoic acid showed any toxic effect on cell growth, and both compounds were determined to be the end products of furfural degradation. Interestingly, unlike under aerobic conditions, most of the furfural was converted to furfuryl alcohol under anaerobic conditions, without affecting the glucose consumption rate. Both the NADH/NAD(+) and NADPH/NADP(+) ratio decreased in the accordance with furfural concentration under both aerobic and anaerobic conditions. These results indicate the presence of a single or multiple endogenous enzymes with broad and high affinity for furfural and co-factors in C. glutamicum ATCC13032.

  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. Transcriptome shifts in response to furfural and acetic acid in Saccharomyces cerevisiae.

    PubMed

    Li, Bing-Zhi; Yuan, Ying-Jin

    2010-05-01

    Furfural and acetic acid are two prevalent inhibitors to microorganisms during cellulosic ethanol production, but molecular mechanisms of tolerance to these inhibitors are still unclear. In this study, genome-wide transcriptional responses to furfural and acetic acid were investigated in Saccharomyces cerevisiae using microarray analysis. We found that 103 and 227 genes were differentially expressed in the response to furfural and acetic acid, respectively. Furfural downregulated genes related to transcriptional control and translational control, while it upregulated stress-responsive genes. Furthermore, furfural also interrupted the transcription of genes involved in metabolism of essential chemicals, such as etrahydrofolate, spermidine, spermine, and riboflavin monophosphate. Acetic acid downregulated genes encoding mitochondrial ribosomal proteins and genes involved in carbohydrate metabolism and regulation and upregulated genes related to amino acid metabolism. The results revealed that furfural and acetic acid had effects on multiple aspects of cellular metabolism on the transcriptional level and that mitochondria might play important roles in response to both furfural and acetic acid. This research has provided insights into molecular response to furfural and acetic acid in S. cerevisiae, and it will be helpful to construct more resistant strains for cellulosic ethanol production.

  6. 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.

  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. Biochemical characterization of ethanol-dependent reduction of furfural by alcohol dehydrogenases.

    PubMed

    Li, Qunrui; Metthew Lam, L K; Xun, Luying

    2011-11-01

    Lignocellulosic biomass is usually converted to hydrolysates, which consist of sugars and sugar derivatives, such as furfural. Before yeast ferments sugars to ethanol, it reduces toxic furfural to non-inhibitory furfuryl alcohol in a prolonged lag phase. Bioreduction of furfural may shorten the lag phase. Cupriavidus necator JMP134 rapidly reduces furfural with a Zn-dependent alcohol dehydrogenase (FurX) at the expense of ethanol (Li et al. 2011). The mechanism of the ethanol-dependent reduction of furfural by FurX and three homologous alcohol dehydrogenases was investigated. The reduction consisted of two individual reactions: ethanol-dependent reduction of NAD(+) to NADH and then NADH-dependent reduction of furfural to furfuryl alcohol. The kinetic parameters of the coupled reaction and the individual reactions were determined for the four enzymes. The data indicated that limited NADH was released in the coupled reaction. The enzymes had high affinities for NADH (e.g., K ( d ) of 0.043 μM for the FurX-NADH complex) and relatively low affinities for NAD(+) (e.g., K ( d ) of 87 μM for FurX-NAD(+)). The kinetic data suggest that the four enzymes are efficient "furfural reductases" with either ethanol or NADH as the reducing power. The standard free energy change (ΔG°') for ethanol-dependent reduction of furfural was determined to be -1.1 kJ mol(-1). The physiological benefit for ethanol-dependent reduction of furfural is likely to replace toxic and recalcitrant furfural with less toxic and more biodegradable acetaldehyde.

  9. 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. PMID:26606935

  10. The Effect of Detergents on the Morphology and Immunomodulatory Activity of Malassezia furfur

    PubMed Central

    Kim, Su-Han; Ko, Hyun-Chang; Kwon, Kyung-Sool; Oh, Chang-Keun

    2009-01-01

    Background Several workers have found that Malassezia are capable of suppressing cytokine release and downregulating the phagocytic function of monocytes. But lipid-depleted Malassezia furfur (M. furfur) extracts have also been shown to induce increased production of TNF-α, IL-6 and IL-1β in monocytes. We thought that the detergents in shampoos or soaps could change the composition of the lipid in the M. furfur cell wall. Objective We studied whether detergents affect the morphology of M. furfur and if the inflammatory cytokine profiles change in the monocytes treated with detergent-treated M. furfur. Methods Commonly used detergents such as sodium lauryl sulfate, ammonium lauryl sulfate and tween-80 were respectively added to the modified Leeming-Notman's media. M. furfur was cultivated in each media (detergent-added or untreated). Thereafter, the surface morphology of the yeast was evaluated by scanning and transmission electron microscopy. The cytokine profiles of monocytes, which were treated by M. furfur with or without detergents, were also evaluated. Results The detergent-treated M. furfur were similar to the lipid-extracted form of M. furfur on the electron microscopic study, with a recessed, withered surface and with thinner and rather electron transparent cell walls than the detergent-untreated M. furfur. The levels of TNF-α were higher in monocytes treated with detergent-treated Malassezia than that in the monocytes treated with the detergent-untreated Malassezia (p<0.05). Conclusion According to the findings in this study, it could be inferred that the detergents in shampoos or soaps affect the lipid layers of the Malassezia cell wall and these lipid-extracted Malassezia induce or aggravate some inflammatory conditions. But to correlate the relationship between detergents and Malassezia-associated diseases, in vivo experiments that will focus on short-term contact with detergents in real life conditions should be done. PMID:20523770

  11. Biomass pyrolysis: Thermal decomposition mechanisms of furfural and benzaldehyde

    NASA Astrophysics Data System (ADS)

    Vasiliou, AnGayle K.; Kim, Jong Hyun; Ormond, Thomas K.; Piech, Krzysztof M.; Urness, Kimberly N.; Scheer, Adam M.; Robichaud, David J.; Mukarakate, Calvin; Nimlos, Mark R.; Daily, John W.; Guan, Qi; Carstensen, Hans-Heinrich; Ellison, G. Barney

    2013-09-01

    The thermal decompositions of furfural and benzaldehyde have been studied in a heated microtubular flow reactor. The pyrolysis experiments were carried out by passing a dilute mixture of the aromatic aldehydes (roughly 0.1%-1%) entrained in a stream of buffer gas (either He or Ar) through a pulsed, heated SiC reactor that is 2-3 cm long and 1 mm in diameter. Typical pressures in the reactor are 75-150 Torr with the SiC tube wall temperature in the range of 1200-1800 K. Characteristic residence times in the reactor are 100-200 μsec after which the gas mixture emerges as a skimmed molecular beam at a pressure of approximately 10 μTorr. Products were detected using matrix infrared absorption spectroscopy, 118.2 nm (10.487 eV) photoionization mass spectroscopy and resonance enhanced multiphoton ionization. The initial steps in the thermal decomposition of furfural and benzaldehyde have been identified. Furfural undergoes unimolecular decomposition to furan + CO: C4H3O-CHO (+ M) → CO + C4H4O. Sequential decomposition of furan leads to the production of HC≡CH, CH2CO, CH3C≡CH, CO, HCCCH2, and H atoms. In contrast, benzaldehyde resists decomposition until higher temperatures when it fragments to phenyl radical plus H atoms and CO: C6H5CHO (+ M) → C6H5CO + H → C6H5 + CO + H. The H atoms trigger a chain reaction by attacking C6H5CHO: H + C6H5CHO → [C6H6CHO]* → C6H6 + CO + H. The net result is the decomposition of benzaldehyde to produce benzene and CO.

  12. Biomass pyrolysis: thermal decomposition mechanisms of furfural and benzaldehyde.

    PubMed

    Vasiliou, AnGayle K; Kim, Jong Hyun; Ormond, Thomas K; Piech, Krzysztof M; Urness, Kimberly N; Scheer, Adam M; Robichaud, David J; Mukarakate, Calvin; Nimlos, Mark R; Daily, John W; Guan, Qi; Carstensen, Hans-Heinrich; Ellison, G Barney

    2013-09-14

    The thermal decompositions of furfural and benzaldehyde have been studied in a heated microtubular flow reactor. The pyrolysis experiments were carried out by passing a dilute mixture of the aromatic aldehydes (roughly 0.1%-1%) entrained in a stream of buffer gas (either He or Ar) through a pulsed, heated SiC reactor that is 2-3 cm long and 1 mm in diameter. Typical pressures in the reactor are 75-150 Torr with the SiC tube wall temperature in the range of 1200-1800 K. Characteristic residence times in the reactor are 100-200 μsec after which the gas mixture emerges as a skimmed molecular beam at a pressure of approximately 10 μTorr. Products were detected using matrix infrared absorption spectroscopy, 118.2 nm (10.487 eV) photoionization mass spectroscopy and resonance enhanced multiphoton ionization. The initial steps in the thermal decomposition of furfural and benzaldehyde have been identified. Furfural undergoes unimolecular decomposition to furan + CO: C4H3O-CHO (+ M) → CO + C4H4O. Sequential decomposition of furan leads to the production of HC≡CH, CH2CO, CH3C≡CH, CO, HCCCH2, and H atoms. In contrast, benzaldehyde resists decomposition until higher temperatures when it fragments to phenyl radical plus H atoms and CO: C6H5CHO (+ M) → C6H5CO + H → C6H5 + CO + H. The H atoms trigger a chain reaction by attacking C6H5CHO: H + C6H5CHO → [C6H6CHO]* → C6H6 + CO + H. The net result is the decomposition of benzaldehyde to produce benzene and CO.

  13. [Assimilation test of Malassezia furfur isolated from the environment].

    PubMed

    Tanaka, R; Nishimura, K; Kamei, K; Murayama, S Y

    2001-01-01

    The lipophilic yeasts Malassezia species are the causative agents of tinea versicolor and known also to be a member of normal skin flora. They are commonly isolated from the skin of humans and animals, but not from the environment. This is the first report of the isolation of Malassezia sp. from the environment (a hospital floor). The results of assimilation tests of lipids and karyotyping showed that these isolates were M. furfur. They assimilated not only lipids including floor wax and car wax but also some ointments (except antifungal agents) used clinically. The results suggest that we need to take care when using such ointments to treat skin diseases.

  14. Bu-shen-he-mai-fang (HMF) Decoction Inhibits Atherosclerosis by Improving Antioxidant and Anti-Inflammatory Activities in ApoE-deficient Mice

    PubMed Central

    Hao, Qingqing; Chen, Xu; Zhou, Xiaoming; Wang, Xiaoyu; Cao, Xinran; Chen, Xingjuan; Jiang, Yuehua; Lu, Feng; You, Ke; Yang, Chuanhua; Dong, Bo

    2014-01-01

    Objective: To observe the effects of Bu–shen- he- mai- fang (HMF) on experimental atherosclerosis in ApoE-deficient mice. Materials an Methods: Thirty male ApoE-deficient mice were randomly divided into 3 groups (10 mice per group) as follows: one group received the standard high- cholesterol diet (high- cholesterol group, HC); Another group received high- cholesterol diet supplemented with HMF decoction 1.37 g/kg/day; the third group received a high- cholesterol diet, supplemented with atrovastatin 5 mg/kg/day for 8 weeks. The extent of atherosclerosis, the expression of LOX-1 protein and macrophage infiltration were evaluated by H&E, oil red O staining, and immunohistochemical staining. SOD was also measured by a spectrophotometer. Results: The degree of atherosclerosis was significantly lower in HMF group and atrovastatin group than that in high-cholesterol group. The expression of LOX-1 protein and macrophage filtration were significantly lower in HMF group and atrovastatin group than that in high-cholesterol group. Also, the SOD was higher in HMF group and atrovastatin group than that in high-cholesterol group. Conclusion: The results suggested that HMF significantly inhibited early atherosclerotic lesions by inhibiting inflammatory response and decreasing the generation of ROS. PMID:25598757

  15. Hydrothermal pentose to furfural conversion and simultaneous extraction with SC-CO2--kinetics and application to biomass hydrolysates.

    PubMed

    Gairola, Krishan; Smirnova, Irina

    2012-11-01

    This work explores hydrothermal d-xylose and hemicellulose to furfural conversion coupled with simultaneous furfural extraction by SC-CO(2) and the underlying reaction pathway. A maximum furfural yield of 68% was attained from d-xylose at 230°C and 12MPa. Additionally missing kinetic data for l-arabinose to furfural conversion was provided, showing close similarity to d-xylose. Furfural yields from straw and brewery waste hydrolysates were significantly lower than those obtained from model compounds, indicating side reactions with other hydrolysate components. Simultaneous furfural extraction by SC-CO(2) significantly increased extraction yield in all cases. The results indicate that furfural reacts with intermediates of pentose dehydration. The proposed processing route can be well integrated into existing lignocellulose biorefinery concepts.

  16. [Effects of furfural on the growth and lipid production of oleaginous yeast Rhodotorula glutinis].

    PubMed

    Yong, Zihan; Zhang, Xu; Tan, Tianwei

    2015-10-01

    In order to illustrate the effects of furfural, one of the most common inhibitory compounds in lignocellulosic hydrolysate, on oleaginous yeast Rhodotorula glutinis, we investigated the effects of different concentrations of furfural (0.1, 0.4, 0.6 and 1.5 g/L) on the biomass and lipid production of R. glutinis, as well as the effects of 1.0 g/L furfural on the utilization of glucose and xylose. Results showed that: when the furfural concentration reached 1.5 g/L, the lag phrase time was extended to 96 h, and the residual glucose was up to 17.7 g/L, with maximum biomass of only 6.6 g/L, which accounted for 47% of that in the basic medium (furfural-free), and the corresponding lipid content was reduced about 50%. Furfural showed lighter inhibitory degree on R. glutinis when xylose acted as the carbon source than glucose was the carbon source; more C18 fatty acids or unsaturated C18 fatty acids were generated in the presence of furfural.

  17. 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.

  18. Combinatorial application of two aldehyde oxidoreductases on isobutanol production in the presence of furfural.

    PubMed

    Seo, Hyung-Min; Jeon, Jong-Min; Lee, Ju Hee; Song, Hun-Suk; Joo, Han-Byul; Park, Sung-Hee; Choi, Kwon-Young; Kim, Yong Hyun; Park, Kyungmoon; Ahn, Jungoh; Lee, Hongweon; Yang, Yung-Hun

    2016-01-01

    Furfural is a toxic by-product formulated from pretreatment processes of lignocellulosic biomass. In order to utilize the lignocellulosic biomass on isobutanol production, inhibitory effect of the furfural on isobutanol production was investigated and combinatorial application of two oxidoreductases, FucO and YqhD, was suggested as an alternative strategy. Furfural decreased cell growth and isobutanol production when only YqhD or FucO was employed as an isobutyraldehyde oxidoreductase. However, combinatorial overexpression of FucO and YqhD could overcome the inhibitory effect of furfural giving higher isobutanol production by 110% compared with overexpression of YqhD. The combinatorial oxidoreductases increased furfural detoxification rate 2.1-fold and also accelerated glucose consumption 1.4-fold. When it compares to another known system increasing furfural tolerance, membrane-bound transhydrogenase (pntAB), the combinatorial aldehyde oxidoreductases were better on cell growth and production. Thus, to control oxidoreductases is important to produce isobutanol using furfural-containing biomass and the combinatorial overexpression of FucO and YqhD can be an alternative strategy.

  19. 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.

  20. 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.

  1. Combinatorial application of two aldehyde oxidoreductases on isobutanol production in the presence of furfural.

    PubMed

    Seo, Hyung-Min; Jeon, Jong-Min; Lee, Ju Hee; Song, Hun-Suk; Joo, Han-Byul; Park, Sung-Hee; Choi, Kwon-Young; Kim, Yong Hyun; Park, Kyungmoon; Ahn, Jungoh; Lee, Hongweon; Yang, Yung-Hun

    2016-01-01

    Furfural is a toxic by-product formulated from pretreatment processes of lignocellulosic biomass. In order to utilize the lignocellulosic biomass on isobutanol production, inhibitory effect of the furfural on isobutanol production was investigated and combinatorial application of two oxidoreductases, FucO and YqhD, was suggested as an alternative strategy. Furfural decreased cell growth and isobutanol production when only YqhD or FucO was employed as an isobutyraldehyde oxidoreductase. However, combinatorial overexpression of FucO and YqhD could overcome the inhibitory effect of furfural giving higher isobutanol production by 110% compared with overexpression of YqhD. The combinatorial oxidoreductases increased furfural detoxification rate 2.1-fold and also accelerated glucose consumption 1.4-fold. When it compares to another known system increasing furfural tolerance, membrane-bound transhydrogenase (pntAB), the combinatorial aldehyde oxidoreductases were better on cell growth and production. Thus, to control oxidoreductases is important to produce isobutanol using furfural-containing biomass and the combinatorial overexpression of FucO and YqhD can be an alternative strategy. PMID:26660478

  2. Isolation and characterization of a furfural-degrading bacterium Bacillus cereus sp. strain DS1.

    PubMed

    Zheng, Dan; Bao, Jianguo; Lu, Jueming; Gao, Chunlei

    2015-02-01

    Furfural was found to be the main organic pollutant in the wastewater coming from the Diosgenin factory. This substance is derived from acidic pentosan in Dioscorea zingiberensis and is also found in a variety of agricultural byproducts, including corncobs, oat, wheat bran, and sawdust. It is regarded as a toxicant and an inhibitor to the growth of microorganism in both sewage disposal and biological fermentation. A furfural-degrading strain (DS1) was isolated from activated sludge of wastewater treatment plant in a diosgenin factory by continuous enrichment culture. The strain was identified as Bacillus cereus based on morphological, physiological tests, as well as on 16S rDNA sequence and Biolog analyses. The capacity of this strain to grow on a mineral salt medium, utilizing furfural as the sole carbon and energy source to degrade furfural, was investigated in this study. Under the condition of pH 9.0, temperature 35 °C, with rotating speed of 150 rpm, and an inoculum of 6 %, the strain showed that the furfural degradation capacity reaches 35 % in 7 days, as measured by high-performance liquid chromatography. The addition of inorganic carbon sources could bring down the biodegradation efficiency of the furfural. The strain DS1 showed better furfural removal capacity, as compared to other inorganic carbon sources in the media. Furthermore, a furfural concentration of as high as 4,000 mg L(-1) was tolerated by the culture. The capacity to degrade furfural was demonstrated for the first time by using the genus B. cereus. This study suggests the possible application in biodegradation strategies.

  3. Isolation and characterization of a furfural-degrading bacterium Bacillus cereus sp. strain DS1.

    PubMed

    Zheng, Dan; Bao, Jianguo; Lu, Jueming; Gao, Chunlei

    2015-02-01

    Furfural was found to be the main organic pollutant in the wastewater coming from the Diosgenin factory. This substance is derived from acidic pentosan in Dioscorea zingiberensis and is also found in a variety of agricultural byproducts, including corncobs, oat, wheat bran, and sawdust. It is regarded as a toxicant and an inhibitor to the growth of microorganism in both sewage disposal and biological fermentation. A furfural-degrading strain (DS1) was isolated from activated sludge of wastewater treatment plant in a diosgenin factory by continuous enrichment culture. The strain was identified as Bacillus cereus based on morphological, physiological tests, as well as on 16S rDNA sequence and Biolog analyses. The capacity of this strain to grow on a mineral salt medium, utilizing furfural as the sole carbon and energy source to degrade furfural, was investigated in this study. Under the condition of pH 9.0, temperature 35 °C, with rotating speed of 150 rpm, and an inoculum of 6 %, the strain showed that the furfural degradation capacity reaches 35 % in 7 days, as measured by high-performance liquid chromatography. The addition of inorganic carbon sources could bring down the biodegradation efficiency of the furfural. The strain DS1 showed better furfural removal capacity, as compared to other inorganic carbon sources in the media. Furthermore, a furfural concentration of as high as 4,000 mg L(-1) was tolerated by the culture. The capacity to degrade furfural was demonstrated for the first time by using the genus B. cereus. This study suggests the possible application in biodegradation strategies. PMID:25274411

  4. Comparison of glucose/xylose cofermentation of poplar hydrolysates processed by different pretreatment technologies.

    PubMed

    Lu, Yulin; Warner, Ryan; Sedlak, Miroslav; Ho, Nancy; Mosier, Nathan S

    2009-01-01

    The inhibitory effects of furfural and acetic acid on the fermentation of xylose and glucose to ethanol in YEPDX medium by a recombinant Saccharomyces cerevisiae strain (LNH-ST 424A) were investigated. Initial furfural concentrations below 5 g/L caused negligible inhibition to glucose and xylose consumption rates in batch fermentations with high inoculum (4.5-6.0 g/L). At higher initial furfural concentrations (10-15 g/L) the inhibition became significant with xylose consumption rates especially affected. Interactive inhibition between acetic acid and pH were observed and quantified, and the results suggested the importance of conditioning the pH of hydrolysates for optimal fermentation performance. Poplar biomass pretreated by various CAFI processes (dilute acid, AFEX, ARP, SO(2)-catalyzed steam explosion, and controlled-pH) under respective optimal conditions was enzymatically hydrolyzed, and the mixed sugar streams in the hydrolysates were fermented. The 5-hydroxymethyl furfural (HMF) and furfural concentrations were low in all hydrolysates and did not pose negative effects on fermentation. Maximum ethanol productivity showed that 0-6.2 g/L initial acetic acid does not substantially affect the ethanol fermentation with proper pH adjustment, confirming the results from rich media fermentations with reagent grade sugars.

  5. 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.

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

    PubMed

    Tao, Furong; Song, Huanling; Chou, Lingjun

    2011-01-01

    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. PMID:21092940

  7. Production of furfural from waste aqueous hemicellulose solution of hardwood over ZSM-5 zeolite.

    PubMed

    Gao, Hongling; Liu, Haitang; Pang, Bo; Yu, Guang; Du, Jian; Zhang, Yuedong; Wang, Haisong; Mu, Xindong

    2014-11-01

    This study aimed to produce furfural from waste aqueous hemicellulose solution of a hardwood kraft-based dissolving pulp production processing in a green method. The maximum furfural yield of 82.4% and the xylose conversion of 96.8% were achieved at 463K, 1.0g ZSM-5, 1.05g NaCl and organic solvent-to-aqueous phase ratio of 30:15 (V/V) for 3h. The furfural yield was just 51.5% when the same concentration of pure xylose solution was used. Under the optimized condition, furfural yield was still up to 67.1% even after the fifth reused of catalyst. Catalyst recycling study showed that ZSM-5 has a certain stability and can be efficiently reused. PMID:25266687

  8. Kinetics of levulinic acid and furfural production from Miscanthus × giganteus.

    PubMed

    Dussan, K; Girisuta, B; Haverty, D; Leahy, J J; Hayes, M H B

    2013-12-01

    This study investigated the kinetics of acid hydrolysis of the cellulose and hemicellulose in Miscanthus to produce levulinic acid and furfural under mild temperature and high acid concentration. Experiments were carried out in an 8L-batch reactor with 9%-wt. biomass loading, acid concentrations between 0.10 and 0.53 M H2SO4, and at temperatures between 150 and 200°C. The concentrations of xylose, glucose, furfural, 5-hydroxymethylfurfural and levulinic acid were used in two mechanistic kinetic models for the prediction of the performance of ideal continuous reactors for the optimisation of levulinic acid and the concurrent production of furfural. A two-stage arrangement was found to maximise furfural in the first reactor (PFR - 185°C, 0.5M H2SO4, 27.3%-mol). A second stage leads to levulinic acid yields between 58% and 72%-mol at temperatures between 160 and 200°C.

  9. Production of furfural from waste aqueous hemicellulose solution of hardwood over ZSM-5 zeolite.

    PubMed

    Gao, Hongling; Liu, Haitang; Pang, Bo; Yu, Guang; Du, Jian; Zhang, Yuedong; Wang, Haisong; Mu, Xindong

    2014-11-01

    This study aimed to produce furfural from waste aqueous hemicellulose solution of a hardwood kraft-based dissolving pulp production processing in a green method. The maximum furfural yield of 82.4% and the xylose conversion of 96.8% were achieved at 463K, 1.0g ZSM-5, 1.05g NaCl and organic solvent-to-aqueous phase ratio of 30:15 (V/V) for 3h. The furfural yield was just 51.5% when the same concentration of pure xylose solution was used. Under the optimized condition, furfural yield was still up to 67.1% even after the fifth reused of catalyst. Catalyst recycling study showed that ZSM-5 has a certain stability and can be efficiently reused.

