n-Butanol

Project ID

1542

Category

IRIS

Added on

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

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Journal Article

Abstract  BACKGROUND: The lack of a brain-derived endothelial cell-based model has led researchers to exploit non-brain endothelial/epithelial cells as in vitro models for blood-brain barrier (BBB) investigations. Of these, the endothelial-like human ECV304 cell line was initially characterized as endothelial cells and has been widely used as an in vitro BBB model. It was later shown to be T24 bladder carcinoma epithelial cells. To pursue its potential as a cell-based model for drug screening and transport machineries, ECV304 cells were evaluated for their barrier and plasma membrane characteristics.

MATERIAL/METHODS: ECV304 cells treated with some tight-junction modulators (e.g. cAMP elevators, butyric acid, dexamethasone, gamma-linolenic acid, and astrocytic factors) were examined for bioelectrical resistance, transcellular/paracellular permeability, and functionality expression of some key transporters.

RESULTS: A significant (p<0.05) increase in trans-endothelial electrical resistance (TEER) was observed in ECV304 cells treated with astrocytic factors and cAMP elevators (i.e. to approximately 110Omega*cm2 vs. approximately 60 Omega*cm2 in the control). Such treatment also yielded high discrimination in the permeability coefficients of the transcellular marker propranolol (25x10-6 cm/sec) and the paracellular marker sucrose (11.3 x 10-6 cm/sec). Carrier-mediated transporters such as GLUT-1, system L, and P-glycoprotein (P-gp) as well as endocytic transport machineries (e.g. clathrin and caveolin) were found to be functionally expressed.

CONCLUSIONS: ECV304 cells failed to generate a discriminative tight barrier even in the presence of tight-junction modulators. Thus their implementation in drug permeability screening is not recommended. They display some important key carrier-mediated transport systems and can be considered as a useful cell-based in vitro model.

Journal Article

Abstract  A fluorescent assay for the evaluation of inhibitors of monoacylglycerol lipase (MAGL) is described. 1,3-Dihydroxypropan-2-yl 4-pyren-1-ylbutanoate was designed and synthesized as novel fluorogenic substrate. Activity of human recombinant MAGL was determined in the presence of the surfactant Triton X-100 without further sample cleanup by measuring the amount of 4-pyren-1-ylbutanoic acid released by the enzyme with reversed-phase high-performance liquid chromatography (HPLC) and fluorescence detection. The known covalent binding MAGL inhibitors methyl arachidonyl fluorophosphonate (MAFP), 4-nitrophenyl 4-[bis(1,3-benzodioxol-5-yl)hydroxymethyl]piperidine-1-carboxylate (JZL184), and [4-(5-methoxy-2-oxo-1,3,4-oxadiazol-3-yl)-2-methylphenyl]carbamic acid benzyl ester (CAY10499) were used to validate the test system. Applying an incubation time of 15 min, the IC(50) values obtained for these compounds were 0.16, 3.7, and 1.1 microM, respectively. A prolongation of the incubation to 45 min results in a two- to threefold decrease of the IC(50) values.

Journal Article

Abstract  This paper reports the effects of changing pH (5-7) and temperature (T, 40-60 degrees C) on the efficiencies of bacterial hydrolysis of suspended organic matter (SOM) in wastewater from food waste recycling (FWR) and the changes in the bacterial community responsible for this hydrolysis. Maximum hydrolysis efficiency (i.e., 50.5% reduction of volatile suspended solids) was predicted to occur at pH 5.7 and T = 44.5 degrees C. Changes in short-chain volatile organic acid profiles and in acidogenic bacterial communities were investigated under these conditions. Propionic and butyric acids concentrations increased rapidly during the first 2 days of incubation. Several band sequences consistent with Clostridium spp. were detected using denaturing gel gradient electrophoresis. Clostridium thermopalmarium and Clostridium novyi seemed to contribute to butyric acid production during the first 1.5 days of acidification of FWR wastewater, and C. thermopalmarium was a major butyric acid producer afterward. C. novyi was an important propionic acid producer. These two species appear to be important contributors to hydrolysis of SOM in the wastewater. Other acidogenic anaerobes, Aeromonas sharmana, Bacillus coagulans, and Pseudomonas plecoglossicida, were also indentified.

