Abstract  The theory of depression is dominated by the monoamine hypothesis but there is increasing evidence that beyond monoamines, glutamate (Glu) and gamma-aminobutyric acid (GABA) play an essential role in the pathogenesis of depression. In this study, the effect of alterations of GABA and Glu were investigated in the congenital learned helplessness paradigm. Proton magnetic resonance spectroscopy is an important monitoring tool to bridge the findings in clinical and preclinical studies. We found increased Glu/GABA ratios in the hippocampus and prefrontal cortex of placebo-treated (saline intraperitoneally) congenital learned helplessness rats versus wild-type rats, and a treatment-induced (desipramine 10 mg/kg intraperitoneally or electroconvulsive shock) decrease of this monoamine ratio in both brain regions. Our results corroborate previous findings of an amino-acid influence on the pathomechanisms of mood disorders.

Abstract  ETHNOPHARMACOLOGICAL RELEVANCE: The herbal formula Xiangdan injection and its modifications have been used in traditional Chinese medicine for about hundreds years to alleviate pain and promoting blood.

AIM: To investigate the anti-hypoxia active fraction of Xiangdan injection.

MATERIALS AND METHODS: Xiangdan injection was extracted by ligarine, chloroform, acetic ether, n-butanol and water, represented respectively by A, B, C, D and E. Five extractions were group on the L12(2(5)) orthogonal designed table. NIH mices anti-hypoxia experiment under normal pressure with rats was adopted on the basis of orthogonal design, prediction pharmacodynamics model of TCM prescriptions was established, and the simulation bias was evaluated by combining two scatterplots. The anti-hypoxia active fraction of Xiangdan injection was determined by experiments.

RESULTS: The prediction model of TCM prescriptions established in this study can predict the drug actions for different formulas, and PE% <or= 25% was observed in 112 mice (93.3%).

CONCLUSION: As indicated in model prediction and experimental confirmation, the pharmacodynamic actions of the 5 formulas are all superior to that of the original formula, and ADE has the best effect.

Abstract  Present work describes the potent antidiabetic fraction from flowers of Cassia auriculata Linn. Hydromethanolic extract along with its ethyl acetate and n-butanol fractions were evaluated for antidiabetic activity in alloxan-induced diabetes in rats. The n-butanol fraction exhibited significant reduction (p<0.001) in blood glucose levels and was also found effective in restoring the blood lipids and proteins to normal level. The activity was found comparable with standard drug phenformin. The hydromethanolic extract and its fractions were subjected to preliminary qualitative chemical investigations which indicated the presence of phenolic compounds, carbohydrates, tannins, steroids and amino acids.

Abstract  The second order standard addition method and spectrofluorimetry were used for determination of ibuprofen enantiomers in human plasma and urine. The methodology was based on chiral recognition of ibuprofen by formation of an inclusion complex with a chiral auxiliary, beta-cyclodextrin, in the presence of 1-butanol. The strategy combines the use of PARAFAC, for extraction of the pure analyte signal, with the standard addition method, for determinations in presence of a matrix effect. A specific PARAFAC model was built for each sample and the scores were related to (S)-ibuprofen concentration using a linear regression in the standard addition method. Feasible results were obtained for determinations in the molar fraction range from 50 to 80% of (S)-ibuprofen, providing absolute errors lowers than 4.0% for plasma and urine. (C) 2010 Elsevier B.V. All rights reserved.

Abstract  The acrosome reaction (AR) is influenced by the action of several molecules such as GABA. P(4). and ET Objective: to determine the interaction between GABA / E(2). and GABA / P(4) in the AR. Methods: Washed human spermatozoa capacitated for 2 h were incubated in the following conditions: BWW medium alone (control) or BWW plus: P(4) E(2) GABA, GABA+ P(4) or GABA+ E(2) The % of AR was determined by FITC-PSA.'ReSults: Spermatozoa incubated with -GABA or P(4) showed higher % of AR: additionally, separate and simultaneous P(4) and GABA incubations showed no significant difference in the % of AR. GABA plus E, incubation showed lower % of AR than GABA only incubated spermatozoa. Conclusions: The AR would be modulated by inductors such as GABA and P4, there is not synergistic interaction between these molecules on AR induction: besides, there are inhibitory hormones such as E,. whose effect prevails in a combined GABA/E, incubation. The localisation of these compounds would determine timely AR occunence.

