Response of methane production via propionate oxidation to carboxylated multiwalled carbon nanotubes in paddy soil enrichments

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Jianchao Zhang

2018-01-01

Full Text Available Carboxylated multiwalled carbon nanotubes (MWCNTs-COOH have become a growing concern in terms of their fate and toxicity in aqueous environments. Methane (CH4 is a major product of organic matter degradation in waterlogged environments. In this study, we determined the effect of MWCNTs-COOH on the production of CH4 from propionate oxidation in paddy soil enrichments. The results showed that the methanogenesis from propionate degradation was accelerated in the presence of MWCNTs-COOH. In addition, the rates of CH4 production and propionate degradation increased with increasing concentrations of MWCNTs-COOH. Scanning electron microscopy (SEM observations showed that the cells were intact and maintained their structure in the presence of MWCNTs-COOH. In addition, SEM and fluorescence in situ hybridization (FISH images revealed that the cells were in direct contact with the MWCNTs and formed cell-MWCNTs aggregates that contained both bacteria and archaea. On the other hand, nontoxic magnetite nanoparticles (Fe3O4 had similar effects on the CH4 production and cell integrity as the MWCNTs-COOH. Compared with no nanomaterial addition, the relative abundances of Geobacter and Methanosarcina species increased in the presence of MWCNTs-COOH. This study suggests that MWCNTs-COOH exerted positive rather than cytotoxic effects on the syntrophic oxidation of propionate in paddy soil enrichments and affected the bacterial and archaeal community structure at the test concentrations. These findings provide novel insight into the consequences of nanomaterial release into anoxic natural environments.

Using a feed-grade zinc propionate to achieve molt induction in laying hens and retain postmolt egg production and quality.

Science.gov (United States)

Park, S Y; Kim, W K; Birkhold, S G; Kubena, L F; Nisbet, D J; Ricke, S C

2004-11-01

A commercial-feed-grade form of zinc propionate was examined as a potential feed amendment at a concentration of 1% zinc to induce molt in 90-wk-old hens. Dietary treatments consisted of 4 treatment groups of 28 birds each randomly assigned to either (1) molted conventionally by feed withdrawal, (2) 1% zinc as Zn acetate, (3) 1% zinc as Zn propionate, or (4) nonmolted control for 9 d. Ovary weights of hens fed Zn acetate or Zn propionate were not significantly different from each other, but hens fed Zn acetate or Zn propionate were significantly (phens. Zinc concentrations in the kidney and liver were significantly (phens when compared to either nonmolted control-fed hens or feed-withdrawal molted hens. Over the entire 3-mo postmolt period, there were no significant differences in interior or exterior egg qualities among the four treatments. Egg production of hens fed Zn acetate was significantly lower than feed-withdrawal hens, Zn propionate-fed hens, or nonmolted control hens (pfeeding a feed grade of Zn propionate (1% Zn)-supplemented diet can induce molt and retain postmolt egg quality and production comparable to hens molted by feed withdrawal.

MR spectroscopy-based brain metabolite profiling in propionic acidaemia: metabolic changes in the basal ganglia during acute decompensation and effect of liver transplantation

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McKiernan Patrick J

2011-05-01

Full Text Available Abstract Background Propionic acidaemia (PA results from deficiency of Propionyl CoA carboxylase, the commonest form presenting in the neonatal period. Despite best current management, PA is associated with severe neurological sequelae, in particular movement disorders resulting from basal ganglia infarction, although the pathogenesis remains poorly understood. The role of liver transplantation remains controversial but may confer some neuro-protection. The present study utilises quantitative magnetic resonance spectroscopy (MRS to investigate brain metabolite alterations in propionic acidaemia during metabolic stability and acute encephalopathic episodes. Methods Quantitative MRS was used to evaluate brain metabolites in eight children with neonatal onset propionic acidaemia, with six elective studies acquired during metabolic stability and five studies during acute encephalopathic episodes. MRS studies were acquired concurrently with clinically indicated MR imaging studies at 1.5 Tesla. LCModel software was used to provide metabolite quantification. Comparison was made with a dataset of MRS metabolite concentrations from a cohort of children with normal appearing MR imaging. Results MRI findings confirm the vulnerability of basal ganglia to infarction during acute encephalopathy. We identified statistically significant decreases in basal ganglia glutamate+glutamine and N-Acetylaspartate, and increase in lactate, during encephalopathic episodes. In white matter lactate was significantly elevated but other metabolites not significantly altered. Metabolite data from two children who had received liver transplantation were not significantly different from the comparator group. Conclusions The metabolite alterations seen in propionic acidaemia in the basal ganglia during acute encephalopathy reflect loss of viable neurons, and a switch to anaerobic respiration. The decrease in glutamine + glutamate supports the hypothesis that they are consumed to

A new highly productive Propionibacterium acidipropionici FL-48 strain with increased resistance to propionic acid and the scaling up of its production for industrial bioreactors

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M. A. Kartashov

2016-09-01

Full Text Available Propionic acid bacteria, including Propionibacterium acidipropionici, are widely used in the chemical industry to produce propionic acid and also for food and feed preservation. However, the efficiency of the industrial production of these bacteria is limited by their sensitivity to high concentrations of propionic acid excreted into the cultivation medium. Therefore, the development of new biotechnological processes and strains able to overcome this limitation and to improve the profitability of the microbiological production remains  a relevant problem. A new P. acidipropionici FL-48 strain characterized by an increased resistance to 10 g/L of propionic acid (the number of viable cells after 24-h cultivation reached 1.05 × 106 was developed by a two-step induced mutagenesis using UV and diethyl sulphate from the P. acidipropionici VKPM B-5723 strain. The mutant strain exceeded the parental strain in the biomass accumulation rate and the amount of produced propionic and acetic acids by 35%, 20%, and 16%, respectively. The stability of such important characteristics as the biomass accumulation rate and the viability on media containing heightened concentrations of propionic acid was confirmed by three sequential monoclonal subculturings on a medium supplemented with 10 g/L of propionic acid. The optimization of the cultivation technology made it possible to determine the optimum seed inoculum dose (10% of the fermentation medium volume and the best pH level for the active growth stage (6.1 ± 0.1. The scaling up of the fermentation to a 100-L bioreactor under observance of optimum cultivation conditions demonstrated a high biomass growth rate with a sufficient reproducability; after 20 h of fermentation, the number of viable cells in the culture broth exceeded 1 × 1010 CFU/mL. The new strain could be interesting as the component of silage and haylage biopreservatives and also could be used as an efficient producer of propionic acid.

Towards the development of an enzyme replacement therapy for the metabolic disorder propionic acidemia

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Mahnaz Darvish-Damavandi

2016-09-01

Full Text Available Propionic acidemia (PA is a life-threatening disease caused by the deficiency of a mitochondrial biotin-dependent enzyme known as propionyl coenzyme-A carboxylase (PCC. This enzyme is responsible for degrading the metabolic intermediate, propionyl coenzyme-A (PP-CoA, derived from multiple metabolic pathways. Currently, except for drastic surgical and dietary intervention that can only provide partial symptomatic relief, no other form of therapeutic option is available for this genetic disorder. Here, we examine a novel approach in protein delivery by specifically targeting and localizing our protein candidate of interest into the mitochondrial matrix of the cells. In order to test this concept of delivery, we have utilized cell penetrating peptides (CPPs and mitochondria targeting sequences (MTS to form specific fusion PCC protein, capable of translocating and localizing across cell membranes. In vitro delivery of our candidate fusion proteins, evaluated by confocal images and enzymatic activity assay, indicated effectiveness of this strategy. Therefore, it holds immense potential in creating a new paradigm in site-specific protein delivery and enzyme replacement therapeutic for PA.

Co-cultivation of Lactobacillus zeae and Veillonella cricetifor the production of propionic acid

Science.gov (United States)

2013-01-01

In this work a defined co-culture of the lactic acid bacterium Lactobacillus zeae and the propionate producer Veillonella criceti has been studied in continuous stirred tank reactor (CSTR) and in a dialysis membrane reactor. It is the first time that this reactor type is used for a defined co-culture fermentation. This reactor allows high mixing rates and working with high cell densities, making it ideal for co-culture investigations. In CSTR experiments the co-culture showed over a broad concentration range an almost linear correlation in consumption and production rates to the supply with complex nutrients. In CSTR and dialysis cultures a strong growth stimulation of L. zeae by V. criceti was shown. In dialysis cultures very high propionate production rates (0.61 g L-1h-1) with final titers up to 28 g L-1 have been realized. This reactor allows an individual, intracellular investigation of the co-culture partners by omic-technologies to provide a better understanding of microbial communities. PMID:23705662

Kinetics of propionate conversion in anaerobic continuously stirred tank reactors

DEFF Research Database (Denmark)

Bangsø Nielsen, Henrik; Mladenovska, Zuzana; Ahring, Birgitte Kiær

2008-01-01

The kinetic parameters of anaerobic propionate degradation by biomass from 7 continuously stirred tank reactors differing in temperature, hydraulic retention time and substrate composition were investigated. In substrate-depletion experiments (batch) the maximum propionate degradation rate, A......-m, was estimated. The results demonstrate that the rate of endogenous substrate (propionate) production should be taken into account when estimating kinetic parameters in biomass from manure-based anaerobic reactors....

Monitoring of clobetasol propionate and betamethasone dipropionate as undeclared steroids in cosmetic products manufactured in Korea.

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Nam, Yun Sik; Kwon, Il Keun; Lee, Kang-Bong

2011-07-15

Some cosmetic products manufactured in Korea have been suspected to contain anti-inflammatory corticosteroids, such as clobetasol propionate and betamethasone dipropionate, for the treatment of eczema, seborrhea and psoriasis, without any indication on the label of the cosmetic products. Due to their severe side effects, such as permanent skin atopy, these two corticosteroids in cosmetic products need to be monitored from a forensic point of view. Cosmetic product samples (number of samples=47) of manufacturers charged by consumers have been collected in local and online markets of Korea, and they were validated and analyzed by a simple high performance liquid chromatography (HPLC) method with ultraviolet diode array (UV-DAD). LC-MS/MS and LC-MS were used to confirm these steroids in cosmetic samples with diagnostic ions (m/z) and isotope ratio. Linearity was studied with 0.5-10μg/mL range in both steroids. Good correlation coefficients (r(2)≥0.999) were found, and their limits of quantifications were 0.59μg/mL and 0.66μg/mL in clobetasol propionate and betamethasone dipropionate, respectively. At three different concentrations spanning the linear dynamic ranges, mean recoveries were always higher than 93%, and precisions for intra-day and inter-day analyses were both less than 3.5%. The results show 32-96.4μg/g levels of clobetasol propionate in five different cosmetic products. Also, betamethasone dipropionate in a sample was monitored at the level of 195.1μg/g. This fact reveals that some manufacturers have added these steroids in their cosmetic products to advertise the treatment effect for skin atopy. Thus, these cosmetic products need to be monitored carefully, and ultimately removed from the market. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Proposed guidelines for the diagnosis and management of methylmalonic and propionic acidemia

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Baumgartner, Matthias R; Hörster, Friederike; Dionisi-Vici, Carlo

2014-01-01

Methylmalonic and propionic acidemia (MMA/PA) are inborn errors of metabolism characterized by accumulation of propionic acid and/or methylmalonic acid due to deficiency of methylmalonyl-CoA mutase (MUT) or propionyl-CoA carboxylase (PCC). MMA has an estimated incidence of ~ 1: 50,000 and PA of ~...... recognition and delayed diagnosis due to nonspecific clinical presentation and insufficient awareness of health care professionals because of disease rarity.......:100'000 -150,000. Patients present either shortly after birth with acute deterioration, metabolic acidosis and hyperammonemia or later at any age with a more heterogeneous clinical picture, leading to early death or to severe neurological handicap in many survivors. Mental outcome tends to be worse in PA...

Propionate oxidation by and methanol inhibition of anaerobic ammonium-oxidizing bacteria.

