Abstract  The relationship between C. tyrobutyricum, C. sporogenes and C. beijerinckii in experimental cheese conditions, and their influences on late-blowing and butyric fermentation, have been investigated. A molecular approach using a PCR-TTGE method in combination with conventional methods, such as microbiological and physico-chemical analysis, was performed to monitor the evolution of these clostridial species, simultaneously with the occurrence of cheese defects. Sixteen Emmental type cheeses were produced from milk inoculated with different clostridial spore associations. In all cheeses inoculated with C. tyrobutyricum, obvious signs of late blowing were detected. In cheeses inoculated with C. beijerinckii or C. sporogenes, a formation of holes in cheese body was observed, with a concomitant slight amount of butyric acid production. Even though C. beijerinckii and C. sporogenes were less metabolically active and less numerically important than C. tyrobutyricum in cheese as shown by TTGE profiles, the association of these species to C. tyrobutyricum enhanced the butyric fermentation and the cheese defects. The level of butyric content in ripened cheese increased to 268 mg 100 g(-1) in presence of C. tyrobutyricum, and reached a maximum of 414 mg 100 g(-1) in presence of the C. beijerinckii-C. tyrobutyricum (1:10) association. The propionic fermentation was also higher in cheese inoculated with C. tyrobutyricum, and was slowed down in presence of C. beijerinckii and C. sporogenes. From 30 days of ripening, a strong correlation between the chemical contents and the intensity of cheese defects was demonstrated. A chemical analysis of cheese associated with a molecular method for microbial spoilage investigation allows the prediction of the level of late blowing at early stages of ripening, and the understanding of the origin of the defect.

Abstract  The formation of SCFA in rats fed fermented oat fibre concentrates was compared with that of rats fed native oat fibre concentrate. The cultures used were lactic acid bacteria consisting of Lactobacillus bulgaricus and Streptococcus thermophilus (V2), the exopolysaccharide-producing strain Pediococcus damnosus 2.6 (Pd) and L. reuteri (Lr). The materials were incorporated into test diets yielding a concentration of indigestible carbohydrates of 80 g/kg (dry weight). Rats fed the V2-fermented fibre-concentrate diet yielded higher caecal and distal concentrations of acetic acid (P < 0.01) than rats fed the native fibre concentrate. All the fermented fibre concentrates resulted in a higher propionic acid concentration in the distal colon (P < 0.05), while rats fed Pd-fermented fibre concentrate resulted in lower concentration of butyric acid (P < 0.05, P < 0.01) in all parts of the hindgut as compared with rats fed the native fibre concentrates. Butyrate concentrations ranged between 5-11 micromol/g (distal colon) and 6-8 micromol/g (13 d faeces). Higher proportions of acetic acid (P < 0.05; P < 0.01) were observed in the caecum of rats fed the fermented fibre concentrates. Rats fed Pd- and Lr-fermented fibre concentrates produced higher proportions of propionic acid (P < 0.05; P < 0.01) in the caecum. Changes in SCFA formation in the caecum, distal colon and faeces of rats fed the fermented samples compared with the native sample indicate that these microbes probably survive in the hindgut and that modification of the microflora composition with fermented foods is possible. This may be important for the gastrointestinal flora balance in relation to colonic diseases.

Abstract  We examined concentration-dependent changes in cell cycle distribution and cell cycle-related proteins induced by butyric acid. Butyric acid enhanced or suppressed the proliferation of Jurkat human T lymphocytes depending on concentration. A low concentration of butyric acid induced a massive increase in the number of cells in S and G2/M phases, whereas a high concentration significantly increased the accumulation of cells in G2/M phase, suppressed the accumulation of cells in G0/G1 and S phases, and induced apoptosis that cell cycle-related protein expression in Jurkat cells treated with high levels of butyric acid caused a marked decrease in cyclin A, cyclin E, cyclin-dependent kinase 2 (CDK2), CDK4 and CDK6 protein levels in G0/G1 and S phases, with apoptosis induction, and a decrease in cyclin B, Cdc25c and p27KIP1 protein levels, as well as an increase in p21CIP1/WAF1 protein level, in the G2/M phase. Taken together, our results indicate that butyric acid has bimodal effects on cell proliferation and survival. The inhibition of cell growth followed by the increase in apoptosis induced by high levels of butyric acid were related to an increase in cell death in G0/G1 and S phases, as well as G2/M arrest of cells. Finally, these results were further substantiated by the expression profile of butyric acid-treated Jurkat cells obtained by means of cDNA array.