Abstract  This study investigated gamma-amino butyric acid (GABA) barley seeds for its potential uses such as in foodstuffs. A simple method was designed to produce "mochi" barley containing a high concentration of GABA. Scaled seeds of "mochi" barley (Hordeum vulgare) were soaked in a glutamic acid solution. After draining off the solution, the processed seeds were allowed to stand at room temperature overnight. During this process, glutamate decarboxylase in the mochi barley converted glutamic acid to GABA. For optimal conversion, seeds were scaled before soaking in a solution containing 0.3-1% glutamic acid at pH 4 to 8. (Received Sep. 27, 2010; Accepted Jan. 7, 2011)

Abstract  A novel microemulsion based on a mixture of diethyl L-tartrate (DET) and SDS was developed for the microemulsion EKC (MEEKC) determination of structurally related steroids. The system consisted of 0.5% w/w DET, 1.7% w/w SDS, 1.2% w/w 1-butanol, 89.6% w/w phosphate buffer (40 mM, pH 7.0), and 7% w/w ACN. With an applied voltage of +10 kV, a baseline separation of aldosterone (A), cortisone acetate (CA), dexamethasone (D), hydrocortisone (H), hydrocortisone acetate (HA), prednisolone (P), prednisolone acetate (PA), prednisone (Ps), triamcinolone (T), and triamcinolone acetonide (TA) could be achieved. Under the optimized conditions, the reproducibility of the retention time (n = 4) for most of the compounds was less than +/-0.8% with the exception of A, Ps, and T. The average number of theoretical plates was 18 800 plates/m. The results were compared with those achieved by the modified micellar EKC (MEKC). MEEKC showed obvious advantages over MEKC for the separation of highly hydrophobic substances. To further evaluate the system, we tested the MEEKC method by analyzing corticosteroids in a spiked urine sample.

Abstract  Phospholipase A(2) (PLA(2)) forms are expressed in spinal cord, and inhibiting spinal PLA(2) induces a potent antihyperalgesia. Here, we examined the antihyperalgesic effects after systemic and i.t. delivery of four compounds constructed with a common motif consisting of a 2-oxoamide with a hydrocarbon tail and a four-carbon tether. These molecules were characterized for their ability to block group IVA calcium-dependent PLA(2) (cPLA(2)) and group VIA calcium-independent PLA(2) (iPLA(2)) in inhibition assays using human recombinant enzyme. The rank ordering of potency in blocking group IVA cPLA(2) was AX048 (ethyl 4-[(2-oxohexadecanoyl)amino]butanoate), AX006 (4-[(2-oxohexadecanoyl)amino]butanoic acid), and AX057 (tert-butyl 4-[(2-oxohexadecanoyl)amino]butanoate) > AX010 (methyl 4-[(2-oxohexadecanoyl)amino]butanoate) and for inhibiting group VIA iPLA(2) was AX048, AX057 > AX006, and AX010. No agent altered recombinant cyclooxygenase activity. In vivo, i.t. (30 mug) and systemic (0.2-3 mg/kg i.p.) AX048 blocked carrageenan hyperalgesia and after systemic delivery in a model of spinally mediated hyperalgesia induced by i.t. substance P (SP). The other agents were without activity. In rats prepared with lumbar i.t. loop dialysis catheters, SP evoked spinal prostaglandin E(2) (PGE(2)) release. AX048 alone inhibited PGE(2) release. Intrathecal SR141617, a cannabinoid CB1 inhibitor at doses that blocked the effects of i.t. anandamide had no effect upon i.t. AX048. These results suggest that AX048 is the first systemically bioavailable compound with a significant affinity for group IVA cPLA(2), which produces a potent antihyperalgesia. The other agents, although demonstrating enzymatic activity in cell-free assays, appear unable to gain access to the intracellular PLA(2) toward which their action is targeted.

Abstract  In this paper, a micellar electrokinetic chromatography (MEKC) method combined with cation-selective exhaustive injection (CSEI) and sweeping was developed to separate and concentrate four tobacco-specific N-nitrosamines (TSNAs) including N'-nitrosoanabasine (NAB), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and 4-(methylnitrosamino)-4-(3-pyridyl)-1-butanol (iso-NNAL). Experimental parameters affecting separation efficiency and enhancement factors were investigated in detail. Under the optimum MEKC condition, NAB, NNK, NNAL and iso-NNAL were baseline separated with high separation efficiencies and good peak shapes. Furthermore, with the preconcentration by CSEI-sweeping-MEKC, the sensitivity enhancement factors for NAB, NNK, NNAL and iso-NNAL in terms of peak areas ranged from 6.0×10(3) to 1.5×10(4), and the detection limits (LOD, S/N=3) of four TSNAs were in the range of 0.004-0.016μg/mL. In addition, this method had fairly good repeatability, and the RSDs of retention time and peak area were less than 1% and 5%, respectively. Finally, this method showed promising capabilities in the application of detecting and analyzing TSNAs in human urine samples.