Journal Article

Abstract  We examined the production of an antimicrobial component, 3-hydroxypropionaldehyde (3-HPA), in laboratory-scale silage inoculated with Lactobacillus coryniformis strain 394, which ferments glycerol to 3-HPA. A modified colorimetric method that used an NaOH-treated blank and determined the absorption spectrum of the samples was employed to detect a 3-HPA-like component (HLC) that was assumed to be 3-HPA. Inoculation with Lb. coryniformis 394 plus glycerol in ensiling produced HLC at 10-460 ppm and contributed to inhibition of butyric fermentation and retardation of aerobic spoilage. HLC was considered to be 3-HPA from its absorption spectrum. These results suggest that the production of 3-HPA by Lb. coryniformis 394 is useful in ensiling and that the modified colorimetric method is effective to detect 3-HPA in silage.

Journal Article

Abstract  The effects of the hydraulic retention time (HRT=8, 10, 12 or 16.7 h) and glucose concentration (30, 40 or 50 g/L) on the production of hydrogen and butyrate by an immobilized Clostridium tyrobutyricum culture, grown under continuous culturing conditions, were evaluated. With 30 g/L glucose, the higher HRTs tested led to greater butyrate concentrations in the culture, i.e., 9.3 g/L versus 12.9 g/L with HRTs of 8 h and 16.7 h, respectively. In contrast, higher biogas and hydrogen production rates were generally seen when the HRT was lower. Experiments with different glucose concentrations saw a significant amount of glucose washed out when 50 g/L was used, the highest being 22.7 g/L when the HRT was 16.7 h. This study found the best conditions for the continuous production of hydrogen and butyric acid by C. tyrobutyricum to be with an HRT of 12 h and a glucose concentration of 50 g/L, respectively.

Journal Article

Abstract  Isobutanol has emerged as a potential biofuel due to recent metabolic engineering efforts. Here we used gene expression and transcription network connectivity data, genetic knockouts, and network component analysis (NCA) to map the initial isobutanol response network of Escherichia coli under aerobic conditions. NCA revealed profound perturbations to respiration. Further investigation showed ArcA as an important mediator of this response. Quinone/quinol malfunction was postulated to activate ArcA, Fur, and PhoB in this study. In support of this hypothesis, quinone-linked ArcA and Fur target expressions were significantly less perturbed by isobutanol under fermentative growth whereas quinol-linked PhoB target expressions remained activated, and isobutanol impeded growth on glycerol, which requires quinones, more than on glucose. In addition, ethanol, n-butanol, and isobutanol response networks were compared. n-Butanol and isobutanol responses were qualitatively similar, whereas ethanol had notable induction differences of pspABCDE and ndh, whose gene products manage proton motive force. The network described here could aid design and comprehension of alcohol tolerance, whereas the approach provides a general framework to characterize complex phenomena at the systems level.

Journal Article

Abstract  The ketogenic diet has long been recognized as an effective treatment for medically refractory epilepsy. Despite nearly a century of use, the mechanisms underlying its clinical efficacy remain unknown. One of the proposed hypotheses for its anti-epileptic actions involves increased GABA concentration in the brain due to ketone bodies that become elevated with a ketogenic diet. In recent years, the notion that astrocytes could play a role in the evolution of abnormal cortical excitability in chronic neurological disorders, such as epilepsy, has received renewed attention. The present study examined the effects of beta-hydroxybutyrate, a ketone body, on GABA metabolism in rat primary cultured astrocytes. When beta-hydroxybutyrate was added to culture medium, GABA-transaminase (GABA-T) mRNA expression was significantly suppressed in time- and dose-dependent manners. GABA-T enzymatic activity in beta-hydroxybutyrate-treated astrocytes was also suppressed, in accordance with its gene expression. These effects were evident after 3 days of culture, which might coincide with depleted intracellular glycogen. GABA transporter, GAT-1, gene expression was strongly suppressed in cultured astrocytes after 5 days of culture with beta-hydroxybutyrate, although other type of GABA transporters did not display significant changes. These results suggest that beta-hydroxybutyrate induced by ketogenic diet may increase GABA concentration in the epileptic brain by suppressing astrocytic GABA degradation, leading to antiepileptic effects.