Abstract  All-trans retinoic acid (ATRA) represents the therapy of choice for patients with acute promyelocytic leukemia (APL). However, patients often relapse due to ATRA-resistance. The molecular basis of APL alterations indicates that addition of a histone deacetylase inhibitor to ATRA may restore the sensitivity to retinoids. We explored the in vitro and in vivo effects of a novel retinoic/butyric hyaluronan ester (HBR) on a retinoic acid (RA)-sensitive human myeloid cell line, NB4, and on its RA-resistant subclone, NB4.007/6. In vitro, HBR induced growth arrest and terminal differentiation in RA-sensitive NB4 cells (as confirmed by an increased expression of CD11 family members and nitroblue tetrazolium assay), whereas it inhibited the growth of RA-resistant cells by apoptosis, paralleled by an increase in the levels of caspase 3 and 7. In vivo, HBR treatment of NB4-inoculated severe combined immunodeficient mice resulted in a statistically significant increase in survival time (P<0.0001), comparable to that induced by a maximum tolerated dose of RA alone. Also on P388-inoculated mice, HBR was active in contrast to RA that was completely ineffective. Present findings suggest that, owing to the simultaneous presence of RA and an histone deacetylases inhibitor, HBR might be useful in controlling the proliferation of RA-resistant cells and the differentiation of RA-sensitive cells.

Abstract  Broadband acoustic emission signals were obtained by attaching a piezoelectric transducer, sensitive up to 750 kHz, to the external wall of a 1 L jacketed glass reactor. Measurements were acquired of itaconic acid particles mixing in toluene; the total area of the acoustic emission signal from 55-500 kHz increased when the particle concentration, particle size or stir rate were increased. Signals at frequencies above 200 kHz were less sensitive to changes in particle size than those at lower frequencies. From calculation of the area of the signal in the range 55-200 kHz as a percentage of the signal area over the range 55-500 kHz, for mixtures of different size ranges of itaconic acid, it was possible to obtain an estimate of the mean particle size of a mixture. The heterogeneous esterification reaction of itaconic acid and 1-butanol was monitored non-invasively. A decrease in the overall acoustic signal area between 60 and 500 kHz was observed as the reaction progressed. Particle size and concentration information were contained in the amplitude of the acoustic emission signal, while the emission frequency yielded information on changes in the mean particle size.

Abstract  Abstract Context: There is a need for the discovery of novel natural antioxidants and acetylcholinesterase inhibitors (AChEIs) that are safe and effective at a global level. This is the first study on antioxidant and anti-acethylcholinesterase activity of Scabiosa arenaria Forssk (Dipsacaceae). Objective: The antioxidant potential and anti-acetylcholinesterase (AChE) activity of S. arenaria were investigated. Material and methods: The crude, ethyl acetate (EtOAc), butanol (n-BuOH) and water extracts prepared from flowers, fruits and stems and leaves of S. arenaria were tested to determine their total polyphenol content (TPC), total flavonoid content (TFC), total condensed tannin content (CTC) and their antioxidant activity by using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), reducing power and β-carotene bleaching inhibition activity. Anti-AChE activity was also determined. Results: EtOAc and n-BuOH fractions of fruits had both the highest (TPC) (269.09 mg gallic acid equivalents/g dry weight). The crude extract of stems and leaves had the highest TFC (10.9 mg quercetin equivalent/g dry weight). The n-BuOH fraction of stems and leaves had the highest CTC (489.75 mg catechin equivalents/g dry weight). The EtOAc fraction of flowers exhibit a higher activity in each antioxidant system with a special attention for DPPH assay (IC(50) = 0.017 mg/mL) and reducing power (EC(50) = 0.02 mg/mL). The EtOAc and n-BuOH fractions of stems and leaves showed strong inhibition of AChE (IC(50) = 0.016 and 0.029 mg/mL, respectively). Discussion and conclusions: These results suggest the potential of S. arenaria as a possible source of novel compounds and as an alternative antioxidant and AChEIs.