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Güven, Didem; Dapena, Ana; Kartal, Boran; Schmid, Markus C; Maas, Bart; van de Pas-Schoonen, Katinka; Sozen, Seval; Mendez, Ramon; Op den Camp, Huub J M; Jetten, Mike S M; Strous, Marc; Schmidt, Ingo

2005-02-01

Anaerobic ammonium oxidation (anammox) is a recently discovered microbial pathway and a cost-effective way to remove ammonium from wastewater. Anammox bacteria have been described as obligate chemolithoautotrophs. However, many chemolithoautotrophs (i.e., nitrifiers) can use organic compounds as a supplementary carbon source. In this study, the effect of organic compounds on anammox bacteria was investigated. It was shown that alcohols inhibited anammox bacteria, while organic acids were converted by them. Methanol was the most potent inhibitor, leading to complete and irreversible loss of activity at concentrations as low as 0.5 mM. Of the organic acids acetate and propionate, propionate was consumed at a higher rate (0.8 nmol min(-1) mg of protein(-1)) by Percoll-purified anammox cells. Glucose, formate, and alanine had no effect on the anammox process. It was shown that propionate was oxidized mainly to CO(2), with nitrate and/or nitrite as the electron acceptor. The anammox bacteria carried out propionate oxidation simultaneously with anaerobic ammonium oxidation. In an anammox enrichment culture fed with propionate for 150 days, the relative amounts of anammox cells and denitrifiers did not change significantly over time, indicating that anammox bacteria could compete successfully with heterotrophic denitrifiers for propionate. In conclusion, this study shows that anammox bacteria have a more versatile metabolism than previously assumed.

Degradation of fructans and production of propionic acid by Bacteroides thetaiotaomicron are enhanced by shortage of amino acids

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Signe eAdamberg

2014-12-01

Full Text Available Bacteroides thetaiotaomicron is commonly found in the human colon and stabilizes its ecosystem by the catabolism of various polysaccharides. A model of cross-talk between the metabolism of amino acids and fructans in B. thetaiotaomicron was proposed. The growth of B. thetaiotaomicron DSM 2079 in two defined media containing mineral salts and vitamins, and supplemented with either 20 or 2 amino acids, was studied in an isothermal microcalorimeter. The polyfructans inulin (from chicory and levan (synthesized using levansucrase from Pseudomonas syringae, two fructooligosaccharide preparations with different composition, sucrose and fructose were tested as substrates. The calorimetric power-time curves were substrate specific and typically multiauxic. A surplus of amino acids reduced the consumption of longer oligosaccharides (DP > 3. Bacterial growth was not detected either in the carbohydrate free medium containing amino acids or in the medium with inulin as a sole carbohydrate. In amino acid-restricted medium, fermentation leading to acetic acid formation was dominant at the beginning of growth (up to 24 h, followed by increased lactic acid production, and mainly propionic and succinic acids were produced at the end of fermentation. In the medium supplemented with 20 amino acids, the highest production of D-lactate (82 ± 33 mmol/gDW occurred in parallel with extensive consumption (up to 17 mmol/gDW of amino acids, especially Ser, Thr and Asp. The production of Ala and Glu was observed at growth on all substrates, and the production was enhanced under amino acid deficiency. The study revealed the influence of amino acids on fructan metabolism in B. thetaiotaomicron and showed that defined growth media are invaluable in elucidating quantitative metabolic profiles of the bacteria. Levan was shown to act as an easily degradable substrate for B. thetaiotaomicron. The effect of levan on balancing or modifying colon microbiota will be studied in

Fast and simple method for semiquantitative determination of calcium propionate in bread samples.

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Phechkrajang, Chutima Matayatsuk; Yooyong, Surin

2017-04-01

Calcium propionate has been widely used as a preservative in bakery and in bread. It is sometimes not carefully used, or a high concentration is added to preserve products. High consumption of calcium propionate can lead to several health problems. This study aims to develop a fast and simple semiquantitative method based on color complex formation for the determination of calcium propionate in a bread sample. A red-brown complex was obtained from the reaction of ferric ammonium sulfate and propionate anion. The product was rapidly formed and easily observed with the concentration of propionate anion >0.4 mg/mL. A high-performance liquid chromatography (HPLC) method was also developed and validated for comparison. Twenty-two bread samples from three markets near Bangkok were randomly selected and assayed for calcium propionate using the above two developed methods. The results showed that 19/22 samples contained calcium propionate >2000 mg/kg. The results of the complex formation method agreed with the HPLC method. Copyright © 2016. Published by Elsevier B.V.

Fast and simple method for semiquantitative determination of calcium propionate in bread samples

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Chutima Matayatsuk Phechkrajang

2017-04-01

Full Text Available Calcium propionate has been widely used as a preservative in bakery and in bread. It is sometimes not carefully used, or a high concentration is added to preserve products. High consumption of calcium propionate can lead to several health problems. This study aims to develop a fast and simple semiquantitative method based on color complex formation for the determination of calcium propionate in a bread sample. A red–brown complex was obtained from the reaction of ferric ammonium sulfate and propionate anion. The product was rapidly formed and easily observed with the concentration of propionate anion >0.4 mg/mL. A high-performance liquid chromatography (HPLC method was also developed and validated for comparison. Twenty-two bread samples from three markets near Bangkok were randomly selected and assayed for calcium propionate using the above two developed methods. The results showed that 19/22 samples contained calcium propionate >2000 mg/kg. The results of the complex formation method agreed with the HPLC method.

Efficient odd straight medium chain free fatty acid production by metabolically engineered Escherichia coli.

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Wu, Hui; San, Ka-Yiu

2014-11-01

Free fatty acids (FFAs) can be used as precursors for the production of biofuels or chemicals. Different composition of FFAs will be useful for further modification of the biofuel/biochemical quality. Microbial biosynthesis of even chain FFAs can be achieved by introducing an acyl-acyl carrier protein thioesterase gene into E. coli. In this study, odd straight medium chain FFAs production was investigated by using metabolic engineered E. coli carrying acyl-ACP thioesterase (TE, Ricinus communis), propionyl-CoA synthase (Salmonella enterica), and β-ketoacyl-acyl carrier protein synthase III (four different sources) with supplement of extracellular propionate. By using these metabolically engineered E. coli, significant quantity of C13 and C15 odd straight-chain FFAs could be produced from glucose and propionate. The highest concentration of total odd straight chain FFAs attained was 1205 mg/L by the strain HWK201 (pXZ18, pBHE2), and 85% of the odd straight chain FFAs was C15. However, the highest percentage of odd straight chain FFAs was achieved by the strain HWK201 (pXZ18, pBHE3) of 83.2% at 48 h. This strategy was also applied successfully in strains carrying different TE, such as the medium length acyl-ACP thioesterase gene from Umbellularia californica. C11 and C13 became the major odd straight-chain FFAs. © 2014 Wiley Periodicals, Inc.

Monitoring and control of the biogas process based on propionate concentration using online VFA measurement.

Science.gov (United States)

Boe, Kanokwan; Steyer, Jean-Philippe; Angelidaki, Irini

2008-01-01

Simple logic control algorithms were tested for automatic control of a lab-scale CSTR manure digester. Using an online VFA monitoring system, propionate concentration in the reactor was used as parameter for control of the biogas process. The propionate concentration was kept below a threshold of 10 mM by manipulating the feed flow. Other online parameters such as pH, biogas production, total VFA, and other individual VFA were also measured to examine process performance. The experimental results showed that a simple logic control can successfully prevent the reactor from overload, but with fluctuations of the propionate level due to the nature of control approach. The fluctuation of propionate concentration could be reduced, by adding a lower feed flow limit into the control algorithm to prevent undershooting of propionate response. It was found that use of the biogas production as a main control parameter, rather than propionate can give a more stable process, since propionate was very persistent and only responded very slowly to the decrease of the feed flow which lead to high fluctuation of biogas production. Propionate, however, was still an excellent parameter to indicate process stress under gradual overload and thus recommended as an alarm in the control algorithm. Copyright IWA Publishing 2008.

Regulation and optimization of the biogas process: Propionate as a key parameter

DEFF Research Database (Denmark)

Bangsø Nielsen, Henrik; Uellendahl, Hinrich; Ahring, Birgitte Kiær

2007-01-01

.6 to 2.9 mM. A process disturbance caused by overloading with industrial waste was reflected by a significant increase in all VFA concentrations. During the recovery of the process, the return of propionate back to the steady-state level was 2-3 days slower than any other VFA and propionate could best......, a process breakdown caused by organic overloading with meat and bone meal and lipids was indicated by changes in propionate concentration 12-18 days before a decrease in methane production was observed. Furthermore, a more efficient and stable utilization of the substrate was observed when propionate...

Shifts in metabolic hydrogen sinks in the methanogenesis-inhibited ruminal fermentation: a meta-analysis

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Emilio M. Ungerfeld

2015-02-01

Full Text Available Maximizing the flow of metabolic hydrogen ([H] in the rumen away from CH4 and towards volatile fatty acids (VFA would increase the efficiency of ruminant production and decrease its environmental impact. The objectives of this meta-analysis were: i To quantify shifts in metabolic hydrogen sinks when inhibiting ruminal methanogenesis in vitro; and ii To understand the variation in shifts of metabolic hydrogen sinks among experiments and between batch and continuous cultures systems when methanogenesis is inhibited. Batch (28 experiments, N=193 and continuous (16 experiments, N=79 culture databases of experiments with at least 50% inhibition in CH4 production were compiled. Inhibiting methanogenesis generally resulted in less fermentation and digestion in most batch culture, but not in most continuous culture, experiments. Inhibiting CH4 production in batch cultures resulted in redirection of metabolic hydrogen towards propionate and H2 but not butyrate. In continuous cultures, there was no overall metabolic hydrogen redirection towards propionate or butyrate, and H2 as a proportion of metabolic hydrogen spared from CH4 production was numerically smaller compared to batch cultures. Dihydrogen accumulation was affected by type of substrate and methanogenesis inhibitor, with highly fermentable substrates resulting in greater redirection of metabolic hydrogen towards H2 when inhibiting methanogenesis, and some oils causing small or no H2 accumulation. In both batch and continuous culture, there was a decrease in metabolic hydrogen recovered as the sum of propionate, butyrate, CH4 and H2 when inhibiting methanogenesis, and it is speculated that as CH4 production decreases metabolic hydrogen could be increasingly incorporated into formate, microbial biomass, and, perhaps, reductive acetogenesis in continuous cultures. Energetic benefits of inhibiting methanogenesis depended on the inhibitor and its concentration and on the in vitro system.

Propionate absorbed from the colon acts as gluconeogenic substrate in a strict carnivore, the domestic cat (Felis catus)

DEFF Research Database (Denmark)

Verbrugghe, A; Hesta, M; Daminet, S

2012-01-01

In six normal-weight and six obese cats, the metabolic effect of propionate absorbed from the colon was assessed. Two colonic infusions were tested in a crossover design with intervals of 4 weeks. The test solution contained 4 mmol sodium propionate per kg ideal body weight in a 0.2% NaCl solutio...

Regulation and optimization of the biogas process: Propionate as a key parameter

International Nuclear Information System (INIS)

Nielsen, Henrik Bangso; Uellendahl, Hinrich; Ahring, Birgitte Kiaer

2007-01-01

The use of volatile fatty acids (VFA) as process indicators in biogas reactors treating manure together with industrial waste was studied. At a full-scale biogas plant, an online VFA sensor was installed in order to study VFA dynamics during stable and unstable operation. During stable operation acetate increased significantly during the feeding periods from a level of 2-4 to 12-17 mM, but the concentration generally dropped to about the same level as before feeding. The fluctuations in the propionate were more moderate than for acetate but the average level rose during 1 week of operation from 0.6 to 2.9 mM. A process disturbance caused by overloading with industrial waste was reflected by a significant increase in all VFA concentrations. During the recovery of the process, the return of propionate back to the steady-state level was 2-3 days slower than any other VFA and propionate could best describe the normalizing of the process. In a lab-scale continuously stirred tank reactor experiment, with manure as main substrate, the prospective of using either propionate concentration or methane production as single process indicators was studied. Propionate was found to be the best indicator. Thus, a process breakdown caused by organic overloading with meat and bone meal and lipids was indicated by changes in propionate concentration 12-18 days before a decrease in methane production was observed. Furthermore, a more efficient and stable utilization of the substrate was observed when propionate was used as process indicator

Thermal decomposition of lutetium propionate

DEFF Research Database (Denmark)

Grivel, Jean-Claude

2010-01-01

The thermal decomposition of lutetium(III) propionate monohydrate (Lu(C2H5CO2)3·H2O) in argon was studied by means of thermogravimetry, differential thermal analysis, IR-spectroscopy and X-ray diffraction. Dehydration takes place around 90 °C. It is followed by the decomposition of the anhydrous...... °C. Full conversion to Lu2O3 is achieved at about 1000 °C. Whereas the temperatures and solid reaction products of the first two decomposition steps are similar to those previously reported for the thermal decomposition of lanthanum(III) propionate monohydrate, the final decomposition...... of the oxycarbonate to the rare-earth oxide proceeds in a different way, which is here reminiscent of the thermal decomposition path of Lu(C3H5O2)·2CO(NH2)2·2H2O...