  10. 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.

  11. Furfural production from Eucalyptus wood using an Acidic Ionic Liquid.

    PubMed

    Peleteiro, Susana; Santos, Valentín; Garrote, Gil; Parajó, Juan Carlos

    2016-08-01

    Eucalyptus globulus wood samples were treated with hot, compressed water to separate hemicelluloses (as soluble saccharides) from a solid phase mainly made up of cellulose and lignin. The liquid phase was dehydrated, and the resulting solids (containing pentoses as well as poly- and oligo- saccharides made up of pentoses) were dissolved and reacted in media containing an Acidic Ionic Liquid (1-butyl-3-methylimidazolium hydrogen sulfate) and a co-solvent (dioxane). The effects of the reaction time on the product distribution were studied at temperatures in the range 120-170°C for reaction times up to 8h, and operational conditions leading to 59.1% conversion of the potential substrates (including pentoses and pentose structural units in oligo- and poly- saccharides) into furfural were identified. PMID:27112846

  12. 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.

  13. 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.

  14. Furfural production from Eucalyptus wood using an Acidic Ionic Liquid.

    PubMed

    Peleteiro, Susana; Santos, Valentín; Garrote, Gil; Parajó, Juan Carlos

    2016-08-01

    Eucalyptus globulus wood samples were treated with hot, compressed water to separate hemicelluloses (as soluble saccharides) from a solid phase mainly made up of cellulose and lignin. The liquid phase was dehydrated, and the resulting solids (containing pentoses as well as poly- and oligo- saccharides made up of pentoses) were dissolved and reacted in media containing an Acidic Ionic Liquid (1-butyl-3-methylimidazolium hydrogen sulfate) and a co-solvent (dioxane). The effects of the reaction time on the product distribution were studied at temperatures in the range 120-170°C for reaction times up to 8h, and operational conditions leading to 59.1% conversion of the potential substrates (including pentoses and pentose structural units in oligo- and poly- saccharides) into furfural were identified.

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

    PubMed

    Hunter, William J; Manter, Daniel K

    2014-10-01

    Furfural is an inhibitor of growth and ethanol production by Zymomonas mobilis. This study used a naturally occurring (not GMO) biological pre-treatment to reduce that amount of furfural in a model fermentation broth. Pre-treatment involved inoculating and incubating the fermentation broth with strains of Leuconostoc mesenteroides or Leuconostoc pseudomesenteroides. The Leuconostoc strains converted furfural to furfuryl alcohol without consuming large amounts of dextrose in the process. Coupling this pre-treatment to ethanolic fermentation reduced furfural in the broth and improved growth, dextrose uptake and ethanol formation. Pre-treatment permitted ethanol formation in the presence of 5.2 g L(-1) furfural, which was otherwise inhibitive. The pre-treatment and presence of the Leuconostoc strains in the fermentation broth did not interfere with Z. mobilis ethanolic fermentation or the amounts of ethanol produced. The method suggests a possible technique for reducing the effect that furfural has on the production of ethanol for use as a biofuel.

  16. Optimization of furfural production from D-xylose with formic acid as catalyst in a reactive extraction system.

    PubMed

    Yang, Wandian; Li, Pingli; Bo, Dechen; Chang, Heying; Wang, Xiaowei; Zhu, Tao

    2013-04-01

    Furfural is one of the most promising platform chemicals derived from biomass. In this study, response surface methodology (RSM) was utilized to determine four important parameters including reaction temperature (170-210°C), formic acid concentration (5-25 g/L), o-nitrotoluene volume percentage (20-80 vt.%), and residence time (40-200 min). The maximum furfural yield of 74% and selectivity of 86% were achieved at 190°C for 20 g/L formic acid concentration and 75 vt.% o-nitrotoluene by 75 min. The high boiling solvent, o-nitrotoluene, was recommended as extraction solvent in a reactive extraction system to obtain high furfural yield and reduce furfural-solvent separation costs. Although the addition of halides to the xylose solutions enhanced the furfural yield and selectivity, the concentration of halides was not an important factor on the furfural yield and selectivity.

  17. 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

    2015-01-01

    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 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. PMID:25819091

  18. 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.

  19. Engineering furfural tolerance in Escherichia coli improves the fermentation of lignocellulosic sugars into renewable chemicals.

    PubMed

    Wang, Xuan; Yomano, Lorraine P; Lee, James Y; York, Sean W; Zheng, Huabao; Mullinnix, Michael T; Shanmugam, K T; Ingram, Lonnie O

    2013-03-01

    Pretreatments such as dilute acid at elevated temperature are effective for the hydrolysis of pentose polymers in hemicellulose and also increase the access of enzymes to cellulose fibers. However, the fermentation of resulting syrups is hindered by minor reaction products such as furfural from pentose dehydration. To mitigate this problem, four genetic traits have been identified that increase furfural tolerance in ethanol-producing Escherichia coli LY180 (strain W derivative): increased expression of fucO, ucpA, or pntAB and deletion of yqhD. Plasmids and integrated strains were used to characterize epistatic interactions among traits and to identify the most effective combinations. Furfural resistance traits were subsequently integrated into the chromosome of LY180 to construct strain XW129 (LY180 ΔyqhD ackA::PyadC'fucO-ucpA) for ethanol. This same combination of traits was also constructed in succinate biocatalysts (Escherichia coli strain C derivatives) and found to increase furfural tolerance. Strains engineered for resistance to furfural were also more resistant to the mixture of inhibitors in hemicellulose hydrolysates, confirming the importance of furfural as an inhibitory component. With resistant biocatalysts, product yields (ethanol and succinate) from hemicellulose syrups were equal to control fermentations in laboratory media without inhibitors. The combination of genetic traits identified for the production of ethanol (strain W derivative) and succinate (strain C derivative) may prove useful for other renewable chemicals from lignocellulosic sugars.

  20. 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.

  1. 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

  2. Engineering furfural tolerance in Escherichia coli improves the fermentation of lignocellulosic sugars into renewable chemicals.

    PubMed

    Wang, Xuan; Yomano, Lorraine P; Lee, James Y; York, Sean W; Zheng, Huabao; Mullinnix, Michael T; Shanmugam, K T; Ingram, Lonnie O

    2013-03-01

    Pretreatments such as dilute acid at elevated temperature are effective for the hydrolysis of pentose polymers in hemicellulose and also increase the access of enzymes to cellulose fibers. However, the fermentation of resulting syrups is hindered by minor reaction products such as furfural from pentose dehydration. To mitigate this problem, four genetic traits have been identified that increase furfural tolerance in ethanol-producing Escherichia coli LY180 (strain W derivative): increased expression of fucO, ucpA, or pntAB and deletion of yqhD. Plasmids and integrated strains were used to characterize epistatic interactions among traits and to identify the most effective combinations. Furfural resistance traits were subsequently integrated into the chromosome of LY180 to construct strain XW129 (LY180 ΔyqhD ackA::PyadC'fucO-ucpA) for ethanol. This same combination of traits was also constructed in succinate biocatalysts (Escherichia coli strain C derivatives) and found to increase furfural tolerance. Strains engineered for resistance to furfural were also more resistant to the mixture of inhibitors in hemicellulose hydrolysates, confirming the importance of furfural as an inhibitory component. With resistant biocatalysts, product yields (ethanol and succinate) from hemicellulose syrups were equal to control fermentations in laboratory media without inhibitors. The combination of genetic traits identified for the production of ethanol (strain W derivative) and succinate (strain C derivative) may prove useful for other renewable chemicals from lignocellulosic sugars. PMID:23431191

  3. Engineering furfural tolerance in Escherichia coli improves the fermentation of lignocellulosic sugars into renewable chemicals

    PubMed Central

    Wang, Xuan; Yomano, Lorraine P.; Lee, James Y.; York, Sean W.; Zheng, Huabao; Mullinnix, Michael T.; Shanmugam, K. T.; Ingram, Lonnie O.

    2013-01-01

    Pretreatments such as dilute acid at elevated temperature are effective for the hydrolysis of pentose polymers in hemicellulose and also increase the access of enzymes to cellulose fibers. However, the fermentation of resulting syrups is hindered by minor reaction products such as furfural from pentose dehydration. To mitigate this problem, four genetic traits have been identified that increase furfural tolerance in ethanol-producing Escherichia coli LY180 (strain W derivative): increased expression of fucO, ucpA, or pntAB and deletion of yqhD. Plasmids and integrated strains were used to characterize epistatic interactions among traits and to identify the most effective combinations. Furfural resistance traits were subsequently integrated into the chromosome of LY180 to construct strain XW129 (LY180 ΔyqhD ackA::PyadC′fucO-ucpA) for ethanol. This same combination of traits was also constructed in succinate biocatalysts (Escherichia coli strain C derivatives) and found to increase furfural tolerance. Strains engineered for resistance to furfural were also more resistant to the mixture of inhibitors in hemicellulose hydrolysates, confirming the importance of furfural as an inhibitory component. With resistant biocatalysts, product yields (ethanol and succinate) from hemicellulose syrups were equal to control fermentations in laboratory media without inhibitors. The combination of genetic traits identified for the production of ethanol (strain W derivative) and succinate (strain C derivative) may prove useful for other renewable chemicals from lignocellulosic sugars. PMID:23431191

  4. 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.

  5. 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

    2016-01-01

    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.

  6. 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

    2016-04-01

    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. PMID:26965182

  7. 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

  8. 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. PMID:26162472

  9. Improving furfural tolerance of Zymomonas mobilis by rewiring a sigma factor RpoD protein.

    PubMed

    Tan, Fu-Rong; Dai, Li-Chun; Wu, Bo; Qin, Han; Shui, Zong-Xia; Wang, Jing-Li; Zhu, Qi-Li; Hu, Qi-Chun; Ruan, Zhi-Yong; He, Ming-Xiong

    2015-06-01

    Furfural from lignocellulosic hydrolysates is the key inhibitor for bio-ethanol fermentation. In this study, we report a strategy of improving the furfural tolerance in Zymomonas mobilis on the transcriptional level by engineering its global transcription sigma factor (σ(70), RpoD) protein. Three furfural tolerance RpoD mutants (ZM4-MF1, ZM4-MF2, and ZM4-MF3) were identified from error-prone PCR libraries. The best furfural-tolerance strain ZM4-MF2 reached to the maximal cell density (OD600) about 2.0 after approximately 30 h, while control strain ZM4-rpoD reached its highest cell density of about 1.3 under the same conditions. ZM4-MF2 also consumed glucose faster and yield higher ethanol; expression levels and key Entner-Doudoroff (ED) pathway enzymatic activities were also compared to control strain under furfural stress condition. Our results suggest that global transcription machinery engineering could potentially be used to improve stress tolerance and ethanol production in Z. mobilis.

  10. 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.

  11. Study of the Influence of Key Process Parameters on Furfural Production.

    PubMed

    Fele Žilnik, Ljudmila; Grilc, Viktor; Mirt, Ivan; Cerovečki, Željko

    2016-01-01

    The present work reports the influence of key process variables on the furfural formation from leached chestnut-wood chips in a pressurized reactor. Effect of temperature, pressure, type and concentration of the catalyst solution, the steam flow rate or stripping module, the moisture content of the wood particles and geometric characteristics such as size and type of the reactor, particle size and bed height were considered systematically. One stage process was only taken into consideration. Lab-scale and pilot-scale studies were performed. The results of the non-catalysed laboratory experiments were compared with an actual non-catalysed (auto-catalysed) industrial process and with experiments on the pilot scale, the latter with 28% higher furfural yield compared to the others. Application of sulphuric acid as catalyst, in an amount of 0.03-0.05 g (H2SO4 100%)/g d.m. (dry material), enables a higher production of furfural at lower temperature and pressure of steam in a shorter reaction time. Pilot scale catalysed experiments have revealed very good performance for furfural formation under less severe operating conditions, with a maximum furfural yield as much as 88% of the theoretical value.

  12. Investigation of furfural biodegradation in a continuous inflow cyclic biological reactor.

    PubMed

    Moussavi, Gholamreza; Leili, Mostafa; Nadafi, Kazem

    2016-01-01

    The performance of a continuous inflow cyclic biological reactor (CBR) containing moving media was investigated for the degradation of high concentrations of furfural. The effects of hydraulic retention time (HRT) and furfural initial concentrations (loading rate), as main operating parameters, on the bioreactor performance were studied. The results indicated that the CBR could remove over 98% of furfural and 71% of its chemical oxygen demand (COD) at inlet furfural concentrations up to 1,200 mg L(-1) (2.38 g L(-1) d(-1)), a 6-h cycle time and HRT of 12.1 h. The removal efficiency decreased slightly from 98 to 94% when HRT decreased from 12.1 to 10.5 h. The average removal efficiency of furfural and COD during the 345-day operational period under steady-state conditions were 97.7% and 82.1%, respectively. The efficiency also increased approximately 17.2% after addition of synthetic polyurethane cubes as moving media at a filling ratio of 10%.

  13. 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.

  14. Effect of structural characteristics of corncob hemicelluloses fractionated by graded ethanol precipitation on furfural production.

    PubMed

    Li, Huiling; Dai, Qingqing; Ren, Junli; Jian, Longfei; Peng, Feng; Sun, Runcang; Liu, Guoliang

    2016-01-20

    In the present study, a graded ethanol precipitation technique was employed to obtain hemicelluloses from the alkali-extracted corncob liquid. The relationship between the structural characteristics of alkali-soluble corncob hemicelluloses and the production of furfural was investigated by a heterogeneous process in a biphasic system. Results showed that alkali-soluble corncob hemicelluloses mainly consisted of glucuronoarabinoxylans and L-arabino-(4-O-methylglucurono)-D-xylans, and the drying way had less influence on the sugar composition, molecular weights and the functional groups of hemicelluloses obtained by the different ethanol concentration precipitation except for the thermal property, the amorphous structure and the ability for the furfural production. Furthermore, alkali-soluble corncob hemicelluloses with higher xylose content, lower branch degree, higher polydispersity and crystallinity contributed to the furfural production. A highest furfural yield of 45.41% with the xylose conversion efficiency of 99.06% and the furfural selectivity of 45.84% was obtained from the oven-dried hemicelluloses precipitated at the 30% (v/v) ethanol concentration.

  15. Catalytic dehydration of xylose to furfural: vanadyl pyrophosphate as source of active soluble species.

    PubMed

    Sádaba, Irantzu; Lima, Sérgio; Valente, Anabela A; López Granados, Manuel

    2011-12-13

    The acid-catalysed, aqueous phase dehydration of xylose (a monosaccharide obtainable from hemicelluloses, e.g., xylan) to furfural was investigated using vanadium phosphates (VPO) as catalysts: the precursors, VOPO(4)·2H(2)O, VOHPO(4)·0.5H(2)O and VO(H(2)PO(4))(2), and the materials prepared by calcination of these precursors, that is, γ-VOPO(4), (VO)(2)P(2)O(7) and VO(PO(3))(2), respectively. The VPO precursors were completely soluble in the reaction medium. In contrast, the orthorhombic vanadyl pyrophosphate (VO)(2)P(2)O(7), prepared by calcination of VOHPO(4)·0.5H(2)O at 550°C/2 h, could be recycled by simply separating the solid acid from the reaction mixture by centrifugation, and no drop in catalytic activity and furfural yields was observed in consecutive 4 h-batch runs (ca. 53% furfural yield, at 170°C). However, detailed catalytic/characterisation studies revealed that the vanadyl pyrophosphate acts as a source of active water-soluble species in this reaction. For a concentration of (VO)(2)P(2)O(7) as low as 5 mM, the catalytic reaction of xylose (ca. 0.67 M xylose in water, and toluene as solvent for the in situ extraction of furfural) gave ca. 56% furfural yield, at 170°C/6 h reaction. PMID:22055820

  16. Study of the Influence of Key Process Parameters on Furfural Production.

    PubMed

    Fele Žilnik, Ljudmila; Grilc, Viktor; Mirt, Ivan; Cerovečki, Željko

    2016-01-01

    The present work reports the influence of key process variables on the furfural formation from leached chestnut-wood chips in a pressurized reactor. Effect of temperature, pressure, type and concentration of the catalyst solution, the steam flow rate or stripping module, the moisture content of the wood particles and geometric characteristics such as size and type of the reactor, particle size and bed height were considered systematically. One stage process was only taken into consideration. Lab-scale and pilot-scale studies were performed. The results of the non-catalysed laboratory experiments were compared with an actual non-catalysed (auto-catalysed) industrial process and with experiments on the pilot scale, the latter with 28% higher furfural yield compared to the others. Application of sulphuric acid as catalyst, in an amount of 0.03-0.05 g (H2SO4 100%)/g d.m. (dry material), enables a higher production of furfural at lower temperature and pressure of steam in a shorter reaction time. Pilot scale catalysed experiments have revealed very good performance for furfural formation under less severe operating conditions, with a maximum furfural yield as much as 88% of the theoretical value. PMID:27333552

  17. 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.

  18. 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.

  19. 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...

  20. Novel Ordered Mesoporous Carbon Based Sulfonic Acid as an Efficient Catalyst in the Selective Dehydration of Fructose into 5-HMF: the Role of Solvent and Surface Chemistry.

    PubMed

    Karimi, Babak; Mirzaei, Hamid M; Behzadnia, Hesam; Vali, Hojatollah

    2015-09-01

    Novel ionic liquid derived ordered mesoporous carbons functionalized with sulfonic acid groups IOMC-ArSO3H and GIOMC-ArSO3H were prepared, characterized, and examined in the dehydration reaction of fructose into 5-hydroxymethylfurfural (5-HMF) both in aqueous and nonaqueous systems. To study and correlate the surface properties of these carbocatalysts and some other SBA-15 typed solid acids with 5-HMF yield, hydrophilicity index (H-index) were employed in the fructose dehydration. Our study systematically declared that almost a criterion may be expected for application of solid acids in which by increasing H-index value up to 0.8 the HMF yield enhances accordingly. More increase in H-index up to 1.3 did not change the HMF yield profoundly. Although, it has been shown that the catalyst with larger H-index (∼1.3) resulted in higher activity both in aqueous and 2-propanol systems, during the recycling process deactivation occurs because of more water uptake and the catalysts with optimum amount of H-index (∼0.8) is more robust in the dehydration of fructose.

  1. Selective aerobic oxidation of 5-HMF into 2,5-furandicarboxylic acid with Pt catalysts supported on TiO2 - and ZrO2 -based supports.

    PubMed

    Ait Rass, Hicham; Essayem, Nadine; Besson, Michèle

    2015-04-13

    Pt catalysts prepared over different metallic oxide supports were investigated in the oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) in alkaline aqueous solutions with air, to examine the combined effect of the support and base addition. The base (nature and amount) played a significant role in the degradation or oxidation of HMF. Increasing amounts of the weak NaHCO3 base improved significantly the overall catalytic activity of Pt/TiO2 and Pt/ZrO2 by accelerating the oxidation steps, especially for the aldehyde group. This was highlighted by a proposed kinetic model that gave very good concentration-time fittings. Moreover, the promotion of the catalyst with bismuth yielded a PtBi/TiO2 catalytic system with improved activity and stability. Y2 O3  and La2 O3 ZrO2 -supported catalysts exhibited lower activity than Pt/ZrO2 , which suggests no cooperative effect of the weakly basic properties introduced and the homogeneous base. Quantitative oxidation of HMF (0.1 M) and high yields of FDCA (>99 %) were obtained in less than 5 h by using an HMF/Pt molar ratio of 100 and Na2 CO3 as a weak base over PtBi/TiO2 (Bi/Pt=0.22). PMID:25736596

  2. Ab initio molecular dynamics simulations for the role of hydrogen in catalytic reactions of furfural on Pd(111)

    NASA Astrophysics Data System (ADS)

    Xue, Wenhua; Dang, Hongli; Liu, Yingdi; Jentoft, Friederike; Resasco, Daniel; Wang, Sanwu

    2014-03-01

    In the study of catalytic reactions of biomass, furfural conversion over metal catalysts with the presence of hydrogen has attracted wide attention. We report ab initio molecular dynamics simulations for furfural and hydrogen on the Pd(111) surface at finite temperatures. The simulations demonstrate that the presence of hydrogen is important in promoting furfural conversion. In particular, hydrogen molecules dissociate rapidly on the Pd(111) surface. As a result of such dissociation, atomic hydrogen participates in the reactions with furfural. The simulations also provide detailed information about the possible reactions of hydrogen with furfural. Supported by DOE (DE-SC0004600). This research used the supercomputer resources of the XSEDE, the NERSC Center, and the Tandy Supercomputing Center.

  3. Solid acids as catalysts for the conversion of D-xylose, xylan and lignocellulosics into furfural in ionic liquid.

    PubMed

    Zhang, Luxin; Yu, Hongbing; Wang, Pan

    2013-05-01

    With the aim to develop an ecologically viable catalytic pathway for furfural production without the use of inorganic acids, H3PW12O40, Amberlyst-5 and NKC-9 (macroporous styrene-based sulfonic acid resin) were used as catalysts for producing furfural from xylose, xylan and lignocellulosic biomass in [BMIM]Cl under microwave irradiation at atmospheric pressure. A surprisingly high furfural yield of 93.7% from xylan was obtained by H3PW12O40 at 160 °C in 10 min. The degradation of furfural affected by single addition of [BMIM]Cl and solid acids was also investigated. The IL could be easily recycled and reused with stable solvent capacity for multiple runs (5×) after the product furfural was extracted with ethyl acetate.

  4. Solid acids as catalysts for the conversion of D-xylose, xylan and lignocellulosics into furfural in ionic liquid.

    PubMed

    Zhang, Luxin; Yu, Hongbing; Wang, Pan

    2013-05-01

    With the aim to develop an ecologically viable catalytic pathway for furfural production without the use of inorganic acids, H3PW12O40, Amberlyst-5 and NKC-9 (macroporous styrene-based sulfonic acid resin) were used as catalysts for producing furfural from xylose, xylan and lignocellulosic biomass in [BMIM]Cl under microwave irradiation at atmospheric pressure. A surprisingly high furfural yield of 93.7% from xylan was obtained by H3PW12O40 at 160 °C in 10 min. The degradation of furfural affected by single addition of [BMIM]Cl and solid acids was also investigated. The IL could be easily recycled and reused with stable solvent capacity for multiple runs (5×) after the product furfural was extracted with ethyl acetate. PMID:23567725

  5. 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.

  6. Polyoxometalates as efficient catalysts for transformations of cellulose into platform chemicals.

    PubMed

    Deng, Weiping; Zhang, Qinghong; Wang, Ye

    2012-09-01

    Efficient utilisation of renewable biomass resources, particularly lignocellulosic biomass, for the production of chemicals and fuels has attracted much attention in recent years. The catalytic conversion of cellulose, the main component of lignocellulosic biomass, selectively into a platform chemical such as glucose, 5-hydroxymethyl furfural (HMF), sorbitol or gluconic acid under mild conditions is the most desirable route. Acid catalysis plays a crucial role in the conversion of cellulose via the cleavage of its glycosidic bonds. Owing to their unique features such as strong acidity, water-tolerance, low corrosiveness and recoverability, polyoxometalates have shown promising performances in transformations of cellulose into platform chemicals both in homogeneous and heterogeneous systems. This article highlights recent studies on polyoxometalates and polyoxometalate-based bifunctional catalysts or catalytic systems for the selective conversions of cellulose and cellobiose, a model molecule of cellulose, into platform chemicals. PMID:22653050

  7. 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. PMID:25549134

  8. 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.

  9. 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.

  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. 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%. PMID:27380022

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

    NASA Astrophysics Data System (ADS)

    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.

    2015-12-01

    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.