Journal Article

Abstract  Latently infected cells harbor the HIV-1 proviral DNA genome primarily integrated into heterochromatin, allowing the persistence of transcriptionally silent proviruses. Hypoacetylation of histone proteins by histone deacetylases (HDAC) is involved in the maintenance of HIV-1 latency by repressing viral transcription. In addition, periodontal diseases, caused by polymicrobial subgingival bacteria including Porphyromonas gingivalis, are among the most prevalent infections of mankind. Here we demonstrate the effects of P. gingivalis on HIV-1 replication. This activity could be ascribable to the bacterial culture supernatant but not to other bacterial components such as fimbriae or LPS. We found that this HIV-1-inducing activity was recovered in the lower molecular mass (<3 kDa) fraction of the culture supernatant. We also demonstrated that P. gingivalis produces high concentrations of butyric acid, acting as a potent inhibitor of HDACs and causing histone acetylation. Chromatin immunoprecipitation assays revealed that the corepressor complex containing HDAC1 and AP-4 was dissociated from the HIV-1 long terminal repeat promoter upon stimulation with bacterial culture supernatant concomitantly with the association of acetylated histone and RNA polymerase II. We thus found that P. gingivalis could induce HIV-1 reactivation via chromatin modification and that butyric acid, one of the bacterial metabolites, is responsible for this effect. These results suggest that periodontal diseases could act as a risk factor for HIV-1 reactivation in infected individuals and might contribute to the systemic dissemination of the virus.

Journal Article

Abstract  OBJECTIVE: To isolate and determine the chemical constituents of Ranunculus japonicus in Liupan Mountain, Ningxia province, China.

METHOD: The herb was extracted with ethanol by ultrasonic bath. The extractives were divided to petroleum ether, ethyl acetate, n-butanol parts. The first two parts were separated and purified with silica gel and Sephadex LH -20 column chromatography. The structures of the separated compounds were idnetefied by physical and chemical properties and spectral analysis.

RESULT: Nine compounds were isolated and identified as follows: scoparone (1), tricin (2), protocatechuic acid (3), luteolin (4), anemonin (5), scopoletin (6), 5-hydroxy-6, 7-dimethoxyflavone (7), ternatolide (8), 5-hydroxy-7, 8-dimethoxy-flavone (9).

CONCLUSION: Compounds 1-9 were isolated from Ranunculus japonicus for the first time.

Journal Article

Abstract  To understand the metabolic characteristics of Clostridium acetobutylicum and to examine the potential for enhanced butanol production, we reconstructed the genome-scale metabolic network from its annotated genomic sequence and analyzed strategies to improve its butanol production. The generated reconstructed network consists of 502 reactions and 479 metabolites and was used as the basis for an in silico model that could compute metabolic and growth performance for comparison with fermentation data. The in silico model successfully predicted metabolic fluxes during the acidogenic phase using classical flux balance analysis. Nonlinear programming was used to predict metabolic fluxes during the solventogenic phase. In addition, essential genes were predicted via single gene deletion studies. This genome-scale in silico metabolic model of C. acetobutylicum should be useful for genome-wide metabolic analysis as well as strain development for improving production of biochemicals, including butanol.