Quantifying Effect of Lactic, Acetic, and Propionic Acids on Growth of Molds Isolated from Spoiled Bakery Products.

Science.gov (United States)

Dagnas, Stéphane; Gauvry, Emilie; Onno, Bernard; Membré, Jeanne-Marie

2015-09-01

The combined effect of undissociated lactic acid (0 to 180 mmol/liter), acetic acid (0 to 60 mmol/liter), and propionic acid (0 to 12 mmol/liter) on growth of the molds Aspergillus niger, Penicillium corylophilum, and Eurotium repens was quantified at pH 3.8 and 25°C on malt extract agar acid medium. The impact of these acids on lag time for growth (λ) was quantified through a gamma model based on the MIC. The impact of these acids on radial growth rate (μ) was analyzed statistically through polynomial regression. Concerning λ, propionic acid exhibited a stronger inhibitory effect (MIC of 8 to 20 mmol/liter depending on the mold species) than did acetic acid (MIC of 23 to 72 mmol/liter). The lactic acid effect was null on E. repens and inhibitory on A. niger and P. corylophilum. These results were validated using independent sets of data for the three acids at pH 3.8 but for only acetic and propionic acids at pH 4.5. Concerning μ, the effect of acetic and propionic acids was slightly inhibitory for A. niger and P. corylophilum but was not significant for E. repens. In contrast, lactic acid promoted radial growth of all three molds. The gamma terms developed here for these acids will be incorporated in a predictive model for temperature, water activity, and acid. More generally, results for μ and λ will be used to identify and evaluate solutions for controlling bakery product spoilage.

Effect of fluticasone propionate on neutrophil chemotaxis, superoxide generation, and extracellular proteolytic activity in vitro.

Science.gov (United States)

Llewellyn-Jones, C G; Hill, S L; Stockley, R A

1994-03-01

Corticosteroids are widely used in the treatment of many inflammatory conditions but the exact mode of action on neutrophil function is uncertain. Fluticasone propionate is a new topically active synthetic steroid which can be measured in body fluids and which undergoes first pass metabolism. The effects of fluticasone propionate on the function of neutrophils isolated from normal, healthy control subjects and on the chemotactic activity of sputum sol phase were assessed. Preincubation of neutrophils with fluticasone propionate reduced the chemotactic response to 10(-8) mol/l F-Met-Leu-Phe (FMLP) and to a 1:5 dilution of sputum sol phase in a dose dependent manner. Furthermore, when fluticasone propionate was added to sputum from eight patients with stable chronic obstructive bronchitis the chemotactic activity of a 1:5 dilution of the sol phase fell from a mean (SE) value of 22.2 (1.21) cells/field to 19.6 (0.89), 17.1 (0.74), and 11.9 (0.6) cells field at 1 mumol/l, 10 mumol/l, and 100 mumol/l, respectively. In further experiments fluticasone propionate preincubated with neutrophils inhibited fibronectin degradation by resting cells and by cells stimulated by FMLP (15.2% inhibition of resting cells, 5.1% inhibition of stimulated cells with 1 mumol/l fluticasone propionate, 24% and 18.7% inhibition respectively at 100 mumol/l fluticasone propionate. Fluticasone propionate had no effect on generation of superoxide anion by resting or stimulated cells. These results indicate that fluticasone propionate has a direct suppressive effect on several aspects of neutrophil function and may suggest a role for this agent in the modulation of neutrophil mediated damage to connective tissue.

Effect of propionic acid on citric acid fermentation in an integrated citric acid-methane fermentation process.

Science.gov (United States)

Xu, Jian; Bao, Jia-Wei; Su, Xian-Feng; Zhang, Hong-Jian; Zeng, Xin; Tang, Lei; Wang, Ke; Zhang, Jian-Hua; Chen, Xu-Sheng; Mao, Zhong-Gui

2016-03-01

In this study, an integrated citric acid-methane fermentation process was established to solve the problem of wastewater treatment in citric acid production. Citric acid wastewater was treated through anaerobic digestion and then the anaerobic digestion effluent (ADE) was further treated and recycled for the next batch citric acid fermentation. This process could eliminate wastewater discharge and reduce water resource consumption. Propionic acid was found in the ADE and its concentration continually increased in recycling. Effect of propionic acid on citric acid fermentation was investigated, and results indicated that influence of propionic acid on citric acid fermentation was contributed to the undissociated form. Citric acid fermentation was inhibited when the concentration of propionic acid was above 2, 4, and 6 mM in initial pH 4.0, 4.5 and, 5.0, respectively. However, low concentration of propionic acid could promote isomaltase activity which converted more isomaltose to available sugar, thereby increasing citric acid production. High concentration of propionic acid could influence the vitality of cell and prolong the lag phase, causing large amount of glucose still remaining in medium at the end of fermentation and decreasing citric acid production.

Effects of concentrate type and chromium propionate on insulin sensitivity, productive and reproductive parameters of lactating dairy cows consuming excessive energy.

Science.gov (United States)

Leiva, T; Cooke, R F; Brandão, A P; Pardelli, U; Rodrigues, R O; Corrá, F N; Vasconcelos, J L M

2017-03-01

This experiment compared insulin sensitivity parameters, milk production and reproductive outcomes in lactating dairy cows consuming excessive energy, and receiving in a 2×2 factorial arrangement design: (1) concentrate based on ground corn (CRN; n=13) or citrus pulp (PLP; n=13), and (2) supplemented (n=14) or not (n=12) with 2.5 g/day of chromium (Cr)-propionate. During the experiment (day 0 to 182), 26 multiparous, non-pregnant, lactating Gir×Holstein cows (initial days in milk=80±2) were offered corn silage for ad libitum consumption, and individually received concentrate formulated to allow diets to provide 160% of their daily requirements of net energy for lactation. Cow BW and body condition score (BCS) were recorded weekly. Milk production was recorded daily and milk samples collected weekly. Blood samples were collected weekly before the morning concentrate feeding. Glucose tolerance tests (GTT; 0.5 g of glucose/kg of BW) were performed on days -3, 60, 120 and 180. Follicle aspiration for in vitro embryo production was performed via transvaginal ovum pick-up on days -1, 82 and 162. No treatment differences were detected (P⩾0.25) for BW and BCS change during the experiment. Within weekly blood samples, concentrations of serum insulin and glucose, as well as insulin : glucose ratio were similar among treatments (P⩾0.19), whereas CRN had less (Pinsulin : glucose ratio. Serum insulin concentrations were less (P=0.04) in CRN supplemented with Cr-propionate compared with non-supplemented CRN (8.2 v. 13.5 µIU/ml, respectively; SEM=1.7), whereas Cr-propionate supplementation did not impact (P=0.70) serum insulin within PLP cows. Milk production, milk fat and solid concentrations were similar (P⩾0.48) between treatments. However, CRN had greater (Pdairy cows consuming excessive energy did not improve insulin sensitivity, milk production and reproductive outcomes, whereas Cr-propionate supplementation only enhanced insulin sensitivity in cows receiving a

Long-term continuous N-carbamylglutamate treatment in frequently decompensated propionic acidemia: a case report.

Science.gov (United States)

Tummolo, Albina; Melpignano, Livio; Carella, Antonella; Di Mauro, Anna Maria; Piccinno, Elvira; Vendemiale, Marcella; Ortolani, Federica; Fedele, Stefania; Masciopinto, Maristella; Papadia, Francesco

2018-04-22

Propionic acidemia is a rare autosomal recessive inherited metabolic disorder that can inhibit the synthesis of N-acetylglutamate, the obligatory activator in urea synthesis, leading to hyperammonemia. N-carbamylglutamate ameliorates hyperammonemia in decompensated propionic acidemia. The effects of long-term continuous N-acetylglutamate administration in such patients are unknown. We report our clinical experience with continuous administration of N-acetylglutamate for 6 years in a patient with propionic acidemia frequently presenting with hyperammonemia. A male Caucasian patient with frequently decompensated propionic acidemia and hyperammonemia was admitted 78 times for acute attacks during the first 9 years of his life. Continuous daily treatment with oral N-carbamylglutamate 100 mg/kg (50 mg/kg after 6 months) was initiated. During 6 years of treatment, he had a significant decrease in his mean plasma ammonia levels (75.7 μmol/L vs. 140.3 μmol/L before N-carbamylglutamate therapy, p N-acetylglutamate administration outside the emergency setting. If this observation is confirmed, future studies should aim to optimize the dosage and explore effects of the dosage requirements on other drugs and on protein tolerance.

21 CFR 184.1081 - Propionic acid.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Propionic acid. 184.1081 Section 184.1081 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1081 Propionic acid. (a) Propionic acid (C3H6O2, CAS Reg. No. 79-09-4) is...

Hypoattenuation of the basal nuclei as a sign of propionic acidemia

International Nuclear Information System (INIS)

Asenjo, M.; Moron, A.; Marti, M.; Dominguez, F.

1999-01-01

The hypoattenuation of the basal ganglia is an uncommon radiological finding that suggests a metabolic or hypoxic disorder. We report a case of propionic acidemia in a five-year-old boy, presenting as a symmetric hypoattenuation of the basal neclei. We discuss this and other causes of this radiological finding, as well as the possible mechanism and underlying pathology. (Author) 17 refs

Vibrational spectroscopic study of fluticasone propionate

Science.gov (United States)

Ali, H. R. H.; Edwards, H. G. M.; Kendrick, J.; Scowen, I. J.

2009-03-01

Fluticasone propionate is a synthetic glucocorticoid with potent anti-inflammatory activity that has been used effectively in the treatment of chronic asthma. The present work reports a vibrational spectroscopic study of fluticasone propionate and gives proposed molecular assignments on the basis of ab initio calculations using BLYP density functional theory with a 6-31G* basis set and vibrational frequencies predicted within the quasi-harmonic approximation. Several spectral features and band intensities are explained. This study generated a library of information that can be employed to aid the process monitoring of fluticasone propionate.

Inhibition of Listeria monocytogenes by propionic acid-based ingredients in cured deli-style Turkey.

Science.gov (United States)

Glass, Kathleen A; McDonnell, Lindsey M; Von Tayson, Roxanne; Wanless, Brandon; Badvela, Mani

2013-12-01

Listeria monocytogenes growth can be controlled on ready-to-eat meats through the incorporation of antimicrobial ingredients into the formulation or by postlethality kill steps. However, alternate approaches are needed to provide options that reduce sodium content but maintain protection against pathogen growth in meats after slicing. The objective of this study was to determine the inhibition of L. monocytogenes by propionic acid-based ingredients in high-moisture, cured turkey stored at 4 or 7°C. Six formulations of sliced, cured (120 ppm of NaNO2 ), deli-style turkey were tested, including control without antimicrobials, 3.2% lactate-diacetate blend (LD), 0.4% of a liquid propionate-benzoate-containing ingredient, or 0.3, 0.4, and 0.5% of a liquid propionate-containing ingredient. Products were inoculated with 5 log CFU L. monocytogenes per 100-g package (3 log CFU/ml rinsate), vacuum-sealed, and stored at 4 or 7°C for up to 12 weeks; and populations were enumerated by plating on modified Oxford agar. As expected, the control without antimicrobials supported rapid growth, with >2 log average per ml rinsate increase within 4 weeks of storage at 4°C, whereas growth was observed at 6 weeks for the LD treatment. For both replicate trials, all treatments that contained liquid propionate or propionate-benzoate limited L. monocytogenes growth to an increase of 1-log increase) was observed in individual samples for all propionate-containing treatments at weeks 10, 11, and 12. As expected, L. monocytogenes grew more rapidly when products were stored at 7°C, but trends in relative inhibition were similar to those observed at 4°C. These results verify that propionate-based ingredients inhibit growth of L. monocytogenes on sliced, high-moisture, cured turkey and can be considered as an alternative to reduce sodium-based salts while maintaining food safety.