Abstract  We generate percolating fullerene-polymer bulk heterostructures that are consistent with the experimental characterization of a nanostructure, in particular neutron reflectometry and small-angle neutron scattering data from as-cast and annealed poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester systems. Transport simulations correlate changes in exciton dissociation efficiency and charge collection efficiency with morphological features including characteristic domain size, fullerene concentration profile, degree of fullerene sequestration, and degree of P3HT crystallization.

Abstract  Upgrading bio-oil by addition reactions across olefins represents a route to refine bio-oil to combustible and stable oxygen-containing fuels. Development and application of highly active strong solid acid catalysts with good hydrothermal stability has become a key determinant for success, because bio-oil's complexity includes large amounts of water. Temperatures of 120°C or more are needed for satisfactory kinetics. Batch upgrading of a model bio-oil (phenol/water/acetic acid/acetaldehyde/hydroxyacetone/d-glucose/2-hydroxymethylfuran) over five water-tolerant solid acid catalysts (Dowex50WX2, Amberlyst15, Amberlyst36, silica sulfuric acid (SSA) and Cs(2.5)H(0.5)PW(12)O(40) supported on K-10 clay (Cs(2.5)/K-10, 30wt.%)) with 1-octene/1-butanol were studied at 120°C/3h. SSA, , exhibited the highest water tolerance and activity. Upgrading using olefin/1-butanol is complex, involving many simultaneous competing esterification, etherification, olefin hydration, phenol alkylation, aldol condensation, sugar dehydration etc. reactions.

Abstract  The pharmacologic management of insomnia has long been dominated by agents that facilitate gamma amino butyric acid inhibition. These agents have served as the clinical model for understanding the pharmacodynamic effects of insomnia agents according to which sleep effects parallel plasma drug levels (pharmacokinetic effects). Agents with other mechanisms also exist for treating insomnia; however, their effects are less well understood. Many of these diminish the activity in one or more of the key wake-promoting systems. This review focuses on one such mechanism, blockade of the wake promoting effects of histamine via H(1) receptor antagonism. Although drugs with H(1) antagonist effects have long been available, this review was prompted by new studies of a selective H(1) antagonist, which provide the first indication of the effects that are specifically associated with H(1) antagonism. The findings do not conform to our long-standing model of insomnia agents in that factors other than drug blood level are needed to explain the clinical effects. We suggest a model for understanding these unique effects based on a review of the basic neurobiology of the histamine system. In addition to drug blood level, clinical effects reflect circadian variation in activity in the histamine system and other parallel wake promoting systems as well as factors such as pain and stress. We hypothesize that significant sleep enhancing effects are likely when the histamine system is relatively active and the activity in other parallel wake promoting systems is relatively minimal. Although the focus of this review is on the novel properties of H(1) antagonism, the principles that emerge from this analysis are most likely relevant to all agents that selectively block wake promoting systems, and as such, this review provides a new paradigm for understanding the effects of insomnia medications.

Abstract  A reliable in vitro regeneration system for the economical and medicinally important Piper nigrum L. has been established. Callus and shoot regeneration was encouraged from leaf portions on Murashige and Skoog (MS) medium augmented with varied concentrations of plant growth regulators. A higher callus production (90 %) was observed in explants incubated on MS medium incorporated with 1.0 mg L(-1) 6-benzyladenine (BA) along with 0.5 mg L(-1) gibberellic acid after 4 weeks of culture. Moreover, a callogenic response of 85 % was also recorded for 1.0 mg L(-1) BA in combination with 0.25 mg L(-1) α-naphthalene acetic acid (NAA) and 0.25 mg L(-1) 2,4-dichlorophenoxyacetic acid or 0.5 mg L(-1) indole butyric acid (IBA) along with 0.25 mg L(-1) NAA and indole acetic acid. Subsequent sub-culturing of callus after 4 weeks of culture onto MS medium supplemented with 1.5 mg L(-1) thiodiazoran or 1.5 mg L(-1) IBA induced 100 % shoot response. Rooted plantlets were achieved on medium containing varied concentrations of auxins. The antioxidative enzyme activities [superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX)] revealed that significantly higher SOD was observed in regenerated plantlets than in other tissues. However, POD, CAT, and APX were higher in callus than in other tissues. A high-performance liquid chromatography (HPLC) fingerprint analysis protocol was established for quality control in different in vitro-regenerated tissues of P. nigrum L. During analysis, most of the common peaks represent the active principle "piperine." The chemical contents, especially piperine, showed variation from callus culture to whole plantlet regeneration. Based on the deviation in chromatographic peaks, the in vitro-regenerated plantlets exhibit a nearly similar piperine profile to acclimated plantlets. The in vitro regeneration system and HPLC fingerprint analysis established here brought a novel approach to the quality control of in vitro plantlets, producing metabolites of interest with substantial applications for the conservation of germplasm.