Journal Article

Abstract  Butyric acid has many applications in chemical, food, and pharmaceutical industries. In the present study, Clostridium tyrobutyricum ATCC 25755 was immobilized in a fibrous-bed bioreactor to evaluate the performance of butyrate production from glucose and xylose. The results showed that the final concentration and yield of butyric acid were 13.70 and 0.46 g g(-1), respectively, in batch fermentation when 30 g L(-1) glucose was introduced into the bioreactor. Furthermore, high concentration 10.10 g L(-1) and yield 0.40 g g(-1) of butyric acid were obtained with 25 g L(-1) xylose as the carbon source. The immobilized cells of C. tyrobutyricum ensured similar productivity and yield from repeated batch fermentation. In the fed-batch fermentation, the final concentration of butyric acid was further improved to 24.88 g L(-1) with one suitable glucose feeding in the fibrous-bed bioreactor. C. tyrobutyricum immobilized in the fibrous-bed bioreactor would provide an economically viable fermentation process to convert the reducing sugars derived from plant biomass into the final bulk chemical (butyric acid).

Journal Article

Abstract  An enzymatic membrane reactor (EMR) for enantioseparation of (R,S)-ketoprofen via Candida antarctica lipase B (CALB) as biocatalyst was investigated. A comparative study of free and immobilized CALB was further conducted. The catalytic behaviour of CALB in an EMR was affected by the process parameters of enzyme load, substrate concentration, substrate molar ratio, lipase solution pH, reaction temperature, and substrate flow rate. Immobilization of CALB in the EMR was able to reduce the amount of enzyme required for the enantioseparation of (R,S)-ketoprofen. Immobilized CALB in the EMR assured higher reaction capacity, better thermal stability, and reusability. It was also found to be more cost effective and practical than free CALB in a batch reactor.

Journal Article

Abstract  The aim of the present study was to investigate the test-retest reliability of the olfactory detection threshold subtest of the Sniffin' Sticks test battery, if administered repeatedly on 4 time points. The detection threshold test was repeatedly conducted in 64 healthy subjects. On the first testing session, the threshold test was accomplished 3 times (T(1) = 0 min, T(2) = 35 min, and T(3) = 105 min), representing a short-term testing. A fourth threshold test was conducted on a second testing session (T(4) = 35.1 days after the first testing session), representing a long-term testing. The average scores for olfactory detection threshold for n-butanol did not differ significantly across the 4 points of time. The test-retest reliability (Pearson's r) between the 4 time points of threshold testing were in a range of 0.43-0.85 (P < 0.01). These results support the notion that the olfactory detection threshold test is a highly reliable method for repeated olfactory testing, even if the test is repeated more than once per day and over a long-term period. It is concluded that the olfactory detection threshold test of the Sniffin' Sticks is suitable for repeated testing during experimental or clinical studies.

Journal Article

Abstract  While a mother's excessive alcohol consumption during pregnancy is known to have adverse effects on fetal neural development, little is known about the underlying mechanism of these effects. In order to investigate these mechanisms, we investigated the toxic effect of ethanol (ETOH) on neural stem/precursor cell (NSC) proliferation. In cultures of NSCs, phospholipase D (PLD) is activated following stimulation with epidermal growth factor (EGF) and fibroblast growth factor 2 (FGF2). Exposure of NSCs to ETOH suppresses cell proliferation, while it has no effect on cell death. Phosphatidic acid (PA), which is a signaling messenger produced by PLD, reverses ETOH inhibition of NSC proliferation. Blocking the PLD signal by 1-butanol suppresses the proliferation. ETOH-induced suppression of NSC proliferation and the protective effect of PA for ETOH-induced suppression are mediated through extracellular signal-regulated kinase signaling. These results indicate that exposure to ETOH impairs NSC proliferation by altering the PLD signaling pathway.