Absolute Configuration of (-)-2-(4-Hydroxyphenyl)propionic acid: Stereochemistry of Soy Isoflavone Metabolism

Energy Technology Data Exchange (ETDEWEB)

Kim, Mihyang; Han, Jaehong [Chung-Ang Univ., Seoul (Korea, Republic of)

2014-06-15

We have elucidated stereochemistry of (-)-2-HPPA. Determination of (R)-2-HPPA stereochemistry also provided stereochemical information of genistein metabolism. Considering the stereochemistry of 2-HPPA, the precursor of (R)-2-HPPA should be (R)-6'-hydroxy-O-DMA. Besides, it is clear that only (S)-dihydrogenistein is the possible precursor of (R)-6'-hydroxy-O-DMA. Therefore, genistein metabolism is suggested to follow the same stereochemical pathway like daidzein. Biotransformation of natural products by human intestinal bacteria has recently drawn a significant interest, due to the emerging strong correlation between gut microbiota and human health. Microbial metabolism of natural products by intestinal bacteria in small intestine and colon proceeds the phase I and II xenobiotic metabolisms in the liver. The metabolites were found to exhibit different biological activities, and affect human etiology. For example, many beneficial effects of dietary polyphenols in human health are attributed to the microbial metabolites produced by intestinal bacteria and the modulation of gut microbiota composition.

Absolute Configuration of (-)-2-(4-Hydroxyphenyl)propionic acid: Stereochemistry of Soy Isoflavone Metabolism

International Nuclear Information System (INIS)

Kim, Mihyang; Han, Jaehong

2014-01-01

We have elucidated stereochemistry of (-)-2-HPPA. Determination of (R)-2-HPPA stereochemistry also provided stereochemical information of genistein metabolism. Considering the stereochemistry of 2-HPPA, the precursor of (R)-2-HPPA should be (R)-6'-hydroxy-O-DMA. Besides, it is clear that only (S)-dihydrogenistein is the possible precursor of (R)-6'-hydroxy-O-DMA. Therefore, genistein metabolism is suggested to follow the same stereochemical pathway like daidzein. Biotransformation of natural products by human intestinal bacteria has recently drawn a significant interest, due to the emerging strong correlation between gut microbiota and human health. Microbial metabolism of natural products by intestinal bacteria in small intestine and colon proceeds the phase I and II xenobiotic metabolisms in the liver. The metabolites were found to exhibit different biological activities, and affect human etiology. For example, many beneficial effects of dietary polyphenols in human health are attributed to the microbial metabolites produced by intestinal bacteria and the modulation of gut microbiota composition

Diagnosis of propionic acidemia by gas chromatography coupled to mass spectrometry in a case analysis

International Nuclear Information System (INIS)

Camayd Viera, Ivette; Robaina Jimenez, Zoe; Contreras Roura, Jiovanna

2011-01-01

Propionic acidemia is an inherited metabolic disease caused by a deficiency in the propionyl-CoA carboxilase, a biotin-dependent mitochondrial enzyme. The disorder is a clinically heterogeneous disease and one of the most frequently occurring organic acidurias. We report the first Cuban case with a severe form of propionic acidemia followed by acidosis and death. The diagnosis was carried out by gas chromatography coupled to mass spectrometry. Our aim is to highlight the importance of organic acids urine analysis as part of the first laboratory tests in undiagnosed seriously ill children. The definitive diagnosis is important as it serves as a clear guideline to establish a suitable treatment and allows geneticists to provide patients with a proper genetic counseling

Multiple paths of electron flow to current in microbial electrolysis cells fed with low and high concentrations of propionate

KAUST Repository

Rao, Hari Ananda

2016-03-03

Microbial electrolysis cells (MECs) provide a viable approach for bioenergy generation from fermentable substrates such as propionate. However, the paths of electron flow during propionate oxidation in the anode of MECs are unknown. Here, the paths of electron flow involved in propionate oxidation in the anode of two-chambered MECs were examined at low (4.5 mM) and high (36 mM) propionate concentrations. Electron mass balances and microbial community analysis revealed that multiple paths of electron flow (via acetate/H2 or acetate/formate) to current could occur simultaneously during propionate oxidation regardless of the concentration tested. Current (57–96 %) was the largest electron sink and methane (0–2.3 %) production was relatively unimportant at both concentrations based on electron balances. At a low propionate concentration, reactors supplemented with 2-bromoethanesulfonate had slightly higher coulombic efficiencies than reactors lacking this methanogenesis inhibitor. However, an opposite trend was observed at high propionate concentration, where reactors supplemented with 2-bromoethanesulfonate had a lower coulombic efficiency and there was a greater percentage of electron loss (23.5 %) to undefined sinks compared to reactors without 2-bromoethanesulfonate (11.2 %). Propionate removal efficiencies were 98 % (low propionate concentration) and 78 % (high propionate concentration). Analysis of 16S rRNA gene pyrosequencing revealed the dominance of sequences most similar to Geobacter sulfurreducens PCA and G. sulfurreducens subsp. ethanolicus. Collectively, these results provide new insights on the paths of electron flow during propionate oxidation in the anode of MECs fed with low and high propionate concentrations.

Methylmalonic aciduria and propionic acidaemia studied by proton nuclear magnetic resonance spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Iles, R A; Hind, A J; Chalmers, R A

1986-12-15

Proton nuclear magnetic resonance spectroscopy has been used to monitor changes in urinary metabolites in a patient with propionic acidaemia over a period of 10 months and in a patient with methylmalonic aciduria over a period of 11 days. Results could be obtained within 5-10 min of sample receipt. In the spectra on the patient with propionic acidaemia not only could fluctuations in 3-hydroxypropionate and propionylglycine excretion be followed, but also variations in creatine, glycine and betaine, which were often present at millimolar concentrations. The patient with methylmalonic aciduria had an acute episode of severe ketoacidosis during which the glycine excretion fell but creatine excretion rose and then fell on recovery from the episode. The changes in the creatine excretion may reflect disorders in intracellular energy supply. Nuclear magnetic resonance is a powerful technique for monitoring metabolic perturbations in the organic acidurias in 'real-time', allowing the planning and evaluation of therapy. (Auth.). 18 refs.; 4 figs.; 3 tabs.

Methylmalonic aciduria and propionic acidaemia studied by proton nuclear magnetic resonance spectroscopy

International Nuclear Information System (INIS)

Iles, R.A.; Hind, A.J.; Chalmers, R.A.

1986-01-01

Proton nuclear magnetic resonance spectroscopy has been used to monitor changes in urinary metabolites in a patient with propionic acidaemia over a period of 10 months and in a patient with methylmalonic aciduria over a period of 11 days. Results could be obtained within 5-10 min of sample receipt. In the spectra on the patient with propionic acidaemia not only could fluctuations in 3-hydroxypropionate and propionylglycine excretion be followed, but also variations in creatine, glycine and betaine, which were often present at millimolar concentrations. The patient with methylmalonic aciduria had an acute episode of severe ketoacidosis during which the glycine excretion fell but creatine excretion rose and then fell on recovery from the episode. The changes in the creatine excretion may reflect disorders in intracellular energy supply. Nuclear magnetic resonance is a powerful technique for monitoring metabolic perturbations in the organic acidurias in 'real-time', allowing the planning and evaluation of therapy. (Auth.)

Concurrent non-ketotic hyperglycinemia and propionic acidemia in an eight year old boy

Directory of Open Access Journals (Sweden)

Paul S. Kruszka

2014-01-01

Full Text Available This is the first reported case of a patient with both non-ketotic hyperglycinemia and propionic acidemia. At 2 years of age, the patient was diagnosed with non-ketotic hyperglycinemia by elevated glycine levels and mutations in the GLDC gene (paternal allele: c.1576_1577insC delT and c.1580delGinsCAA; p.S527Tfs*13, and maternal allele: c.1819G>A; p.G607S. At 8 years of age after having been placed on ketogenic diet, he became lethargic and had severe metabolic acidosis with ketonuria. Urine organic acid analysis and plasma acylcarnitine profile were consistent with propionic acidemia. He was found to have an apparently homozygous mutation in the PCCB gene: c.49C>A; p.Leu17Met. The patient was also treated with natural protein restriction, carnitine, biotin, and thiamine and had subjective and biochemical improvement.

Pathway of propionate formation in Desulfobulbus propionicus

NARCIS (Netherlands)

Stams, A.J.M.; Kremer, D.R.; Nicolaij, K.; Weenk, G.; Hansen, T.A.

1984-01-01

Whole cells of Desulfobulbus propionicus fermented [1-13C]ethanol to [2-13C] and [3-13C]propionate and [1-13C]-acetate, which indicates the involvement of a randomizing pathway in the formation of propionate. Cell-free extracts prepared from cells grown on lactate (without sulfate) contained high

Propionate induces cell swelling and K+ accumulation in shark rectal gland

International Nuclear Information System (INIS)

Feldman, G.M.; Ziyadeh, F.N.; Mills, J.W.; Booz, G.W.; Kleinzeller, A.

1989-01-01

Small organic anions have been reported to induce cell solute accumulation and swelling. To investigate the mechanism of swelling, we utilized preparations of rectal gland cells from Squalus acanthias incubated in medium containing propionate. Propionate causes cells to swell by diffusing across membranes in its nonionic form, acidifying cell contents, and activating the Na+-H+ antiporter. The Na+-H+ exchange process tends to correct intracellular pH (pHi), and thus it maintains a favorable gradient for propionic acid diffusion and allows propionate to accumulate. Activation of the Na+-H+ antiport also facilitates Na+ entry into the cell and Nai accumulation. At the same time Na+-K+-ATPase activity, unaffected by propionate, replaces Nai with Ki, whereas the K+ leak rate, decreased by propionate, allows Ki to accumulate. As judged by 86 Rb+ efflux, the reduction in K+ leak was not due to propionate-induced cell acidification or reduction in Cli concentration. Despite inducing cell swelling, propionate did not disrupt cell structural elements and F actin distribution along cell membranes

Propionate induces cell swelling and K+ accumulation in shark rectal gland

Energy Technology Data Exchange (ETDEWEB)

Feldman, G.M.; Ziyadeh, F.N.; Mills, J.W.; Booz, G.W.; Kleinzeller, A. (Mount Desert Island Biological Laboratory, Salsbury Cove, ME (USA))

1989-08-01

Small organic anions have been reported to induce cell solute accumulation and swelling. To investigate the mechanism of swelling, we utilized preparations of rectal gland cells from Squalus acanthias incubated in medium containing propionate. Propionate causes cells to swell by diffusing across membranes in its nonionic form, acidifying cell contents, and activating the Na+-H+ antiporter. The Na+-H+ exchange process tends to correct intracellular pH (pHi), and thus it maintains a favorable gradient for propionic acid diffusion and allows propionate to accumulate. Activation of the Na+-H+ antiport also facilitates Na+ entry into the cell and Nai accumulation. At the same time Na+-K+-ATPase activity, unaffected by propionate, replaces Nai with Ki, whereas the K+ leak rate, decreased by propionate, allows Ki to accumulate. As judged by {sup 86}Rb+ efflux, the reduction in K+ leak was not due to propionate-induced cell acidification or reduction in Cli concentration. Despite inducing cell swelling, propionate did not disrupt cell structural elements and F actin distribution along cell membranes.

Study of benzoate, propionate, and sorbate salts as mould spoilage inhibitors on intermediate moisture bakery products of low pH (4.5-5.5).