Abstract  Aggregation of two porphyrin derivatives with carboxylic groups, 4-oxo-4-((4-(10,15,20-triphenyl-21H,23H-porphin-5-yl)phenyl)amino)butanoic acid (MAC) and 4,4',4'',4'''-[21H,23H-porphine-5,10,15,20-tetrayltetrakis(4,1-phenyleneimino)]tetrakis(4-oxo-butanoic acid) (TA4C), and their affinity to bovine serum albumin were investigated via absorption spectrometry, (1)H NMR and fluorescence spectrometry. MAC and its complexes with beta-cyclodextrin could form aggregates in an aqueous solution while TA4C was self-associated loosely. From the absorbance profiles of MAC in the titration of bovine serum albumin, hypochromicity was observed without any shift of the maximum absorbance wavelength. In both absorption spectra of TA4C in aqueous solutions and in solid state, three Q bands appeared in the visible region. In the measurements of absorption and fluorescence spectra upon titration of BSA, some spectral changes of TA4C were observed. The whole procedure of titration could be divided into three successive stages. The three-banded profiles of TA4C might be explained according to a loose dimer model.

Abstract  Lysophosphatidylcholine (LPC) is a bioactive lipid generated by phospholipase A2-mediated hydrolysis of phosphatidylcholine. In the present study, we demonstrate that LPC stimulates phospholipase D2 (PLD2) activity in rat pheochromocytoma PC12 cells. Serum deprivation induced cell death of PC12 cells, as demonstrated by decreased viability, DNA fragmentation, and increased sub-G1 fraction of cell cycle. LPC treatment protected PC12 cells partially from the cell death and induced neurite outgrowth of the cells. Overexpression of PLD2 drastically enhanced the LPC-induced inhibition of apoptosis and neuritogenesis. Pretreatment of the cells with 1-butanol, a PLD inhibitor, completely abrogated the LPC-induced inhibition of apoptosis and neurite outgrowth in PC12 cells overexpressing PLD2. These results indicate that LPC possesses the neurotrophic effects, such as anti-apoptosis and neurite outgrowth, through activation of PLD2.

Abstract  Substrate binding and the subsequent reaction are the two principal phenomena that underlie the activity of enzymes, and many enzyme-like catalysts were generated based on the phenomena. The single chain variable region fragment of antibody 2F3 (scFv2F3) was elicited against hapten GSH-S-DN2phBu, a conjugate of glutathione (GSH), butyl alcohol, and 1-chloro-2,4-dinitrobenzene (CDNB); it can therefore bind both GSH and CDNB, the substrates of native glutathione S-transferases (GSTs). It was shown previously that there is a serine residue that is the catalytic group of GST in the CDR regions of scFv2F3 close to the sulfhydryl of GSH. Thus, we anticipated that scFv2F3 will display GST activity. The experimental results showed that scFv2F3 indeed displayed GST activity that is equivalent to the rat-class GST T-2-2 and exhibited pH- and temperature-dependent catalytic activity. Steady-state kinetic studies showed that the Km values for the substrates are close to those of native GSTs, indicating that scFv2F3 has strong affinities for the substrates. Compared with some other GSTs, its kcat value was found to be low, which could be caused by the similarity between the GSH-S-DN2phBu and the reaction product of GSH and CDNB. These results showed that our approach to imitating enzymes is correct, which is that an active site may catalyze a chemical reaction when a catalytic group locates beside a substrate-binding site of a receptor. It is important to consider product inhibition in hapten design in order to obtain a mimic with a high catalytic efficiency.