  13. Conversion of xylose into furfural using lignosulfonic acid as catalyst in ionic liquid.

    PubMed

    Wu, Changyan; Chen, Wei; Zhong, Linxin; Peng, Xinwen; Sun, Runcang; Fang, Junjie; Zheng, Shaobo

    2014-07-30

    Preparation of biopolymer-based catalysts for the conversion of carbohydrate polymers to new energies and chemicals is a hot topic nowadays. With the aim to develop an ecological method to convert xylose into furfural without the use of inorganic acids, a biopolymer-derived catalyst (lignosulfonic acid) was successfully used to catalyze xylose into furfural in ionic acid ([BMIM]Cl). The characteristics of lignosulfonic acid (LS) and effects of solvents, temperature, reaction time, and catalyst loading on the conversion of xylose were investigated in detail, and the reusability of the catalytic system was also studied. Results showed that 21.0% conversion could be achieved at 100 °C for 1.5 h. The method not only avoids pollution from conventional mineral acid catalysts and organic liquids but also maked full use of a byproduct (lignin) from the pulp and paper industry, thus demonstrating an environmentally benign process for the conversion of carbohydrates into furfural.

  14. Pretreatment of furfural industrial wastewater by Fenton, electro-Fenton and Fe(II)-activated peroxydisulfate processes: a comparative study.

    PubMed

    Yang, C W; Wang, D; Tang, Q

    2014-01-01

    The Fenton, electro-Fenton and Fe(II)-activated peroxydisulfate (PDS) processes have been applied for the treatment of actual furfural industrial wastewater in this paper. Through the comparative study of the three processes, a suitable pretreatment technology for actual furfural wastewater treatment was obtained, and the mechanism and dynamics process of this technology is discussed. The experimental results show that Fenton technology has a good and stable effect without adjusting pH of furfural wastewater. At optimal conditions, which were 40 mmol/L H₂O₂ initial concentration and 10 mmol/L Fe²⁺ initial concentration, the chemical oxygen demand (COD) removal rate can reach 81.2% after 90 min reaction at 80 °C temperature. The PDS process also has a good performance. The COD removal rate could attain 80.3% when Na₂S₂O₈ initial concentration was 4.2 mmol/L, Fe²⁺ initial concentration was 0.1 mol/L, the temperature remained at 70 °C, and pH value remained at 2.0. The electro-Fenton process was not competent to deal with the high-temperature furfural industrial wastewater and only 10.2% COD was degraded at 80 °C temperature in the optimal conditions (2.25 mA/cm² current density, 4 mg/L Na₂SO₄, 0.3 m³/h aeration rate). For the Fenton, electro-Fenton and PDS processes in pretreatment of furfural wastewater, their kinetic processes follow the pseudo first order kinetics law. The pretreatment pathways of furfural wastewater degradation are also investigated in this study. The results show that furfural and furan formic acid in furfural wastewater were preferentially degraded by Fenton technology. Furfural can be degraded into low-toxicity or nontoxic compounds by Fenton pretreatment technology, which could make furfural wastewater harmless and even reusable.

  15. Insertion of transposon in the vicinity of SSK2 confers enhanced tolerance to furfural in Saccharomyces cerevisiae.

    PubMed

    Kim, Hyun-Soo; Kim, Na-Rae; Kim, Wankee; Choi, Wonja

    2012-07-01

    Furfural is one of the major inhibitors generated during sugar production from cellulosic materials and, as an aldehyde, inhibits various cellular activities of microorganisms used, leading to prolonged lag time during ethanologenic fermentation. Since Saccharomyces cerevisiae strains tolerant to furfural are of great economic benefit in producing bioethanol, much effort to obtain more efficient strains continues to be made. In this study, we examined the furfural tolerance of transposon mutant strains (Tn 1-5) with enhanced ethanol tolerance and found that one of them (Tn 2), in which SSK2 is downregulated at the transcriptional level, displayed improved furfural tolerance. Such phenotype was abolished by complementation of the entire open reading frame of SSK2, which encodes a mitogen-activated protein (MAP) kinase kinase kinase of the high osmolarity glycerol (HOG) signaling pathway, suggesting an inhibitory effect of SSK2 in coping with furfural stress. Tn 2 showed a significant decrease in the intracellular level of reactive oxygen species (ROS) and early and high activation of Hog1p, a MAP kinase integral to the HOG pathway in response to furfural. The transcriptional levels of CTT1 and GLR1, two of known Hog1p downstream target genes whose protein products are involved in reducing ROS, were increased by 43 % and 56 % respectively compared with a control strain, probably resulting in the ROS decrease. Tn 2 also showed a shortened lag time during fermentation in the presence of furfural, resulting from efficient conversion of furfural to non-toxic (or less toxic) furfuryl alcohol. Taken together, the enhanced furfural tolerance of Tn 2 is suggested to be conferred by the combined effect of an early event of less ROS accumulation and a late event of efficient detoxification of furfural.

  16. 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.

  17. 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.

  18. One-step Conversion of Furfural into 2-Methyltetrahydrofuran under Mild Conditions.

    PubMed

    Dong, Fang; Zhu, Yulei; Ding, Guoqiang; Cui, Jinglei; Li, Xianqing; Li, Yongwang

    2015-05-11

    One-step direct conversion of biomass-derived furfural to 2-methyltetrahydrofuran was realized under atmospheric pressure over a dual solid catalyst based on two-stage-packed Cu-Pd in a reactor; this is the first report that one-step conversion of furfural resulted in high yield of 2-methyltetrahydrofuran (97.1 %) under atmospheric pressure. This strategy provided a successive hydrogenation process, which avoids high H2 pressure, uses the reactor efficiently, and eliminates the product-separation step. Therefore, it could enhance the overall efficiency as a result of low cost and high yield. PMID:25873007

  19. One-step Conversion of Furfural into 2-Methyltetrahydrofuran under Mild Conditions.

    PubMed

    Dong, Fang; Zhu, Yulei; Ding, Guoqiang; Cui, Jinglei; Li, Xianqing; Li, Yongwang

    2015-05-11

    One-step direct conversion of biomass-derived furfural to 2-methyltetrahydrofuran was realized under atmospheric pressure over a dual solid catalyst based on two-stage-packed Cu-Pd in a reactor; this is the first report that one-step conversion of furfural resulted in high yield of 2-methyltetrahydrofuran (97.1 %) under atmospheric pressure. This strategy provided a successive hydrogenation process, which avoids high H2 pressure, uses the reactor efficiently, and eliminates the product-separation step. Therefore, it could enhance the overall efficiency as a result of low cost and high yield.

  20. Formation of degradation compounds from lignocellulosic biomass in the biorefinery: sugar reaction mechanisms.

    PubMed

    Rasmussen, Helena; Sørensen, Hanne R; Meyer, Anne S

    2014-02-19

    The degradation compounds formed during pretreatment when lignocellulosic biomass is processed to ethanol or other biorefinery products include furans, phenolics, organic acids, as well as mono- and oligomeric pentoses and hexoses. Depending on the reaction conditions glucose can be converted to 5-(hydroxymethyl)-2-furaldehyde (HMF) and/or levulinic acid, formic acid and different phenolics at elevated temperatures. Correspondingly, xylose can follow different reaction mechanisms resulting in the formation of furan-2-carbaldehyde (furfural) and/or various C-1 and C-4 compounds. At least four routes for the formation of HMF from glucose and three routes for furfural formation from xylose are possible. In addition, new findings show that biomass monosaccharides themselves can react further to form pseudo-lignin and humins as well as a wide array of other compounds when exposed to high temperatures. Hence, several aldehydes and ketones and many different organic acids and aromatic compounds may be generated during hydrothermal treatment of lignocellulosic biomass. The reaction mechanisms are of interest because the very same compounds that are possible inhibitors for biomass processing enzymes and microorganisms may be valuable biobased chemicals. Hence a new potential for industrial scale synthesis of chemicals has emerged. A better understanding of the reaction mechanisms and the impact of the reaction conditions on the product formation is thus a prerequisite for designing better biomass processing strategies and forms an important basis for the development of new biorefinery products from lignocellulosic biomass as well. PMID:24412507

  1. Effect of inhibitors released during steam-explosion treatment of poplar wood on subsequent enzymatic hydrolysis and SSF.

    PubMed

    Cantarella, Maria; Cantarella, Laura; Gallifuoco, Alberto; Spera, Agata; Alfani, Francesco

    2004-01-01

    Steam-exploded (SE) poplar wood biomass was hydrolyzed by means of a blend of Celluclast and Novozym cellulase complexes in the presence of the inhibiting compounds produced during the preceding steam-explosion pretreatment process. The SE temperature and time conditions were 214 degrees C and 6 min, resulting in a log R(0) of 4.13. In enzymatic hydrolysis tests at 45 degrees C, the biomass loading in the bioreactor was 100 g(DW)/L (dry weight) and the enzyme-to-biomass ratio 0.06 g/g(DW). The enzyme activities for endo-glucanase, exo-glucanase, and beta-glucosidase were 5.76, 0.55, and 5.98 U/mg, respectively. The inhibiting effects of components released during SE (formic, acetic, and levulinic acids, furfural, 5-hydroxymethyl furfural (5-HMF), syringaldehyde, 4-hydroxy benzaldehyde, and vanillin) were studied at different concentrations in hydrolysis runs performed with rinsed SE biomass as model substrate. Acetic acid (2 g/L), furfural, 5-HMF, syringaldehyde, 4-hydroxybenzaldehyde, and vanillin (0.5 g/L) did not significantly effect the enzyme activity, whereas formic acid (11.5 g/L) inactivated the enzymes and levulinic acid (29.0 g/L) partially affected the cellulase. Synergism and cumulative concentration effects of these compounds were not detected. SSF experiments show that untreated SE biomass during the enzymatic attack gives rise to a nonfermentable hydrolysate, which becomes fermentable when rinsed SE biomass is used. The presence of acetic acid, vanillin, and 5-HMF (0.5 g/L) in SSF of 100 g(DW) /L biomass gave rise to ethanol yields of 84.0%, 73.5%, and 91.0% respectively, with respective lag phases of 42, 39, and 58 h.

  2. Increase in furfural tolerance in ethanologenic Escherichia coli LY180 by plasmid-based expression of thyA.

    PubMed

    Zheng, Huabao; Wang, Xuan; Yomano, Lorraine P; Shanmugam, Keelnatham T; Ingram, Lonnie O

    2012-06-01

    Furfural is an inhibitory side product formed during the depolymerization of hemicellulose by mineral acids. Genomic libraries from three different bacteria (Bacillus subtilis YB886, Escherichia coli NC3, and Zymomonas mobilis CP4) were screened for genes that conferred furfural resistance on plates. Beneficial plasmids containing the thyA gene (coding for thymidylate synthase) were recovered from all three organisms. Expression of this key gene in the de novo pathway for dTMP biosynthesis improved furfural resistance on plates and during fermentation. A similar benefit was observed by supplementation with thymine, thymidine, or the combination of tetrahydrofolate and serine (precursors for 5,10-methylenetetrahydrofolate, the methyl donor for ThyA). Supplementation with deoxyuridine provided a small benefit, and deoxyribose was of no benefit for furfural tolerance. A combination of thymidine and plasmid expression of thyA was no more effective than either alone. Together, these results demonstrate that furfural tolerance is increased by approaches that increase the supply of pyrimidine deoxyribonucleotides. However, ThyA activity was not directly affected by the addition of furfural. Furfural has been previously shown to damage DNA in E. coli and to activate a cellular response to oxidative damage in yeast. The added burden of repairing furfural-damaged DNA in E. coli would be expected to increase the cellular requirement for dTMP. Increased expression of thyA (E. coli, B. subtilis, or Z. mobilis), supplementation of cultures with thymidine, and supplementation with precursors for 5,10-methylenetetrahydrofolate (methyl donor) are each proposed to increase furfural tolerance by increasing the availability of dTMP for DNA repair.

  3. Liquid-Phase Catalytic Transfer Hydrogenation of Furfural over Homogeneous Lewis Acid-Ru/C Catalysts.

    PubMed

    Panagiotopoulou, Paraskevi; Martin, Nickolas; Vlachos, Dionisios G

    2015-06-22

    The catalytic performance of homogeneous Lewis acid catalysts and their interaction with Ru/C catalyst are studied in the catalytic transfer hydrogenation of furfural by using 2-propanol as a solvent and hydrogen donor. We find that Lewis acid catalysts hydrogenate the furfural to furfuryl alcohol, which is then etherified with 2-propanol. The catalytic activity is correlated with an empirical scale of Lewis acid strength and exhibits a volcano behavior. Lanthanides are the most active, with DyCl3 giving complete furfural conversion and a 97 % yield of furfuryl alcohol at 180 °C after 3 h. The combination of Lewis acid and Ru/C catalysts results in synergy for the stronger Lewis acid catalysts, with a significant increase in the furfural conversion and methyl furan yield. Optimum results are obtained by using Ru/C combined with VCl3 , AlCl3 , SnCl4 , YbCl3 , and RuCl3 . Our results indicate that the combination of Lewis acid/metal catalysts is a general strategy for performing tandem reactions in the upgrade of furans.

  4. 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...

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

    PubMed

    Chang, Fei; Dutta, Saikat; Becnel, James J; Estep, Alden S; Mascal, Mark

    2014-01-15

    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-based pyrethroids against the yellow fever mosquito Aedes aegypti indicates promising insecticidal activities.

  6. 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.

  7. 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.

  8. Physicochemical pretreatments and hydrolysis of furfural residues via carbon-based sulfonated solid acid.

    PubMed

    Ma, Bao Jun; Sun, Yuan; Lin, Ke Ying; Li, Bing; Liu, Wan Yi

    2014-03-01

    Potential commercial physicochemical pretreatment methods, NaOH/microwave and NaOH/ultrasound were developed, and the carbon-based sulfonated solid acid catalysts were prepared for furfural residues conversion into reducing sugars. After the two optimum pretreatments, both the content of cellulose increased (74.03%, 72.28%, respectively) and the content of hemicellulose (94.11%, 94.17% of removal rate, respectively) and lignin (91.75%, 92.09% of removal rate, respectively) decreased in furfural residues. The reducing sugar yields of furfural residues with the two physicochemical pretreatments on coal tar-based solid acid reached 33.94% and 33.13%, respectively, higher than that pretreated via NaOH alone (27%) and comparable to that pretreated via NaOH/H2O2 (35.67%). The XRD patterns, IR spectra and SEM images show microwave and ultrasound improve the pretreatment effect. The results demonstrate the carbon-based sulfonated solid acids and the physicochemical pretreatments are green, effective, low-cost for furfural residues conversion.

  9. Biomass conversion to high value chemicals: from furfural to chiral hydrofuroins in two steps.

    PubMed

    Kabro, Anzhelika; Escudero-Adán, Eduardo C; Grushin, Vladimir V; van Leeuwen, Piet W N M

    2012-08-01

    Catalytic asymmetric transfer hydrogenation of rac-furoin and furil produces hydrofuroin with up to 99% ee and 9:1 dr. This reaction provides an exceptionally easy access to optically active hydrofuroins in two straightforward steps from biomass-derived furfural (global production 200,000-300,000 t annually) using benzoin condensation. PMID:22831386

  10. Acid-catalyzed conversion of xylose, xylan and straw into furfural by microwave-assisted reaction.

    PubMed

    Yemiş, Oktay; Mazza, Giuseppe

    2011-08-01

    Furfural is a biomass derived-chemical that can be used to replace petrochemicals. In this study, the acid-catalyzed conversion of xylose and xylan to furfural by microwave-assisted reaction was investigated at selected ranges of temperature (140-190°C), time (1-30 min), substrate concentration (1:5-1:200 solid:liquid ratio), and pH (2-0.13). We found that a temperature of 180°C, a solid:liquid ratio of 1:200, a residence time of 20 min, and a pH of 1.12 gave the best furfural yields. The effect of different Brønsted acids on the conversion efficiency of xylose and xylan was also evaluated, with hydrochloric acid being found to be the most effective catalyst. The microwave-assisted process provides highly efficient conversion: furfural yields obtained from wheat straw, triticale straw, and flax shives were 48.4%, 45.7%, and 72.1%, respectively. PMID:21620690

  11. Furfural reduction mechanism of a zinc-dependent alcohol dehydrogenase from Cupriavidus necator JMP134

    PubMed Central

    Kang, ChulHee; Hayes, Robert; Sanchez, Emiliano J.; Webb, Brian N.; Li, Qunrui; Hooper, Travis; Nissen, Mark S.; Xun, Luying

    2012-01-01

    Summary FurX is a tetrameric Zn-dependent alcohol dehydrogenase (ADH) from Cupriavidus necator JMP134. The enzyme rapidly reduces furfural with NADH as the reducing power. For the first time among characterized ADHs, the high-resolution structures of all reaction steps were obtained in a time-resolved manner, thereby illustrating the complete catalytic events of NADH-dependent reduction of furfural and the dynamic Zn2+ coordination among Glu66, water, substrate and product. In the fully closed conformation of the NADH complex, the catalytic turnover proved faster than observed for the partially closed conformation due to an effective proton transfer network. The domain motion triggered by NAD(H) association/dissociation appeared to facilitate dynamic interchanges in Zn2+ coordination with substrate and product molecules, ultimately increasing the enzymatic turnover rate. NAD+ dissociation appeared to be a slow process, involving multiple steps in concert with a domain opening and reconfiguration of Glu66. This agrees with the report that the cofactor is not dissociated from FurX during ethanol-dependent reduction of furfural, in which ethanol reduces NAD+ to NADH that is subsequently used for furfural reduction. PMID:22081946

  12. 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

  13. 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.

  14. Theoretical Elucidation of Glucose Dehydration to 5-Hydroxymethylfurfural Catalyzed by a SO3H-Functionalized Ionic Liquid.

    PubMed

    Li, Jingjing; Li, Jinghua; Zhang, Dongju; Liu, Chengbu

    2015-10-22

    While the catalytic conversion of glucose to 5-hydroxymethyl furfural (HMF) catalyzed by SO3H-functioned ionic liquids (ILs) has been achieved successfully, the relevant molecular mechanism is still not understood well. Choosing 1-butyl-3-methylimidazolium chloride [C4SO3HmimCl] as a representative of SO3H-functioned IL, this work presents a density functional theory (DFT) study on the catalytic mechanism for conversion of glucose into HMF. It is found that the conversion may proceed via two potential pathways and that throughout most of elementary steps, the cation of the IL plays a substantial role, functioning as a proton shuttle to promote the reaction. The chloride anion interacts with the substrate and the acidic proton in the imidazolium ring via H-bonding, as well as provides a polar environment together with the imidazolium cation to stabilize intermediates and transition states. The calculated overall barriers of the catalytic conversion along two potential pathways are 32.9 and 31.0 kcal/mol, respectively, which are compatible with the observed catalytic performance of the IL under mild conditions (100 °C). The present results provide help for rationalizing the effective conversion of glucose to HMF catalyzed by SO3H-functionalized ILs and for designing IL catalysts used in biomass conversion chemistry. PMID:26434955

  15. Production of hybrid diesel fuel precursors from carbohydrates and petrochemicals using formic acid as a reactive solvent.

    PubMed

    Zhou, Xiaoyuan; Rauchfuss, Thomas B

    2013-02-01

    We report the one-pot alkylation of mesitylene with carbohydrate-derived 5-(hydroxymethyl)furfural (HMF) as a step toward diesel-range liquids. Using FeCl(3) as a catalyst, HMF is shown to alkylate toluene, xylene, and mesitylene in high yields in CH(2)Cl(2) and MeNO(2) solvents. Efforts to extend this reaction to greener or safer solvents showed that most ether-based solvents are unsatisfactory. Acid catalysts (e.g, p-TsOH) also proved to be ineffective. Using formic acid as a reactive solvent, mesitylene could be alkylated to give mesitylmethylfurfural (MMF) starting from fructose with yields up to approximately 70 %. The reaction of fructose with formic acid in the absence of mesitylene gave rise to low yields of the formate ester of HMF, which indicates the stabilizing effect of replacing the hydroxyl substituent with mesityl. The arene also serves as a second phase into which the product is extracted. Even by using formic acid, the mesitylation of less expensive precursors such as glucose and cellulose proceeded only in modest yields (ca. 20 %). These simpler substrates were found to undergo mesitylation by using hydrogen chloride/formic acid via the intermediate chloromethylfurfural. PMID:23281330

  16. Production of hybrid diesel fuel precursors from carbohydrates and petrochemicals using formic acid as a reactive solvent.

    PubMed

    Zhou, Xiaoyuan; Rauchfuss, Thomas B

    2013-02-01

    We report the one-pot alkylation of mesitylene with carbohydrate-derived 5-(hydroxymethyl)furfural (HMF) as a step toward diesel-range liquids. Using FeCl(3) as a catalyst, HMF is shown to alkylate toluene, xylene, and mesitylene in high yields in CH(2)Cl(2) and MeNO(2) solvents. Efforts to extend this reaction to greener or safer solvents showed that most ether-based solvents are unsatisfactory. Acid catalysts (e.g, p-TsOH) also proved to be ineffective. Using formic acid as a reactive solvent, mesitylene could be alkylated to give mesitylmethylfurfural (MMF) starting from fructose with yields up to approximately 70 %. The reaction of fructose with formic acid in the absence of mesitylene gave rise to low yields of the formate ester of HMF, which indicates the stabilizing effect of replacing the hydroxyl substituent with mesityl. The arene also serves as a second phase into which the product is extracted. Even by using formic acid, the mesitylation of less expensive precursors such as glucose and cellulose proceeded only in modest yields (ca. 20 %). These simpler substrates were found to undergo mesitylation by using hydrogen chloride/formic acid via the intermediate chloromethylfurfural.

  17. Catalytic conversion of xylose and corn stalk into furfural over carbon solid acid catalyst in γ-valerolactone.

    PubMed

    Zhang, Tingwei; Li, Wenzhi; Xu, Zhiping; Liu, Qiyu; Ma, Qiaozhi; Jameel, Hasan; Chang, Hou-min; Ma, Longlong

    2016-06-01

    A novel carbon solid acid catalyst was synthesized by the sulfonation of carbonaceous material which was prepared by carbonization of sucrose using 4-BDS as a sulfonating agent. TEM, N2 adsorption-desorption, elemental analysis, XPS and FT-IR were used to characterize the catalyst. Then, the catalyst was applied for the conversion of xylose and corn stalk into furfural in GVL. The influence of the reaction time, temperature and dosage of catalyst on xylose dehydration were also investigated. The Brønsted acid catalyst exhibited high activity in the dehydration of xylose, with a high furfural yield of 78.5% at 170°C in 30min. What's more, a 60.6% furfural yield from corn stalk was achieved in 100min at 200°C. The recyclability of the sulfonated carbon catalyst was perfect, and it could be reused for 5times without the loss of furfural yields. PMID:26967333

  18. Catalytic conversion of xylose and corn stalk into furfural over carbon solid acid catalyst in γ-valerolactone.

    PubMed

    Zhang, Tingwei; Li, Wenzhi; Xu, Zhiping; Liu, Qiyu; Ma, Qiaozhi; Jameel, Hasan; Chang, Hou-min; Ma, Longlong

    2016-06-01

    A novel carbon solid acid catalyst was synthesized by the sulfonation of carbonaceous material which was prepared by carbonization of sucrose using 4-BDS as a sulfonating agent. TEM, N2 adsorption-desorption, elemental analysis, XPS and FT-IR were used to characterize the catalyst. Then, the catalyst was applied for the conversion of xylose and corn stalk into furfural in GVL. The influence of the reaction time, temperature and dosage of catalyst on xylose dehydration were also investigated. The Brønsted acid catalyst exhibited high activity in the dehydration of xylose, with a high furfural yield of 78.5% at 170°C in 30min. What's more, a 60.6% furfural yield from corn stalk was achieved in 100min at 200°C. The recyclability of the sulfonated carbon catalyst was perfect, and it could be reused for 5times without the loss of furfural yields.