Science.gov (United States)

Guynot, M E; Ramos, A J; Sanchis, V; Marín, S

2005-05-25

A hurdle technology approach has been applied to control common mold species causing spoilage of intermediate moisture bakery products (Eurotium spp., Aspergillus spp., and Penicillium corylophilum), growing on a fermented bakery product analogue (FBPA). The factors studied included a combination of different levels of weak acid preservatives (potassium sorbate, calcium propionate, and sodium benzoate; 0-0.3%), pH (4.5-5.5), and water activity (a(w); 0.80-0.90). Potassium sorbate was found to be the most effective in preventing fungal spoilage of this kind of products at the maximum concentration tested (0.3%) regardless of a(w). The same concentration of calcium propionate and sodium benzoate was effective only at low a(w) levels. On the other hand, potassium sorbate activity was slightly reduced at pH 5.5, the 0.3% being only effective at 0.80 a(w). These findings indicate that potassium sorbate may be a suitable preserving agent to inhibit deterioration of a FBPA of slightly acidic pH (near 4.5) by xerophilic fungi. Further studies have to be done in order to adjust the minimal inhibitory concentration necessary to obtain a product with the required shelf life.

Effect of long-distance transportation on serum metabolic profiles of steer calves.

Science.gov (United States)

Takemoto, Satoshi; Tomonaga, Shozo; Funaba, Masayuki; Matsui, Tohru

2017-12-01

Long-distance transportation is sometimes inevitable in the beef industry because of the geographic separation of major breeding and fattening areas. Long-distance transportation negatively impacts production and health of cattle, which may, at least partly, result from the disturbance of metabolism during and after transportation. However, alteration of metabolism remains elusive in transported cattle. We investigated the effects of transportation on the metabolomic profiles of Holstein steer calves. Non-targeted analysis of serum concentrations of low molecular weight metabolites was performed by gas chromatography mass spectrometry. Transportation affected 38 metabolites in the serum. A pathway analysis suggested that 26, 10, and 10 pathways were affected immediately after transportation, and 3 and 7 days after transportation, respectively. Some pathways were disturbed only immediately after transportation, likely because of feed and water withdrawal during transit. Nicotinate and nicotinamide metabolism, and citric acid cycle were affected for 3 days after transportation, whereas propionate metabolism, phenylalanine and tyrosine metabolism were affected throughout the experiment. Four pathways were not affected immediately after transportation, but were altered thereafter. These results suggested that many metabolic pathways had marked perturbations during transportation. Metabolites such as citric acid, propionate, tyrosine and niacin can be candidate supplements for mitigating transportation-induced adverse effects. © 2017 Japanese Society of Animal Science.

Effects of calcium propionate by different numbers of applications in first week postpartum of dairy cows on hypocalcemia, milk production and reproductive disorders

Directory of Open Access Journals (Sweden)

Arda Kovanlıkaya

2010-01-01

Full Text Available This study was conducted to evaluate effects of calcium propionate on hypocalcemia, dry matter intake, body condition score, milk production and reproductive disorders in dairy cows. Twenty four multiparous Holstein cows were sorted by parity, body condition score (BCS in close-up period and season of calving and assigned to one of the three treatments. The cows in treatment 1 (T1 received two drenches at calving and 24h after calving. The cows in treatment 2 (T2 received three drenches at calving, 24h after calving and 7 days after calving. The cows in treatment 3 (T3 were the control. Each drench contained 143g of calcium as calcium propionate (0.68kg. Parameters studied were serum calcium, glucose and nonesterified fatty acid (NEFA concentrations, dry matter intake (DMI, BCS, milk production (MP, incidence of retained placenta (RP and metritis. Milk fever developed in 5 of 8 cows, in 3 of 8 cows and in 3 of 8 cows in T1, T2 and T3, respectively, at calving. There was no cow with milk fever in T1 and T2 at 4h after second drench (about 28h after calving but 3 of 8 cows in T3 had still milk fever at this time. The cows receiving two drenches recovered from milk fever in a shorter term as compared to the cows in T3. There were no differences among treatments for DMI, BCS, MP, RP, serum glucose and NEFA concentrations during the experimental period. There was no difference for metritis between T1 and T3 but incidence of metritis in T2 was significantly lower as compared to T3 (P<0.05. Two drenches of calcium propionate were beneficial in treating milk fever and three drenches of calcium propionate were considered to have had a preventive effect for metritis.

Plasma total odd-chain fatty acids in the monitoring of disorders of propionate, methylmalonate and biotin metabolism

NARCIS (Netherlands)

Coker, M.; de Klerk, J. B.; Poll-The, B. T.; Huijmans, J. G.; Duran, M.

1996-01-01

Total plasma odd-numbered long-chain fatty acids were analysed in patients with methylmalonic acidaemia (vitamin B12-responsive and unresponsive), combined methylmalonic acidaemia/homocystinuria (CblC), propionic acidaemia (both neonatal-onset and late-onset), biotinidase deficiency and

Antifungal Activity of Selected Lactic Acid Bacteria and Propionic Acid Bacteria against Dairy-Associated Spoilage Fungi

DEFF Research Database (Denmark)

Aunsbjerg, Stina Dissing

Bacterial cultures of lactic and propionic acid bacteria are widely used in fermented products including dairy products. Spoilage fungi may constitute a quality and safety issue in these products. The antifungal properties of some lactic and propionic acid bacteria make them potential candidates...... defined interaction medium (CDIM) was developed allowing growth of protective Lb. paracasei and P. freudenreichii subsp. shermaniii as well as the spoilage fungi, Penicillium spp., Rhodotorula mucilaginosa and Debaryomyces hansenii isolated from fermented dairy products. Lb. paracasei and P....... freudenreichii subsp. shermanii grew in CDIM and showed antifungal properties similar to those observed in milk-based systems. Most of the antifungal effect of the protective bacterial ferment was lost after removal of cells. This was explained by a marked decrease in diacetyl concentration, which...

Oxidation of propionic acid-3-14C with alkaline permanganate

International Nuclear Information System (INIS)

Zielinski, M.

1981-01-01

The mechanism of oxidation of propionic acid with permanganate in alkaline medium was reinvestigated using methyl- 14 C labelled propionate. The preferential rupture of the αC-βC bond in propionate in highly concentrated alkaline solutions of NaOH (and KOH) was confirmed and the appearance of 14 C-labelled oxalate explained by the formation of the symmetrical intermediate which decomposes in two different modes. (author)

Propionate supplementation improves nitrogen use by reducing urea flux in sheep.

Science.gov (United States)

Agarwal, U; Hu, Q; Bequette, B J

2015-10-01

Feeding and postruminal infusion of propionate is known to increase N retention in ruminants. Our aim was to determine the role of rumen propionate on urea N recycling and gluconeogenesis in growing sheep. In Exp. 1, wether sheep ( = 6; 32.5 ± 3.57 kg BW) fitted with a rumen cannula were fed to 1.8 × ME requirement a concentrate-type ration (172 g CP/kg DM and 10.4 MJ ME/kg DM) and continuously infused into the rumen with isoenergetic (10% of dietary ME intake) solutions of either sodium acetate (control) or sodium propionate for 9-d periods in a crossover design. In Exp. 2, a different group of wether sheep ( = 5; 33.6 ± 3.70 kg BW) fitted with a rumen cannula were fed, on an isonitrogenous basis, either a control (151 g CP/kg DM and 8.4 MJ ME/kg DM) or sodium propionate-supplemented (139 g CP/kg DM and 8.9 MJ ME/kg DM) diet at 2-h intervals. [N] urea was continuously infused intravenously for the last 5 d of each period, and total urine was collected by vacuum and feces were collected by a harness bag. Over the last 12 h, [C]glucose was continuously infused intravenously and hourly blood samples were collected during the last 5 h. Propionate treatments increased ( urea entry (synthesis) rate (UER) in Exp. 1; however, sodium propionate infusion tended ( urea elimination (UUE). In Exp. 2, feeding propionate increased ( urea N/d, leading to a reduction ( urea N/d). Between the 2 experiments, the proportion of UER recycled to the gut was greater with the forage-type diet in Exp. 2 (approximately 60%) compared with the concentrate-type diet in Exp. 1 (approximately 40%), although urea N fluxes across the gut remained unchanged in both experiments. In Exp. 1, glucose entry and gluconeogenesis were greater ( < 0.05) and plasma glucose tended ( < 0.1) to be greater with sodium propionate infusion than with sodium acetate infusion, but there was no difference in Cori cycling. In Exp. 2, glucose entry, gluconeogenesis, Cori cycling, and plasma glucose increased ( < 0

Determination of propionate in bread using capillary zone electrophoresis

NARCIS (Netherlands)

Ackermans, M.T.; Ackermans-Loonen, J.C.J.M; Beckers, J.L.

1992-01-01

A method for the determination of propionate in bread is described. The propionate was extracted from the bread with a repeated extraction procedure and measured using capillary zone electrophoresis in the indirect UV mode applying a background electrolyte of 0.005 M Tris adjusted at pH 4.6 by

Comparison of Clobetasol Propionate Generics Using Simplified in Vitro Bioequivalence Method for Topical Drug Products.

Science.gov (United States)

Soares, Kelen Carine Costa; de Souza, Weidson Carlos; de Souza Texeira, Leonardo; da Cunha-Filho, Marcilio Sergio Soares; Gelfuso, Guilherme Martins; Gratieri, Tais

2017-11-20

The aim of this paper is to propose a simple in vitro skin penetration experiment in which the drug is extracted from the whole skin piece as a test valid for formulation screening and optimization during development process, equivalence assessment during quality control or post-approval after changes to the product. Twelve clobetasol propionate (CP) formulations (six creams and six ointments) from the local market were used as a model to challenge the proposed methodology in comparison to in vitro skin penetration following tape-stripping for drug extraction. To support the results, physicochemical tests for pH, viscosity, density and assay, as well as in vitro release were performed. Both protocols, extracting the drug from the skin using the tape-stripping technique or extracting from the full skin were capable of differentiating CP formulations. Only one formulation did not present statistical difference from the reference drug product in penetration tests and only other two oitments presented equivalent release to the reference. The proposed protocol is straightforward and reproducible. Results suggest the bioinequavalence of tested CP formulations reinforcing the necessity of such evaluations. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Enhancement of Esterification of Propionic Acid with Isopropyl Alcohol by Pervaporation Reactor

Directory of Open Access Journals (Sweden)

Ajit P. Rathod

2014-01-01

Full Text Available With increasing cost of raw materials and energy, there is an increasing inclination of chemical process industries toward new processes that result in lesser waste generation, greater efficiency, and substantial yield of the desired products. Esterification is a chemical reaction in which two reactants carboxylic acid and alcohol react to form an ester and water. This reaction is a reversible reaction and the equilibrium conversion can be altered by varying the process parameters. Pervaporation reactor can enhance the conversion by shifting the equilibrium of reversible esterification reactions. Polyvinyl alcohol-polyether sulfone composite hydrophilic membrane was used for pervaporation-assisted esterification of propionic acid with isopropyl alcohol. The experiments were carried out in the presence of sulphuric acid as a catalyst at 50°C to 80°C with various reactants ratios. The esterification was carried out for catalyst loadings of 0.089 kmol/m3 to 0.447 kmol/m3. The molar ratios of isopropyl to propionic acid used for the experiment were 1 to 1.5. Maximum conversion was obtained for the ratio of 1.4. Also effect of other parameters such as process temperature and catalyst concentration was discussed. It was found that the use of pervaporation reactor increased the conversion of the propionic acid considerably.

Thermophilic Biohydrogen Production

DEFF Research Database (Denmark)

Karakashev, Dimitar Borisov; Angelidaki, Irini

2011-01-01

Dark fermentative hydrogen production at thermophilic conditions is attractive process for biofuel production. From thermodynamic point of view, higher temperatures favor biohydrogen production. Highest hydrogen yields are always associated with acetate, or with mixed acetate- butyrate type...... fermentation. On the contrary the hydrogen yield decreases, with increasing concentrations of lactate, ethanol or propionate. Major factors affecting dark fermentative biohydrogen production are organic loading rate (OLR), pH, hydraulic retention time (HRT), dissolved hydrogen and dissolved carbon dioxide...... concentrations, and soluble metabolic profile (SMP). A number of thermophilic and extreme thermophilic cultures (pure and mixed) have been studied for biohydrogen production from different feedstocks - pure substrates and waste/wastewaters. Variety of process technologies (operational conditions...