Abstract  Abstract Mentha longifolia is an aromatic plant used in flavoring and preserving foods and as an anti-inflammatory folk medicine remedy. The present study assessed the effects of M. longifolia extracts, including essential oil and crude methanol extract and its fractions (ethyl acetate, butanol and hexane), on nitric oxide (NO) production and inducible NO synthase (iNOS) mRNA expression in lipopolysaccharide (LPS)-stimulated J774A.1 cells using real-time polymerase chain reaction (PCR). The cytotoxic effects of the extracts on the cells were examined and non-cytotoxic concentrations (<0.2 mg/ml) were used to examine their effects on NO production and iNOS mRNA expression. Only the hexane fraction that contained high levels of phenolic and flavonoid compounds at concentrations from 0.05-0.20 mg/ml significantly reduced NO production in LPS-stimulated cells (p < 0.001). Real-time PCR analysis indicated the ability of this fraction at the same concentrations to significantly decrease iNOS as well as TNFα mRNA expression in the cells (p < 0.001). All extracts were able to scavenge NO radicals in a concentration-dependent manner. At concentrations greater than 0.2 mg/ml, total radicals were 100% scavenged. In conclusion, M. longifolia possibly reduces NO secretion in macrophages by scavenging NO and inhibiting iNOS mRNA expression, and also decreases TNFα pro-inflammatory cytokine expression, thus showing its usefulness in the inflammatory disease process.

Abstract  A multidisciplinary approach has been adopted to investigate and identify the source of malodour in washing machines and the potential for cross-contamination of laundry. Four washing machines were olfactively graded and the number of CFUs bacteria determined in four specific locations. Then, samples of terry-towel and fleece were washed, without the use of detergent, in the machines and the occurrence of malodour over a 52 hour period was assessed. Analysis of the scrapings from the 4 locations in the two malodorous machines identified a plethora of volatile organic compounds (VOCs) by either olfactory detection or mass spectral identification post-gas chromatographic separation. In addition, microbiological analysis from the swabs from the 4 locations within all four washing machines was done. Quantitative analysis of VOCs from 66 microbiological isolates from either the washing machines or fabrics was done. In total 10 VOCs were identified: dimethyl disulfide, 3-methyl-1-butanol, 2,4-dithiapentane, dimethyl trisulfide, 2-tridecanone, indole, 2-phenylethanol, isovaleric acid, isobutyric acid, and 1-undecene. © 2013 The Authors Letters in Applied Microbiology © 2013 The Society for AppliedMicrobiology.

Abstract  In this paper a comparative study is carried out on the CdSe QDs synthesized from water and ethanol. Our purpose is to present an insight understanding on how hydrogen bonds affect particle agglomeration and consequently photoluminescence (PL) behavior of the QDs. In comparison with those from water, the CdSe QDs from ethanol show super PL with high brightness. Detailed characterization gives the only difference of large agglomerates presented in the QDs from ethanol. The TEM and HRTEM observations reveal a tri-level microstructure for the QDs from ethanol while in the case of those from water it is bi-level. With these direct evidences weak hydrogen bond of TGA with ethanol is proposed to be responsible for these large agglomerates and consequently super PL behavior. Additional investigations on some other alcohols of methanol, n-propanol, and i-butanol yield positive results and confirm the truth of our proposal.

Abstract  Glycans are essential regulators of protein function and are now in the focus of research in many physiological and pathophysiological processes. There are numerous modes of regulating their biosynthesis, including epigenetic mechanisms implicated in the expression of glyco-genes. Since N-glycans located at the cell membrane define intercellular communication as well as a cellular response to a given environment, we developed a method to preferentially analyze this fraction of glycans. The method is based on incorporation of living cells into polyacrylamide gels, partial denaturation of membrane proteins with 3 M urea and subsequent release of N-glycans with PNGase F followed by HPLC analysis. Using this newly developed method, we revealed multiple effects of epigenetic inhibitors Trichostatin A, sodium butyrate and zebularine on the composition of N-glycans in human cells. The induced changes were found to be reversible after inhibitor removal. Given that many epigenetic inhibitors are currently explored as a therapeutic strategy in treatment of cancer, wherein surface glycans play an important role, the presented work contributes to our understanding of their efficiency in altering the N-glycan profile of cancer cells in culture.