Abstract  The heartwood or root of Dalbergia odorifera T. Chen is an important traditional Chinese medicine. Antioxidant activities of seed extracts from D. odorifera T. Chen were first investigated in this study. Ethanolic extracts were suspended in distilled water and partitioned successively with petroleum ether, ethyl acetate, n-butanol (n-BuOH) and water, yielding four extracts named as PE, EE, BE and WE, respectively. The EE exhibited the highest total phenolic, total flavonoid, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, reducing power, linoleic acid and lard peroxidation inhibition, but lowest chelating ability. Liquid chromatography mass spectrometry (LC/MS) analysis of EE revealed that there was a predominant component with negative molecular ion [M-H](-) at m/z 373.2, a fragment at m/z 343.2 and UV Lambda(max) at 263 and 297nm. The mechanisms of antioxidant activities of seed extracts were exploited. Positive linear correlations were observed between reducing power and DPPH radical scavenging activity (R(2) = 0.836), and linoleic acid peroxidation inhibition (R(2) = 0.920), respectively. Similarly, high positive linear correlations of the total phenolic and total flavonoid with DPPH radical scavenging activity, reducing power and linoleic acid peroxidation inhibition were observed. This study therefore suggests that seeds of D. odorifera T. Chen have the potential to be used as natural antioxidants in food or pharmaceutical industry.

Abstract  Three organic extracts (chloroform, ethyl acetate and n-butanol) of ten cyanobacterial species (Anabaena solitaria, Anabaena variabilis, Anabaena cylindrical, Anabaena spiroides, Anabaena circinalis, Oscillatoria ornate, Oscillatoria salins, Oscillatoria tenuis, Oscillatoria rubescens and Oscillatoria prolifica) were investigated for their antibacterial activities against 4 fish pathogenic bacterial species belonging to genus Aeromonas, namely, Aer. salmonicida, Aer. hydrophila, Aer. formicans and Aer. liquefaciens using oxytetracycline as reference antibiotic. Of all cyanobacterial samples, only ethyl acetate extracts of A. variabilis and A. circinalis were proved to be the most effective against all tested Aeromonas species. Bioautographic investigation for 13 organic solvent systems indicate that the spot with R(f) = 0.79 for A. variabilis and that of R(f) = 0.84 for A. circinalis were the most effective. The median lethal doses (LD(50)) for the purified antibacterial compounds against mice were 246.67 and 231.67 mg/kg for that extracted from A. variabilis and A. circinalis, respectively.

Abstract  Metabolite accumulation has pleiotropic, toxic, or beneficial effects on cell physiology, but such effects are not well understood at the molecular level. Cells respond and adapt to metabolite stress by mechanisms largely unexplored, especially in the context of multiple and simultaneous stresses. Solventogenic and related clostridia have an inherent advantage for production of biofuels and chemicals directly from cellulosic material and other complex carbohydrates, but issues of product/metabolite tolerance and related culture productivities remain. Using DNA microarray-based gene expression analysis, the transcriptional-stress responses of Clostridium acetobutylicum to fermentation acids acetate and butyrate and the solvent product butanol were analyzed and compared in the context of cell physiology. Ontological analysis demonstrated that stress by all three metabolites resulted in upregulation of genes related to post-translational modifications and chaperone activity, and downregulation of the translation-machinery genes. Motility genes were downregulated by acetate-stress only. The general metabolite stress included upregulation of numerous stress genes (dnaK, groES, groEL, hsp90, hsp18, clpC, and htrA), the solventogenic operon aad-ctfA-ctfB, and other solventogenic genes. Acetate stress downregulated expression of the butyryl-CoA- and butyrate-formation genes, while butyrate stress downregulated expression of acetate-formation genes. Pyrimidine-biosynthesis genes were downregulated by most stresses, but purine-biosynthesis genes were upregulated by acetate and butyrate, possibly for thiamine and histidine biosynthesis. Methionine-biosynthesis genes were upregulated by acetate stress, indicating a possibly conserved stress response mechanism also observed in Escherichia coli. Nitrogen-fixation gene expression was upregulated by acetate stress. Butyrate stress upregulated many iron-metabolism genes, riboflavin-biosynthesis genes, and several genes related to cellular repair from oxidative stress, such as perR and superoxide dismutases. Butanol stress upregulated the glycerol metabolism genes glpA and glpF. Surprisingly, metabolite stress had no apparent effect on the expression of the sporulation-cascade genes. It is argued that the list of upregulated genes in response to the three metabolite stresses includes several genes whose overexpression would likely impart tolerance, thus making the information generated in this study, a valuable source for the development of tolerant recombinant strains.

