Abstract  Floral scent plays important roles in basal angiosperms such as the pantropical woody family Annonaceae. The North American genus Asimina ( Adans.) ( Annonaceae) includes eight species of shrubs and small trees, of which Asimina triloba has the broadest and northernmost distribution. We characterized the yeastlike fragrance of these flowers using gas chromatography - mass spectrometry in natural populations in South Carolina. The odors of A. triloba and baker's yeast Saccharomyces cerevisiae shared ethanol, ethyl acetate, acetic acid, and other compounds but differed in relative amounts of 3-methyl-1-butanol, 3-OH-2- butanone, and butane-2,3-diol. Immature green flowers of A. triloba produced sesquiterpenes common to the foliage of many plants. In contrast, sexually mature flowers emitted fermentation volatiles, with additional nitrogenous compounds (androgynoecium) and butanediols ( outer corolla) emitted by male flowers. Some compounds were detected only when scent was sampled from at least 10 flowers. Chemical composition was more complex during day than night for immature and female flowers but not for males. Emission rates were fourfold greater in male than female flowers during the day but were comparable at night, perhaps because of overlapping gender expression. The yeasty odor of A. triloba is unusual in angiosperms and may serve to attract novel fly and beetle pollinators.

Abstract  Clostridium beijerinckii mutant strain IB4, which has a high level of inhibitor tolerance, was screened by low-energy ion implantation and used for butanol fermentation from a non-detoxified hemicellulosic hydrolysate of corn fiber treated with dilute sulfuric acid (SAHHC). Evaluation of toxicity showed C. beijerinckii IB4 had a higher level of tolerance than parent strain C. beijerinckii NCIMB 8052 for five out of six phenolic compounds tested (the exception was vanillin). Using glucose as carbon source, C. beijerinckii IB4 produced 9.1 g l(-1) of butanol with an acetone/butanol/ethanol (ABE) yield of 0.41 g g(-1). When non-detoxified SAHHC was used as carbon source, C. beijerinckii NCIMB 8052 grew well but ABE production was inhibited. By contrast, C. beijerinckii IB4 produced 9.5 g l(-1) of ABE with a yield of 0.34 g g(-1), including 2.2 g l(-1) acetone, 6.8 g l(-1) butanol, and 0.5 g l(-1) ethanol. The remarkable fermentation and inhibitor tolerance of C. beijerinckii IB4 appears promising for ABE production from lignocellulosic materials.

Abstract  Activity-directed fractionation and purification processes were employed to identify the anti-Alzheimer active compounds from the root of Angelica sinensis. In this study, the ability of Angelica root to inhibit the aggregated amyloid beta-peptide (agg A beta(1-40)) induced damage of differentiated PC-12 cells (dPC-12), a well-known cell model for Alzheimer disease, was investigated. Air-dried roots of A sinensis were extracted with methanol and then separated into ethyl acetate, n-butanol and water layers. Among them, only the ethyl acetate layer showed strong activity and therefore, subjected to separation and purification using various chromatographic techniques. Four compounds showing potent activity were identified by comparing spectral data (UV, NMR, and ESI-MS) with literature values to be Z-ligustilide, 11-angeloylsenkyunolide F, coniferyl ferulate and ferulic acid. They were found to significantly inhibit A beta(1-40) toxicity on dPC-12 cells at lower concentrations (1-10 mu g/ml), but at high concentrations (>50 mu g/ml) they were toxic to the dPC-12 cells, except 11-angeloylsenkyunolide F. DPPH scavenging activity of the extracts and isolated compounds have also been carried out to find the possible mechanism of the activity. (C) 2008 Published by Elsevier Ltd.