Journal Article

Abstract  Diacylglycerides (DAGs) such as 1-oleoyl-2-acetyl-sn-glycerol (OAG) stimulate 5-lipoxygenase (5-LO) enzyme activity and function as agonists for human polymorphonuclear leukocytes (PMNL) to induce 5-LO product synthesis. Here, we addressed the role of endogenous DAG generation in agonist-induced 5-LO activation in human PMNL. Preincubation of PMNL with the phospholipase D (PLD) inhibitor 1-butanol potently suppressed 5-LO product synthesis induced by the Ca(2)(+) ionophore A23187 or thapsigargin (TG) and blocked A23187-evoked translocation of 5-LO from the cytosol to the nuclear membrane, analyzed by subcellular fractionation as well as by indirect immunofluorescence microscopy. Tertiary-butanol, a rather poor inhibitor of PLD, caused only moderate suppression of 5-LO and hardly inhibited 5-LO translocation. Interestingly, 1-butanol failed to inhibit 5-LO product formation when PMNL were stimulated with OAG (30 microM). Moreover, coincubation of A23187- or TG-stimulated PMNL with OAG reversed inhibition of 5-LO product formation by 1-butanol in a concentration-dependent manner (EC(50), approximately 1 muM) and also restored 5-LO translocation. In addition, inhibition of phosphatidic acid phosphatase (PA-P) by propranolol or bromoenol lactone caused suppression of 5-LO product formation and of translocation, which could be reversed by addition of exogenous OAG. Together, our data suggest that in agonist-stimulated PMNL, the endogenous formation of DAGs via the PLD/PA-P pathway determines 5-LO activation.

Journal Article

Abstract  The immediate-early (IE) BZLF1 gene of Epstein-Barr virus (EBV) regulates the switch between latent and lytic infection by EBV. We previously showed that the cellular transcription factor ZEB1 binds to a sequence element, ZV, located at nt -17 to -12 relative to the transcription initiation site of the BZLF1 promoter, Zp, repressing transcription from Zp in a transient transfection assay. Here, we report the phenotype in the context of a whole EBV genome of a variant of EBV strain B95.8 containing a 2-bp substitution mutation in the ZV element of Zp that reduced, but did not eliminate, ZEB1 binding to Zp. Strikingly, epithelial 293 cells latently infected with the EBV ZV mutant spontaneously produced IE-, early-, and late-gene products and infectious virus, while wild-type (WT)-infected 293 cells did not and have never been reported to do so. Furthermore, treatment with the chemical inducers sodium butyrate and 12-O-tetradecanoyl-phorbol-13-acetate (TPA) led to an additional order-of-magnitude production of infectious virus in the ZV mutant-infected 293 cells, but still no virus in the WT-infected 293 cells. Similarly, ZV mutant-infected Burkitt's lymphoma BJAB cells accumulated at least 10-fold more EBV IE mRNAs than did WT-infected BJAB cells, with TPA or sodium butyrate treatment leading to an additional 5- to 10-fold accumulation of EBV IE mRNAs in the ZV mutant-infected cells. Thus, we conclude that ZEB1 binding to Zp plays a central role in regulating the latent-lytic switch in EBV-infected epithelial and B cells, suggesting ZEB1 as a target for lytic-induction therapies in EBV-associated malignancies.

Journal Article

Abstract  OBJECTIVE: To compare the anti-fertility effects of the four extracts from the roots of Rhynchosia volubilis Lour on male mice, that is, ethanolic extract, ethyl acetate extract, n-butanol extract and aqueous extract.

METHODS: Four extracts from the roots of Rhynchosia volubilis Lour (1%, 0.1 ml/10 g), were administered orally for 11 weeks to adult male mice. The fertility and testicular function of the mice were assessed by mating tests and analyses of sperm motility in cauda epididymides and biochemical and histological indexes in the blood samples and reproductive organs.

RESULTS: The four extracts, especially aqueous extract, gradually decreased the pregnancy rate of the experimental mice from the 77th day of the treatment, with an obvious reduction in the number of spermatozoa. Morphological observation of the reproductive organs by light microscopy showed that the numbers of the secondary spermatocytes and spermatids were decreased in varied degrees, and the seminiferous tubules were disarranged, while the numbers and shapes of and spermatids were decreased in varied degrees, and the seminiferous tubules were disarranged, while the numbers and shapes of spermatogonia, Sertoli cells and Leydig cells remained unchanged.