  19. Catalytic conversion of furfural into a 2,5-furandicarboxylic acid-based polyester with total carbon utilization.

    PubMed

    Pan, Tao; Deng, Jin; Xu, Qing; Zuo, Yong; Guo, Qing-Xiang; Fu, Yao

    2013-01-01

    One divided into two combined into one: The catalytic conversion of furfural into a 2,5-furandicarboxylic acid-based polyester, linked by the disproportionation of furoate to furan and 2,5-furandicarboxylate, is reported. In this manner, all carbons are utilized, demonstrating the success of combining a platform molecule from C(5) sugars (furfural) to one from C(6) sugars (2,5-FDCA). PMID:23239596

  20. Production of furfural from xylose, xylan and corncob in gamma-valerolactone using FeCl3·6H2O as catalyst.

    PubMed

    Zhang, Luxin; Yu, Hongbing; Wang, Pan; Li, Yong

    2014-01-01

    An efficient and simple one-pot monophasic reaction system with small carbon footprint for converting xylose, xylan and corncob into furfural was developed in gamma-valerolactone (GVL, an ideal sustainable solvent derived from lignocelluloses) by using FeCl3·6H2O as catalyst. Good yields of furfural from xylose were obtained, and the system was shown to work for xylan and corncob as well. A surprisingly high furfural yield of 79.6% from untreated corncob was achieved at 458 K for 100 min. Contrary to what was generally believed, the addition of water, reduced the rate of the reactions, but showed positive effect on preventing the furfural from degradation in GVL. Besides, the C6 sugars (glucose and cellulose) afforded 11.4-24.5% furfural yields when employing this catalytic approach. The reaction system proposed in this manuscript showed great potential for optimizing the catalytic process in furfural production.

  1. Silencing of NADPH-dependent oxidoreductase genes (yqhD and dkgA) in furfural-resistant ethanologenic Escherichia coli.

    PubMed

    Miller, E N; Jarboe, L R; Yomano, L P; York, S W; Shanmugam, K T; Ingram, L O

    2009-07-01

    Low concentrations of furfural are formed as a side product during the dilute acid hydrolysis of hemicellulose. Growth is inhibited by exposure to furfural but resumes after the complete reduction of furfural to the less toxic furfuryl alcohol. Growth-based selection was used to isolate a furfural-resistant mutant of ethanologenic Escherichia coli LY180, designated strain EMFR9. Based on mRNA expression levels in the parent and mutant in response to furfural challenge, genes encoding 12 oxidoreductases were found to vary by more than twofold (eight were higher in EMFR9; four were higher in the parent). All 12 genes were cloned. When expressed from plasmids, none of the eight genes in the first group increased furfural tolerance in the parent (LY180). Expression of three of the silenced genes (yqhD, dkgA, and yqfA) in EMFR9 was found to decrease furfural tolerance compared to that in the parent. Purified enzymes encoded by yqhD and dkgA were shown to have NADPH-dependent furfural reductase activity. Both exhibited low K(m) values for NADPH (8 microM and 23 microM, respectively), similar to those of biosynthetic reactions. Furfural reductase activity was not associated with yqfA. Deleting yqhD and dkgA in the parent (LY180) increased furfural tolerance, but not to the same extent observed in the mutant EMFR9. Together, these results suggest that the process of reducing furfural by using an enzyme with a low K(m) for NADPH rather than a direct inhibitory action is the primary cause for growth inhibition by low concentrations of furfural.

  2. Increased furfural tolerance due to overexpression of NADH-dependent oxidoreductase FucO in Escherichia coli strains engineered for the production of ethanol and lactate.

    PubMed

    Wang, X; Miller, E N; Yomano, L P; Zhang, X; Shanmugam, K T; Ingram, L O

    2011-08-01

    Furfural is an important fermentation inhibitor in hemicellulose sugar syrups derived from woody biomass. The metabolism of furfural by NADPH-dependent oxidoreductases, such as YqhD (low K(m) for NADPH), is proposed to inhibit the growth and fermentation of xylose in Escherichia coli by competing with biosynthesis for NADPH. The discovery that the NADH-dependent propanediol oxidoreductase (FucO) can reduce furfural provided a new approach to improve furfural tolerance. Strains that produced ethanol or lactate efficiently as primary products from xylose were developed. These strains included chromosomal mutations in yqhD expression that permitted the fermentation of xylose broths containing up to 10 mM furfural. Expression of fucO from plasmids was shown to increase furfural tolerance by 50% and to permit the fermentation of 15 mM furfural. Product yields with 15 mM furfural were equivalent to those of control strains without added furfural (85% to 90% of the theoretical maximum). These two defined genetic traits can be readily transferred to enteric biocatalysts designed to produce other products. A similar strategy that minimizes the depletion of NADPH pools by native detoxification enzymes may be generally useful for other inhibitory compounds in lignocellulosic sugar streams and with other organisms.

  3. Resistance of Saccharomyces cerevisiae to high concentrations of furfural is based on NADPH-dependent reduction by at least two oxireductases.

    PubMed

    Heer, Dominik; Heine, Daniel; Sauer, Uwe

    2009-12-01

    Biofuels derived from lignocellulosic biomass hold promises for a sustainable fuel economy, but several problems hamper their economical feasibility. One important problem is the presence of toxic compounds in processed lignocellulosic hydrolysates, with furfural as a key toxin. While Saccharomyces cerevisiae has some intrinsic ability to reduce furfural to the less-toxic furfuryl alcohol, higher resistance is necessary for process conditions. By comparing an evolved, furfural-resistant strain and its parent in microaerobic, glucose-limited chemostats at increasing furfural challenge, we elucidate key mechanism and the molecular basis of both natural and high-level furfural resistance. At lower concentrations of furfural, NADH-dependent oxireductases are the main defense mechanism. At furfural concentrations above 15 mM, however, (13)C-flux and global array-based transcript analysis demonstrated that the NADPH-generating flux through the pentose phosphate pathway increases and that NADPH-dependent oxireductases become the major resistance mechanism. The transcript analysis further revealed that iron transmembrane transport is upregulated in response to furfural. While these responses occur in both strains, high-level resistance in the evolved strain was based on strong induction of ADH7, the uncharacterized open reading frame (ORF) YKL071W, and four further, likely NADPH-dependent, oxireductases. By overexpressing the ADH7 gene and the ORF YKL071W, we inversely engineered significantly increased furfural resistance in the parent strain, thereby demonstrating that these two enzymes are key elements of the resistance phenotype.

  4. Increased furfural tolerance due to overexpression of NADH-dependent oxidoreductase FucO in Escherichia coli strains engineered for the production of ethanol and lactate.

    PubMed

    Wang, X; Miller, E N; Yomano, L P; Zhang, X; Shanmugam, K T; Ingram, L O

    2011-08-01

    Furfural is an important fermentation inhibitor in hemicellulose sugar syrups derived from woody biomass. The metabolism of furfural by NADPH-dependent oxidoreductases, such as YqhD (low K(m) for NADPH), is proposed to inhibit the growth and fermentation of xylose in Escherichia coli by competing with biosynthesis for NADPH. The discovery that the NADH-dependent propanediol oxidoreductase (FucO) can reduce furfural provided a new approach to improve furfural tolerance. Strains that produced ethanol or lactate efficiently as primary products from xylose were developed. These strains included chromosomal mutations in yqhD expression that permitted the fermentation of xylose broths containing up to 10 mM furfural. Expression of fucO from plasmids was shown to increase furfural tolerance by 50% and to permit the fermentation of 15 mM furfural. Product yields with 15 mM furfural were equivalent to those of control strains without added furfural (85% to 90% of the theoretical maximum). These two defined genetic traits can be readily transferred to enteric biocatalysts designed to produce other products. A similar strategy that minimizes the depletion of NADPH pools by native detoxification enzymes may be generally useful for other inhibitory compounds in lignocellulosic sugar streams and with other organisms. PMID:21685167

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Malassezia furfur: a fungus belonging to the physiological skin flora and its relevance in skin disorders.

    PubMed

    Schmidt, A

    1997-01-01

    Malassezia furfur is an anthropophilic fungus that belongs to the physiological skin flora. The fungus can grow in a yeast phase as well as in a mycelial phase; on nonaffected skin the fungus is mainly prevalent in the yeast phase. The organism has complex lipid requirements for growth, which also explains its occurrence on the skin. This also leads to the requirement for specially supplemented media for in vitro cultivation. Malassezia furfur is the causative agent of pityriasis versicolor. It also seems to be associated with seborrheic dermatitis and dandruff formation, folliculitis, confluent and reticulate papillomatosis, and the provocation of psoriatic lesions. Many substances for topical application, such as azole antimycotics, ciclopirox olamine, piroctone-olamine, zinc pyrithione, or sulfur-containing substances are effective in the treatment of these diseases. In recent years rare cases of systemic infections and fungemias caused by Malassezia have been reported. PMID:9013067

  14. Furfural Synthesis from d-Xylose in the Presence of Sodium Chloride: Microwave versus Conventional Heating.

    PubMed

    Xiouras, Christos; Radacsi, Norbert; Sturm, Guido; Stefanidis, Georgios D

    2016-08-23

    We investigate the existence of specific/nonthermal microwave effects for the dehydration reaction of xylose to furfural in the presence of NaCl. Such effects are reported for sugars dehydration reactions in several literature reports. To this end, we adopted three approaches that compare microwave-assisted experiments with a) conventional heating experiments from the literature; b) simulated conventional heating experiments using microwave-irradiated silicon carbide (SiC) vials; and at c) different power levels but the same temperature by using forced cooling. No significant differences in the reaction kinetics are observed using any of these methods. However, microwave heating still proves advantageous as it requires 30 % less forward power compared to conventional heating (SiC vial) to achieve the same furfural yield at a laboratory scale. PMID:27416892

  15. Comparison of genome-wide selection strategies to identify furfural tolerance genes in Escherichia coli.

    PubMed

    Glebes, Tirzah Y; Sandoval, Nicholas R; Gillis, Jacob H; Gill, Ryan T

    2015-01-01

    Engineering both feedstock and product tolerance is important for transitioning towards next-generation biofuels derived from renewable sources. Tolerance to chemical inhibitors typically results in complex phenotypes, for which multiple genetic changes must often be made to confer tolerance. Here, we performed a genome-wide search for furfural-tolerant alleles using the TRackable Multiplex Recombineering (TRMR) method (Warner et al. (2010), Nature Biotechnology), which uses chromosomally integrated mutations directed towards increased or decreased expression of virtually every gene in Escherichia coli. We employed various growth selection strategies to assess the role of selection design towards growth enrichments. We also compared genes with increased fitness from our TRMR selection to those from a previously reported genome-wide identification study of furfural tolerance genes using a plasmid-based genomic library approach (Glebes et al. (2014) PLOS ONE). In several cases, growth improvements were observed for the chromosomally integrated promoter/RBS mutations but not for the plasmid-based overexpression constructs. Through this assessment, four novel tolerance genes, ahpC, yhjH, rna, and dicA, were identified and confirmed for their effect on improving growth in the presence of furfural.

  16. Catalytic hydrothermal pretreatment of corncob into xylose and furfural via solid acid catalyst.

    PubMed

    Li, Huiling; Deng, Aojie; Ren, Junli; Liu, Changyu; Lu, Qi; Zhong, Linjie; Peng, Feng; Sun, Runcang

    2014-04-01

    Selectively catalytic hydrothermal pretreatment of corncob into xylose and furfural has been developed in this work using solid acid catalyst (SO4(2-)/TiO2-ZrO2/La(3+)). The effects of corncob-to-water ratio, reaction temperature and residence time on the performance of catalytic hydrothermal pretreatment were investigated. Results showed that the solid residues contained mainly lignin and cellulose, which was indicative of the efficient removal of hemicelluloses from corncob by hydrothermal method. The prepared catalyst with high thermal stability and strong acid sites originated from the acid functional groups was confirmed to contribute to the hydrolysis of polysaccharides into monosaccharides followed by dehydration into furfural. Highest furfural yield (6.18 g/100g) could be obtained at 180°C for 120 min with 6.80 g/100g xylose yield when the corncob/water ratio of was 10:100. Therefore, selectively catalytic hydrothermal pretreatment of lignocellulosic biomass into important platform chemicals by solid acids is considered to be a potential treatment for biodiesel and chemical production.

  17. 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.

  18. 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.

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

    PubMed Central

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

    2015-01-01

    Malassezia furfur yeast strains isolated from diseased human skin preferentially biosynthesize indole alkaloids which can be detected in 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 assays in recombinant cell lines derived from four different species, although significant species differences in relative potency was 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. Malassezia furfur produces an expanded collection of extremely potent naturally occurring AhR agonists, which produce their biological effects in a species-specific manner.1 PMID:25721496

  20. 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. PMID:19827026

  1. 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. PMID:21710859

  2. Improving Escherichia coli FucO for furfural tolerance by saturation mutagenesis of individual amino acid positions.

    PubMed

    Zheng, Huabao; Wang, Xuan; Yomano, Lorraine P; Geddes, Ryan D; Shanmugam, Keelnatham T; Ingram, Lonnie O

    2013-05-01

    Furfural is an inhibitory side product formed during the depolymerization of hemicellulose with mineral acids. In Escherichia coli, furfural tolerance can be increased by expressing the native fucO gene (encoding lactaldehyde oxidoreductase). This enzyme also catalyzes the NADH-dependent reduction of furfural to the less toxic alcohol. Saturation mutagenesis was combined with growth-based selection to isolate a mutated form of fucO that confers increased furfural tolerance. The mutation responsible, L7F, is located within the interfacial region of FucO homodimers, replacing the most abundant codon for leucine with the most abundant codon for phenylalanine. Plasmid expression of the mutant gene increased FucO activity by more than 10-fold compared to the wild-type fucO gene and doubled the rate of furfural metabolism during fermentation. No inclusion bodies were evident with either the native or the mutated gene. mRNA abundance for the wild-type and mutant fucO genes differed by less than 2-fold. The Km (furfural) for the mutant enzyme was 3-fold lower than that for the native enzyme, increasing efficiency at low substrate concentrations. The L7F mutation is located near the FucO N terminus, within the ribosomal binding region associated with translational initiation. Free-energy calculations for mRNA folding in this region (nucleotides -7 to +37) were weak for the native gene (-4.1 kcal mol(-1)) but weaker still for the fucO mutant (-1.0 to -0.1 kcal mol(-1)). The beneficial L7F mutation in FucO is proposed to increase furfural tolerance by improving gene expression and increasing enzyme effectiveness at low substrate levels.

  3. 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.

  4. 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

  5. [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.

  6. Direct transformation of xylan-type hemicelluloses to furfural via SnCl₄ catalysts in aqueous and biphasic systems.

    PubMed

    Wang, Wenju; Ren, Junli; Li, Huiling; Deng, Aojie; Sun, Runcang

    2015-05-01

    Direct catalytic transformation of xylan-type hemicelluloses to furfural in the aqueous system and the biphasic system were comparatively investigated under mild conditions. Screening of several promising chlorides for conversion of beech xylan in the aqueous system revealed the Lewis acid SnCl4 was the most effective catalyst. Comparing to the single aqueous system, the bio-based 2-methyltetrahydrofuran (2-MTHF)/H2O biphasic system was more conducive to the synthesis of furfural, in which the highest furfural yield of 78.1% was achieved by using SnCl4 as catalysts under the optimized reaction conditions (150°C, 120 min). Additionally, the influences of xylan-type hemicelluloses with different chemical and structural features from beech, corncob and bagasse on the furfural production were studied. It was found that furfural yield to some extent was determined by the xylose content in hemicelluloses and also had relationships with the molecular weight of hemicelluloses and the degree of crystallization.

  7. Selective conversion of furfural to maleic anhydride and furan with VO(x)/Al(2)O(3) catalysts.

    PubMed

    Alonso-Fagúndez, Noelia; Granados, Manuel López; Mariscal, Rafael; Ojeda, Manuel

    2012-10-01

    Furfural can be converted into maleic anhydride (73 % yield) through selective gas phase oxidation at 593 K with O(2) by using VO(x)/Al(2)O(3) (10 at(V) nm(-2)) as solid catalysts. The use of lower temperatures and/or O(2) pressures result in the additional formation of furan (maximum 9 % yield). Mechanistically, furfural (C(5)H(4)O(2)) is oxidized stepwise to furan (C(4)H(4)O), 2-furanone (C(4)H(4)O(2)), and finally, maleic anhydride (C(4)H(2)O(3)). The specific structure of the supported vanadium oxides and reaction conditions (temperature and reactants pressures) all influence furfural oxidation catalysis. We have found that Al(2)O(3)-supported polyvanadates are intrinsically more active (2.70 mmol h(-1) g-at V(-1)) than monovanadates (VO(4)) and V(2)O(5) crystals (0.89 and 0.70 mmol h(-1) g-at V(-1), respectively) in maleic anhydride and furan formation rates (553 K, 1.6 kPa furfural, 2.5 kPa O(2)). Our alternative approach enables the use of biomass instead of petroleum to synthesize maleic anhydride and furan from furfural. The potential variety of industrial applications is of enormous interest for the development of future biorefineries.

  8. 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.

  9. Selective conversion of furfural to maleic anhydride and furan with VO(x)/Al(2)O(3) catalysts.

    PubMed

    Alonso-Fagúndez, Noelia; Granados, Manuel López; Mariscal, Rafael; Ojeda, Manuel

    2012-10-01

    Furfural can be converted into maleic anhydride (73 % yield) through selective gas phase oxidation at 593 K with O(2) by using VO(x)/Al(2)O(3) (10 at(V) nm(-2)) as solid catalysts. The use of lower temperatures and/or O(2) pressures result in the additional formation of furan (maximum 9 % yield). Mechanistically, furfural (C(5)H(4)O(2)) is oxidized stepwise to furan (C(4)H(4)O), 2-furanone (C(4)H(4)O(2)), and finally, maleic anhydride (C(4)H(2)O(3)). The specific structure of the supported vanadium oxides and reaction conditions (temperature and reactants pressures) all influence furfural oxidation catalysis. We have found that Al(2)O(3)-supported polyvanadates are intrinsically more active (2.70 mmol h(-1) g-at V(-1)) than monovanadates (VO(4)) and V(2)O(5) crystals (0.89 and 0.70 mmol h(-1) g-at V(-1), respectively) in maleic anhydride and furan formation rates (553 K, 1.6 kPa furfural, 2.5 kPa O(2)). Our alternative approach enables the use of biomass instead of petroleum to synthesize maleic anhydride and furan from furfural. The potential variety of industrial applications is of enormous interest for the development of future biorefineries. PMID:22847991

  10. Direct transformation of xylan-type hemicelluloses to furfural via SnCl₄ catalysts in aqueous and biphasic systems.

    PubMed

    Wang, Wenju; Ren, Junli; Li, Huiling; Deng, Aojie; Sun, Runcang

    2015-05-01

    Direct catalytic transformation of xylan-type hemicelluloses to furfural in the aqueous system and the biphasic system were comparatively investigated under mild conditions. Screening of several promising chlorides for conversion of beech xylan in the aqueous system revealed the Lewis acid SnCl4 was the most effective catalyst. Comparing to the single aqueous system, the bio-based 2-methyltetrahydrofuran (2-MTHF)/H2O biphasic system was more conducive to the synthesis of furfural, in which the highest furfural yield of 78.1% was achieved by using SnCl4 as catalysts under the optimized reaction conditions (150°C, 120 min). Additionally, the influences of xylan-type hemicelluloses with different chemical and structural features from beech, corncob and bagasse on the furfural production were studied. It was found that furfural yield to some extent was determined by the xylose content in hemicelluloses and also had relationships with the molecular weight of hemicelluloses and the degree of crystallization. PMID:25742750

  11. 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).

  12. Screening of Yeasts for Selection of Potential Strains and Their Utilization for In Situ Microbial Detoxification (ISMD) of Sugarcane Bagasse Hemicellulosic Hydrolysate.

    PubMed

    Soares, Luma C S R; Chandel, Anuj K; Pagnocca, Fernando C; Gaikwad, Swapnil C; Rai, Mahendra; da Silva, Silvio S

    2016-06-01

    Many toxic compounds are produced and released in the hemicellulosic hydrolyzates during the acid pretreatment step, which are required for the disruption of the lignocelluloses matrix and sugars release. The conventional methods of detoxification i.e. overliming, activated charcoal, ion exchange or even membrane-based separations have the limitations in removal of these toxic inhibitors in fermentation process. Hence, it is imperative to explore biological methods to overcome the inhibitors by minimizing the filtration steps, sugar loss and chemical additions. In the present study we screened sixty-four strains of yeasts to select potential strains for detoxification of furfural, acetic acid, ferulic acid, 5-hydroxymethyl furfural (5-HMF) as carbon and energy source. Among these strains Pichia occidentalis M1, Y1'a, Y1'b and Y3' showed a significant decrease in the toxic compounds but we selected two best yeast strains i.e. P. occidentalis Y1'a and P. occidentalis M1 for the further experiments with an aim to remove the fermentation inhibitors. The yeasts P. occidentalis Y1'a and P. occidentalis M1 were grown aerobically in sugarcane bagasse hemicellulose hydrolysate under submerged cultivation. For each yeast, a 2(2) full factorial design was performed considering the variables-pH (4.0 or 5.0) and agitation rate (100 or 300 rpm), and the percentage removal of HMF, furfural, acetic acid and phenols from hemicellulosic hydrolysates were responsive variables. After 96 h of biological treatment, P. occidentalis M1 and P. occidentalis Y1'a showed 42.89 and 46.04 % cumulative removal of inhibitors, respectively. PMID:27570309

  13. 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.

  14. First-principles quantum-mechanical investigations: The role of water in catalytic conversion of furfural on Pd(111)

    NASA Astrophysics Data System (ADS)

    Xue, Wenhua; Borja, Miguel Gonzalez; Resasco, Daniel E.; Wang, Sanwu

    2015-03-01

    In the study of catalytic reactions of biomass, furfural conversion over metal catalysts with the presence of water has attracted wide attention. Recent experiments showed that the proportion of alcohol product from catalytic reactions of furfural conversion with palladium in the presence of water is significantly increased, when compared with other solvent including dioxane, decalin, and ethanol. We investigated the microscopic mechanism of the reactions based on first-principles quantum-mechanical calculations. We particularly identified the important role of water and the liquid/solid interface in furfural conversion. Our results provide atomic-scale details for the catalytic reactions. Supported by DOE (DE-SC0004600). This research used the supercomputer resources at NERSC, of XSEDE, at TACC, and at the Tandy Supercomputing Center.

  15. 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.

  16. 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.

  17. Complete genome sequence of Enterobacter cloacae GGT036: a furfural tolerant soil bacterium.

    PubMed

    Gong, Gyeongtaek; Um, Youngsoon; Park, Tai Hyun; Woo, Han Min

    2015-01-10

    Enterobacter cloacae is a facultative anaerobic bacterium to be an important cause of nosocomial infection. However, the isolated E. cloacae GGT036 showed higher furfural-tolerant cellular growth, compared to industrial relevant strains such as Escherichia coli and Corynebacterium glutamicum. Here, we report the complete genome sequence of E. cloacae GGT036 isolated from Mt. Gwanak, Seoul, Republic of Korea. The genomic DNA sequence of E. cloacae GGT036 will provide valuable genetic resources for engineering of industrially relevant strains being tolerant to cellular inhibitors present in lignocellulosic hydrolysates. PMID:25444880

  18. Synthesis and functionalization of bicyclic N,O-acetal scaffolds from furfural.

    PubMed

    van der Pijl, Ferdi; van Delft, Floris L; Rutjes, Floris P J T

    2015-06-01

    We have synthesized biologically relevant 6-aza-8-oxa[3.2.1]bicyclooctane scaffolds in a five-step procedure starting from furfural. Besides showing that these scaffolds are amenable to decoration via standard functional group interconversions, we also describe investigations for further functionalization via Lewis acid-mediated N,O-acetal opening, followed by nucleophilic trapping of the resulting intermediate cation. By using different nucleophiles, we have successfully prepared a modest library of 2,6-trans-disubstituted pyrans in good yields and in a highly diastereoselective manner.