Abstract  We recently developed two biomarker sets for oxidative damage: one for determination of lipid peroxidation (LPO) degradation products; acetaldehyde, propanal, butanal, pentanal, hexanal, heptanal, octanal, nonanal, malondialdehyde and acetone, by a gas chromatography-electron capture detection method, and the other for protein oxidation products such as o,o'-dityrosine, by an isotope dilution high performance liquid chromatography-tandem mass spectrometry method. In the present study, we explored the possibility to utilize these biomarkers for determining the oxidative damage in liver mammalian cells in vitro. Two different treatments were chosen for inducing oxidative stress in Chinese Hamster ovary cells: menadione and copper plus hydrogen peroxide (Cu2+/H2O2). Cells were incubated with the model compounds in the presence or absence of vitamin E and C, and cytotoxicity was evaluated by a nuclear-dye method. Results were compared to two fluorescent probes, H2DCF-DA and C11 -BODIPY581/591, which have been used for determining the formation of free radicals in the cells. From ten LPO degradation products, eight were increased significantly following incubation with menadione in cell lysate or incubation media. Menadione-induced oxidative stress was also confirmed by oxidation of fluorescent probes. However, no increased formation of protein oxidation products was observed. Vitamin E and C did not diminish the formation of LPO degradation products that were increased by menadione. Although Cu2+/H2O2 did not induce oxidation of fluorescent probes, it induced formation of six out of ten LPO degradation products. Vitamin E and C did not diminish the formation of LPO degradation products; vitamin C even substantially increased the formation of acetaldehyde and propanal, which is in line with its reported prooxidant action under certain conditions. Vitamin C also caused two-fold increase in Cu2+/H2O2-induced o,o'-dityrosine formation when applied simultaneously. In conclusion, our present results show that the LPO biomarker set can be used for evaluation of oxidant capacity and the toxic potential of various chemicals in an in vitro cell model. These biomarkers might even be more sensitive than measuring protein oxidation products or oxidation of fluorescent probes.

Abstract  To improve the dissolution behavior of lipophilic drugs, a novel bottom-up process based upon freeze drying which allows for the production of nanocrystalline particles was developed: "controlled crystallization during freeze drying". This novel process could strongly increase the dissolution behavior of fenofibrate. For example at a drug load of 30% w/w, 80% of the drug dissolved within 10 min from tablets prepared from the controlled crystallized dispersions, while from tablets prepared from the physical mixture only 50% was dissolved after 120 min. Furthermore it was found that faster freezing or using a solution with a lower water/tertiary butyl alcohol (TBA) ratio resulted in faster dissolution, indicating that the crystalline dispersions contained smaller crystals. Crystallization of the drug could occur during freezing or during drying. When crystallization occurs during freezing, faster freezing or using solutions with a lower water/TBA ratio results in the formation of more nuclei and consequently smaller crystals. When crystallization occurs during drying, faster freezing or using solutions with a higher water/TBA ratio results in the formation of smaller solvent crystals and therefore smaller interstitial spaces which contain the freeze-concentrated fraction. Since crystallization occurs in the freeze-concentrated fraction and the size of the crystals are limited to the size of the interstitial spaces, smaller crystals are formed in these situations.

Abstract  Methyl tert-butyl ether (MTBE) is one of the main additives in gasoline. Its degradation is known to be difficult in natural environments. In this study, significant MTBE degradation is demonstrated at a contaminated site in Leuna (eastern Germany). Since the extent of the plume appeared to be constant over the last 5 years, an extended study was performed to elucidate the degradation processes. Special attention was paid to the production, accumulation and degradation of metabolites and by-products. Groundwater samples from 105 monitoring wells were used to measure 20 different substances. During the degradation process, several intermediates such as tert-butyl alcohol (TBA), tert-butyl formate, formate and lactate were produced. However, the potentially carcinogenic by-product methacrylate was not detected in several hundred samples. At the Leuna site, MTBE degradation occurred under microaerobic conditions. In contrast to hydrocarbons and BTEX, there was no evidence for anaerobic MTBE degradation. Among the degradation products, TBA was found to be a useful intermediate to identify MTBE degradation, at least under microaerobic conditions. TBA accumulation was strongly correlated to MTBE degradation according to the kinetic properties of both degradation processes. Since maximum degradation rates (v(max)) and k(m) values were higher for MTBE (v(max)=2.3 mg/l/d and k(m)=3.2 mg/l) than for TBA (v(max)=1.35 mg/l/d and k(m)=0.05 mg/l), TBA significantly accumulated as an intermediate by-product. The field results were supported by bench scale model aquifer experiments.