CONCLUSION: The four extracts from the roots of Rhynchosia volubilis Lour all have anti-fertility effects on male mice, and that of the aqueous extract is more obvious.

Journal Article

Abstract  Pretreatment and hydrolysis of lignocellulosic biomass using either dilute acid, liquid hot water (LHW), or ammonium fiber expansion (AFEX) results in a complex mixture of sugars such as hexoses (glucose, galactose, mannose), and pentoses (xylose, arabinose). A detailed description of the utilization of representative mixed sugar streams (pentoses and hexoses) and their sugar preferences by the solventogenic clostridia (Clostridium beijerinckii BA101, C. acetobutylicum 260, C. acetobutylicum 824, Clostridium saccharobutylicum 262, and C. butylicum 592) is presented. In these experiments, all the sugars were utilized concurrently throughout the fermentation, although the rate of sugar utilization was sugar specific. For all clostridia tested, the rate of glucose utilization was higher than for the other sugars in the mixture. In addition, the availability of excess fermentable sugars in the bioreactor is necessary for both the onset and the maintenance of solvent production otherwise the fermentation will become acidogenic leading to premature termination of the fermentation process. During an investigation on the effect of some of the known lignocellulosic hydrolysate inhibitors on the growth and ABE production by clostridia, ferulic and p-coumaric acids were found to be potent inhibitors of growth and ABE production. Interestingly, furfural and HMF were not inhibitory to the solventogenic clostridia; rather they had a stimulatory effect on growth and ABE production at concentrations up to 2.0g/L.

Journal Article

Abstract  Although organelles such as the endoplasmic reticulum and Golgi apparatus are highly compartmentalized, these organelles are interconnected through a network of vesicular trafficking. The marine sponge metabolite ilimaquinone (IQ) is known to induce Golgi membrane fragmentation and is widely used to study the mechanism of vesicular trafficking. Although IQ treatment causes protein kinase D (PKD) activation, the detailed mechanism of IQ-induced Golgi membrane fragmentation remains unclear. In this work, we found that IQ treatment of cells caused a robust activation of phospholipase D (PLD). In the presence of 1-butanol but not 2-butanol, IQ-induced Golgi membrane fragmentation was completely blocked. In addition, IQ failed to induce Golgi membrane fragmentation in PLD knock-out DT40 cells. Furthermore, IQ-induced PKD activation was completely blocked by treatment with either 1-butanol or propranolol. Notably, IQ-induced Golgi membrane fragmentation was also blocked by propranolol treatment. These results indicate that PLD-catalyzed formation of phosphatidic acid is a prerequisite for IQ-induced Golgi membrane fragmentation and that enzymatic conversion of phosphatidic acid to diacylglycerol is necessary for subsequent activation of PKD and IQ-induced Golgi membrane fragmentation.

Journal Article

Abstract  PURPOSE: To characterize the physicochemical properties of drug-loaded oil-in-water (o/w) and water-in-oil (w/o) Brij 97-based microemulsions in comparison to their blank counterparts and to investigate the influence of microemulsion type on in vitro skin permeation of model hydrophobic drugs and their hydrophilic salts.

METHODS: The microemulsion systems were composed of isopropyl palmitate (IPP), water and a 2:1 w/w mixture of Brij 97 and 1-butanol. The samples were characterized by visual appearance, pH, refractive index, electrical conductivity, viscosity and determination of the state of water and IPP in the formulations using differential scanning calorimetry (DSC). Transdermal flux of lidocaine, tetracaine, dibucaine and their respective hydrochloride salts through heat-separated human epidermis was investigated in vitro using modified Franz diffusion cells.

RESULTS: The physicochemical properties of drug-loaded microemulsions and their blank counterparts were generally similar; however, slight changes in some physicochemical properties (apparent pH and conductivity) were observed due to the intrinsic properties of the drugs. The o/w microemulsions resulted in the highest flux of lidocaine, tetracaine and dibucaine as compared to the other formulations with in the same group of drugs.