Biokinetics and bacterial communities of propionate oxidizing bacteria in phased anaerobic sludge digestion systems.

Science.gov (United States)

Zamanzadeh, Mirzaman; Parker, Wayne J; Verastegui, Yris; Neufeld, Josh D

2013-03-15

Phased anaerobic digestion is a promising technology and may be a potential source of bio-energy production. Anaerobic digesters are widely used for sewage sludge stabilization and thus a better understanding of the microbial process and kinetics may allow increased volatile solids reduction and methane production through robust process operation. In this study, we analyzed the impact of phase separation and operational conditions on the bio-kinetic characteristics and communities of bacteria associated with four phased anaerobic digestion systems. In addition to significant differences between bacterial communities associated with different digester operating temperatures, our results also revealed that bacterial communities in the phased anaerobic digestion systems differed between the 1st and 2nd phase digesters and we identified strong community composition correlations with several measured physicochemical parameters. The maximum specific growth rates of propionate oxidizing bacteria (POB) in the mesophilic and thermophilic 1st phases were 11 and 23.7 mgCOD mgCOD(-1) d(-1), respectively, while those of the mesophilic and thermophilic 2nd-phase digesters were 6.7 and 18.6 mgCOD mgCOD(-1) d(-1), respectively. Hence, the biokinetic characteristics of the POB population were dependent on the digester loading. In addition, we observed that the temperature dependency factor (θ) values were higher for the less heavily loaded digesters as compared to the values obtained for the 1st-phase digesters. Our results suggested the appropriate application of two sets of POB bio-kinetic that reflect the differing growth responses as a function of propionate concentration (and/or organic loading rates). Also, modeling acetogenesis in phased anaerobic sludge digestion systems will be improved considering a population shift in separate phases. On the basis of the bio-kinetic values estimated in various digesters, high levels of propionate in the thermophilic digesters may be

Interspecies electron transfer in suspended and aggregated methanogenic propionate-degrading consortia

NARCIS (Netherlands)

Bok, de F.A.M.; Plugge, C.M.; Stams, A.J.M.

2002-01-01

Propionate is a key intermediate in the conversion of complex organic matter under methanogenic conditions. Oxidation of propionate to acetate is energetically unfavorable under standard conditions. Therefore, micro organisms are only able to gain energy from this conversion if the concentrations of

Gas chromatographic determination of calcium propionate added as preservative to bread.

Science.gov (United States)

Lamkin, W M; Unruh, N C; Pomeranz, Y

1987-01-01

A simple and rapid gas chromatographic procedure was developed for determining low concentrations of propionate added as a preservative to bread. A bread sample to be analyzed was ground in a meat grinder with a 3 mm hole plate and finely divided by rubbing through a No. 8 sieve. The propionate was then extracted into 0.050M formic acid in a blender at low speed for 5 min, and an aliquot of a filtrate was analyzed directly by gas chromatography. Chromatographic separation was accomplished on a Carbopack C column coated with 0.3% (w/w) Carbowax 20M and 0.1% (w/w) phosphoric acid. Less than 0.2 ppm propionic acid could be detected in the aqueous extract. Over the range of 0.03-0.23% calcium propionate, average relative error was -1.20% with an average coefficient of variation of 2.02%.

Bubble point pressures of binary system of methanol and methyl propionate

NARCIS (Netherlands)

Shariati, A.; Florusse, L.J.; Kroon, M.C.; Peters, C.J.

2016-01-01

In this work, bubble point pressures of the system of methanol + methyl propionate were measured for several isopleths within temperature and pressure ranges of 382-444 K and 0.437-2.285 MPa, respectively. The vapor pressures of pure methanol and methyl propionate were also measured. The two-suffix

A Urinary Metabolic Signature for Multiple Sclerosis and Neuromyelitis Optica

DEFF Research Database (Denmark)

Gebregiworgis, Teklab; Nielsen, Helle H; Massilamany, Chandirasegaran

2016-01-01

a statistically distinct metabolic signature from healthy and NMO-SD controls. A total of 27 metabolites were differentially altered in the urine from MS and NMO-SD patients and were associated with synthesis and degradation of ketone bodies, amino acids, propionate and pyruvate metabolism, tricarboxylic acid...

In vivo enzyme activity in inborn errors of metabolism

Energy Technology Data Exchange (ETDEWEB)

Thompson, G.N.; Walter, J.H.; Leonard, J.V.; Halliday, D. (Clinical Research Centre, Harrow (England))

1990-08-01

Low-dose continuous infusions of (2H5)phenylalanine, (1-13C)propionate, and (1-13C)leucine were used to quantitate phenylalanine hydroxylation in phenylketonuria (PKU, four subjects), propionate oxidation in methylmalonic acidaemia (MMA, four subjects), and propionic acidaemia (PA, four subjects) and leucine oxidation in maple syrup urine disease (MSUD, four subjects). In vivo enzyme activity in PKU, MMA, and PA subjects was similar to or in excess of that in adult controls (range of phenylalanine hydroxylation in PKU, 3.7 to 6.5 mumol/kg/h, control 3.2 to 7.9, n = 7; propionate oxidation in MMA, 15.2 to 64.8 mumol/kg/h, and in PA, 11.1 to 36.0, control 5.1 to 19.0, n = 5). By contrast, in vivo leucine oxidation was undetectable in three of the four MSUD subjects (less than 0.5 mumol/kg/h) and negligible in the remaining subject (2 mumol/kg/h, control 10.4 to 15.7, n = 6). These results suggest that significant substrate removal can be achieved in some inborn metabolic errors either through stimulation of residual enzyme activity in defective enzyme systems or by activation of alternate metabolic pathways. Both possibilities almost certainly depend on gross elevation of substrate concentrations. By contrast, only minimal in vivo oxidation of leucine appears possible in MSUD.

In vivo enzyme activity in inborn errors of metabolism

International Nuclear Information System (INIS)

Thompson, G.N.; Walter, J.H.; Leonard, J.V.; Halliday, D.

1990-01-01

Low-dose continuous infusions of [2H5]phenylalanine, [1-13C]propionate, and [1-13C]leucine were used to quantitate phenylalanine hydroxylation in phenylketonuria (PKU, four subjects), propionate oxidation in methylmalonic acidaemia (MMA, four subjects), and propionic acidaemia (PA, four subjects) and leucine oxidation in maple syrup urine disease (MSUD, four subjects). In vivo enzyme activity in PKU, MMA, and PA subjects was similar to or in excess of that in adult controls (range of phenylalanine hydroxylation in PKU, 3.7 to 6.5 mumol/kg/h, control 3.2 to 7.9, n = 7; propionate oxidation in MMA, 15.2 to 64.8 mumol/kg/h, and in PA, 11.1 to 36.0, control 5.1 to 19.0, n = 5). By contrast, in vivo leucine oxidation was undetectable in three of the four MSUD subjects (less than 0.5 mumol/kg/h) and negligible in the remaining subject (2 mumol/kg/h, control 10.4 to 15.7, n = 6). These results suggest that significant substrate removal can be achieved in some inborn metabolic errors either through stimulation of residual enzyme activity in defective enzyme systems or by activation of alternate metabolic pathways. Both possibilities almost certainly depend on gross elevation of substrate concentrations. By contrast, only minimal in vivo oxidation of leucine appears possible in MSUD

Methylmalonic and propionic acidemias: lipid profiles of normal and affected human skin fibroblasts incubated with [1-14C]propionate

International Nuclear Information System (INIS)

Giudici, T.A.; Chen, R.G.; Oizumi, J.; Shaw, K.N.; Ng, W.G.; Donnell, G.N.

1986-01-01

Normal human skin fibroblasts and those from methylmalonic acidemia and propionic acidemia patients were grown in culture. Following incubation with [1- 14 C]propionate, the major lipid classes in the cells were separated by thin layer chromatography and isolated fractions analyzed by radio gas chromatography for the presence of odd-numbered long-chain fatty acids; the pattern of even-numbered long-chain fatty acids was obtained also. Normal fibroblasts incorporated a small percentage of propionate into odd-numbered fatty acids which were present in all lipids studied. The abnormal cells incorporated a larger amount while maintaining the characteristic ratios of odd-numbered fatty acids found in the normal line. Most of the radioactivity was associated with phospholipids which are the predominant constituents of cell membranes. A characteristic C15/C17 ratio was found for different phospholipids and the triglyceride fraction; pentadecanoic acid was the principal odd-numbered fatty acid utilized in the assembly of complex lipids. Compared to even-numbered long-chain fatty acids the absolute amount of odd-numbered fatty acids was low (1-2%), even in affected cells. An unusual polar lipid fraction was isolated in the course of the study. In the normal cell it contained several unlabeled eicosanoids which were missing from the same fraction of both affected cell lines

Evaluating the potential impact of proton carriers on syntrophic propionate oxidation

Science.gov (United States)

Juste-Poinapen, Natacha M. S.; Turner, Mark S.; Rabaey, Korneel; Virdis, Bernardino; Batstone, Damien J.

2015-12-01

Anaerobic propionic acid degradation relies on interspecies electron transfer (IET) between propionate oxidisers and electron acceptor microorganisms, via either molecular hydrogen, formate or direct transfers. We evaluated the possibility of stimulating direct IET, hence enhancing propionate oxidation, by increasing availability of proton carriers to decrease solution resistance and reduce pH gradients. Phosphate was used as a proton carrying anion, and chloride as control ion together with potassium as counter ion. Propionic acid consumption in anaerobic granules was assessed in a square factorial design with ratios (1:0, 2:1, 1:1, 1:2 and 0:1) of total phosphate (TP) to Cl-, at 1X, 10X, and 30X native conductivity (1.5 mS.cm-1). Maximum specific uptake rate, half saturation, and time delay were estimated using model-based analysis. Community profiles were analysed by fluorescent in situ hybridisation and 16S rRNA gene pyrosequencing. The strongest performance was at balanced (1:1) ratios at 10X conductivity where presumptive propionate oxidisers namely Syntrophobacter and Candidatus Cloacamonas were more abundant. There was a shift from Methanobacteriales at high phosphate, to Methanosaeta at low TP:Cl ratios and low conductivity. A lack of response to TP, and low percentage of presumptive electroactive organisms suggested that DIET was not favoured under the current experimental conditions.

Possibility of using apple pomaces in the process of propionic-acetic fermentation

Directory of Open Access Journals (Sweden)

Kamil Piwowarek

2016-09-01

Conclusions: Utilization of by-products is a significant challenge for manufacturing sites and the natural environment. The solution to this problem may involve the use of pomace as a medium component for microorganism cultivation, which is a source of industrially useful metabolites. This study examined the possibility of using apple pomace as a carbon source in the process of propionic-acetic fermentation via wild strain Propionibacterium freudenreichii T82 bacteria.

Short-contact clobetasol propionate shampoo 0.05% improves quality of life in patients with scalp psoriasis.

Science.gov (United States)

Tan, Jerry; Thomas, Richard; Wang, Béatrice; Gratton, David; Vender, Ronald; Kerrouche, Nabil; Villemagne, Hervé

2009-03-01

Scalp psoriasis has a considerable impact on the quality of life (QOL) of patients, and most patients are dissatisfied with available treatments. Clobetasol propionate shampoo 0.05% has been shown to be effective and safe for moderate to severe scalp psoriasis. We evaluated the effect of clobetasol propionate shampoo on QOL and the degree of participant satisfaction with the product. Participants received once-daily treatment for up to 4 weeks. Their QOL and degree of satisfaction were evaluated by questionnaires. The mean (standard deviation) Dermatology Life Quality Index (DLQI) score decreased significantly from 7.0 (4.9) at baseline to 3.2 (3.2) at week 4 (Pshampoo improved the QOL of participants and resulted in high satisfaction.