Abstract  ANG II stimulates phospholipase D (PLD) activity and growth of vascular smooth muscle cells (VSMC). The atypical protein kinase C-zeta (PKCzeta) plays a central role in the regulation of cell survival and proliferation. This study was conducted to determine the relationship between ANG II-induced activation of PKCzeta and PLD and their implication in VSMC adhesion, spreading, and hypertrophy. ANG II stimulated PKCzeta activity with maximal activation at 30 s followed by a decline in its activity to 45% above basal at 5 min. Inhibition of PKCzeta activity with a myristoylated pseudosubstrate peptide or overexpression of a kinase-inactive form of PKCzeta decreased ANG II-induced PLD activity. Moreover, depletion of PKCzeta with selective antisense oligonucleotides also decreased ANG II-induced PLD activity. Interaction between PLD2 and PKCzeta in VSMC was detected by coimmunoprecipitation. ANG II-induced PLD activity was inhibited by the primary alcohol n-butanol but not the tertiary alcohol t-butanol. The functional significance of PKCzeta and PLD2 in VSMC adhesion, spreading, and hypertrophy was investigated. Inhibition of PKCzeta and PLD2 activity or expression attenuated VSMC adhesion to collagen I and ANG II-induced cell spreading and hypertrophy. These results demonstrate that ANG II-induced PLD activation is regulated by PKCzeta and suggest a crucial role of PKCzeta-dependent PLD2 in VSMC functions such as adhesion, spreading, and hypertrophy, which are associated with the pathogenesis of atherosclerosis and malignant hypertension.

Abstract  OBJECTIVES: The aim of this study was to determine if spray-drying could successfully produce microparticles containing the model protein trypsin in a form suitable for inhalation.

METHODS: Trypsin was spray-dried with raffinose from a methanol : n-butyl acetate solvent system (MeOH : BA). The solvent system was then adjusted to include water, and trypsin was co-spray-dried with raffinose, trehalose or hydroxpropyl-β-cyclodextrin. The spray-dried products were characterised by SEM, XRD, DSC, TGA and FTIR. Protein biological activity and in-vitro deposition of trypsin : excipient nanoporous/nanoparticulate microparticles (NPMPs) was also assessed.

KEY FINDINGS: The inclusion of water in a MeOH : BA solvent system allowed for the successful production of NPMPs of trypsin : excipient by spray-drying. Trypsin formulated as trypsin : excipient NPMPs retained biological activity on processing and showed no deterioration in activity or morphological characteristics when stored with desiccant at either 4 or 25°C. Hydroxpropyl-β-cyclodextrin showed advantages over the sugars in terms of producing powders with appropriate density and with greater physical stability under high-humidity conditions. Fine particle fractions of between 41 and 45% were determined for trypsin : excipient NPMPs.

CONCLUSIONS: NPMPs of trypsin : excipient systems can be produced by spray-drying by adjustment of the solvent system to allow for adequate solubility of trypsin.

Abstract  A chemiresistor type sensor for selective alcohol sensing has been realized from gallium nitride (GaN) nanowires (NWs) functionalized with sputter-deposited tin dioxide (SnO2) nanoparticles. Two-terminal devices were fabricated using standard microfabrication techniques with the individual NWs air-bridged between the two metal contact pads. Through a combination of X-ray diffraction (XRD), electron-backscatter-diffraction (EBSD), and TEM/STEM techniques, we confirmed the presence of rutile SnO2 nanocrystals on the GaN surface. A change in device current is observed when the device is exposed to alcohol vapors (methanol, ethanol, propanol, and butanol) at room temperature under 215-400 nm UV illumination with 3.75 mW/m(2) intensity at 365 nm wavelength. The sensor reproducibly responded to a wide range of alcohol vapor concentrations, from 5000 mu mol/mol (ppm) down to 1 mu mol/mol (ppm) in air. Notably, the devices show low sensitivity to acetone and hexane, which allows them to selectively detect the primary alcohol vapors mixed with these two common volatile organic compounds (VOCs). The sensor response was not observed without UV excitation. From the experimental results we found a relationship between the response towards the alcohol vapors and the length of carbon chain in the molecule: the chemiresistive response decreases with the increasing carbon chain from methanol to n-butanol. In addition, we observed that the isomeric branching in i-propanol and i-butanol caused reduced response as compared to n-propanol and n-butanol, respectively. We have qualitatively explained the sensor operation by employing a mechanism, which includes oxidation of analyte molecules on the SnO2 surface, leading to enhanced photoconductivity in GaN nanowire. (C) 2012 Elsevier B.V. All rights reserved.