Abstract  The knowledge of the chemical stability as a function of the temperature of ionic liquids (ILs) in the presence of other molecules such as water is crucial prior to developing any industrial application and process involving these novel materials. Fluid phase equilibria and density over large range of temperature and composition can give basic information on IL purity and chemical stability. The IL scientific community requires accurate measurements accessed from reference data. In this work, the stability of different alkylsulfates-based ILs in the presence of water and various alcohols (methanol, ethanol, 1-butanol and 1-octanol) was investigated to understand their stability as a function of temperature up to 423.15 K over the hydrolysis and transesterification reactions, respectively. From this investigation, it was clear that methylsulfate- and ethylsulfate- based ILs are not stable in presence of water since hydrolysis of the methylsulfate or ethylsulfate anions to methanol or ethanol and hydrogenate anion is undoubtedly observed. Such observations could help explain the differences observed for the physical properties published in the literature by various groups. Furthermore, it appears that a thermodynamic equilibrium process drives these hydrolysis reactions. In other words, these hydrolysis reactions are in fact reversible, providing the possibility to reform the desired alkylsulfate anions by a simple transesterification reaction between hydrogen sulfate-based ILs and the corresponding alcohol (methanol or ethanol). Additionally, butylsulfate and octylsulfate-based ILs appear to follow this pattern but under more drastic conditions. In these systems hydrolysis is observed in both cases after several months for temperature up to 423 K in presence of water. Therein, the partial miscibility of hydrogen sulfate-based ILs with long chain alcohols (1-butanol and 1-octanol) can help explain the enhanced hydrolytic stability of the butylsulfate- and octylsulfate-based ILs compared with the methyl- or ethysulfate systems. Additionally, rapid transesterification reactions are observed during liquid-liquid equilibrium studies as a function of temperature for binary systems of (hydrogen sulfate-based ionic liquids + 1-butanol) and of (hydrogen sulfate-based ionic liquids + 1-octanol). Finally, this atom efficient catalyst-free transesterification reaction between hydrogen sulfate -based ILs and alcohol was then tested to provide a novel way to synthesize new ILs with various anion structures containing the alkylsulfate group.

Abstract  INTRODUCTION: The health benefits of sea buckthorn (Hippophae rhamnoides L.) are well documented due to its rich content in bioactive phytochemicals (pigments, phenolics and vitamins) as well as volatiles responsible for specific flavours and bacteriostatic action. The volatile compounds are good biomarkers of berry freshness, quality and authenticity. OBJECTIVE: To develop a fast and efficient GC-MS method including a minimal sample preparation technique (in-tube extraction, ITEX) for the discrimination of sea buckthorn varieties based on their chromatographic volatile fingerprint. MATERIAL AND METHODS: Twelve sea buckthorn varieties (wild and cultivated) were collected from forestry departments and experimental fields, respectively. The extraction of volatile compounds was performed using the ITEX technique whereas separation and identification was performed using a GC-MS QP-2010. Principal component analysis (PCA) was applied to discriminate the differences among sample composition. RESULTS: Using GC-MS analysis, from the headspace of sea buckthorn samples, 46 volatile compounds were separated with 43 being identified. The most abundant derivatives were ethyl esters of 2-methylbutanoic acid, 3-methylbutanoic acid, hexanoic acid, octanoic acid and butanoic acid, as well as 3-methylbutyl 3-methylbutanoate, 3-methylbutyl 2-methylbutanoate and benzoic acid ethyl ester (over 80% of all volatile compounds). Principal component analysis showed that the first two components explain 79% of data variance, demonstrating a good discrimination between samples. CONCLUSION: A reliable, fast and eco-friendly ITEX/GC-MS method was applied to fingerprint the volatile profile and to discriminate between wild and cultivated sea buckthorn berries originating from the Carpathians, with relevance to food science and technology. Copyright © 2013 John Wiley & Sons, Ltd.