Enantioselective radical addition/trapping reactions with alpha,beta-disubstituted unsaturated imides. Synthesis of anti-propionate aldols.

Science.gov (United States)

Sibi, Mukund P; Petrovic, Goran; Zimmerman, Jake

2005-03-02

This manuscript describes a highly diastereo- and enantioselective intermolecular radical addition/hydrogen atom transfer to alpha,beta-disubstituted enoates. Additionally, we show that anti-propionate aldol-like products can be easily prepared from alpha-methyl-beta-acyloxyenoates in good yields and high diastereo- and enantioselectivities.

Response of Syntrophic Propionate Degradation to pH Decrease and Microbial Community Shifts in an UASB Reactor.

Science.gov (United States)

Zhang, Liguo; Ban, Qiaoying; Li, Jianzheng; Jha, Ajay Kumar

2016-08-28

The effect of pH on propionate degradation in an upflow anaerobic sludge blanket (UASB) reactor containing propionate as a sole carbon source was studied. Under influent propionate of 2,000 mg/l and 35ºC, propionate removal at pH 7.5-6.8 was above 93.6%. Propionate conversion was significantly inhibited with stepwise pH decrease from pH 6.8 to 6.5, 6.0, 5.5, 5.0, 4.5, and then to 4.0. After long-term operation, the propionate removal at pH 6.5-4.5 maintained an efficiency of 88.5%-70.1%, whereas propionate was hardly decomposed at pH 4.0. Microbial composition analysis showed that propionate-oxidizing bacteria from the genera Pelotomaculum and Smithella likely existed in this system. They were significantly reduced at pH ≤5.5. The methanogens in this UASB reactor belonged to four genera: Methanobacterium, Methanospirillum, Methanofollis, and Methanosaeta. Most detectable hydrogenotrophic methanogens were able to grow at low pH conditions (pH 6.0-4.0), but the acetotrophic methanogens were reduced as pH decreased. These results indicated that propionate-oxidizing bacteria and acetotrophic methanogens were more sensitive to low pH (5.5-4.0) than hydrogenotrophic methanogens.

Comparison of lactate, formate, and propionate as hydrogen donors for the reductive dehalogenation of trichloroethene in a continuous-flow column

Science.gov (United States)

Azizian, Mohammad F.; Marshall, Ian P. G.; Behrens, Sebastian; Spormann, Alfred M.; Semprini, Lewis

2010-04-01

A continuous-flow column study was conducted to analyze the reductive dehalogenation of trichloroethene (TCE) with aquifer material with high content of iron oxides. The column was bioaugmented with the Point Mugu (PM) culture, which is a mixed microbial enrichment culture capable of completely transforming TCE to ethene (ETH). We determined whether lactate, formate, or propionate fermentation resulted in more effective dehalogenation. Reductive dehalogenation, fermentation, and sulfate, Fe(III), and Mn(IV) reduction were all exhibited within the column. Different steady-states of dehalogenation were achieved based on the concentration of substrates added, with effective transformation to ETH obtained when ample electron donor equivalents were provided. Most of the metabolic reducing equivalents were channeled to sulfate, Fe(III), and Mn(IV) reduction. When similar electron reducing equivalents were added, the most effective dehalogenation was achieved with formate, with 14% of the electron equivalents going towards dehalogenation reactions, compared to 6.5% for lactate and 9.6% for propionate. Effective dehalogenation was maintained over 1000 days of column operation. Over 90% of electron equivalents added could be accounted for by the different electron accepting processes in the column, with 50% associated with soluble and precipitated Fe(II) and Mn(II). Bulk Fe(III) and Mn(IV) reduction was rather associated with lactate and propionate addition than formate addition. Sulfate reduction was a competing electron acceptor reaction with all three electron donors. DNA was extracted from solid coupon samples obtained during the course of the experiment and analyzed using 16S rRNA gene clone libraries and quantitative PCR. Lactate and propionate addition resulted in a significant increase in Geobacter, Spirochaetes, and Desulfitobacterium phylotypes relative to " Dehalococcoides" when compared to formate addition. Results from the molecular biological analyses support

Role of formate and hydrogen in the syntrophic degradation of propionate and butyrate

NARCIS (Netherlands)

Xiuzhu Dong,

1994-01-01

Under methanogenic conditions, complex organic matter is mineralized by fermentative, acetogenic and methanogenic bacteria. Propionate and butyrate are two important intermediates; they account for 35% and 8% of the total methane formation, respectively. Propionate and butyrate are

Beneficial effects on host energy metabolism of short-chain fatty acids and vitamins produced by commensal and probiotic bacteria.

Science.gov (United States)

LeBlanc, Jean Guy; Chain, Florian; Martín, Rebeca; Bermúdez-Humarán, Luis G; Courau, Stéphanie; Langella, Philippe

2017-05-08

The aim of this review is to summarize the effect in host energy metabolism of the production of B group vitamins and short chain fatty acids (SCFA) by commensal, food-grade and probiotic bacteria, which are also actors of the mammalian nutrition. The mechanisms of how these microbial end products, produced by these bacterial strains, act on energy metabolism will be discussed. We will show that these vitamins and SCFA producing bacteria could be used as tools to recover energy intakes by either optimizing ATP production from foods or by the fermentation of certain fibers in the gastrointestinal tract (GIT). Original data are also presented in this work where SCFA (acetate, butyrate and propionate) and B group vitamins (riboflavin, folate and thiamine) production was determined for selected probiotic bacteria.

Fundamental Insights into Propionate Oxidation in Microbial Electrolysis Cells Using a Combination of Electrochemical, Molecular biology and Electron Balance Approaches

KAUST Repository

Rao, Hari Ananda

2016-11-01

Increasing demand for freshwater and energy is pushing towards the development of alternative technologies that are sustainable. One of the realistic solutions to address this is utilization of the renewable resources like wastewater. Conventional wastewater treatment processes can be highly energy demanding and can fails to recover the full potential of useful resources such as energy in the wastewater. As a consequence, there is an urgent necessity for sustainable wastewater treatment technologies that could harness such resources present in wastewaters. Advanced treatment process based on microbial electrochemical technologies (METs) such as microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) have a great potential for the resources recovery through a sustainable wastewater treatment process. METs rely on the abilities of microorganisms that are capable of transferring electrons extracellularly by oxidizing the organic matter in the wastewater and producing electrical current for electricity generation (MFC) or H2 and CH4 production (MEC). Propionate is an important volatile fatty acid (VFA) (24-70%) in some wastewaters and accumulation of this VFA can cause a process failure in a conventional anaerobic digestion (AD) system. To address this issue, MECs were explored as a novel, alternative wastewater treatment technology, with a focus on a better understanding of propionate oxidation in the anode of MECs. Having such knowledge could help in the development of more robust and efficient wastewater treatment systems to recover energy and produce high quality effluents. Several studies were conducted to: 1) determine the paths of electron flow in the anode of propionate fed MECs low (4.5 mM) and high (36 mM) propionate concentrations; 2) examine the effect of different set anode potentials on the electrochemical performance, propionate degradation, electron fluxes, and microbial community structure in MECs fed propionate; and 3) examine the temporal

Antifungal properties of fermentates and their potential to replace sorbate and propionate in pound cake.

Science.gov (United States)

Samapundo, S; Devlieghere, F; Vroman, A; Eeckhout, M

2016-11-21

The major objective of this study was to assess the antifungal activities of commercially available 'clean label' fermentates and their potential to replace the preservative function of sorbate and propionate in cake. This study was performed in two parts. In the first part of the study the inhibitory activities of selected fermentates - FA, FB, FC and FD - towards Aspergillus tritici and Aspergillus amstelodami were assessed as a function of pH (5.0-6.5) on malt extract agar (MEA). In the second part of the study, challenge, shelf-life and sensorial tests were used to determine the suitability of these fermentates to replace potassium sorbate and calcium propionate in quarter pound cake. All the fermentates evaluated in this study all had significant (prange for application in bakery products. In all cases, the inhibitory activity of the fermentates increased with a decrease in the pH and an increase in concentration. FC was generally the most inhibitory whilst FD was the least inhibitory. Significant (p0.05) in flavour from the reference cake (0.5% calcium propionate and 0.54% potassium sorbate). However, the challenge and shelf-life tests showed that cakes produced with ≤1% FC were not as microbiologically shelf-stable as the reference cake, especially when sliced. Therefore, it can be concluded that whilst fermentates have appreciable antifungal effects, their use could potentially result in reduced shelf-stabilities. Robust challenge and shelf-life tests would be recommended before the marketing of cakes were propionate and/or sorbate has been replaced to ensure accurate shelf-lives are stated. Copyright © 2016 Elsevier B.V. All rights reserved.

Solubility of ethylene in methyl propionate

NARCIS (Netherlands)

Shariati - Sarabi, A.; Florusse, L.J.; Peters, C.J.

2015-01-01

In this work, the solubility of ethylene in methyl propionate was measured within a temperature range of 283.5–464.8 K and pressures up to 10.7 MPa. Experiments were carried out using the Cailletet apparatus, which uses a synthetic method for the experiments. The critical points of several isopleths

High-temperature unimolecular decomposition of ethyl propionate

KAUST Repository

Giri, Binod; Alabbad, Mohammed; Farooq, Aamir

2016-01-01

This work reports rate coefficients of the thermal unimolecular decomposition reaction of ethyl propionate (EP) behind reflected shock waves over the temperature range of 976–1300 K and pressures of 825–1875 Torr. The reaction progress was monitored

Response of preschool children with asthma symptoms to fluticasone propionate

DEFF Research Database (Denmark)

Roorda, R J; Mezei, G; Bisgaard, H

2001-01-01

with after placebo (7% to 35%, P =.002) and a significantly higher proportion of exacerbation-free patients (61% to 76%, P =.02). Children with less frequent symptoms, no family history of asthma, or both showed no significant treatment effect. There seemed to be no association between response...... to fluticasone propionate and history of rhinitis or eczema or the number of previous exacerbations. CONCLUSIONS: Children with frequent symptoms, a family history of asthma, or both showed the greatest response to fluticasone propionate treatment. These findings may help to predict treatment outcome and guide...

Dual roles of glucose in the freeze-tolerant earthworm Dendrobaena octaedra: cryoprotection and fuel for metabolism

DEFF Research Database (Denmark)

Calderon, Sofia; Holmstrup, Martin; Westh, Peter

2009-01-01

Ectothermic animals inhabiting the subarctic and temperate regions have evolved strategies to deal with periods of continuous frost during winter. The earthworm Dendrobaena octaedra is freeze tolerant and accumulates large concentrations of glucose upon freezing. The present study investigates...... the roles of glucose accumulation for long-term freeze tolerance in worms kept frozen at -2 degrees C for 47 days. During this period, worms were sampled periodically for determination of survival and for measurements of glucose, glycogen, lactate, alanine and succinate. In addition we performed...... increased slightly whereas succinate levels remained constant. However, it is argued that other waste products (particularly propionate) could be the primary end product of a continued anaerobic metabolism. Calorimetric measures of the metabolic rate of frozen worms were in accord with values calculated...

Studies on potential effects of fumaric acid on rumen microbial fermentation, methane production and microbial community.

Science.gov (United States)

Riede, Susanne; Boguhn, Jeannette; Breves, Gerhard

2013-01-01

The greenhouse gas methane (CH4) contributes substantially to global climate change. As a potential approach to decrease ruminal methanogenesis, the effects of different dosages of fumaric acid (FA) on ruminal microbial metabolism and on the microbial community (archaea, bacteria) were studied using a rumen simulation technique (RUSITEC). FA acts as alternative hydrogen acceptor diverting 2H from methanogenesis of archaea towards propionate formation of bacteria. Three identical trials were conducted with 12 fermentation vessels over a period of 14 days. In each trial, four fermentation vessels were assigned to one of the three treatment groups differing in FA dosage: low fumaric acid (LFA), high fumaric acid (HFA) and without FA (control). FA was continuously infused with the buffer. Grass silage and concentrate served as substrate. FA led to decreases in pH and to higher production rates of total short chain fatty acids (SCFA) mediated by increases in propionate for LFA of 1.69 mmol d(-1) and in propionate and acetate production for HFA of 4.49 and 1.10 mmol d(-1), respectively. Concentrations of NH3-N, microbial crude protein synthesis, their efficiency, degradation of crude nutrients and detergent fibre fraction were unchanged. Total gas and CH4 production were not affected by FA. Effects of FA on structure of microbial community by means of single strand conformation polymorphism (SSCP) analyses could not be detected. Given the observed increase in propionate production and the unaffected CH4 production it can be supposed that the availability of reduction equivalents like 2H was not limited by the addition of FA in this study. It has to be concluded from the present study that the application of FA is not an appropriate approach to decrease the ruminal CH4 production.