Abstract  The Present study was conducted to investigate the biological activities of the plant O. monacantha cladodes. The plant cladodes were extracted with methanol and then fractionized with various organic solvents (n-hexane, chloroform, ethyl acetate and n-butanol). The extract and fractions thus obtained were analyzed for their phytochemical, antioxidant and antimicrobial analysis. The percentage yield of methanolic extract and various fractions was found to be 2.7-28.9%. Phytochemical analysis exposed the presence of alkaloids, tannins, saponins and flavonoids in methanolic extract. The plant extract and fractions contained total phenolic contents (14.5-249 GAE, mg/100 g of dry plant matter) and total flavonoid contents (10-433.8 CE, mg/100 g of dry plant matter). DPPH radical scavenging activity was determined by measuring IC50 that was found to be 41.4-838.8 mu g/mL. Nevertheless, minute variation was observed in reducing power. Methanol extract exhibited highest antioxidant activity among various solvent fractions. The antimicrobial activity was determined by disc diffusion method and minimum inhibitory concentration against a panel of microorganisms. Significant variations (p < 0.05) were observed in the results.

Abstract  The present study aimed to investigate the direct in vitro effects of several distinct Citrullus colocynthis seed extracts on glucose-stimulated insulin release from pancreatic islets isolated from rats. Six extracts were tested, a crude aqueous, defatted aqueous, ethyl acetate, H2O-methanol and n-butanol extract and an extract containing a major component (fraction A) identified by gel chromatography in the ethyl acetate, n-butanol and H2O-methanol extracts. Under selected experimental conditions, the majority of extracts exhibited a positive insulinotropic action, at least when tested in the presence of 8.3 mM D-glucose. The concentration-response correlation observed with distinct extracts revealed the participation of distinct chemical compounds, including compounds with an inhibitory insulinotropic potential, in the modulation of the insulin secretory response to D-glucose. The results of the present study are relevant for further investigations which aim to identify compounds exhibiting positive insulinotropic actions. These agents may be suitable for the treatment of human diabetic subjects.

Abstract  The role of aliphatic carboxylic acids in host-seeking response of the malaria mosquito Anopheles gambiae sensu stricto was examined both in a dual-choice olfactometer and with indoor traps. A basic attractive blend of ammonia + lactic acid served as internal standard odor. Single carboxylic acids were tested in a tripartite blend with ammonia + lactic acid. Four different airflow stream rates (0.5, 5, 50, and 100 ml/min) carrying the compounds were tested for their effect on trap entry response in the olfactometer. In the olfactometer, propanoic acid, butanoic acid, 3-methylbutanoic acid, pentanoic acid, heptanoic acid, octanoic acid, and tetradecanoic acid increased attraction relative to the basic blend. While several carboxylic acids were attractive only at one or two flow rates, tetradecanoic acid was attractive at all flow rates tested. Heptanoic acid was attractive at the lowest flow rate (0.5 ml/min), but repellent at 5 and 50 ml/min. Mixing the air stream laden with these 7 carboxylic acids together with the headspace of the basic blend increased attraction in two quantitative compositions. Subtraction of single acids from the most attractive blend revealed that 3-methylbutanoic acid had a negative effect on trap entry response. In the absence of tetradecanoic acid, the blend was repellent. In assays with MM-X traps, both a blend of 7 carboxylic acids + ammonia + lactic acid (all applied from low density polyethylene-sachets) and a simple blend of ammonia + lactic acid + tetradecanoic acid were attractive. The results show that carboxylic acids play an essential role in the host-seeking behavior of An. gambiae, and that the contribution to blend attractiveness depends on the specific compound studied.

Abstract  Hydromorphic soils have a low drainage capacity and are used mainly for the cultivation of irrigated rice. This condition favors the development of anaerobic microorganisms that produce phytotoxic substances. The objective of this study was to evaluate the response of rice mutants to the phytotoxicity caused by butyric acid under anaerobic conditions. The experiment consisted of four treatments arranged in a randomized block design. Plants of 40 families were grown in a hydroponic system and the measured variables were root length and length of aerial part (LAP), number of roots (NR) and root dry matter (RDM) and aerial part dry matter (DMAP). The analysis of variance was performed, the relative performance calculated and linear regressions were fitted. Only the treatment effect for NR and effect of interaction for LAP were not significant. Root length was most affected by the acid and the regressions expressed positive as well as negative effects for acid tolerance in the mutant families.