  19. Furfural production in biphasic media using an acidic ionic liquid as a catalyst.

    PubMed

    Peleteiro, Susana; Santos, Valentín; Parajó, Juan C

    2016-11-20

    Ionic liquids are valuable tools for biorefineries. This study provides an experimental assessment on the utilization of an acidic ionic liquid (1-butyl-3-methylimidazolium hydrogen sulfate) as a catalyst for furfural production in water/solvent media. The substrates employed in experiments were commercial xylose (employed as a reference compound) or hemicellulosic saccharides obtained by hydrothermal processing of Eucalyptus globulus wood (which were employed as produced, after membrane concentration or after freeze-drying). A variety of reaction conditions (defined by temperature, reaction time and type of organic solvent) were considered. The possibility of recycling the catalyst was assessed in selected experiments. PMID:27561513

  20. Complete genome sequence of Enterobacter cloacae GGT036: a furfural tolerant soil bacterium.

    PubMed

    Gong, Gyeongtaek; Um, Youngsoon; Park, Tai Hyun; Woo, Han Min

    2015-01-10

    Enterobacter cloacae is a facultative anaerobic bacterium to be an important cause of nosocomial infection. However, the isolated E. cloacae GGT036 showed higher furfural-tolerant cellular growth, compared to industrial relevant strains such as Escherichia coli and Corynebacterium glutamicum. Here, we report the complete genome sequence of E. cloacae GGT036 isolated from Mt. Gwanak, Seoul, Republic of Korea. The genomic DNA sequence of E. cloacae GGT036 will provide valuable genetic resources for engineering of industrially relevant strains being tolerant to cellular inhibitors present in lignocellulosic hydrolysates.

  1. Xylose Isomerization to Xylulose and Its Dehydration to Furfural in Aqueous Media

    SciTech Connect

    Choudhary, Vinit; Pinar, Ana B; Sandler, Stanley I; Vlachos, Dion G.; Lobo, Raul F

    2011-12-02

    A nonenzymatic route for xylose isomerization in an aqueous medium using zeolite Sn-beta as a catalyst is demonstrated. Xylulose and lyxose are the primary and secondary products. The maximum yield to xylulose is 27%, with an 11% yield to lyxose at ~60% xylose conversion at 100 °C. When the Sn-beta zeolite is combined with a Brønsted acid catalyst, furfural forms in a single pot from xylose in an aqueous medium at much lower temperatures than typically employed for this reaction.

  2. Furfural production in biphasic media using an acidic ionic liquid as a catalyst.

    PubMed

    Peleteiro, Susana; Santos, Valentín; Parajó, Juan C

    2016-11-20

    Ionic liquids are valuable tools for biorefineries. This study provides an experimental assessment on the utilization of an acidic ionic liquid (1-butyl-3-methylimidazolium hydrogen sulfate) as a catalyst for furfural production in water/solvent media. The substrates employed in experiments were commercial xylose (employed as a reference compound) or hemicellulosic saccharides obtained by hydrothermal processing of Eucalyptus globulus wood (which were employed as produced, after membrane concentration or after freeze-drying). A variety of reaction conditions (defined by temperature, reaction time and type of organic solvent) were considered. The possibility of recycling the catalyst was assessed in selected experiments.

  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. 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.

  5. A Novel Method for the Discrimination of Semen Arecae and Its Processed Products by Using Computer Vision, Electronic Nose, and Electronic Tongue

    PubMed Central

    Xu, Min; Yang, Shi-Long; Peng, Wei; Liu, Yu-Jie; Xie, Da-Shuai; Li, Xin-Yi; Wu, Chun-Jie

    2015-01-01

    Areca nut, commonly known locally as Semen Arecae (SA) in China, has been used as an important Chinese herbal medicine for thousands of years. The raw SA (RAW) is commonly processed by stir-baking to yellow (SBY), stir-baking to dark brown (SBD), and stir-baking to carbon dark (SBC) for different clinical uses. In our present investigation, intelligent sensory technologies consisting of computer vision (CV), electronic nose (E-nose), and electronic tongue (E-tongue) were employed in order to develop a novel and accurate method for discrimination of SA and its processed products. Firstly, the color parameters and electronic sensory responses of E-nose and E-tongue of the samples were determined, respectively. Then, indicative components including 5-hydroxymethyl furfural (5-HMF) and arecoline (ARE) were determined by HPLC. Finally, principal component analysis (PCA) and discriminant factor analysis (DFA) were performed. The results demonstrated that these three instruments can effectively discriminate SA and its processed products. 5-HMF and ARE can reflect the stir-baking degree of SA. Interestingly, the two components showed close correlations to the color parameters and sensory responses of E-nose and E-tongue. In conclusion, this novel method based on CV, E-nose, and E-tongue can be successfully used to discriminate SA and its processed products. PMID:26366185

  6. 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.

  7. 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. PMID:25649983

  8. Integrated catalytic process to directly convert furfural to levulinate ester with high selectivity.

    PubMed

    Chen, Bingfeng; Li, Fengbo; Huang, Zhijun; Lu, Tao; Yuan, Yin; Yuan, Guoqing

    2014-01-01

    Levulinic acid is an important platform molecule from biomass-based renewable resources. A sustainable manufacturing process for this chemical and its derivatives is the enabling factor to harness the renewable resource. An integrated catalytic process to directly convert furfural to levulinate ester was developed based on a bifunctional catalyst of Pt nanoparticles supported on a ZrNb binary phosphate solid acid. The hydrogenation of furfural and the following alcoholysis of furfuryl alcohol were performed over this catalyst in a one-pot conversion model. Mesoporous ZrNb binary phosphate was synthesized by a sol-gel method and had a high surface area of 170.1 m(2) g(-1) and a large average pore size of around 8.0 nm. Pt nanoparticles remained in a monodisperse state on the support, and the reaction over Pt/ZrNbPO4 (Pt loading: 2.0 wt%; Zr/Nb, 1:1) gave a very high selectivity to levulinate derivatives (91% in total). The sustainability of this conversion was greatly improved by the process intensification based on the new catalyst, mild reaction conditions, cost abatement in separation and purification, and utilization of green reagents and solvents.

  9. Synthesis and characterization of carbon cryogel microspheres from lignin-furfural mixtures for biodiesel production.

    PubMed

    Zainol, Muzakkir Mohammad; Amin, Nor Aishah Saidina; Asmadi, Mohd

    2015-08-01

    The aim of this work was to study the potential of biofuel and biomass processing industry side-products as acid catalyst. The synthesis of carbon cryogel from lignin-furfural mixture, prepared via sol-gel polycondensation at 90°C for 0.5h, has been investigated for biodiesel production. The effect of lignin to furfural (L/F) ratios, lignin to water (L/W) ratios and acid concentration on carbon cryogel synthesis was studied. The carbon cryogels were characterized and tested for oleic acid conversion. The thermally stable amorphous spherical carbon cryogel has a large total surface area with high acidity. Experimental results revealed the optimum FAME yield and oleic acid conversion of 91.3wt.% and 98.1wt.%, respectively were attained at 65°C for 5h with 5wt.% catalyst loading and 20:1 methanol to oleic acid molar ratio. Therefore, carbon cryogel is highly potential for heterogeneous esterification of free fatty acid to biodiesel.

  10. 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.

  11. Integrated catalytic process to directly convert furfural to levulinate ester with high selectivity.

    PubMed

    Chen, Bingfeng; Li, Fengbo; Huang, Zhijun; Lu, Tao; Yuan, Yin; Yuan, Guoqing

    2014-01-01

    Levulinic acid is an important platform molecule from biomass-based renewable resources. A sustainable manufacturing process for this chemical and its derivatives is the enabling factor to harness the renewable resource. An integrated catalytic process to directly convert furfural to levulinate ester was developed based on a bifunctional catalyst of Pt nanoparticles supported on a ZrNb binary phosphate solid acid. The hydrogenation of furfural and the following alcoholysis of furfuryl alcohol were performed over this catalyst in a one-pot conversion model. Mesoporous ZrNb binary phosphate was synthesized by a sol-gel method and had a high surface area of 170.1 m(2) g(-1) and a large average pore size of around 8.0 nm. Pt nanoparticles remained in a monodisperse state on the support, and the reaction over Pt/ZrNbPO4 (Pt loading: 2.0 wt%; Zr/Nb, 1:1) gave a very high selectivity to levulinate derivatives (91% in total). The sustainability of this conversion was greatly improved by the process intensification based on the new catalyst, mild reaction conditions, cost abatement in separation and purification, and utilization of green reagents and solvents. PMID:24194497

  12. 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. PMID:19702622

  13. [Kinetics of furfural formation as related to heating, concentration and storage of orange juices and concentrates].

    PubMed

    Herrmann, J; Partassidou, V

    1979-01-01

    According to studies on an orange concentrate diluted back with distilled water to the desired extract content, the formation of furfural follows the pattern of a consequent reaction. After the induction period, the reaction curve takes a linear course cooresponding to a reaction of a zero order. The temperature dependence of the resultant reaction constant k obeys the ARRHENIUS equation and yields the same energy of activation for all the extract contents under investigation. This is a case of specific acid catalysis, because the reaction velocity is directly proportional to the hydronium ion activity. On a semilogarithmic scale, the dependence of the k values of the extract contents of the concentrates and of the re-constituted juice can be presented for various temperatures in the form of parallels. According to the literature, the amount of the furfural produced correlates with the quality of the orange juices and concentrates. Consequently, this amount might be used as an indicator in evaluating quality deteriorations due to unsuitable manufacturing and storage on the one hand, and for the computation and optimization of the manufacturing processes and parameters on the other hand.

  14. [Rapid quantitative analysis of hydrocarbon composition of furfural extract oils using attenuated total reflection infrared spectroscopy].

    PubMed

    Li, Na; Yuan, Hong-Fu; Hu, Ai-Qin; Liu, Wei; Song, Chun-Feng; Li, Xiao-Yu; Song, Yi-Chang; He, Qi-Jun; Liu, Sha; Xu, Xiao-Xuan

    2014-07-01

    A set of rapid analysis system for hydrocarbon composition of heavy oils was designed using attenuated total reflection FTIR spectrometer and chemometrics to determine the hydrocarbon composition of furfural extract oils. Sixty two extract oil samples were collected and their saturates and aromatics content data were determined according to the standard NB/SH/T0509-2010, then the total contents of resins plus asphaltenes were calculated by the subtraction method in the percentage of weight. Based on the partial least squares (PLS), calibration models for saturates, aromatics, and resin+asphaltene contents were established using attenuated total reflection FTIR spectroscopy, with their SEC, 1.43%, 0.91% and 1.61%, SEP, 1.56%, 1.24% and 1.81%, respectively, meeting the accuracy and repeatability required for the standard. Compared to the present standard method, the efficiency of hydrocarbon composition analysis for furfural extract oils is significantly improved by the new method which is rapid and simple. The system could also be used for other heavy oil analysis, with excellent extension and application foreground.

  15. Comparison of peak height of the F2-layer (hmF2) measurements with IRI-2012, IRI-2007 and IRI-2001 models predictions above Roquetes station (Spain) during the ascending phase of the solar cycle 24

    NASA Astrophysics Data System (ADS)

    Mohammed, Fahmi A.

    2015-09-01

    This research aims to validate IRI-2012 program and examine its accuracy in predicting peak height of the F2- layer (hmF2) above Roquetes. The seasonal hourly means of the ionosphere F2 peak height parameter (hmF2) above Roquetes station, Spain, (located at latitude close to the latitude of Iraq, 41°N) were analyzed and the results were compared with IRI-2012, IRI-2007 and IRI-2001, using CCIR (Comite´ Consultatif International des Radio Communications) option. The analysis covered quiet and disturbed days during various seasons of 2013 (the ascending phase of the solar cycle 24). In general, it is found that the predicted values of hmF2 overestimate the observed ones during all seasons, except Summer, whereas it underestimate at day hours. Also, it is found that the maximum percentage relative deviation of hmF2 occurred during Winter at 8 LT, while the minimum occurred during Autumnat 22 LT.

  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

    2015-06-01

    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. 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...

  18. 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. PMID:24512536

  19. 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

    2015-06-01

    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. PMID:25891431

  20. Extreme thermophilic ethanol production from rapeseed straw: using the newly isolated Thermoanaerobacter pentosaceus and combining it with Saccharomyces cerevisiae in a two-step process.

    PubMed

    Tomás, Ana Faria; Karagöz, Pınar; Karakashev, Dimitar; Angelidaki, Irini

    2013-06-01

    The newly isolated extreme thermophile Thermoanaerobacter pentosaceus was used for ethanol production from alkaline-peroxide pretreated rapeseed straw (PRS). Both the liquid and solid fractions of PRS were used. T. pentosaceus was able to metabolize the typical process inhibitors present in lignocellulosic hydrolysate, namely 5-hydroxymethyl furfural (HMF) and furfural, up to concentrations of 1 and 0.5 g L(-1) , respectively. Above these levels, xylose consumption was inhibited up to 70% (at 3.4 g-furfural L(-1) ) and 75% (at 3.4 g-HMF L(-1) ). T. pentosaceus was able to grow and produce ethanol directly from the liquid fraction of PRS, without any dilution or need for additives. However, when the hydrolysate was used undiluted the ethanol yield was only 37% compared to yield of the control, in which pure sugars in synthetic medium were used. The decrease of ethanol yield was attributed to the high amounts of salts resulting from the alkaline-peroxide pretreatment. Finally, a two-stage ethanol production process from PRS using Saccharomyces cerevisiae (utilization of hexoses in the first step) and T. pentosaceus (utilization of pentoses in the second step) was developed. Results showed that the two strains together could achieve up to 85% of the theoretical ethanol yield based on the sugar composition of the rapeseed straw, which was 14% and 50% higher compared to the yield with the yeast or the bacteria alone, respectively.

  1. 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.

  2. 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. PMID:26724548

  3. Global regulator engineering significantly improved Escherichia coli tolerances toward inhibitors of lignocellulosic hydrolysates.

    PubMed

    Wang, Jianqing; Zhang, Yan; Chen, Yilu; Lin, Min; Lin, Zhanglin

    2012-12-01

    Lignocellulosic biomass is regarded as the most viable source of feedstock for industrial biorefinery, but the harmful inhibitors generated from the indispensable pretreatments prior to fermentation remain a daunting technical hurdle. Using an exogenous regulator, irrE, from the radiation-resistant Deinococcus radiodurans, we previously showed that a novel global regulator engineering (GRE) approach significantly enhanced tolerances of Escherichia coli to alcohol and acetate stresses. In this work, an irrE library was subjected to selection under various stresses of furfural, a typical hydrolysate inhibitor. Three furfural tolerant irrE mutants including F1-37 and F2-1 were successfully obtained. The cells containing these mutants reached OD(600) levels of 4- to 16-fold of that for the pMD18T cells in growth assay under 0.2% (v/v) furfural stress. The cells containing irrE F1-37 and F2-1 also showed considerably reduced intracellular oxygen species (ROS) levels under furfural stress. Moreover, these two irrE mutants were subsequently found to confer significant cross tolerances to two other most common inhibitors, 5-hydroxymethyl-2-furaldehyde (HMF), vanillin, as well as real lignocellulosic hydrolysates. When evaluated in Luria-Bertani (LB) medium supplemented with corn stover cellulosic hydrolysate (prepared with a solid loading of 30%), the cells containing the mutants exhibited lag phases markedly shortened by 24-44 h in comparison with the control cells. This work thus presents a promising step forward to resolve the inhibitor problem for E. coli. From the view of synthetic biology, irrE can be considered as an evolvable "part" for various stresses. Furthermore, this GRE approach can be extended to exploit other exogenous global regulators from extremophiles, and the native counterparts in E. coli, for eliciting industrially useful phenotypes.

  4. A feasible process for furfural production from the pre-hydrolysis liquor of corncob via biochar catalysts in a new biphasic system.

    PubMed

    Deng, Aojie; Lin, Qixuan; Yan, Yuhuan; Li, Huiling; Ren, Junli; Liu, Chuanfu; Sun, Runcang

    2016-09-01

    A feasible approach was developed to produce furfural from the pre-hydrolysis liquor of corncob via biochar catalysts as the solid acid catalyst in a new biphasic system with dichloromethane (DCM) as the organic phase and the concentrated pre-hydrolysis liquor (CPHL) containing NaCl as the aqueous phase. The biochar catalyst possessing many acidity groups (SO3H, COOH and phenolic OH groups) was prepared by the carbonization and sulfonation process of the corncob hydrolyzed residue. The influence of the catalytic condition on furfural yield and selectivity was comparatively studied. It was found that 81.14% furfural yield and 83.0% furfural selectivity were obtained from CPHL containing 5wt% xylose using this biochar catalyst in the CPHL-NaCl/DCM biphasic system at 170°C for 60min. In addition, with the regeneration process, this catalyst displayed the high performance and excellent recyclability. PMID:27295253

  5. 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.

  6. 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.

  7. Inhibiting effect of furfural on corrosion of zinc in ethanolic solutions

    SciTech Connect

    Chagas, L.V. das; Goncalves, R.S.

    1996-09-01

    Interest in the corrosion of metals in alcohol systems is increasing because of the fact that alcohol can substitute for conventional fuels as an energy source. A large fraction of Brazilian vehicles use this compound instead of conventional hydrocarbon fuels. Since some components of engines are made with Zn or Zn alloys, corrosion problems are possible. Furfural (C{sub 4}H{sub 3}OCHO) was shown to inhibit the corrosion processes of Zn in ethanolic solutions. Results obtained from different electrochemical methods confirmed this effect. Inhibition depended upon the adsorption step and was affected by the incidence of polychromatic light on the metal surface. Protection efficiency of C{sub 4}H{sub 3}OCHO was higher when the system was kept in the dark than when under illumination. An inhibition process involving an adsorption step of C{sub 4}H{sub 3}OCHO was proposed.

  8. From furfural to fuel: synthesis of furoins by organocatalysis and their hydrodeoxygenation by cascade catalysis.

    PubMed

    Wegenhart, Benjamin L; Yang, Linan; Kwan, Soon Cheong; Harris, Remi; Kenttämaa, Hilkka I; Abu-Omar, Mahdi M

    2014-09-01

    The synthesis of furoins from biomass-derived furfural and 2-methylfurfural is demonstrated in high yields in green and renewable solvents using N-heterocyclic carbene organocatalysts. The resulting furoin molecules are used as precursors for fuels using cascade catalysis, first by using Pd/C with acidic co-catalysts under very mild conditions to yield oxygenated C12 molecules. Two main products were formed, which we identified as 1,2-bis(5-methyltetrahydrofuran-2-yl)ethane and 1-(5-methyltetrahydrofuran-2-yl)heptanol. The use of a Pd/Zeolite-β catalyst under more extreme conditions resulted in the complete hydrodeoxygenation of 5,5'-dimethylfuroin to dodecanes in high yields (76%) and exceptional selectivity (94%) for n-dodecane. PMID:25088205

  9. 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. PMID:25130750

  10. From furfural to fuel: synthesis of furoins by organocatalysis and their hydrodeoxygenation by cascade catalysis.

    PubMed

    Wegenhart, Benjamin L; Yang, Linan; Kwan, Soon Cheong; Harris, Remi; Kenttämaa, Hilkka I; Abu-Omar, Mahdi M

    2014-09-01

    The synthesis of furoins from biomass-derived furfural and 2-methylfurfural is demonstrated in high yields in green and renewable solvents using N-heterocyclic carbene organocatalysts. The resulting furoin molecules are used as precursors for fuels using cascade catalysis, first by using Pd/C with acidic co-catalysts under very mild conditions to yield oxygenated C12 molecules. Two main products were formed, which we identified as 1,2-bis(5-methyltetrahydrofuran-2-yl)ethane and 1-(5-methyltetrahydrofuran-2-yl)heptanol. The use of a Pd/Zeolite-β catalyst under more extreme conditions resulted in the complete hydrodeoxygenation of 5,5'-dimethylfuroin to dodecanes in high yields (76%) and exceptional selectivity (94%) for n-dodecane.

  11. 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.

  12. The electron-furfural scattering dynamics for 63 energetically open electronic states

    NASA Astrophysics Data System (ADS)

    da Costa, Romarly F.; do N. Varella, Márcio T.; Bettega, Márcio H. F.; Neves, Rafael F. C.; Lopes, Maria Cristina A.; Blanco, Francisco; García, Gustavo; Jones, Darryl B.; Brunger, Michael J.; Lima, Marco A. P.

    2016-03-01

    We report on integral-, momentum transfer- and differential cross sections for elastic and electronically inelastic electron collisions with furfural (C5H4O2). The calculations were performed with two different theoretical methodologies, the Schwinger multichannel method with pseudopotentials (SMCPP) and the independent atom method with screening corrected additivity rule (IAM-SCAR) that now incorporates a further interference (I) term. The SMCPP with N energetically open electronic states (Nopen) at either the static-exchange (Nopen ch-SE) or the static-exchange-plus-polarisation (Nopen ch-SEP) approximation was employed to calculate the scattering amplitudes at impact energies lying between 5 eV and 50 eV, using a channel coupling scheme that ranges from the 1ch-SEP up to the 63ch-SE level of approximation depending on the energy considered. For elastic scattering, we found very good overall agreement at higher energies among our SMCPP cross sections, our IAM-SCAR+I cross sections and the experimental data for furan (a molecule that differs from furfural only by the substitution of a hydrogen atom in furan with an aldehyde functional group). This is a good indication that our elastic cross sections are converged with respect to the multichannel coupling effect for most of the investigated intermediate energies. However, although the present application represents the most sophisticated calculation performed with the SMCPP method thus far, the inelastic cross sections, even for the low lying energy states, are still not completely converged for intermediate and higher energies. We discuss possible reasons leading to this discrepancy and point out what further steps need to be undertaken in order to improve the agreement between the calculated and measured cross sections.

  13. The electron-furfural scattering dynamics for 63 energetically open electronic states.

    PubMed

    da Costa, Romarly F; do N Varella, Márcio T; Bettega, Márcio H F; Neves, Rafael F C; Lopes, Maria Cristina A; Blanco, Francisco; García, Gustavo; Jones, Darryl B; Brunger, Michael J; Lima, Marco A P

    2016-03-28

    We report on integral-, momentum transfer- and differential cross sections for elastic and electronically inelastic electron collisions with furfural (C5H4O2). The calculations were performed with two different theoretical methodologies, the Schwinger multichannel method with pseudopotentials (SMCPP) and the independent atom method with screening corrected additivity rule (IAM-SCAR) that now incorporates a further interference (I) term. The SMCPP with N energetically open electronic states (N(open)) at either the static-exchange (N(open) ch-SE) or the static-exchange-plus-polarisation (N(open) ch-SEP) approximation was employed to calculate the scattering amplitudes at impact energies lying between 5 eV and 50 eV, using a channel coupling scheme that ranges from the 1ch-SEP up to the 63ch-SE level of approximation depending on the energy considered. For elastic scattering, we found very good overall agreement at higher energies among our SMCPP cross sections, our IAM-SCAR+I cross sections and the experimental data for furan (a molecule that differs from furfural only by the substitution of a hydrogen atom in furan with an aldehyde functional group). This is a good indication that our elastic cross sections are converged with respect to the multichannel coupling effect for most of the investigated intermediate energies. However, although the present application represents the most sophisticated calculation performed with the SMCPP method thus far, the inelastic cross sections, even for the low lying energy states, are still not completely converged for intermediate and higher energies. We discuss possible reasons leading to this discrepancy and point out what further steps need to be undertaken in order to improve the agreement between the calculated and measured cross sections. PMID:27036451

  14. 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

  15. 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, M3000F2, 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 M3000F2, variability of B0 parameter in Bil-2000, Gul-1987, and ABT-2009 option, were taken into consideration.

  16. Humoral immunity to Malassezia furfur serovars A, B and C in patients with pityriasis versicolor, seborrheic dermatitis and controls.

    PubMed

    Ashbee, H R; Fruin, A; Holland, K T; Cunliffe, W J; Ingham, E

    1994-10-01

    This study examined the humoral immune responses to Malassezia furfur serovars A, B and C of 10 patients with pityriasis versicolor, 10 patients with seborrheic dermatitis and 20 age- and sex-matched controls. A transferable solid-phase ELISA was used to determine titres of total Igs, IgM, IgA and IgG specific to M. furfur serovars A, B and C. The results demonstrated that patients with seborrheic dermatitis had a significantly higher titre of total Igs to serovar A than patients with pityriasis versicolor; and that patients with seborrheic dermatitis had a significantly higher titre of IgA to serovar C than patients with pityriasis versicolor. The titres of total Igs for controls and patients with seborrheic dermatitis were significantly lower to serovar B than to serovar C. A modified TSP ELISA was used to determine the titres of the IgG subclasses. Titres of IgG1,3,4 to serovar B were significantly higher in seborrheic dermatitis patients than pityriasis versicolor patients and titres of IgG3 to serovar A were significantly higher in seborrheic dermatitis patients than pityriasis versicolor patients. However, despite the differences between the patient groups, none of these results was significantly different to those of controls. Thus, this study did not demonstrate any differences in humoral immunity of patients suffering from Malassezia-associated dermatoses when compared to normal controls. These results may suggest that the humoral immune response to M. furfur is not related to the pathogenesis of Malassezia-associated dermatoses, but simply to the carriage of M. furfur on the skin.