Abstract  The phytochemical study of Astragalus lusitanicus conducted in parallel to the toxicity assays in lambs has shown that the extracts with organic solvents (petroleum ether, ether, ethyl acetate and 1-butanol) are not toxic. In the contrary, the aqueous extract as well as the decoction is toxic. While the lethal dose of the fresh plant is about 30 g/kg body weight (BW), the lethal dose of the decoction is only 1.5 g/kg BW. The fractionation of the decoction allowed to obtain a fraction more concentrated in the toxic principle and was lethal at the dose of aroximately 40 mg /kg only.

Abstract  Studies have shown that C(60) fullerene can form stable colloidal suspensions in water that result in C(60) aqueous concentrations many orders of magnitude above C(60)'s aqueous solubility; however, quantitative methods for the analysis of C(60) and other fullerenes in environmental media are scarce. Using a 80/20v/v toluene-acetonitrile mobile phase and a 4.6 mm x 150 mm Cosmosil 5micron PYE column, C(60), C(70), and PCBM ([6,6]-phenyl C(61)-butyric acid methyl ester) were fully resolved. Selectivity factors (alpha) for C(60) relative to PCBM and C(70) relative to C(60) were 3.18 and 2.19, respectively. The best analytical wavelengths for the fullerenes were determined to be 330, 333, and 333 nm with log molar absorption coefficients (log epsilon) of 4.63, 4.82, and 4.60 for PCBM, C(60), C(70), respectively. Extraction and quantitation of all three fullerenes in aqueous suspensions over a range of pH (4-10) and ionic strengths were very good. Whole-method quantification limits for ground and surface suspensions were 2.87, 2.48, and 6.54 microg/L for PCBM, C(60), and C(70), respectively.

Abstract  This study aimed to quantitatively evaluate the correlations between butanol (BtOH) tolerance of solvent-producing bacteria (SPB) and the performance of fermentative butanol production. The toxicity potency of BtOH was revealed to suggest the feasibility of butanol formation with a Clostridial species-dominated bacterial consortium. When the mixed culture was grown on the optimal medium comprising 60 g/L glucose, 0.5 g/L FeSO4 center dot 7H(2)O and 5.13 g/L yeast extract, the maximal tolerant butanol concentration, butanol production, hydrogen production and glucose consumption were ca. 16 g/L, 10.64 +/- 0.60 g/L, 4153 +/- 815 mL/L and 54.99 +/- 1.92 g/L, respectively. Moreover, almost all the dose-response curves representing toxicity potency of butanol on microbial characteristics was nearly identical in order of magnitude. Thus, although generations of by-products during butanol fermentation are interactive, the maintenance of microbial growth capability still plays a crucial role to control the performance of butanol production. The quantitative findings in toxicological terms directly suggest that the BtOH toxicity seemed to be inevitable during BtOH production. In addition, butanol inhibition could be reversibly attenuated by removal of butanol to make it below the critical level (ca. 7.83-9.52 g/L or EC50). C 2012 Elsevier B.V. All rights reserved.

Abstract  An effective intracellular protein delivery system was developed based on functionalized linear poly(amidoamine)s (PAAs) that form self-assembled cationic nanocomplexes with oppositely charged proteins. Three differently functionalized PAAs were synthesized, two of these having repetitive disulfide bonds in the main chain, by Michael-type polyaddition of 4-amino-1-butanol (ABOL) to cystamine bisacrylamide (CBA), histamine (HIS) to CBA, and ABOL to bis(acryloyl)piperazine (BAP). These water-soluble PAAs efficiently condense β-galactosidase by self-assembly into nanoscaled and positively-charged complexes. Stable under neutral extracellular conditions, the disulfide-containing nanocomplexes rapidly destabilized in a reductive intracellular environment. Cell-internalization and cytotoxicity experiments showed that the PAA-based nanocomplexes were essentially non-toxic. β-Galactosidase was successfully internalized into cells, with up to 94% of the cells showing β-galactosidase activity, whereas the enzyme alone was not taken up by the cells. The results indicate that these poly(amidoamine)s have excellent properties as highly potent and non-toxic intracellular protein carriers, which should create opportunities for novel applications in protein delivery.