Abstract  Solubility data for triclosan and iodopropynyl butylcarbamate (IPBC) in ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, and 1-heptanol were measured. Solid-liquid phase equilibrium measurements were conducted at several temperatures (from 278.15 to 318.15 K). After drying the equilibrium saturated solutions, gravimetric measurement was used to determine experimental solubility. The data were correlated using a equation for the solubility of a solid in a liquid and the nonrandom two liquid (NRTL), universal quasi-chemical (UNIQUAC) and Wilson models for activity coefficients. The data are well fitted with all three models for the six pure alcohols studied here. (C) 2012 Elsevier B.V. All rights reserved.

Abstract  Novel nanosize SnO2 particles were synthesized by a hard template method. The crystal structure and morphologies were characterized by X-ray diffraction and transmission electron microscopy. The particle size is around 4 nm, which is less than two times the depth (L) of the of the surface depletion layer. The sensing properties towards a series of gases, including ethanol, isopropanol, 1-butanol, formaldehyde, acetic acid, acetone, and 92# gasoline, were tested at different gas concentrations. The results reveal that the SnO2 nanoparticles have high responsivity towards forementioned toxic and flammable gases.

Abstract  The solventogenic bacterium Clostridium acetobutylicum is the most important species of Clostridium used in the fermentation industry. However, the intolerance to butanol hampers the efficient production of solvents. Butanol toxicity has been attributed to the chaotropic effect on the cell membrane, but the knowledge on the effect of butanol on membrane associated proteins is quite limited. Using 2-DE combined with MALDI-TOF MS/MS and 1-DE integrated with LC-MS/MS, 341 proteins in the membrane fractions of cell lysate were identified, thus establishing the first comprehensive membrane proteome of C. acetobutylicum. The identified proteins are mainly involved in transport, cellular membrane/wall machinery, formation of surface coat and flagella, and energy metabolism. Comparative analysis on the membrane proteomes of the wild type strain DSM 1731 and its butanol-tolerant mutant Rh8 revealed 73 differentially expressed proteins. Hierarchical clustering analysis suggested that mutant Rh8 may have evolved a more stabilized membrane structure, and have developed a cost-efficient energy metabolism strategy, to cope with the butanol challenge. This comparative membrane proteomics study, together with our previous published work on comparative cytoplasmic proteomics, allows us to obtain a systemic understanding of the effect of butanol on cellular physiology of C. acetobutylicum.

Abstract  Rhodococcus erythropolis is a promising Gram-positive bacterium capable of numerous bioconversions including those involving alcohol dehydrogenases (ADHs). In this work, we compared and optimized the redox biocatalytic performances of 1- butanol-grown R. erythropolis NCIMB 13064 cells in aqueous and in non-conventional gas phase using the 1-butanol-hexanal oxidation-reduction as model reaction. Oxidation of 1-butanol to butanal is tightly coupled to the reduction of hexanal to 1-hexanol at the level of a nicotinoprotein-ADH-like enzyme. Cell viability is dispensable for reaction. In aqueous batch conditions, fresh and lyophilized cells are efficient redox catalysts (oxidation-reduction rate = 765 mu mol min(-1) g cell dry mass(-1)) being also reactive towards benzyl alcohol, (S)-2- pentanol, and geraniol as reductants. However, butanol-hexanal oxidation-reduction is strongly limited by product accumulation and by hexanal toxicity that is a major factor influencing cell behavior and performance. Reaction rate is maximal at 40 degrees C-pH 7.0 in aqueous phase and at 60 degrees C-pH 7.0-9.0 in gas phase. Importantly, lyophilized cells also showed to be promising redox catalysts in the gas phase (at least 65 mu mol min(-1) g cell dry mass(-1)). The system is notably stable for several days at moderate thermodynamic activities of hexanal (0.06-0.12), 1- butanol (0.12) and water (0.7). (C) 2008 Elsevier Inc. All rights reserved.

Abstract  BACKGROUND: Butanol fermentation is product limiting owing to butanol toxicity to microbial cells. Butanol (boiling point: 118 degrees C) boils at a higher temperature than water (boiling point: 100 degrees C) and application of vacuum technology to integrated acetonebutanolethanol (ABE) fermentation and recovery may have been ignored because of direct comparison of boiling points of water and butanol. This research investigated simultaneous ABE fermentation using Clostridium beijerinckii 8052 and in situ butanol recovery by vacuum. To facilitate ABE mass transfer and recovery at fermentation temperature, batch fermentation was conducted in triplicate at 35 degrees C in a 14 L bioreactor connected in series with a condensation system and vacuum pump. RESULTS: Concentration of ABE in the recovered stream was greater than that in the fermentation broth (from 15.7 g L-1 up to 33 g L-1). Integration of the vacuum with the bioreactor resulted in enhanced ABE productivity by 100% and complete utilization of glucose as opposed to a significant amount of residual glucose in the control batch fermentation. CONCLUSION: This research demonstrated that vacuum fermentation technology can be used for in situ butanol recovery during ABE fermentation and that C. beijerinckii 8052 can tolerate vacuum conditions, with no negative effect on cell growth and ABE production. (C) 2011 Society of Chemical Industry