  17. 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.

  18. 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

  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. 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.

  1. 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.

  2. 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. PMID:25461009

  3. Theoretical and experimental differential cross sections for electron impact excitation of the electronic bands of furfural

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

    We report results from a joint experimental and theoretical investigation into electron scattering from the important industrial species furfural (C5H4O2). Specifically, differential cross sections (DCSs) have been measured and calculated for the electron-impact excitation of the electronic states of C5H4O2. The measurements were carried out at energies in the range 20-40 eV, and for scattered-electron angles between 10° and 90°. The energy resolution of those experiments was typically ˜80 meV. Corresponding Schwinger multichannel method with pseudo-potential calculations, for energies between 6-50 eV and with and without Born-closure, were also performed for a sub-set of the excited electronic-states that were accessed in the measurements. Those calculations were undertaken at the static exchange plus polarisation-level using a minimum orbital basis for single configuration interaction (MOB-SCI) approach. Agreement between the measured and calculated DCSs was qualitatively quite good, although to obtain quantitative accord, the theory would need to incorporate even more channels into the MOB-SCI. The role of multichannel coupling on the computed electronic-state DCSs is also explored in some detail.

  4. Deoxygenation of glycolaldehyde and furfural on Mo2C/Mo(100)

    NASA Astrophysics Data System (ADS)

    McManus, Jesse R.; Vohs, John M.

    2014-12-01

    The desire to produce fuels and chemicals in an energy conscious, environmentally sympathetic approach has motivated considerable research on the use of cellulosic biomass feedstocks. One of the major challenges facing the utilization of biomass is finding effective catalysts for the efficient and selective removal of oxygen from the highly-oxygenated, biomass-derived platform molecules. Herein, a study of the reaction pathways for the biomass-derived platform molecule furfural and biomass-derived sugar model compound glycolaldehyde provides insight into the mechanisms of hydrodeoxygenation (HDO) on a model molybdenum carbide catalyst, Mo2C/Mo(100). Using temperature programmed desorption (TPD) and high resolution electron energy loss spectroscopy (HREELS), it was found that the Mo2C/Mo(100) catalyst was active for selective deoxygenation of the aldehyde carbonyl by facilitating adsorption of the aldehyde in an η2(C,O) bonding configuration. Furthermore, the catalyst showed no appreciable activity for furanic ring hydrogenation, highlighting the promise of relatively inexpensive Mo2C catalysts for selective HDO chemistry.

  5. Theoretical insight into the conversion of xylose to furfural in the gas phase and water.

    PubMed

    Wang, Meng; Liu, Chao; Li, Qibin; Xu, Xiaoxiao

    2015-11-01

    Furfural (FF) is a valuable ring-containing organic compound in the decomposition of xylose and can be produced massively in hydrothermal condition. In this study, density functional theory (DFT) methods are employed to investigate the formation mechanism of FF from xylose and the solvent effects on FF formation. Kinetic and thermodynamic analyses indicate that xylulose could be the intermediate that leads to the formation of FF in the gas phase and water. The formation of xylulose is initiated by a six-membered transition state with energy barriers of 163.6 and 150.8 kJ mol(-1) in the gas phase and water, respectively. It is found that the strong stabilization of the reactants and transition states and the overall energy barriers of formation pathways of FF are reduced in water. The formation of FF is more thermodynamically favored in water compared with that in the gas phase. In addition, the inclusion of an explicit water molecule transforms four-membered transition states of ring-opening reaction, hydrogenation-cyclization, and dehydrations into less distorted six-membered transition states, which leads to the significant reduction of reaction barriers of FF formation.

  6. 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; 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 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

  7. 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.

  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 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.

  10. 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

    2016-03-01

    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.

  11. 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.

  12. Cell-mediated immune responses to Malassezia furfur serovars A, B and C in patients with pityriasis versicolor, seborrheic dermatitis and controls.

    PubMed

    Ashbee, H R; Ingham, E; Holland, K T; Cunliffe, W J

    1994-06-01

    It has been postulated that patients with Malassezia furfur-associated dermatoses have a deficient cell-mediated immune response to M. furfur. This study examined the cell-mediated immune responses to M. furfur serovars A, B and C of 10 patients with pityriasis versicolor and 10 age- and sex-matched controls; and 10 patients with seborrheic dermatitis and 10 age- and sex-matched controls. The responses to each serovar of M. furfur were assessed using the lymphocyte transformation assay and the leukocyte migration inhibition assay. The lymphocyte transformation responses of the patients with pityriasis versicolor to M. furfur serovars A, B and C (0/10, 6/10 and 5/10 respectively) were not significantly different from those of controls (0/10, 2/10 and 1/10). However, for patients with seborrheic dermatitis, significantly more patients' lymphocytes responded to serovars B and C (6/10 and 6/10 respectively) than those of controls (1/10 and 1/10). No patient or control responded to serovar A. In the leukocyte migration inhibition assay, the leukocytes from a greater proportion of patients with pityriasis versicolor (5/7) responded to serovar B than controls (2/10); and the leukocytes from a greater proportion of patients with seborrheic dermatitis (4/10) responded to serovar C than controls (0/9). Thus, this data did not indicate the presence of any cell-mediated immune deficiency to M. furfur in patients with pityriasis versicolor or seborrheic dermatitis, as measured by the lymphocyte transformation assay or the leukocyte migration inhibition assay. The greater responsiveness of T lymphocytes from patients may indicate that T lymphocytes might be involved in the pathogenesis of these diseases.

  13. 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. PMID:24902118

  14. 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.

  15. 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

    2014-10-01

    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. PMID:25194623

  16. 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. PMID:24807741

  17. 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; Wang, Lin -Lin; Gustafson, Jeffrey; Pei, Yuchen; Qi, Zhiyuan; Johnson, Duane D.; Zhang, Shiran; Tao, Franklin; et al

    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

  18. 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...

  19. 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.

  20. 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

  1. Conversion of xylan, d-xylose and lignocellulosic biomass into furfural using AlCl3 as catalyst in ionic liquid.

    PubMed

    Zhang, Luxin; Yu, Hongbing; Wang, Pan; Dong, Heng; Peng, Xinhong

    2013-02-01

    In order to define a new green catalytic pathway for the production of furfural, the catalyzed conversion of xylan into furfural in 1-butyl-3-methylimidazolium chloride was studied by using mineral acids and metal chlorides as catalysts under microwave irradiation. Amongst these catalysts, AlCl(3) resulted in the highest furfural yield of 84.8% at 170°C for 10s. The effect of AlCl(3) on the conversion efficiency of d-xylose and untreated lignocellulosic biomass was also investigated, the yields of furfural from corncob, grass and pine wood catalyzed by AlCl(3) in [BMIM]Cl were in the range of 16-33%. [BMIM]Cl and AlCl(3) could be recycled for four runs with stable catalytic activity. AlCl(3) is less corrosive than mineral acids, and the use of ionic liquid as reaction medium will no longer generate toxic wastewater, thus this reaction system is more ecologically viable. PMID:23306118

  2. 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

  3. Analysis of volatile compounds of Malaysian Tualang (Koompassia excelsa) honey using gas chromatography mass spectrometry.

    PubMed

    Nurul Syazana, M S; Gan, S H; Halim, A S; Shah, Nurul Syazana Mohamad; Gan, Siew Hua; Sukari, Halim Ahmad

    2013-01-01

    The constituents of honey's volatile compounds depend on the nectar source and differ depending on the place of origin. To date, the volatile constituents of Tualang honey have never been investigated. The objective of this study was to analyze the volatile compounds in local Malaysian Tualang honey. A continuous extraction of Tualang honey using five organic solvents was carried out starting from non-polar to polar solvents and the extracted samples were analysed using gas chromatography-mass spectrometry (GC-MS). Overall, 35 volatile compounds were detected. Hydrocarbons constitute 58.5% of the composition of Tualang honey. Other classes of chemical compounds detected included acids, aldehydes, alcohols, ketones, terpenes, furans and a miscellaneous group. Methanol yielded the highest number of extracted compounds such as acids and 5-(Hydroxymethyl) furfural (HMF). This is the first study to describe the volatile compounds in Tualang honey. The use of a simple one tube, stepwise, non-thermal liquid-liquid extraction of honey is a advantageous as it prevents sample loss. Further research to test the clinical benefits of these volatile compounds is recommended.

  4. 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. PMID:21604807

  5. 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.

  6. 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. PMID:27041327

  7. 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.

  8. 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.

  9. 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

    2016-06-01

    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. PMID:27144965

  10. 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.

  11. CEDAR Electrodynamics Thermosphere Ionosphere (ETI) Challenge for systematic assessment of ionosphere/thermosphere models: NmF2, hmF2, and vertical drift using ground-based observations

    NASA Astrophysics Data System (ADS)

    Shim, J. S.; Kuznetsova, M.; RastäTter, 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.

    2011-12-01

    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.

  12. 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.

  13. Electronic excitation of furfural as probed by high-resolution vacuum ultraviolet spectroscopy, electron energy loss spectroscopy, and ab initio calculations

    NASA Astrophysics Data System (ADS)

    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.

    2015-10-01

    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.

  14. Furfural Production from d-Xylose and Xylan by Using Stable Nafion NR50 and NaCl in a Microwave-Assisted Biphasic Reaction.

    PubMed

    Le Guenic, Sarah; Gergela, David; Ceballos, Claire; Delbecq, Frederic; Len, Christophe

    2016-01-01

    Pentose dehydration and direct transformation of xylan into furfural were performed in a water-cyclopentyl methyl ether (CPME) biphasic system under microwave irradiation. Heated up between 170 and 190 °C in the presence of Nafion NR50 and NaCl, d-xylose, l-arabinose and xylan gave furfural with maximum yields of 80%, 42% and 55%, respectively. The influence of temperature and reaction time on the reaction kinetics was discussed. This study was also completed by the survey of different reactant ratios, such as organic layer-water or catalyst-inorganic salt ratios. The exchange between proton and cation induced by an excess of NaCl was monitored, and a synergetic effect between the remaining protons and the released HCl was also discovered. PMID:27556444

  15. Chemical synthesis of fully biomass-based poly(butylene succinate) from inedible-biomass-based furfural and evaluation of its biomass carbon ratio.

    PubMed

    Tachibana, Yuya; Masuda, Takashi; Funabashi, Masahiro; Kunioka, Masao

    2010-10-11

    We have produced fully biomass-based poly(butylene succinate) (PBS) from furfural produced from inedible agricultural cellulosic waste. Furfural was oxidized to give fumaric acid. Fumaric acid was hydrogenated under high pressure with a palladium-rhenium/carbon catalyst to give 1,4-butanediol, and with a palladium/carbon catalyst to give succinic acid. Dimethyl succinate was synthesized from fumaric acid by esterification and hydrogenation under normal pressure. Fully biomass-based PBS was obtained by polycondensation of biomass-based 1,4-butanediol and biomass-based succinic acid or dimethyl succinate. The biomass carbon ratio calculated from (14)C concentrations measured by accelerator mass spectroscopy (AMS) verified that the PBS obtained in this study contained only biomass carbon. The polycondensation of biomass-based 1,4-butanediol and petroleum-based terephthalic acid or dimethyl terephthalate gave partially biomass-based poly(butylene terephthalate), which is an engineering plastic.

  16. 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.

  17. 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. PMID:26472380

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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; 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 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

  4. 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.

  5. 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. PMID:25970091

  6. Improvement of the enzymatic hydrolysis of furfural residues by pretreatment with combined green liquor and ethanol organosolv.

    PubMed

    Yu, Hailong; Xing, Yang; Lei, Fuhou; Liu, Zhiping; Liu, Zuguang; Jiang, Jianxin

    2014-09-01

    Furfural residues (FRs) were pretreated with ethanol and a green liquor (GL) catalyst to produce fermentable sugar. Anthraquinone (AQ) was used as an auxiliary reagent to improve delignification and reduce cellulose decomposition. The results showed that 42.7% of lignin was removed and 96.5% of cellulose was recovered from substrates pretreated with 1.0 mL GL/g of dry substrate and 0.4% (w/w) AQ at 140°C for 1h. Compared with raw material, ethanol-GL pretreatment of FRs increased the glucose yield from 69.0% to 85.9% after 96 h hydrolysis with 18 FPU/g-cellulose for cellulase, 27 CBU/g-cellulose for β-glucosidase. The Brauner-Emmett-Teller surface area was reduced during pretreatment, which did not inhibit the enzymatic hydrolysis. Owing to the reduced surface area, the unproductive binding of cellulase to lignin was decreased, thus improving the enzymatic hydrolysis. The degree of polymerization of cellulose from FRs was too low to be a key factor for improving enzymatic hydrolysis.

  7. Processed Lignin as a Byproduct of the Generation of 5-(Chloromethyl)furfural from Biomass: A Promising New Mesoporous Material.

    PubMed

    Budarin, Vitaliy L; Clark, James H; Henschen, Jonatan; Farmer, Thomas J; Macquarrie, Duncan J; Mascal, Mark; Nagaraja, Gundibasappa K; Petchey, Tabitha H M

    2015-12-21

    The lignin by-product of the conversion of lignocellulosic biomass to 5-(chloromethyl)furfural (CMF) has been characterised by thermogravimetric analysis, N2 physisorption porosimetry, attenuated internal reflectance IR spectroscopy, elemental analysis and solid-state NMR spectroscopy. The lignin (LCMF) has a moderate level of mesoporosity before thermal treatment and a surface area of 63 m(2)  g(-1) , which increases dramatically on pyrolysis at temperatures above 400 °C. An assessment of the functionality and textural properties of the material was achieved by analysing LCMF treated thermally over a range of pyrolysis temperatures. Samples were sulfonated to test their potential as heterogeneous acid catalysts in the esterification of levulinic acid. It was shown that unpyrolysed catalysts gave the highest ester yields of up to 93 %. To the best of our knowledge, this is the first example of mesoporous lignin with an appreciable surface area that is produced directly from a bio-refinery process and with further textural modification of the material demonstrated.

  8. High glucose recovery from direct enzymatic hydrolysis of bisulfite-pretreatment on non-detoxified furfural residues.

    PubMed

    Xing, Yang; Bu, Lingxi; Sun, Dafeng; Liu, Zhiping; Liu, Shijie; Jiang, Jianxin

    2015-10-01

    This study reports four schemes to pretreat wet furfural residues (FRs) with sodium bisulfite for production of fermentable sugar. The results showed that non-detoxified FRs (pH 2-3) had great potential to lower the cost of bioconversion. The optimal process was that unwashed FRs were first pretreated with bisulfite, and the whole slurry was then directly used for enzymatic hydrolysis. A maximum glucose yield of 99.4% was achieved from substrates pretreated with 0.1 g NaHSO3/g dry substrate (DS), at a relatively low temperature of 100 °C for 3 h. Compared with raw material, enzymatic hydrolysis at a high-solid of 16.5% (w/w) specifically showed more excellent performance with bisulfite treated FRs. Direct bisulfite pretreatment improved the accessibility of substrates and the total glucose recovery. Lignosulfonate in the non-detoxified slurry decreased the non-productive adsorption of cellulase on the substrate, thus improving enzymatic hydrolysis.

  9. Processed Lignin as a Byproduct of the Generation of 5-(Chloromethyl)furfural from Biomass: A Promising New Mesoporous Material.

    PubMed

    Budarin, Vitaliy L; Clark, James H; Henschen, Jonatan; Farmer, Thomas J; Macquarrie, Duncan J; Mascal, Mark; Nagaraja, Gundibasappa K; Petchey, Tabitha H M

    2015-12-21

    The lignin by-product of the conversion of lignocellulosic biomass to 5-(chloromethyl)furfural (CMF) has been characterised by thermogravimetric analysis, N2 physisorption porosimetry, attenuated internal reflectance IR spectroscopy, elemental analysis and solid-state NMR spectroscopy. The lignin (LCMF) has a moderate level of mesoporosity before thermal treatment and a surface area of 63 m(2)  g(-1) , which increases dramatically on pyrolysis at temperatures above 400 °C. An assessment of the functionality and textural properties of the material was achieved by analysing LCMF treated thermally over a range of pyrolysis temperatures. Samples were sulfonated to test their potential as heterogeneous acid catalysts in the esterification of levulinic acid. It was shown that unpyrolysed catalysts gave the highest ester yields of up to 93 %. To the best of our knowledge, this is the first example of mesoporous lignin with an appreciable surface area that is produced directly from a bio-refinery process and with further textural modification of the material demonstrated. PMID:26601798

  10. High glucose recovery from direct enzymatic hydrolysis of bisulfite-pretreatment on non-detoxified furfural residues.

    PubMed

    Xing, Yang; Bu, Lingxi; Sun, Dafeng; Liu, Zhiping; Liu, Shijie; Jiang, Jianxin

    2015-10-01

    This study reports four schemes to pretreat wet furfural residues (FRs) with sodium bisulfite for production of fermentable sugar. The results showed that non-detoxified FRs (pH 2-3) had great potential to lower the cost of bioconversion. The optimal process was that unwashed FRs were first pretreated with bisulfite, and the whole slurry was then directly used for enzymatic hydrolysis. A maximum glucose yield of 99.4% was achieved from substrates pretreated with 0.1 g NaHSO3/g dry substrate (DS), at a relatively low temperature of 100 °C for 3 h. Compared with raw material, enzymatic hydrolysis at a high-solid of 16.5% (w/w) specifically showed more excellent performance with bisulfite treated FRs. Direct bisulfite pretreatment improved the accessibility of substrates and the total glucose recovery. Lignosulfonate in the non-detoxified slurry decreased the non-productive adsorption of cellulase on the substrate, thus improving enzymatic hydrolysis. PMID:26150072

  11. 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

    2015-09-01

    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.

  12. 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

    2015-09-01

    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. PMID:26005158

  13. 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...

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Alcohol dehydrogenases from Scheffersomyces stipitis involved in the detoxification of aldehyde inhibitors derived from lignocellulosic biomass conversion.

    PubMed

    Ma, Menggen; Wang, Xu; Zhang, Xiaoping; Zhao, Xianxian

    2013-09-01

    Aldehyde inhibitors such as furfural and 5-hydroxymethylfurfural (HMF) are generated from biomass pretreatment. Scheffersomyces stipitis is able to reduce furfural and HMF to less toxic furanmethanol and furan-2,5-dimethanol; however, the enzymes involved in the reductive reaction still remain unknown. In this study, transcription responses of two known and five putative alcohol dehydrogenase genes from S. stipitis were analyzed under furfural and HMF stress conditions. All the seven alcohol dehydrogenase genes were also cloned and overexpressed for their activity analyses. Our results indicate that transcriptions of SsADH4 and SsADH6 were highly induced under furfural and HMF stress conditions, and the proteins encoded by them exhibited NADH- and/or NADPH-dependent activities for furfural and HMF reduction, respectively. For furfural reduction, NADH-dependent activity was also observed in SsAdh1p and NAD(P)H-dependent activities were also observed in SsAdh5p and SsAdh7p. For HMF reduction, NADPH-dependent activities were also observed in SsAdh5p and SsAdh7p. SsAdh4p displayed the highest NADPH-dependent specific activity and catalytic efficiency for reduction of both furfural and HMF among the seven alcohol dehydrogenases. Enzyme activities of all SsADH proteins were more stable under acidic condition. For most SsADH proteins, the optimum temperature for enzyme activities was 30 °C and more than 50 % enzyme activities remained at 60 °C. Reduction activities of formaldehyde, acetaldehyde, isovaleraldehyde, benzaldehyde, and phenylacetaldehyde were also observed in some SsADH proteins. Our results indicate that multiple alcohol dehydrogenases in S. stipitis are involved in the detoxification of aldehyde inhibitors derived from lignocellulosic biomass conversion. PMID:23912116

  20. 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. PMID:27283710

  1. 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

  2. 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

  3. Determination of furfural and hydroxymethylfurfural from baby formula using headspace solid phase microextraction based on nanostructured polypyrrole fiber coupled with ion mobility spectrometry.

    PubMed

    Kamalabadi, Mahdie; Ghaemi, Elham; Mohammadi, Abdorreza; Alizadeh, Naader

    2015-08-15

    Furfural (Fu) and hydroxymethylfurfural (HMFu) are extracted using a dodecylbenzenesulfonate-doped polypyrrole coating as a fiber for headspace solid phase microextraction (HS-SPME) method in baby formula samples and detected using ion mobility spectrometry (IMS). Sample pH, salt effect, extraction time and temperature were investigated and optimized as effective parameters in HS-SPME. The calibration curves were linear in the range of 20-300 ng g(-1) (R(2)>0.99). Limits of detection for Fu and HMFu were 6 ng g(-1) and 5 ng g(-1), respectively. The RSD% of Fu and HMFu for five analyses was 4.4 and 4.9, respectively. The proposed method was successfully applied to determine of Fu and HMFu in the different baby formula samples with satisfactory result. The results were in agreement with those obtained using HPLC analysis. The HS-SPME-IMS is precise, selective and sensitive analytical method for determination of Fu and HMFu in baby formula samples, without any derivatization process.

  4. Hydrothermal Conversion of Giant Reed to Furfural and Levulinic Acid: Optimization of the Process under Microwave Irradiation and Investigation of Distinctive Agronomic Parameters.

    PubMed

    Antonetti, Claudia; Bonari, Enrico; Licursi, Domenico; Nassi O Di Nasso, Nicoletta; Raspolli Galletti, Anna Maria

    2015-11-30

    The hydrothermal conversion of giant reed (Arundo donax L.) to furfural (FA) and levulinic acid (LA) was investigated in the presence of dilute hydrochloric acid. FA and LA yields were improved by univariate optimization of the main reaction parameters: concentration of the acid catalyst, solid/liquid ratio of the reaction mixture, hydrolysis temperature, and reaction time. The catalytic performances were investigated adopting the efficient microwave (MW) irradiation, allowing significant energy and time savings. The best FA and LA yields were further confirmed using a traditionally heated autoclave reactor, giving very high results, when compared with the literature. Hydrolysis temperature and time were the main reaction variables to be carefully optimized: FA formation needed milder reaction conditions, while LA more severe ones. The effect of the crop management (e.g., harvest time) on FA/LA production was discussed, revealing that harvest time was not a discriminating parameter for the further optimization of both FA and LA production, due to the very high productivity of the giant reed throughout the year. The promising results demonstrate that giant reed represents a very interesting candidate for a very high contemporary production of FA and LA of up to about 70% and 90% of the theoretical yields, respectively.

  5. 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.

  6. 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.

  7. 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...

  8. 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. PMID:23362138

  9. Catalytic selective etherification of hydroxyl groups in 5-hydroxymethylfurfural over H4SiW12O40/MCM-41 nanospheres for liquid fuel production.

    PubMed

    Che, Penghua; Lu, Fang; Zhang, Junjie; Huang, Yizheng; Nie, Xin; Gao, Jin; Xu, Jie

    2012-09-01

    5-Hydroxymethylfurfural (HMF) is an important biomass-derived building block, but production and sustainable utilization of HMF remain challenging due to reactions of the highly reactive functional groups of this compound. H(4)SiW(12)O(40)/MCM-41 nanospheres were developed that exhibit 84.1% selectivity to 5-ethoxymethylfurfural (EMF) when HMF conversion reaches 92.0%, during etherification of 5-hydroxymethylfurfural (HMF) with ethanol under mild conditions. The catalyst could be reused, and its activity remained unaffected over five cycles. The strong acidity of the catalyst significantly enhanced etherification. The acetalized byproducts, 5-(diethoxymethyl)-2-furanmethanol and the HMF-dimer (5,5'(oxy-bis(methylene))bis-2-furfural), can be converted into HMF and then transformed to the main product, EMF, by using this catalyst to shift the reaction equilibrium. PMID:22749371

  10. 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. PMID:25356540

  11. 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.; 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 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

  12. 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

  13. Predicted thermochemistry for chemical conversions of 5-hydroxymethylfurfural

    NASA Astrophysics Data System (ADS)

    Assary, Rajeev S.; Redfern, Paul C.; Hammond, Jeff R.; Greeley, Jeffrey; Curtiss, Larry A.