Abstract  Background, aim, and scope: The adverse environmental impacts of chlorinated hydrocarbons on the Earth's ozone layer have focused attention on the effort to replace these compounds by nonchlorinated substitutes with environmental acceptability. Hydrofluoroethers (HFEs) and fluorinated alcohols are currently being introduced in many applications for this purpose. Nevertheless, the presence of a great number of C-F bonds drives to atmospheric long-lived compounds with infrared absorption features. Thus, it is necessary to improve our knowledge about lifetimes and global warming potentials (GWP) for these compounds in order to get a complete evaluation of their environmental impact. Tropospheric degradation is expected to be initiated mainly by OH reactions in the gas phase. Nevertheless, Cl atoms reaction may also be important since rate constants are generally larger than those of OH. In the present work, we report the results obtained in the study of the reactions of Cl radicals with HFE-7000 (CF(3)CF(2)CF(2)OCH(3)) (1) and its isomer CF(3)CF(2)CF(2)CH(2)OH (2). Materials and methods: Kinetic rate coefficients with Cl atoms have been measured using the discharge flow tube-mass spectrometric technique at 1 Torr of total pressure. The reactions of these chlorofluorocarbons (CFCs) substitutes have been studied under pseudo-first-order kinetic conditions in excess of the fluorinated compounds over Cl atoms. The temperature ranges were 266-333 and 298-353 K for reactions of HFE-7000 and CF(3)CF(2)CF(2)CH(2)OH, respectively. Results: The measured room temperature rate constants were k(Cl+CF(3)CF(2)CF(2)OCH(3)) = (1.24 +/- 0.28) x 10(-13) cm(3) molecule(-1) s(-1)and k(Cl+CF(3)CF(2)CF(2)CH(2)OH) = (8.35 +/- 1.63) x 10(-13) cm(3) molecule(-1) s(-1) (errors are 2sigma + 10% to cover systematic errors). The Arrhenius expression for reaction 1 was k (1)(266-333 K) = (6.1 +/- 3.8) x 10(-13)exp[-(445 +/- 186)/T] cm(3) molecule(-1) s(-1) and k (2)(298-353 K) = (1.9 +/- 0.7) x 10(-12)exp[-(244 +/- 125)/T] cm(3) molecule(-1) s(-1) (errors are 2sigma). The reactions are reported to proceed through the abstraction of an H atom to form HCl and the corresponding halo-alkyl radical. At 298 K and 1 Torr, yields on HCl of 0.95 +/- 0.38 and 0.97 +/- 0.16 (errors are 2sigma) were obtained for CF(3)CF(2)CF(2)OCH(3) and CF(3)CF(2)CF(2)CH(2)OH, respectively. Discussion: The obtained kinetic rate constants are related to the previous data in the literature, showing a good agreement taking into account the error limits. Comparing the obtained results at room temperature, k (1) and k (2), HFE-7000 is significantly less reactive than its isomer C(3)F(7)CH(2)OH. A similar behavior has been reported for the reactions of other fluorinated alcohols and their isomeric fluorinated ethers with Cl atoms. Literature data, together with the results reported in this work, show that, for both fluorinated ethers and alcohols, the kinetic rate constant may be considered as not dependent on the number of -CF(2)- in the perfluorinated chain. This result may be useful since it is possible to obtain the required physicochemical properties for a given application by changing the number of -CF(2)- without changes in the atmospheric reactivity. Furthermore, lifetimes estimations for these CFCs substitutes are calculated and discussed. The average estimated Cl lifetimes are 256 and 38 years for HFE-7000 and C(3)H(7)CH(2)OH, respectively. Conclusions: The studied CFCs' substitutes are relatively short-lived and OH reaction constitutes their main reactive sink. The average contribution of Cl reactions to global lifetime is about 2% in both cases. Nevertheless, under local conditions as in the marine boundary layer, tau (Cl) values as low as 2.5 and 0.4 years for HFE-7000 and C(3)H(7)CH(2)OH, respectively, are expected, showing that the contribution of Cl to the atmospheric degradation of these CFCs substitutes under such conditions may constitute a relevant sink. In the case of CF(3)CF(2)CF(2)OCH(3), significant activation energy has been measured, thus the use of kinetic rate coefficient only at room temperature would result in underestimations of lifetimes and GWPs. Recommendations and perspectives: The results obtained in this work may be helpful within the database used in the modeling studies of coastal areas. The knowledge of the atmospheric behavior and the structure-reactivity relationship discussed in this work may also contribute to the development of new environmentally acceptable chemicals. New volatile materials susceptible of emission to the troposphere should be subject to the study of their reactions with OH and Cl in the range of temperature of the troposphere. The knowledge of the temperature dependence of the kinetic rate constants, as it is now reported for the case of reactions 1 and 2, will allow more accurate lifetimes and related magnitudes like GWPs. Nevertheless, a better knowledge of the vertical Cl tropospheric distribution is still required.