Abstract  The tea green leafhopper, Empoasca vitis Gothe, is one of the most serious insect pests of tea plantations in mainland China. Over the past decades, this pest has been controlled mainly by spraying pesticides. Insecticide applications not only have become less effective in controlling damage, but even more seriously, have caused high levels of toxic residues in teas, which ultimately threatens human health. Therefore, we should seek a safer biological control approach. In the present study, key components of tea shoot volatiles were identified and behaviorally tested as potential leafhopper attractants. The following 13 volatile compounds were identified from aeration samples of tea shoots using gas chromatography-mass spectrometry (GC-MS): (E)-2-hexenal, (Z)-3-hexen-1-ol, (Z)-3-hexenyl acetate, 2-ethyl-1-hexanol, (E)-ocimene, linalool, nonanol, (Z)-butanoic acid, 3-hexenyl ester, decanal, tetradecane, beta-caryophyllene, geraniol and hexadecane. In Y-tube olfactometer tests, the following individual compounds were identified: (E)-2-hexenal, (E)-ocimene, (Z)-3-hexenyl acetate and linalool, as well as two synthetic mixtures (called blend 1 and blend 2) elicited significant taxis, with blend 2 being the most attractive. Blend 1 included linalool, (Z)-3-hexen-1-ol and (E)-2-hexenal at a 1 : 1 : 1 ratio, whereas blend 2 was a mixture of eight compounds at the same loading ratio: (E)-2-hexenal, (Z)-3-hexen-1-ol, (Z)-3-hexenyl acetate, 2-penten-1-ol, (E)-2-pentenal, pentanol, hexanol and 1-penten-3-ol. In tea fields, the bud-green sticky board traps baited with blend 2, (E)-2-hexenal or hexane captured adults and nymphs of the leafhoppers, with blend 2 being the most attractive, followed by (E)-2-hexenal and hexane. Placing sticky traps baited with blend 2 or (E)-2-hexenal in the tea fields significantly reduced leafhopper populations. Our results indicate that the bud-green sticky traps baited with tea shoot volatiles can provide a new tool for monitoring and managing the tea leafhopper.

Abstract  This article reviews bioconversion of plant materials such as wheat straw (WS), corn stover (CS), barley straw (BS), and switchgrass (SG) to butanol and process technology that converts these materials into this superior biofuel. Successful fermentation of low-value WS makes butanol fermentation economically attractive. Simultaneous hydrolysis, fermentation, and product recovery has been successfully performed in a single reactor using WS and C. beijerinckii P260. Research on the production of butanol from other agricultural residues including CS, BS, and SG has steadily progressed. Use of several product- recovery technologies such as liquid-liquid extraction, gas stripping, perstraction, and pervaporation has been successfully applied in laboratory-scale bioreactors. It is expected that these recovery technologies will play a major role in commercialization of this fermentation. By employing in line/in situ product-recovery systems during fermentation, butanol toxicity to the culture has been drastically reduced. In addition to the use of low-cost plant materials for the production of this biofuel, process integration is expected to play a major role in the economics of this product. (C) 2008 Society of Chemical Industry and John Wiley & Sons, Ltd

Abstract  Fermentation of dilute sulfuric acid barley straw hydrolysate (BSH; undiluted/untreated) by Clostridium beijerinckii P260 resulted in the production of 7.09 gL(-1) ABE (acetone butanol ethanol), an ABE yield of 0.33, and productivity of 0.10 gL(-1) h(-1). This level of ABE is much less than that observed in a control experiment (21.06 gL(-1)) where glucose (initial concentration 60 gL(-1)) was used as a substrate. In the control experiment, an ABE yield of 0.41 and productivity of 0.31 gL(-1) h(-1) were observed. This comparison suggested that BSH is toxic to the culture. To reduce this potential toxicity effect, BSH was treated with lime [Ca(OH)(2)] followed by fermentation. The treated BSH resulted in a successful fermentation and ABE concentration of 26.64 was achieved. This was superior to both glucose and untreated BSH (initial sugar 60 gL(-1)) fermentations. In this fermentation, an ABE yield of 0.43 and productivity of 0.39 gL(-1) h(-1) (390% of untreated/undiluted BSH) was obtained. It should be noted that using lime treated BSH, a specific productivity of 0.55 h(-1) was obtained as compared to 0.12 h(-1) in the control fermentation suggesting that more carbon was directed to product formation. Published by Elsevier Ltd.