    2010-09-01

    The thermochemistry of various chemical transformations of 5-hydroxy methyl furfural (HMF) were investigated using highly accurate G AUSSIAN-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 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.

  14. 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.

  15. Optimization of a Dynamic Hot Water Pretreatment of Switchgrass using Catalysis by Carbonation to Maximize Carbochemical Yields

    NASA Astrophysics Data System (ADS)

    Dhamdere, Rohit Tanaji

    A bio-refinery is a facility that converts renewable bio-resources into value-added chemicals and products. In this context of a bio-refinery, the production of the carbochemicals such as HMF, furfural and organic acids illustrate that multiple products can be produced from a renewable source such as lignocellulosic biomass (switchgrass). Traditionally, carbochemicals such as furfural and HMF are produced using inorganic acids such as H 2SO4, HCL, and H3PO4. The use of such acids requires the application of high cost materials of construction such as Hastelloy-C, titanium etc. The objective of this study is to develop a semi-continuous process for the conversion of switchgrass to carbochemicals such as HMF, furfural and organic acids. Moreover, the application of water as a green reaction medium and the utilization of carbonated water as a "green catalyst" were studied in this research. For the purpose of this study, we constructed a semi-continuous flow apparatus using three high precision Isco syringe pumps and a constant temperature oven to allow carbonation of the water over a range of temperatures and pressure to reactively pretreat switchgrass. Carbochemicals (furan-based aldehydes) and acids that were formed were detected using a Waters HPLC employing a Bio-Rad Aminex HPX-87H column with a PDA (photo diode array) detector at wavelengths range of 210 and 280nm. Oligosaccharides were detected using Dionex HPLC employing Bio-Rad Aminex HPX-87P column using a Shodex RI-101 refractive index detector. The kinetics of the formation and degradation of HMF and furfural were studied using the solver function in Microsoft Excel. Carbonated water clearly showed catalytic activity by increasing the yields of the HMF and furfural at temperatures of 220, 250 and 280°C. The highest catalytic activity was observed for HMF formation in carbonated water with a nine-fold increase in yields over that using neat subcritical water.

  16. 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 ...

  17. 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...

  18. Novel endophytic yeast Rhodotorula mucilaginosa strain PTD3 II: production of xylitol and ethanol in the presence of inhibitors.

    PubMed

    Vajzovic, Azra; Bura, Renata; Kohlmeier, Kevin; Doty, Sharon L

    2012-10-01

    A systematic study was conducted characterizing the effect of furfural, 5-hydroxymethylfurfural (5-HMF), and acetic acid concentration on the production of xylitol and ethanol by a novel endophytic yeast, Rhodotorula mucilaginosa strain PTD3. The influence of different inhibitor concentrations on the growth and fermentation abilities of PTD3 cultivated in synthetic nutrient media containing 30 g/l xylose or glucose were measured during liquid batch cultures. Concentrations of up to 5 g/l of furfural stimulated production of xylitol to 77 % of theoretical yield (10 % higher compared to the control) by PTD3. Xylitol yields produced by this yeast were not affected in the presence of 5-HMF at concentrations of up to 3 g/l. At higher concentrations of furfural and 5-HMF, xylitol and ethanol yields were negatively affected. The higher the concentration of acetic acid present in a media, the higher the ethanol yield approaching 99 % of theoretical yield (15 % higher compared to the control) was produced by the yeast. At all concentrations of acetic acid tested, xylitol yield was lowered. PTD3 was capable of metabolizing concentrations of 5, 15, and 5 g/l of furfural, 5-HMF, and acetic acid, respectively. This yeast would be a potent candidate for the bioconversion of lignocellulosic sugars to biochemicals given that in the presence of low concentrations of inhibitors, its xylitol and ethanol yields are stimulated, and it is capable of metabolizing pretreatment degradation products.

  19. 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.

  20. 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.

  1. Catalytic hydrothermal conversion of carboxymethyl cellulose to value-added chemicals over metal-organic framework MIL-53(Al).

    PubMed

    Zi, Guoli; Yan, Zhiying; Wang, Yangxia; Chen, Yongjuan; Guo, Yunlong; Yuan, Fagui; Gao, Wenyu; Wang, Yanmei; Wang, Jiaqiang

    2015-01-22

    Catalytic hydrolysis of biomass over solid catalysts can be one of the most efficient pathways for a future sustainable society dependent on cellulose biomass. In this work metal-organic framework MIL-53(Al) without any functionalization was directly employed as an efficient heterogeneous catalyst for the hydrolysis of carboxymethyl cellulose (CMC) to 5-hydroxymethyl-furaldehyde (5-HMF) in aqueous phase. A 5-HMF molar yield of 40.3% and total reducing sugar (TRS) molar yield of 54.2% were obtained with water as single solvent at 473 K for 4 h. The catalyst could be reused three times without losing activity to a greater extent. With the remarkable advantages such as the use of water as single solvent and MIL-53(Al) as a novel heterogeneous green catalyst, the work provides a new platform for the production of value added chemicals and liquid fuels from biomass. PMID:25439879

  2. 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. PMID:11170615

  3. 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.

  4. Isolation of bioactive phytoconstituent from Alpinia galanga L. with anti-hyperlipidemic activity.

    PubMed

    Iyer, Deepa; Sharma, Brajesh K; Patil, U K

    2013-12-01

    The present study was undertaken to explore the antihyperlipidemic effect of ethanolic extract of rhizomes of Alpinia galanga L. and its chloroform fraction in Triton-induced hyperlipidemic rats. Bioactivity guided fractionation was followed by chromatographic studies. Flash chromatography was done for the most active fraction resulting in the isolation of 5-(hydroxymethyl) furfural. Animals were administered with i.p. injection of Triton WR 1339 at dose of 400 mg/kg body weight. After 24 hr of Triton administration, the ethanolic extract and its fraction were administered orally at doses of 200 and 400 mg/kg body weight in rats. The treatment was continued for 5 days with a view to see the effect on lipid profile. Serum samples were subjected to biochemical analysis. The study dose dependently inhibited the total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL) level, and significantly increased high-density lipoprotein (HDL) level. Phytochemical screening revealed the presence of tannins, coumarins, flavanoids, sterols, and glycosides. Phytochemical investigation of the chloroform fraction of A. galanga L. resulted in the isolation of 5-(hydroxymethyl) furfural. UV λmax was found to be 276 nm for the isolated component. Acute treatment caused a stimulatory effect on the HDL level and inhibition in TC and TG elevation induced by triton.

  5. Pyrolysis of Table Sugar

    PubMed Central

    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 (1H-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. PMID:24223500

  6. 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. PMID:27003269

  7. Conversion of different part core oil palm trunk into methyl levulinate & hydroxymethylfurfural production

    NASA Astrophysics Data System (ADS)

    Khosnan, Afifah Aqilah Alias; Jahar, NoorHasmiera Abu; Jaafar, Sharifah Nabihah Syed; Zakaria, Sarani; Hua, Chin Chia

    2015-09-01

    In this study, sugar was extracted from the of core oil palm trunk (OPT) and undergoes methanolysis process. The objective of this research is to study the production of methyl levulinate (MLA) and hydroxymethyl furfurals (HMF) from four different parts of OPT such as inner, middle, outer and whole. After methanolysis, samples were characterized by gas chromatography mass spectrometry (GC-MS) and high performance liquid chromatography (HPLC).

  8. 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.

  9. YqhD: a broad-substrate range aldehyde reductase with various applications in production of biorenewable fuels and chemicals.

    PubMed

    Jarboe, Laura R

    2011-01-01

    The Escherichia coli NADPH-dependent aldehyde reductase YqhD has contributed to a variety of metabolic engineering projects for production of biorenewable fuels and chemicals. As a scavenger of toxic aldehydes produced by lipid peroxidation, YqhD has reductase activity for a broad range of short-chain aldehydes, including butyraldehyde, glyceraldehyde, malondialdehyde, isobutyraldehyde, methylglyoxal, propanealdehyde, acrolein, furfural, glyoxal, 3-hydroxypropionaldehyde, glycolaldehyde, acetaldehyde, and acetol. This reductase activity has proven useful for the production of biorenewable fuels and chemicals, such as isobutanol and 1,3- and 1,2-propanediol; additional capability exists for production of 1-butanol, 1-propanol, and allyl alcohol. A drawback of this reductase activity is the diversion of valuable NADPH away from biosynthesis. This YqhD-mediated NADPH depletion provides sufficient burden to contribute to growth inhibition by furfural and 5-hydroxymethyl furfural, inhibitory contaminants of biomass hydrolysate. The structure of YqhD has been characterized, with identification of a Zn atom in the active site. Directed engineering efforts have improved utilization of 3-hydroxypropionaldehyde and NADPH. Most recently, two independent projects have demonstrated regulation of yqhD by YqhC, where YqhC appears to function as an aldehyde sensor.

  10. Nickel-tungsten carbide catalysts for the production of 2,5-dimethylfuran from biomass-derived molecules.

    PubMed

    Huang, Yao-Bing; Chen, Meng-Yuan; Yan, Long; Guo, Qing-Xiang; Fu, Yao

    2014-04-01

    The development of new catalytic systems for the conversion of biomass-derived molecules into liquid fuels has attracted much attention. We propose a non-noble bimetallic catalyst based on nickel-tungsten carbide for the conversion of the platform molecules 5-(hydroxymethyl)furfural into the liquid-fuel molecule 2,5-dimethylfuran (DMF). Different catalysts, metal ratios and reaction conditions have been tested and give rise to a 96% yield of DMF. The catalysts have been characterized and are discussed. The reaction mechanism is also explored through capture of reaction intermediates. The analysis of the reaction mixture over different catalysts is presented and helps to understand the role of nickel and tungsten carbide during the reaction. PMID:24574062

  11. On the Diels-Alder approach to solely biomass-derived polyethylene terephthalate (PET): conversion of 2,5-dimethylfuran and acrolein into p-xylene.

    PubMed

    Shiramizu, Mika; Toste, F Dean

    2011-10-24

    Polyethylene terephthalate (PET) is a polymeric material with high global demand. Conventionally, PET is produced from fossil-fuel-based materials. Herein, we explored the feasibility of a sustainable method for PET production by using solely bio-renewable resources. Specifically, 2,5-dimethylfuran (derived from lignocellulosic biomass through 5-(hydroxymethyl)furfural) and acrolein (produced from glycerol, a side product of biodiesel production) were converted into the key intermediate p-xylene (a precursor of terephthalic acid). This synthesis consists of a sequential Diels-Alder reaction, oxidation, dehydration, and decarboxylation. In particular, the pivotal first step, the Diels-Alder reaction, was studied in detail to provide useful kinetic and thermodynamic data. Although it was found that this reaction requires low temperature to proceed efficiently, which presents a limitation on economic feasibility on an industrial scale, the concept was realized and bio-derived p-xylene was obtained in 34% overall yield over four steps. PMID:21922576

  12. 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.

  13. [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.

  14. 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. PMID:23454803

  15. Synthesis of terephthalic acid via Diels-Alder reactions with ethylene and oxidized variants of 5-hydroxymethylfurfural

    PubMed Central

    Pacheco, Joshua J.; Davis, Mark E.

    2014-01-01

    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. PMID:24912153

  16. 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. PMID:24912153

  17. 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.

  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. PMID:26639478

  19. 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.

  20. Evaluation of antioxidant capacity in coffees marketed in Colombia: Relationship with the extent of non-enzymatic browning.

    PubMed

    Contreras-Calderón, José; Mejía-Díaz, Diana; Martínez-Castaño, Marcela; Bedoya-Ramírez, Daniel; López-Rojas, Natalia; Gómez-Narváez, Faver; Medina-Pineda, Yaqueline; Vega-Castro, Oscar

    2016-10-15

    Fifty-eight samples of commercial Colombian coffee with different characteristics (soluble, ground, decaffeinated, etc) were evaluated for antioxidant capacity (AC) (ABTS and FRAP), total soluble phenolics (TP), browning index (BI), color parameters (L(∗), a(∗), b(∗), c(∗) and h(∗)), HMF and furfural. The AC in Colombian coffees was very varied (164-1000, 100.8-885.9μmol of Trolox equiv/g and 12.5-127mg gallic acid equiv/g, respectively for ABTS, FRAP and TP). AC, TP, BI, color, HMF and furfural values were higher (p<0.05) in soluble coffees than in ground ones, showing the lyophilized samples which showed the highest average values. Significant lineal correlations (p<0.05) were found between AC and color parameters, BI, HMF. No significant (p<0.05) differences in the AC between the different types of coffee were found. This work confirms the direct relationship between the rate of non-enzymatic browning and antioxidant capacity.

  1. Evaluation of antioxidant capacity in coffees marketed in Colombia: Relationship with the extent of non-enzymatic browning.

    PubMed

    Contreras-Calderón, José; Mejía-Díaz, Diana; Martínez-Castaño, Marcela; Bedoya-Ramírez, Daniel; López-Rojas, Natalia; Gómez-Narváez, Faver; Medina-Pineda, Yaqueline; Vega-Castro, Oscar

    2016-10-15

    Fifty-eight samples of commercial Colombian coffee with different characteristics (soluble, ground, decaffeinated, etc) were evaluated for antioxidant capacity (AC) (ABTS and FRAP), total soluble phenolics (TP), browning index (BI), color parameters (L(∗), a(∗), b(∗), c(∗) and h(∗)), HMF and furfural. The AC in Colombian coffees was very varied (164-1000, 100.8-885.9μmol of Trolox equiv/g and 12.5-127mg gallic acid equiv/g, respectively for ABTS, FRAP and TP). AC, TP, BI, color, HMF and furfural values were higher (p<0.05) in soluble coffees than in ground ones, showing the lyophilized samples which showed the highest average values. Significant lineal correlations (p<0.05) were found between AC and color parameters, BI, HMF. No significant (p<0.05) differences in the AC between the different types of coffee were found. This work confirms the direct relationship between the rate of non-enzymatic browning and antioxidant capacity. PMID:27173548

  2. 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

  3. Co-Utilization of Glucose and Xylose for Enhanced Lignocellulosic Ethanol Production with Reverse Membrane Bioreactors.

    PubMed

    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 also allows the reuse of the yeast for several batches. PMID:26633530

  4. 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).

  5. Effects of the Deslagging Process on some Physicochemical Parameters of Honey

    PubMed Central

    Ranjbar, Ali Mohammad; Sadeghpour, Omid; Khanavi, Mahnaz; Shams Ardekani, Mohammad Reza; Moloudian, Hamid; Hajimahmoodi, Mannan

    2015-01-01

    Some physicochemical parameters of honey have been introduced by the International Honey Commission to evaluate its quality and origin but processes such as heating and filtering can affect these parameters. In traditional Iranian medicine, deslagging process involves boiling honey in an equal volume of water and removing the slag formed during process. The aim of this study was to determine the effects of deslagging process on parameters of color intensity, diastase evaluation, electrical conductivity, pH, free acidity, refractive index, hydroxy methyl furfural (HMF), proline and water contents according to the International Honey Committee (IHC) standards. The results showed that deslagged honey was significantly different from control honey in terms of color intensity, pH, diastase number, HMF and proline content. It can be concluded that the new standards are needed to regulate deslagged honey. PMID:25901175

  6. Glucose and fructose to platform chemicals: understanding the thermodynamic landscapes of acid-catalysed reactions using high-level ab initio methods.

    PubMed

    Assary, Rajeev S; Kim, Taejin; Low, John J; Greeley, Jeff; 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. PMID:22932938

  7. 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

  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. 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. PMID:27118074

  10. Valorization of humin-based byproducts from biomass processing-a route to sustainable hydrogen.

    PubMed

    Hoang, Thi Minh Chau; Lefferts, Leon; Seshan, K

    2013-09-01

    The synthesis of biomass-based top value-added chemical platforms, for example, 5-hydroxymethyl furfural, furfural, or levulinic acid from the acid-catalyzed dehydration of sugars results in high yields of insoluble by-products, referred to as humin. Valorization of humin by steam reforming for H2 is discussed. Both thermal and catalytic steam gasification were investigated systematically. Humin undergoes drastic changes under thermal pre-treatment to the gasification temperature. Alkali-metal-based catalysts were screened for the reactions. Na2 CO3 showed the highest activity and was selected for further study. The presence of Na2 CO3 enhances the gasification rate drastically, and gas-product analysis shows that the selectivity to CO and CO2 is 75% and 25%, respectively, which is a H2 /CO ratio of 2 (corresponding to 81.3% H2 as compared to the thermodynamic equilibrium). A possible process for the complete, efficient conversion of humin is outlined. PMID:23939662

  11. Effects of biopretreatment on pyrolysis behaviors of corn stalk by methanogen.

    PubMed

    Wang, Tipeng; Ye, Xiaoning; Yin, Jun; Lu, Qiang; Zheng, Zongming; Dong, Changqing

    2014-07-01

    The study investigated the effects of methanogen pretreatment on pyrolysis behaviors of corn stalk (CS) by using Py-GC/MS analysis and thermogravimetric analysis. Results indicated that biopretreatment changed considerably the pyrolysis behaviors of CS from four weight loss stages to two weight loss stages. Increasing biopretreatment time from 5 days to 25 days enhanced the kinds and contents of chemicals in volatile products. In pyrolysis products, the contents of sugars, linear ketones and furans decreased from 1.43%, 12.60% and 7.38% to 1.25%, 10.22% and 3.25%, respectively, and the contents of phenols increased from 15.08% to 27.84%. The most content change from 6.83% to 13.63% indicated that methanogen pretreatment improved the pyrolysis selectivity of CS to product the 4-VP, but it was disadvantageous to 5-hydroxymethyl furfural, levoglucose and furfural. The changes of chemical compositions and structure of CS after biopretreatment were the main reason of the differences. PMID:24855936

  12. 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.

  13. 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.

  14. 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...

  15. [Activity of ajoene on dermatophytes, Candida albicans and Malassezia furfur.].

    PubMed

    de González, M I; Mendoza, M; Bastardo de Albornoz, M; Apitz-Castro, R

    1998-12-01

    The sensitivity in vitro of an isolate of Trichophyton rubrum and another of Trichophyton mentagrophytes to ajoene. This compound inhibited the growth of both isolates, showing an minimal inhibitory concentration (MIC) of 60 microg/ml and a minimal fungicidal concentration (MFC) of 75 microg/ml. In vivo, the ajoene cream at 0.4% used once a day and every five days in 38 patients (thirty dermatophytosis and eight Candida intertrigo cases) achieved a low percentage of cures (23.3% and 12.5%, respectively). However, an excellent clinic response was obtained in eight patients with pityriasis versicolor, with a cure in 87.5% of the cases.

  16. 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.

  17. 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.

  18. 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.

  19. 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. PMID:24240182

  20. One-pot conversions of lignocellulosic and algal biomass into liquid fuels.

    PubMed

    De, Sudipta; Dutta, Saikat; Saha, Basudeb

    2012-09-01

    The one-pot conversion of lignocellulosic and algal biomass into a liquid fuel, 2,5-dimethylfuran (DMF), has been achieved by using a multicomponent catalytic system comprising [DMA]⁺ [CH₃SO₃]⁻ (DMA=N,N-dimethylacetamide), Ru/C, and formic acid. The synthesis of DMF from all substrates was carried out under mild reaction conditions. The reaction progressed via 5-hydroxyemthylfurfural (HMF) in the first step followed by hydrogenation and hydrogenolysis of HMF with the Ru/C catalyst and formic acid as a hydrogen source. This report discloses the effectiveness of the Ru/C catalyst for the first time for DMF synthesis from inexpensive and readily abundant biomass sources, which gives a maximum yield of 32 % DMF in 1 h. A reaction route involving 5-(formyloxymethyl)furfural (FMF) as an intermediate has been elucidated based on the ¹H and ¹³C NMR spectroscopic data. Another promising biofuel, 5-ethoxymethylfurfural (EMF), was also synthesized with high selectivity from polymeric carbohydrate-rich biomass substrates by using a Brønsted acidic ionic liquid catalyst, that is [DMA]⁺ [CH₃SO₃]⁻, by etherification of HMF in ethanol. PMID:22639414

  1. 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.

  2. Fermentable sugars recovery from lignocellulosic waste-newspaper by catalytic hydrolysis.

    PubMed

    Orozco, Angela M; Al-Muhtaseb, Ala'a H; Rooney, David; Walker, Gavin M; Aiouache, Farid; Ahmad, Mohammad

    2013-01-01

    The urgent need for alternative renewable energies to supplement petroleum-based fuels and the reduction of landfill sites for disposal of solid wastes makes it increasingly attractive to produce inexpensive biofuels from the organic fraction of the municipal solid waste. Therefore, municipal waste in the form of newspaper was investigated as a potential feedstock for fermentable sugars production. Hydrolysis of newspaper by dilute phosphoric acid was carried out in autoclave Parr reactor, where reactor temperature and acid concentration were examined. Xylose concentration reached a maximum value of 14 g/100 g dry mass corresponding to a yield of 94% at the best identified conditions of 2.5 wt% H3PO4, 135 degrees C, 120 min reaction time, and at 2.5 wt% H3PO4, 150 degrees C, and 60 min reaction time. For glucose, an average yield of 26% was obtained at 2.5 wt% H3PO4, 200 degrees C, and 30 min. Furfural and 5-hydroxymethylfurfural (HMF) formation was clearly affected by reaction temperature, where the higher the temperature the higher the formation rate. The maximum furfural formed was an average of 3 g/100 g dry mass, corresponding to a yield of 28%. The kinetic study of the acid hydrolysis was also carried out using the Saeman and the two-fraction models. It was found for both models that the kinetic constants (K) depend on the acid concentration and temperature. The degradation of HMF to levulinic acid is faster than the degradation of furfural to formic acid. Also, the degradation rate is higher than the formation rate for both inhibitors when degradation is observed.

  3. [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.

  4. Connecting lignin-degradation pathway with pre-treatment inhibitor sensitivity of Cupriavidus necator.

    PubMed

    Wang, Wei; Yang, Shihui; Hunsinger, Glendon B; Pienkos, Philip T; Johnson, David K

    2014-01-01

    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. PMID:24904560

  5. Effect of water on hydrolytic cleavage of non-terminal α-glycosidic bonds in cyclodextrins to generate monosaccharides and their derivatives in a dimethyl sulfoxide-water mixture.

    PubMed

    Kimura, Hiroshi; Hirayama, Masaki; Yoshida, Ken; Uosaki, Yasuhiro; Nakahara, Masaru

    2014-02-27

    Hydrolytic cleavage of the non-terminal α-1,4-glycosidic bonds in α-, β-, and γ-cyclodextrins and the anomeric-terminal one in d-maltose was investigated to examine how the cleavage rate for α-, β-, and γ-cyclodextrins is slower than that for d-maltose. Effects of water and temperature were studied by applying in situ (13)C NMR spectroscopy and using a dimethyl sulfoxide (DMSO)-water mixture over a wide range of water mole fraction, xw = 0.004-1, at temperatures of 120-180 °C. The cleavage rate constant for the non-anomeric glycosidic bond was smaller by a factor of 6-10 than that of the anomeric-terminal one. The glycosidic-bond cleavage is significantly accelerated through the keto-enol tautomerization of the anomeric-terminal d-glucose unit into the d-fructose one. The smaller the size of the cyclodextrin, the easier the bond cleavage due to the ring strain. The remarkable enhancement in the cleavage rate with decreasing water content was observed for the cyclodextrins and d-maltose as well as d-cellobiose. This shows the important effect of the solitary water whose hydrogen bonding to other water molecules is prohibited by the presence of the organic dipolar aprotic solvent, DMSO, and which has more naked partial charges and higher reactivity. A high 5-hydroxymethyl-2-furaldehyde (5-HMF) yield of 64% was attained in a non-catalytic conversion by tuning the water content to xw = 0.30, at which the undesired polymerization by-paths can be most effectively suppressed. This study provides a step toward designing a new optimal, earth-benign generation process of 5-HMF starting from biomass.