Abstract  Dietary fibers can be fermented in the colon, resulting in production of short-chain fatty acids (SCFA) and secretion of satiety-related peptides. Fermentation characteristics (fermentation kinetics and SCFA-profile) differ between fibers and could impact their satiating potential. We investigated the effects of fibers with varying fermentation characteristics on feeding motivation in adult female pigs. Sixteen pair-housed pigs received four diets in four periods in a Latin square design. Starch from a control (C) diet was exchanged, based on gross energy, for inulin (INU), guar gum (GG), or retrograded tapioca starch (RS), each at a low (L) and a high (H) inclusion level. This resulted in a decreased metabolizable energy intake when feeding fiber diets as compared with the C diet. According to in vitro fermentation measurements, INU is rapidly fermentable and yields relatively high amounts of propionate, GG is moderately rapidly fermentable and yields relatively high amounts of acetate, and RS is slowly fermentable and yields relatively high amounts of butyrate. Feeding motivation was assessed using behavioral tests at 1h, 3h and 7h after the morning meal, and home pen behavioral observations throughout the day. The number of wheel turns paid for a food reward in an operant test was unaffected by diet. Pigs on H-diets ran 25% slower for a food reward in a runway test than pigs on L-diets, and showed less spontaneous physical activity and less stereotypic behavior in the hours before the afternoon meal, reflecting increased interprandial satiety. Reduced feeding motivation with increasing inclusion level was most pronounced for RS, as pigs decreased speed in the runway test and tended to have a lower voluntary food intake in an ad libitum food intake test when fed RS-H. In conclusion, increasing levels of fermentable fibers in the diet seemed to enhance satiety in adult pigs, despite a reduction in metabolizable energy supply. RS was the most satiating fiber, possibly due to its slow rate of fermentation and high production of butyrate.

Abstract  OBJECTIVE: To observe the effect of ginsenoside Rg1 on behavior and hippocampal amino acids in depressive-like rats.

METHOD: SD rats were randomly divided into 5 groups: control, model, fluxetine, low dose ginsenoside Rg1 and high dose of ginsenoside Rg1. The chronic unpredictable mild stress (CUMS) was performed to induce depressive-like animal model. Fluxetine group was orally given fluxetine in dose of 10 mg x kg(-1) for 21 days, low dose ginsenoside Rg1 group was orally given ginsenoside Rg1 in dose of 20 mg x kg(-1) for 21 days, high dose ginsenoside Rg1 group was orally given ginsenoside Rg1 in dose of 40 mg x kg(-1) for 21 days. The control and model group was orally given saline for 21 days. The sucrose consumption was detected before and after the CUMS procedure. The horizontal and vertical activities of rats were determined by open-field test. HPLC was adopted to detect the contents of amino acids in hippocampus.

RESULT: The sucrose consumption, horizontal and vertical activities in CUMS rats were decreased compared with those in control group. Compared with control group, the contents of glutamate (Glu) and aspartate (Asp) in hippocampus of CUMS group were increased, while the gamma amino butyric acid (GABA) and taurine (Tau) were decreased. Ginsenoside Rg1 treatment significantly increased the CUMS-induced decrease in sucrose consumption, horizontal and vertical activities. Administrated with ginsenoside Rg1 also decreased Glu and Asp and increased the GABA and Tau in hippocampus in a dose dependent manner.

CONCLUSION: Ginsenoside Rg1 could alleviate the behavior changes of depressive-like rats, which might be related to regulate the levels of amino acids in hippocampus during CUMS and prevent the neuro-toxicity of excitatory amino acids.

Abstract  Lipase-displaying whole cells appear to be efficient biocatalysts because of their low preparation costs and simple recycling procedure. The combined utilization of Candida antarctica lipase B (CALB) and Rhizomucor miehei lipase (RML), separately displayed on Pichia pastoris whole cells, to produce biodiesel in co-solvent media was investigated. A response surface methodology incorporating a D-optimal design was employed to obtain the optimum reaction conditions for methyl ester (ME) synthesis. The synergistic effect of the two displayed lipases and the use of tert-butanol and isooctane as the co-solvent media were found to significantly improve the transesterification reaction. Scaled-up reactions using various types of feedstock were carried out in a 0.5-l stirred reactor under optimum conditions, affording ME yields over 90% in 12h. Moreover, the ME yields remained above 85% after 20 repeated batch cycles. In conclusion, this biocatalyst affords a promising route to efficient biodiesel production.