Abstract  Using fermentation to replace chemical processes in the production of acetone and butanol depends largely on the availability of inexpensive and abundant raw materials and efficient conversion of these materials to solvents. In this study solvent production of Clostridium acetobutylicum ATCC824 from nano-membrane concentrated hemicellulosic hydrolysate was investigated. Alkali pretreatment methods were applied to improve fermentability of nano-membrane concentrated hemicellulosic hydrolysate and solvent production by ATCC824. Results demonstrated that though nanofiltration could remove nearly all small molecular organic acids (acetic acid, formic acid), furfural and HMF, the resulting hydrolysate found to be still inhibiting solvent production of C. acetobutylicum. Solid particles separated from filtering hydrolysate were found not toxic to cells when xylose or glucose was used as carbon resource. Overliming treatment can significantly improve the ultimate butanol concentration to 7g l(-1) from 0.8 g l(-1). Providing cells with more carbon source at the final stage of fermentation was found to have no impact on butanol production, but acetic acid and butyric acid production were found to increase significantly. The reasons leading to low solvent yield at later fermentation stages is not cell degeneration, but the toxicity of butanol and inhibitors remaining in the hydrolysate. (C) 2010 Elsevier Ltd. All rights reserved.

Abstract  By Michael addition polymerization of N,N'-cystaminebisacrylamide (CBA) with variable ratios of 4-amino-1-butanol (ABOL) and ethylene diamine (EDA) or triethylenetetramine (TETA), poly(amido amine) copolymers could be obtained with tunable charge densities. The copolymers were optimized to serve as nonviral vectors in RNA interference (RNAi) to form stable, nanosized polyplexes with siRNA with maximum transfection efficacy. It was observed that at least 20-30% EDA or TETA amino units in the copolymers is necessary to encapsulate siRNA into small and stable polyplexes (< 200 nm). Incorporation of higher amounts of EDA or TETA in the copolymers did not further improve polyplex formation and stability, but the increased cationic charge in these copolymers resulted in increased cytotoxicity and hemolytic activity. Copolymers with 20% EDA showed excellent gene silencing properties in vitro (70% luciferase knockdown in H1299 cells) with negligible cytotoxicity.

Abstract  Formation of compounds that are toxic to fermenting organisms during pretreatment and hydrolysis of lignocellulosic biomass has long been identified as one of the key factors affecting bioconversion of biomass to biofuels. In this study, fermentation was carried out to convert electrolyzed water pretreated dried distillers' grains and solubles (DDGS) hydrolysates to acetone butanol ethanol (ABE) using the hyper-butanol producing Clostridium beijerinckii BA 101. The presence of inhibitors in the DDGS hydrolysates resulted in a 40 h adjustment phase before the initiation of fermentation while the mixed sugar control fermentation was completed in less than 16 hours. While the ABE yield (ABE produced per unit of sugar utilized) obtained from the fermentation of DDGS hydrolysates was comparable to the yield obtained from the mixed sugar control fermentation, ABE productivity (ABE produced per unit of fermentation time) from the DDGS hydrolysates was lower than that of the mixed sugar control due to the long adjustment time experienced by C. beijerinckii BA101 in DGGS hydrolysates fermentation. Consequently, C. beijerinckii BA101 spores which had sporulated in DDGS hydrolysates were collected and used to ferment inhibitors-containing DDGS hydrolysates. Results demonstrated that inhibitor-adapted C. beijerinckii cells were able to adjust to the inhibitory environment in less than 20 hours and produce approximately the same amount of ABE as in the case for the control fermentation. Challenging the microorganism using the inhibitors present in the hydrolysates is believed to have enhanced the tolerance of C. beijerinckii to the inhibitors and resulted in significantly shorter lag phase. The results from this study demonstrated that the use of inhibitor-adapted Clostridium may be a promising option for ABE production.