  6. A mass spectrometric study of the acid-catalysed d-fructose dehydration in the gas phase.

    PubMed

    Pepi, Federico; Ricci, Andreina; Garzoli, Stefania; Troiani, Anna; Salvitti, Chiara; Di Rienzo, Brunella; Giacomello, Pierluigi

    2015-09-01

    5-hydroxymethylfuraldehyde (5-HMF) and simpler compounds, such as levulinic acid (LA) and glyceraldehyde, are platform molecules produced by the thermal acid-catalyzed dehydration of carbohydrates coming from biomass. Understanding sugar degradation pathways on a molecular level is necessary to increase selectivity, reduce degradation by-products yields and optimize catalytic strategies, fundamental knowledge for the development of a sustainable renewable industry. In this work gaseous protonated d-fructose ions, generated in the ESI source of a triple quadrupole mass spectrometer, were allowed to undergo Collisionally Activated Decomposition (CAD) into the quadrupole collision cell. The ionic intermediates and products derived from protonated d-fructose dehydration were structurally characterized by their fragmentation patterns and the relative water-loss dehydration energies measured by energy-resolved CAD mass spectra. The data were compared with those obtained from protonated d-glucose decomposition in the same experimental conditions. In the gas phase, d-fructose dehydration leads to the formation of a mixed population of isomeric [C6H6O3]H(+) ions, whose structures do not correspond exclusively to 5-hydroxymethyl-2-furaldehyde protonated at the more basic aldehydic group.

  7. 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.

  8. 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. PMID:19031321

  9. Phenolic constituents, furans, and total antioxidant status of distilled spirits.

    PubMed

    Goldberg, D M; Hoffman, B; Yang, J; Soleas, G J

    1999-10-01

    The concentrations of 11 phenols and 5 furans were measured in 12 categories of distilled spirits by HPLC methodology, together with the total antioxidant status (TAS) of the same beverages. Ellagic acid was the phenol present in highest concentration in all beverages. Moderate amounts of syringaldehyde, syringic acid, and gallic acid, as well as lesser amounts of vanillin and vanillic acid, were measurable in most samples of whiskey, brandy, and rum but were largely undetectable in gin, vodka, liqueurs, and miscellaneous spirits. 5-(Hydroxymethyl)furfural was the predominant furan in the former three beverages, notably cognac, with 2-furaldehyde the next highest, but these were undetectable in most of the latter beverages. Highest TAS values were given by armagnac, cognac, and bourbon whiskey, all three of which tended toward the highest concentrations of phenols. Negative TAS values were exhibited by rum, vodka, gin, and miscellaneous spirits in line with the low or undetectable phenol concentrations in these beverages. Wood aging is the most likely source of phenols and furans in distilled spirits. Those beverages exposed to this treatment contain significant antioxidant activity, which is between the ranges for white and red wines, with the potential to augment the antiatherosclerotic functions attributable to the ethanol that they contain.

  10. Detection limits of electron and electron capture negative ionization-mass spectrometry for aldehydes derivatized with o-(2,3,4,5,6-pentafluorobenzyl)-hydroxylamine hydrochloride.

    PubMed

    Beránek, Josef; Muggli, Darrin A; Kubátová, Alena

    2010-04-01

    In contrast to common expectations, the differences in limits of detection (LODs) between electron capture negative ionization (ECNI) and electron ionization (EI) mass spectrometry (MS) were found to be insignificant for a wide range of aldehydes derivatized with o-(2,3,4,5,6-pentafluorobenzyl)-hydroxylamine hydrochloride. Comparison of the two ionization methods based on LOD confidence intervals revealed that a traditional presentation of the LOD or limit of quantitation (LOQ) as a single value may over/underestimate the significance of obtained results. LODs were between 20 and 150 pg injected for the majority of tested derivatized carbonyls using both ionization methods. ECNI-MS improved LODs by approximately 10- to 20-fold only for two derivatized aldehydes, 4-hydroxybenzaldehyde and 5-(hydroxymethyl)furfural. Selectivity of ECNI did not appear to be beneficial when analyzing a wood smoke particulate matter (WS-PM) extract, possibly because the majority of interferences were removed during sample preparation (i.e., liquid-liquid extraction). The impact of four different data acquisition modes of transmission quadrupole (TQ)-MS on LODs and their precisions was also investigated. As expected, LODs in the selected ion monitoring (SIM) were approximately two to four times lower than those obtained using total ion current (TIC) mode. More importantly, TQ-MS in the selected ion-total ion (SITI) mode (i.e., acquiring SIM and TIC data in a single analysis) provided signal-to-noise ratios and precisions, which were comparable to SIM alone.

  11. 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.

  12. 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

  13. Quality Evaluation of Polar and Active Components in Crude and Processed Fructus Corni by Quantitative Analysis of Multicomponents with Single Marker

    PubMed Central

    Jiang, Yuhong; Chen, Hui; Wang, Liling; Zou, Jing; Zheng, Xiao

    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. PMID:27446632

  14. Validated HPLC-Diode Array Detector Method for Simultaneous Evaluation of Six Quality Markers in Coffee.

    PubMed

    Gant, Anastasia; Leyva, Vanessa E; Gonzalez, Ana E; Maruenda, Helena

    2015-01-01

    Nicotinic acid, N-methylpyridinium ion, and trigonelline are well studied nutritional biomarkers present in coffee, and they are indicators of thermal decomposition during roasting. However, no method is yet available for their simultaneous determination. This paper describes a rapid and validated HPLC-diode array detector method for the simultaneous quantitation of caffeine, trigonelline, nicotinic acid, N-methylpyridinium ion, 5-caffeoylquinic acid, and 5-hydroxymethyl furfural that is applicable to three coffee matrixes: green, roasted, and instant. Baseline separation among all compounds was achieved in 30 min using a phenyl-hexyl RP column (250×4.6 mm, 5 μm particle size), 0.3% aqueous formic buffer (pH 2.4)-methanol mobile phase at a flow rate of 1 mL/min, and a column temperature at 30°C. The method showed good linear correlation (r2>0.9985), precision (less than 3.9%), sensitivity (LOD=0.023-0.237 μg/mL; LOQ=0.069-0.711 μg/mL), and recovery (84-102%) for all compounds. This simplified method is amenable for a more complete routine evaluation of coffee in industry. PMID:25857885

  15. Analytical method of free and conjugated neutral aroma components in tobacco by solvent extraction coupled with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry.

    PubMed

    Ding, Yu; Zhu, Lijun; Liu, Shaomin; Yu, Hanqing; Dai, Ya

    2013-03-01

    A reliable and simple method for quantitative analysis of free and conjugated neutral aroma components (including aldehydes, ketones, alcohols, esters and alkenes) in tobacco using comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC × GC-TOFMS) is described. Simple solvent extraction using methyl tert-butyl ether (MTBE) ensured extraction of the neutral aroma components in their free form. The components present as conjugates were isolated using MTBE extraction following acid-catalysed hydrolysis. The GC × GC-TOFMS analysis was performed to comprehensively identify different forms of neutral aroma components in tobacco. Compared with the conventional methods, our method not only simplified the process but also saved time and solvent. It also exhibited higher selectivity and sensitivity and demonstrated the following results: the limit of detection of the neutral aroma components varied from 0.006 μg/g for 2-acetylfuran to 0.133 μg/g for 5-(hydroxymethyl)-2-furfural, the relative standard deviations were from 0.5% to 6.8% and the recovery ranged from 82.4% to 118.2%. The optimized method was successfully employed to analyse real tobacco samples. Eighty-three neutral aroma components of interest were identified. PMID:23357748

  16. Analytical method of free and conjugated neutral aroma components in tobacco by solvent extraction coupled with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry.

    PubMed

    Ding, Yu; Zhu, Lijun; Liu, Shaomin; Yu, Hanqing; Dai, Ya

    2013-03-01

    A reliable and simple method for quantitative analysis of free and conjugated neutral aroma components (including aldehydes, ketones, alcohols, esters and alkenes) in tobacco using comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC × GC-TOFMS) is described. Simple solvent extraction using methyl tert-butyl ether (MTBE) ensured extraction of the neutral aroma components in their free form. The components present as conjugates were isolated using MTBE extraction following acid-catalysed hydrolysis. The GC × GC-TOFMS analysis was performed to comprehensively identify different forms of neutral aroma components in tobacco. Compared with the conventional methods, our method not only simplified the process but also saved time and solvent. It also exhibited higher selectivity and sensitivity and demonstrated the following results: the limit of detection of the neutral aroma components varied from 0.006 μg/g for 2-acetylfuran to 0.133 μg/g for 5-(hydroxymethyl)-2-furfural, the relative standard deviations were from 0.5% to 6.8% and the recovery ranged from 82.4% to 118.2%. The optimized method was successfully employed to analyse real tobacco samples. Eighty-three neutral aroma components of interest were identified.

  17. 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. PMID:26213025

  18. Phenolic constituents, furans, and total antioxidant status of distilled spirits.

    PubMed

    Goldberg, D M; Hoffman, B; Yang, J; Soleas, G J

    1999-10-01

    The concentrations of 11 phenols and 5 furans were measured in 12 categories of distilled spirits by HPLC methodology, together with the total antioxidant status (TAS) of the same beverages. Ellagic acid was the phenol present in highest concentration in all beverages. Moderate amounts of syringaldehyde, syringic acid, and gallic acid, as well as lesser amounts of vanillin and vanillic acid, were measurable in most samples of whiskey, brandy, and rum but were largely undetectable in gin, vodka, liqueurs, and miscellaneous spirits. 5-(Hydroxymethyl)furfural was the predominant furan in the former three beverages, notably cognac, with 2-furaldehyde the next highest, but these were undetectable in most of the latter beverages. Highest TAS values were given by armagnac, cognac, and bourbon whiskey, all three of which tended toward the highest concentrations of phenols. Negative TAS values were exhibited by rum, vodka, gin, and miscellaneous spirits in line with the low or undetectable phenol concentrations in these beverages. Wood aging is the most likely source of phenols and furans in distilled spirits. Those beverages exposed to this treatment contain significant antioxidant activity, which is between the ranges for white and red wines, with the potential to augment the antiatherosclerotic functions attributable to the ethanol that they contain. PMID:10552753

  19. Flavonolignans and other constituents from Lepidium meyenii with activities in anti-inflammation and human cancer cell lines.

    PubMed

    Bai, Naisheng; He, Kan; Roller, Marc; Lai, Ching-Shu; Bai, Lu; Pan, Min-Hsiung

    2015-03-11

    From the roots of Lepidium meyenii Walpers (Brassicaceae) have been isolated and identified 2 flavonolignans, tricin 4'-O-[threo-β-guaiacyl-(7″-O-methyl)-glyceryl] ether (1) and tricin 4'-O-(erythro-β-guaiacyl-glyceryl) ether (2), along with 11 other known compounds, tricin (3), pinoresinol (4), 4-hydroxycinnamic acid (5), guanosine (6), glucotropaeolin (7), desulfoglucotropaeolin (8), 3-hydroxybenzylisothiocyanate (9), malic acid benzoate (10), 5-(hydroxymethyl)-2-furfural (11), d-phenylalanine (12), and vanillic acid 4-O-β-d-glucoside (13). Structures were elucidated on the basis of NMR and MS data. Some isolates and previously isolated lepidiline B (14) were tested for cytotoxicity in a small panel of human cancer cell lines (Hep G2, COLO 205, and HL-60) and for anti-inflammatory activities in LPS-treated RAW 264.7 macrophage. Among them, compounds 1 and 14 were modestly active for inhibiting nitrite production in macrophage. Compounds 1, 14, and 3 were demonstrated to be selectively active against HL-60 cells with IC50 values of 40.4, 52.0, and 52.1 μM, respectively. PMID:25667964

  20. Grape products and oral health.

    PubMed

    Wu, Christine D

    2009-09-01

    Oral diseases, including dental caries, periodontal disease, and tooth loss, affect the majority of the population and can affect a person's overall health. Raisins contain polyphenols, flavonoids, and high levels of iron that may benefit human health. However, their oral health benefits are less well understood. We hypothesized that raisins contain antimicrobial phytochemicals capable of suppressing oral pathogens associated with caries or periodontal diseases and thus benefit oral health. Through antimicrobial assay-guided fractionation and purification, compounds identified with growth inhibition against oral pathogens were oleanolic acid, oleanolic aldehyde, linoleic acid, linolenic acid, betulin, betulinic acid, 5-(hydroxymethyl)-2-furfural, rutin, beta-sitosterol, and beta-sitosterol glucoside. Oleanolic acid suppressed in vitro adherence of cariogenic Streptococcus mutans biofilm. When the effect of raisins and raisin-containing bran cereal on in vivo plaque acidogenicity was examined in 7- to 11-y-old children, it was found that raisins did not reduce the plaque pH decline below pH 6 over the 30-min test period. Compared with commercial bran flakes or raisin bran cereal, a lower plaque pH drop was noted in children who consumed a raisin and bran flake mixture when no sugar was added (P < 0.05). Grape seed extract, high in proanthocyanidins, positively affected the in vitro demineralization and/or remineralization processes of artificial root caries lesions, suggesting its potential as a promising natural agent for noninvasive root caries therapy. Raisins represent a healthy alternative to the commonly consumed sugary snack foods.

  1. Protective Effect of Salicornia europaea Extracts on High Salt Intake-Induced Vascular Dysfunction and Hypertension.

    PubMed

    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

  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. PMID:24585634

  3. 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.

  4. Degradation mechanism of monosaccharides and xylan under pyrolytic conditions with theoretic modeling on the energy profiles.

    PubMed

    Wang, Shurong; Ru, Bin; Lin, Haizhou; Luo, Zhongyang

    2013-09-01

    Xylan and three monosaccharides (mannose, galactose, and arabinose) were selected as model compounds to investigate the mechanism of hemicellulose pyrolysis. The evolution of several typical pyrolysis products were observed by thermogravimetric analysis coupled to Fourier transform infrared spectroscopy. Monosaccharides underwent similar pyrolysis routes involving ring opening and secondary decomposition. Breakage of the O-acetyl groups and 4-O-methylglucuronic acid units in xylan branches resulted in its different pyrolysis behavior for the formation of acetic acid, CO2, and CO. The detailed reaction pathways of the monosaccharides were studied using density functional theory calculations. Furfural formation was more favorable than the formation of 1-hydroxy-2-propanone and 4-hydroxydihydrofuran-2(3H)-one during xylose degradation. However, in the pyrolysis of mannose and galactose, formation of 5-hydroxymethyl-2-furaldehyde was preferred because of the high energy barrier of the dissociation of the hydroxymethyl group. Meanwhile, the breakage of O-acetyl groups leading to acetic acid formation easily occurred because of its lower energy barrier. PMID:23819973

  5. Acidic processing of hemicellulosic saccharides from pine wood: product distribution and kinetic modeling.

    PubMed

    Rivas, Sandra; González-Muñoz, María Jesús; Santos, Valentín; Parajó, Juan Carlos

    2014-06-01

    Water soluble compounds were removed from Pinus pinaster wood by a mild aqueous extraction, and the treated wood was subjected to hydrothermal processing to convert most hemicelluloses into soluble saccharides (including low molecular weight polymers, oligomers and monosaccharides). The liquid phase containing hemicellulose-derived saccharides was acidified with sulfuric acid and heated up to 130-250°C to obtain furans and levulinic acid as major products. The concentration profiles of the major compounds participating in the reactions were interpreted by a kinetic model. A maximum conversion of pentoses into furfural near 80% was predicted at high temperature and short time, conditions leading to 24% conversion of hexoses into HMF. Production of levulinic acid was favored at low temperatures. Maximum molar conversion of hexoses into levulinic acid (66.7% at 130°C) needed a long reaction time (235 h). A value of 53.0% can be achieved at 170°C after 5 h.

  6. 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.

  7. 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.; 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 componentmore » in making biofuels production from lignocellulosic biomass feasible.« less

  8. Inhibitor degradation and lipid accumulation potentials of oleaginous yeast Trichosporon cutaneum using lignocellulose feedstock.

    PubMed

    Wang, Juan; Gao, Qiuqiang; Zhang, Huizhan; Bao, Jie

    2016-10-01

    Oleaginous yeast Trichosporon cutaneum is robust to high levels of lignocellulose derived inhibitor compounds with considerable lipid accumulation capacity. The potential of lipid accumulation of T. cutaneum ACCC 20271 was investigated using corn stover hydrolysates with varying sugar and inhibitor concentrations. Biodiesel was synthesized using the extracted lipid and the product satisfied the ASTM standards. Among the typical inhibitors, T. cutaneum ACCC 20271 is relatively sensitive to furfural and 4-hydroxybenzaldehyde, but strongly tolerant to high titers of formic acid, acetic acid, levulinic acid, HMF, vanillin, and syringaldehyde. It is capable of complete degradation of formic acid, acetic acid, vanillin and 4-hydroxybenzaldehyde. Finally, the inhibitor degradation pathways of T. cutaneum ACCC 20271 were constructed based on the newly sequenced whole genome information and the experimental results. The study provided the first insight to the inhibitor degradation of T. cutaneum and demonstrated the potentials of lipid production from lignocellulose.

  9. Inhibitor degradation and lipid accumulation potentials of oleaginous yeast Trichosporon cutaneum using lignocellulose feedstock.

    PubMed

    Wang, Juan; Gao, Qiuqiang; Zhang, Huizhan; Bao, Jie

    2016-10-01

    Oleaginous yeast Trichosporon cutaneum is robust to high levels of lignocellulose derived inhibitor compounds with considerable lipid accumulation capacity. The potential of lipid accumulation of T. cutaneum ACCC 20271 was investigated using corn stover hydrolysates with varying sugar and inhibitor concentrations. Biodiesel was synthesized using the extracted lipid and the product satisfied the ASTM standards. Among the typical inhibitors, T. cutaneum ACCC 20271 is relatively sensitive to furfural and 4-hydroxybenzaldehyde, but strongly tolerant to high titers of formic acid, acetic acid, levulinic acid, HMF, vanillin, and syringaldehyde. It is capable of complete degradation of formic acid, acetic acid, vanillin and 4-hydroxybenzaldehyde. Finally, the inhibitor degradation pathways of T. cutaneum ACCC 20271 were constructed based on the newly sequenced whole genome information and the experimental results. The study provided the first insight to the inhibitor degradation of T. cutaneum and demonstrated the potentials of lipid production from lignocellulose. PMID:27441826

  10. Effect of thermal, acid, alkaline and alkaline-peroxide pretreatments on the biochemical methane potential and kinetics of the anaerobic digestion of wheat straw and sugarcane bagasse.

    PubMed

    Bolado-Rodríguez, Silvia; Toquero, Cristina; Martín-Juárez, Judit; Travaini, Rodolfo; García-Encina, Pedro Antonio

    2016-02-01

    The effect of thermal, acid, alkaline and alkaline-peroxide pretreatments on the methane produced by the anaerobic digestion of wheat straw (WS) and sugarcane bagasse (SCB) was studied, using whole slurry and solid fraction. All the pretreatments released formic and acetic acids and phenolic compounds, while 5-hydroxymetilfurfural (HMF) and furfural were generated only by acid pretreatment. A remarkable inhibition was found in most of the whole slurry experiments, except in thermal pretreatment which improved methane production compared to the raw materials (29% for WS and 11% for SCB). The alkaline pretreatment increased biodegradability (around 30%) and methane production rate of the solid fraction of both pretreated substrates. Methane production results were fitted using first order or modified Gompertz equations, or a novel model combining both equations. The model parameters provided information about substrate availability, controlling step and inhibitory effect of compounds generated by each pretreatment.

  11. Quality changes of pasteurised orange juice during storage: A kinetic study of specific parameters and their relation to colour instability.

    PubMed

    Wibowo, Scheling; Grauwet, Tara; Santiago, Jihan Santanina; Tomic, Jovana; Vervoort, Liesbeth; Hendrickx, Marc; Van Loey, Ann

    2015-11-15

    In view of understanding colour instability of pasteurised orange juice during storage, to the best of our knowledge, this study reports for the first time in a systematic and quantitative way on a range of changes in specific quality parameters as a function of time and as well as temperature (20-42 °C). A zero-order (°Brix, fructose, glucose), a first-order (vitamin C), a second-order (sucrose) and a fractional conversion model (oxygen) were selected to model the evolution of the parameters between parentheses. Activation energies ranged from 22 to 136 kJ mol(-1), HMF formation being the most temperature sensitive. High correlations were found between sugars, ascorbic acid, their degradation products (furfural and HMF) and total colour difference (ΔE(∗)). Based on PLS regression, the importance of the quality parameters for colour degradation was ranked relatively among each other: the acid-catalysed degradation of sugars and ascorbic acid degradation reactions appeared to be important for browning development in pasteurised orange juice during ambient storage. PMID:25977009

  12. Stability and quality of herb (Pueraria Tuberosa)-milk model system.

    PubMed

    Sawale, Pravin Digambar; Singh, R R B; Arora, Sumit

    2015-02-01

    The medicinal benefits of herbs could be conveyed via certain foods as carriers. Milk is one of the important carrier which has been effectively used to deliver phytochemicals presents in herbs (mainly polyphenols) for targeted health benefits in the traditional Indian system of medical science. The present study was conducted to evaluate the effect of herb components (Pueraria tuberosa) on properties of Pueraria tuberosa-milk model system. The herb was added into cow milk on the basis of sensory evaluation (0.4 %) by using 9-point hedonic scale. The physical and chemical changes were evaluated after various processing treatments viz. pasteurization (72 °C, 15 s), sterilization (121 °C, 15 min), separation etc. These changes were determined using viscosity, hydroxy methyl furfural (HMF) value, ethanol stability, colour characteristics and trolox equivalent antioxidant capacity (TEAC). It was observed that addition of Pueraria tuberosa to milk resulted in decreased HMF content, ethanol stability and lightness whereas antioxidant activity, redness and yellowness increased as compared to control. It can be concluded that addition of Pueraria tuberosa to milk at 0.4 % concentration altered the functional properties of milk and Pueraira tuberosa could be suitable for preparation of low heat treated functional dairy food products. PMID:25694723

  13. Quality changes of pasteurised orange juice during storage: A kinetic study of specific parameters and their relation to colour instability.

    PubMed

    Wibowo, Scheling; Grauwet, Tara; Santiago, Jihan Santanina; Tomic, Jovana; Vervoort, Liesbeth; Hendrickx, Marc; Van Loey, Ann

    2015-11-15

    In view of understanding colour instability of pasteurised orange juice during storage, to the best of our knowledge, this study reports for the first time in a systematic and quantitative way on a range of changes in specific quality parameters as a function of time and as well as temperature (20-42 °C). A zero-order (°Brix, fructose, glucose), a first-order (vitamin C), a second-order (sucrose) and a fractional conversion model (oxygen) were selected to model the evolution of the parameters between parentheses. Activation energies ranged from 22 to 136 kJ mol(-1), HMF formation being the most temperature sensitive. High correlations were found between sugars, ascorbic acid, their degradation products (furfural and HMF) and total colour difference (ΔE(∗)). Based on PLS regression, the importance of the quality parameters for colour degradation was ranked relatively among each other: the acid-catalysed degradation of sugars and ascorbic acid degradation reactions appeared to be important for browning development in pasteurised orange juice during ambient storage.

  14. 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. PMID:24924637

  15. A linear discrete dynamic system model for temporal gene interaction and regulatory network influence in response to bioethanol conversion inhibitor HMF for ethanologenic yeast

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A linear discrete dynamic system model is constructed to represent the temporal interactions among significantly expressed genes in response to bioethanol conversion inhibitor 5-hydroxymethylfurfural for ethanologenic yeast Saccharomyces cerevisiae. This study identifies the most significant linear...

  16. 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

  17. Feasibility of removing furfurals from sugar solutions using activated biochars made from agricultural residues

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lignocellulosic feedstocks are often prepared for ethanol fermentation by treatment with a dilute mineral acid catalyst that hydrolyzes the hemicellulose and possibly cellulose into soluble carbohydrates. The acid catalyzed reaction scheme is sequential whereby released monosaccharides are further ...

  18. 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...

  19. 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.

  20. 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