Abstract  In this study, the production of ethyl butyrate was investigated by using immobilized lipase enzyme in shake flasks. In order to determine optimum conditions for the production, response surface methodology was used. The model indicated the optimum conditions for maximum conversion (9.1%) at the 0.31 M substrate concentration, acid- alcohol molar ratio of 0.49, immobilized enzyme 25% (w/v) at 35°C, for 3 hours which were in good agreement with the experimental value. At the end of the 55 hours conversion was obtained as 61.3%. When Na(2)HPO(4) was used in reaction medium conversion increased to 90.3% for 55 hours.

Abstract  The influence of butanol on the expression of ompC gene encoding synthesis of OmpC porin in the MG 1655 strain of E. coli and butanol-tolerant mutant ButR was studied. It was shown that in the case of wild bacteria, the addition of butanol to the growth medium results in an increased level of ompC transcription. However, OmpC porin is not detected in the membrane fraction of cells. ButR mutant exhibits a higher level of ompC gene expression. A direct correlation is observed between the level of OmpC porin expression and its content in the membrane fraction of ButR mutant cells. In the regulatory region of the ompC gene of the ButR mutant, three nucleotide substitutions located in the binding sites of OmpR and CpxR activator proteins were identified. It was shown that mutations in the regulatory region of the ompC gene in the ButR mutant are responsible for the decreased level of OmpC porin expression under normal growth conditions. However, these mutations lead to an increased level of OmpC porin synthesis in the presence of butanol. These data suggest an additional mechanism of ompC gene regulation with the participation of butanol as a positive transcription effector.

Abstract  An investigation was carried out to develop an efficient micropropagation protocol for Catharanthus roseus. Experiments were conducted to optimize suitable media for in vitro shoot multiplication and root induction. Out of the different media compared for in vitro shoot multiplication, Murashige and Skoog (MS) medium supplemented with 1 mg/l of 6-benzylaminopurine and 0.2 mg/l α-naphthaleneacetic acid showed better response in terms of the emergence of shoots from axillary buds as well as proliferation and multiplication of shoots. The shoots when placed on half strength of MS medium having 1 mg/l indole 3-butyric acid and 0.25 % charcoal showed cent percent root induction with maximum number of roots per shoot (4.2) as well as maximum root length (1.72 cm). Further, clonal fidelity of the in vitro-raised plants was carried out using randomly amplified polymorphic DNA marker and results indicated that all the tissue culture-derived plants are true-to-type and there were no somaclonal variations among these plants.

Abstract  Though pesticide mixtures are commonly encountered in fresh water systems, the knowledge of their effects on non-target aquatic species is scarce. The present investigation was undertaken to explore the in vivo inhibition of the freshwater gastropod snail Planorbarius corneus cholinesterase (ChE) and carboxylesterases (CES) activities by the organophosphorus pesticides azinphos-methyl (AZM) and chlorpyrifos (CPF). To this end, snails were exposed for 48h to different concentrations of AZM and CPF in single-chemical and binary-mixture studies, and ChE and CES activities were measured in the whole soft body tissues and hemolymph. ChE activity was measured with acetylthiocholine as substrate and CES activity was measured with four substrates: p-nitrophenyl acetate, p-nitrophenyl butyrate, 1- and 2-naphthyl acetate. Single-chemical experiments showed that CPF was a more potent inhibitor of ChE activity than AZM (350 and 27 times for the whole soft tissue and hemolymph, respectively). CES were 15 times more sensitive than ChE when the activities were measured in the whole soft tissue of the animals exposed to AZM. Based on a default assumption of concentration addition, P. corneus snails were exposed to mixtures of AZM+CPF designed to yield predicted soft tissue ChE inhibitions of 31% (mixture 1), 50% (mixture 2) and 61% (mixture 3). Results showed that ChE inhibition produced by mixture 1 followed a model of concentration addition. In contrast, the other mixtures showed synergism, both in whole soft tissue and hemolymph. In addition, results obtained when the snails were exposed sequentially to the pesticides showed that the sequence AZM/CPF produced at 48h a higher ChE inhibition than the sequence CPF/CPF. A range of metabolic pathways and responses associated with bioactivation or detoxification may play important roles in organophosphorus interactions. In particular, the data presented in the present study indicate that CES enzymes would be important factors in determining the effects of the mixtures of OPs on P. corneus ChE activity.