Abstract  Anaerobic bacteria such as the solventogenic clostridia can ferment a wide range of carbon sources (e.g., glucose, galactose, cellobiose, mannose, xylose, and arabinose) to produce carboxylic acids (acetic and butyric) and solvents such as acetone, butanol, and ethanol (ABE). The fermentation process typically proceeds in two phases (acidogenic and solventogenic) in a batch mode. Poor solvent resistance by the solventogenic clostridia and other fermenting microorganisms is a major limiting factor in the profitability of ABE production by fermentation. The toxic effect of solvents, especially butanol, limits the concentration of these solvents in the fermentation broth, limiting solvent yields and adding to the cost of solvent recovery from dilute solutions. The accepted dogma is that toxicity in the ABE fermentation is due to chaotropic effects of butanol on the cell membranes of the fermenting microorganisms, which poses a challenge for the biotechnological whole-cell bio-production of butanol. This mini-review is focused on (1) the effects of solvents on inhibition of cell metabolism (nutrient transport, ion transport, and energy metabolism); (2) cell membrane fluidity, death, and solvent tolerance associated with the ability of cells to tolerate high concentrations of solvents without significant loss of cell function; and (3) strategies for overcoming poor solvent resistance in acetone and butanol-producing microorganisms.

Abstract  Emission of odorous compounds from intensive livestock production is a cause of nuisance in populated rural areas. Knowledge on the chemical composition of odor and temporal variations in emissions are needed in order to identify factors of importance for emission rates and select proper abatement technologies. In this work, a method based on proton-transfer-reaction mass spectrometry (PTR-MS) has been developed and tested for continuous measurements of odorant emissions from intensive pig production facilities. The method is assessed to cover all presently known important odorants from this type of animal production with adequate sensitivity and a time resolution of less than one minute. The sensitivity toward hydrogen sulfide is demonstrated to exhibit a pronounced humidity dependency, which can be included in the calibration procedure in order to achieve quantitative results for this compound. Application of the method at an experimental pig facility demonstrated strong temporal variations in emissions, including diurnal variation. Based on these first results, air exchange and animal activity are suggested to be of importance for emission rates of odorants. Highest emissions are seen for hydrogen sulfide and acetic acid, whereas key odorants are evaluated from tabulated odor threshold values to be hydrogen sulfide, methanethiol, 4-methylphenol, and butanoic acid.

Abstract  Currently, the predominant microbially produced biofuel is starch- or sugar-derived ethanol. However, ethanol is not an ideal fuel molecule, and lignocellulosic feedstocks are considerably more abundant than both starch and sugar. Thus, many improvements in both the feedstock and the fuel have been proposed. In this paper, we examine the prospects for bioproduction of four second-generation biofuels (n-butanol, 2-butanol, terpenoids, or higher lipids) from four feedstocks (sugars and starches, lignocellulosics, syngas, and atmospheric carbon dioxide). The principal obstacle to commercial production of these fuels is that microbial catalysts of robust yields, productivities, and titers have yet to be developed. Suitable microbial hosts for biofuel production must tolerate process stresses such as end-product toxicity and tolerance to fermentation inhibitors in order to achieve high yields and titers. We tested seven fast-growing host organisms for tolerance to production stresses, and discuss several metabolic engineering strategies for the improvement of biofuels production.

Abstract  The effects of alcohol treatment on the activity and loading amount of Candida rugosa lipase (CRL), Candida Antarctica lipase B (CALB) and Porcine Pancreas lipase (PPL) immobilized on methyl-modified silica aerogels were investigated, and the fluorescent analysis was used to explore the change of lipase hydrophobicity in aqueous solution caused by alcohols. It is found that alcohol types and the stages at which alcohol was added significantly influenced the performance of immobilized lipases through changing the hydrophobicity of the molecules. For CRL and PPL, five kinds of alcohol were added in the adsorption process, and n-butanol and isopropanol improved the apparent activity of CRL and PPL up to 2.5 times and 2 times those of the untreated ones, respectively; however, for CALB, it is better to activate the immobilized CALB after the adsorption process, and the apparent activity of CALB increased up to 2.76 times through n-butanol treatment.