CONCLUSIONS: The characterization results showed that incorporation of the model drugs into the microemulsions did not change the microemulsion type. The permeation data exhibited that the nature of the microemulsions was a crucial parameter for transdermal drug delivery. The o/w microemulsions containing hydrophobic drugs provided the highest skin permeation enhancement. In addition, skin permeation was depended on the molecular weight of the model drugs.

Journal Article

Abstract  Anaerobic treatment of undiluted cow dung (15% total solids), so-called dry fermentation, produced hydrogen (743 ml-H(2)/kg-cow dung) at an optimum temperature of 60 degrees C, with butyrate and acetate formation. The hydrogen production was inhibited by the addition of NH(4)(+) in a dose-dependent manner. A bacterium with similarity to Clostridium cellulosi was detected in the fermented dung by a 16S rDNA analysis.

Journal Article

Abstract  Butyrate degradation for hydrogen production under conditions suppressing methanogenesis was evaluated in continuously fed-tank reactors operated at 55 degrees C and started up with digested manure as inoculum. This study shows that the reaction of butyrate degradation to acetate and hydrogen could happen when gas sparging was applied. Gas sparging was very important for reducing hydrogen partial pressure and made the reaction thermodynamically possible. Almost no hydrogen or methane (methane production was prevented by the addition of 2-bromoethane-sulfonic acid) was detected, indicating that the H2 produced from butyrate oxidation was consumed in a subsequent step. It was found by isotope experiments that hydrogen produced from butyrate degradation reacted immediately with CO2 to form acetate via homoacetogenesis. When CO2/HCO(3-) was not provided in the system, butyrate degradation was no longer possible and butyrate-degrading cultures were washed out. It was furthermore found that the microorganisms responsible for homoacetogenesis were likely present in normal anaerobic environments, such as biogas reactors.

Journal Article

Abstract  Butanol is produced chemically using either the oxo process starting from propylene (with H2 and CO over a rhodium catalyst) or the aldol process starting from acetaldehyde. The key problems associated with the bioproduction of butanol are the cost of substrate and butanol toxicity/inhibition of the fermenting microorganisms, resulting in a low butanol titer in the fermentation broth. Recent interest in the production of biobutanol from biomass has led to the re-examination of acetone-butanol-ethanol (ABE) fermentation, including strategies for reducing or eliminating butanol toxicity to the culture and for manipulating the culture to achieve better product specificity and yield. Advances in integrated fermentation and in situ product removal processes have resulted in a dramatic reduction of process streams, reduced butanol toxicity to the fermenting microorganisms, improved substrate utilization, and overall improved bioreactor performance.

Journal Article

Abstract  We have developed a mixed ester of hyaluronan with butyric and retinoic acid (HBR) that acted as a novel cardiogenic/vasculogenic agent in human mesenchymal stem cells isolated from bone marrow, dental pulp, and fetal membranes of term placenta (FMhMSCs). HBR remarkably enhanced vascular endothelial growth factor (VEGF), KDR, and hepatocyte growth factor (HGF) gene expression and the secretion of the angiogenic, mitogenic, and antiapoptotic factors VEGF and HGF, priming stem cell differentiation into endothelial cells. HBR also increased the transcription of the cardiac lineage-promoting genes GATA-4 and Nkx-2.5 and the yield of cardiac markerexpressing cells. These responses were notably more pronounced in FMhMSCs. FMhMSC transplantation into infarcted rat hearts was associated with increased capillary density, normalization of left ventricular function, and significant decrease in scar tissue. Transplantation of HBR-preconditioned FMhM-SCs further enhanced capillary density and the yield of human vWF-expressing cells, additionally decreasing the infarct size. Some engrafted, HBR-pretreated FMhMSCs were also positive for connexin 43 and cardiac troponin I. Thus, the beneficial effects of HBR-exposed FMhMSCs may be mediated by a large supply of angiogenic and antiapoptotic factors, and FMhMSC differentiation into vascular cells. These findings may contribute to further development in cell therapy of heart failure.

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