Engineering strategy of yeast metabolism for higher alcohol production

Directory of Open Access Journals (Sweden)

Shimizu Hiroshi

2011-09-01

Full Text Available Abstract Background While Saccharomyces cerevisiae is a promising host for cost-effective biorefinary processes due to its tolerance to various stresses during fermentation, the metabolically engineered S. cerevisiae strains exhibited rather limited production of higher alcohols than that of Escherichia coli. Since the structure of the central metabolism of S. cerevisiae is distinct from that of E. coli, there might be a problem in the structure of the central metabolism of S. cerevisiae. In this study, the potential production of higher alcohols by S. cerevisiae is compared to that of E. coli by employing metabolic simulation techniques. Based on the simulation results, novel metabolic engineering strategies for improving higher alcohol production by S. cerevisiae were investigated by in silico modifications of the metabolic models of S. cerevisiae. Results The metabolic simulations confirmed that the high production of butanols and propanols by the metabolically engineered E. coli strains is derived from the flexible behavior of their central metabolism. Reducing this flexibility by gene deletion is an effective strategy to restrict the metabolic states for producing target alcohols. In contrast, the lower yield using S. cerevisiae originates from the structurally limited flexibility of its central metabolism in which gene deletions severely reduced cell growth. Conclusions The metabolic simulation demonstrated that the poor productivity of S. cerevisiae was improved by the introduction of E. coli genes to compensate the structural difference. This suggested that gene supplementation is a promising strategy for the metabolic engineering of S. cerevisiae to produce higher alcohols which should be the next challenge for the synthetic bioengineering of S. cerevisiae for the efficient production of higher alcohols.

THE EFFECTS OF ORAL ADMINISTRATION OF PROPYLENE GLYCOL AND CALCIUM PROPIONATE IN DAIRY COWS

Directory of Open Access Journals (Sweden)

C. GAVAN

2009-10-01

Full Text Available This study was designed to determine the effects of the oral administration of propylene glycol and calcium propionate on performance of dairy cows. Treatments were 10 l water (control, 10 l water+300 ml propylene glycol (GP and 10 l water+500 g calcium propionate (CP. Animals were mainly of Holstein breeds and were fed and managed in a commercial setting. The cows were divided randomly into an experimental group, n=24 (n=12 with PG and n=12 with CP and a control group, n=11. Cows received the assigned treatment within 10 hours of calving and 24 hours after calving. Health events were recorded during calving and for the first 21 days in milk (DIM. Health examinations were performed on cows that appeared not well. The cows were milked three times daily and milk production was recorded electronically. Milk solid content and somatic cell score were determinate from three consecutive milking weekly till 20 DIM and than monthly till 110 DIM. Retained placenta, hypocalcaemia, displaced abomasums, ketosis and metritis were low in treatment groups (with PG and CP. The cows receiving PG had 2.8 Kg/day grater milk production than control group. The cows receiving CP had 1.7 kg/day grater milk production than control group. Prophylactic administration of PG and CP drenches to Holstein cows may be justified by potentially higher milk yields and reduced health complications.

Fundamental Insights into Propionate Oxidation in Microbial Electrolysis Cells Using a Combination of Electrochemical, Molecular biology and Electron Balance Approaches

KAUST Repository

Rao, Hari Ananda

2016-01-01

for electricity generation (MFC) or H2 and CH4 production (MEC). Propionate is an important volatile fatty acid (VFA) (24-70%) in some wastewaters and accumulation of this VFA can cause a process failure in a conventional anaerobic digestion (AD) system

The effect of sourdough and calcium propionate on the microbial shelf-life of salt reduced bread.

Science.gov (United States)

Belz, Markus C E; Mairinger, Regina; Zannini, Emanuele; Ryan, Liam A M; Cashman, Kevin D; Arendt, Elke K

2012-10-01

The consumption of low-salt bread represents an efficient way to improve public health by decreasing cardiovascular health issues related to increased intakes of sodium chloride (NaCl). The reduction of NaCl influences the bread quality characteristics, in particular the shelf-life. Calcium propionate (CP) is commonly used in bread as an antifungal agent. Alternatively, sourdough can be used as a natural preservative. This work addresses the feasibility of NaCl reduction in wheat bread focussing on shelf-life and the compensation using sourdough as well as chemical preservatives. The impact of NaCl reduction and the addition of preservative agents in conjunction with different NaCl concentrations on the shelf-life of bread were tested under 'environmental' conditions in a bakery as well as using challenge tests against selected fungi. The challenge tests were performed using fungi commonly found in the bakery environment such as Penicillium expansum, Fusarium culmorum and Aspergillus niger. NaCl reduction decreased the shelf-life by 1-2 days. The addition of sourdough with antifungal activity prolonged the shelf-life to 12-14 days whereas the addition of 0.3 % calcium propionate prolonged the shelf-life to 10-12 days only. The fungal challenge tests revealed differences in the determined shelf-life between the different fungi based on their resistance. Similar antifungal performance was observed in sourdough breads and calcium propionate breads when tested against the different indicator moulds. The findings of this study indicate that addition of sourdough fermented using a specifically selected antifungal Lactobacillus amylovorus DSM 19280 can replace the chemical preservative calcium propionate addition and compensate for the reduced level and, therefore, guarantee the product safety of low-salt bread.

The influence of sodium propionate on blood glucose, insulin and cortisol concentrations in calves of different ages

Directory of Open Access Journals (Sweden)

Biljana Radojičić

2016-01-01

Full Text Available The process of gluconeogenesis in ruminants is under the direct influence of insulin and glucocorticoid hormones. The goal of this study was to determine the effects of added Na-propionate on the neuroendocrine regulation of blood glucose in calves at three specific physiological periods: on exclusive milk nutrition; on mixed milk and forage nutrition; and with established ruminant digestion. The influence of Na-propionate on blood glucose, insulin and cortisol concentrations was examined in the same 20 female Holstein calves at different stages of forestomach development (15 days, 2 months, and 4 months of age of calves. Group 1 of calves (n = 10 received Na-propionate intravenously; group 2 (n = 10 received Na-propionate mixed in milk. Blood sampling was performed 1 and 3 h after Na-propionate administration. After i.v. administration of Na-propionate, a significant increase (P < 0.05 in blood glucose concentration was observed 1 h after administration only in calves aged 2 and 4 months; blood insulin concentration was significantly higher (P < 0.01 1 and 3 h after i.v. administration in 2-month-old calves; and cortisol concentration increased (P < 0.01 1 h after administration in each selected calf in all testing periods. Orally administered Na-propionate led to a significant increase (P < 0.01 of insulin concentration 1 and 3 h after administration in 15-day-old calves, and 3 h after administration in 2-month-old calves. Based on these results it could be assumed that i.v. and p.o. administration of Na-propionate affects the neuroendocrine regulation of glycaemia in calves of different age.

Tyrosine B10 triggers a heme propionate hydrogen bonding network loop with glutamine E7 moiety

International Nuclear Information System (INIS)

Ramos-Santana, Brenda J.; López-Garriga, Juan

2012-01-01

Highlights: ► H-bonding network loop by PheB10Tyr mutation is proposed. ► The propionate group H-bonding network restricted the flexibility of the heme. ► The hydrogen bonding interaction modulates the electron density of the iron. ► Propionate H-bonding network loop explains the heme-ligand stabilization. -- Abstract: Propionates, as peripheral groups of the heme active center in hemeproteins have been described to contribute in the modulation of heme reactivity and ligand selection. These electronic characteristics prompted the question of whether the presence of hydrogen bonding networks between propionates and distal amino acids present in the heme ligand moiety can modulate physiological relevant events, like ligand binding association and dissociation activities. Here, the role of these networks was evaluated by NMR spectroscopy using the hemoglobin I PheB10Tyr mutant from Lucina pectinata as model for TyrB10 and GlnE7 hemeproteins. 1 H-NMR results for the rHbICN PheB10Tyr derivative showed chemical shifts of TyrB10 OHη at 31.00 ppm, GlnE7 N ε1 H/N ε2 H at 10.66 ppm/−3.27 ppm, and PheE11 C δ H at 11.75 ppm, indicating the presence of a crowded, collapsed, and constrained distal pocket. Strong dipolar contacts and inter-residues crosspeaks between GlnE7/6-propionate group, GlnE7/TyrB10 and TyrB10/CN suggest that this hydrogen bonding network loop between GlnE7, TyrB10, 6-propionate group, and the heme ligand contribute significantly to the modulation of the heme iron electron density as well as the ligand stabilization mechanism. Therefore, the network loop presented here support the fact that the electron withdrawing character of the hydrogen bonding is controlled by the interaction of the propionates and the nearby electronic environments contributing to the modulation of the heme electron density state. Thus, we hypothesize that in hemeproteins with similar electrostatic environment the flexibility of the heme-6-propionate promotes a hydrogen

Interspecies electron transfer in methanogenic propionate degrading consortia

NARCIS (Netherlands)

Bok, de F.A.M.; Plugge, C.M.; Stams, A.J.M.

2004-01-01

Propionate is a key intermediate in the conversion of complex organic matter under methanogenic conditions. Oxidation of this compound requires obligate syntrophic consortia of acetogenic proton- and bicarbonate reducing bacteria and methanogenic archaea. Although H-2 acts as an electron-carrier in

Responses of Blood Glucose, Insulin, Glucagon, and Fatty Acids to Intraruminal Infusion of Propionate in Hanwoo

Directory of Open Access Journals (Sweden)

Y. K. Oh

2015-02-01

Full Text Available This study was carried out to investigate the effects of intraruminal infusion of propionate on ruminal fermentation characteristics and blood hormones and metabolites in Hanwoo (Korean cattle steers. Four Hanwoo steers (average body wt. 270 kg, 13 month of age equipped with rumen cannula were infused into rumens with 0.0 M (Water, C, 0.5 M (37 g/L, T1, 1.0 M (74 g/L, T2 and 1.5 M (111 g/L, T3 of propionate for 1 hour per day and allotted by 4×4 Latin square design. On the 5th day of infusion, samples of rumen and blood were collected at 0, 60, 120, 180, and 300 min after intraruminal infusion of propionate. The concentrations of serum glucose and plasma glucagon were not affected (p>0.05 by intraruminal infusion of propionate. The serum insulin concentration at 60 min after infusion was significantly (p<0.05 higher in T3 than in C, while the concentration of non-esterified fatty acid (NEFA at 60 and 180 min after infusion was significantly (p<0.05 lower in the propionate treatments than in C. Hence, intraruminal infusion of propionate stimulates the secretion of insulin, and decreases serum NEFA concentration rather than the change of serum glucose concentration.

Effects of targeted delivery of propionate to the human colon on appetite regulation, body weight maintenance and adiposity in overweight adults

Science.gov (United States)

Chambers, Edward S; Viardot, Alexander; Psichas, Arianna; Morrison, Douglas J; Murphy, Kevin G; Zac-Varghese, Sagen E K; MacDougall, Kenneth; Preston, Tom; Tedford, Catriona; Finlayson, Graham S; Blundell, John E; Bell, Jimmy D; Thomas, E Louise; Mt-Isa, Shahrul; Ashby, Deborah; Gibson, Glen R; Kolida, Sofia; Dhillo, Waljit S; Bloom, Stephen R; Morley, Wayne; Clegg, Stuart; Frost, Gary

2015-01-01

Objective The colonic microbiota ferment dietary fibres, producing short chain fatty acids. Recent evidence suggests that the short chain fatty acid propionate may play an important role in appetite regulation. We hypothesised that colonic delivery of propionate would increase peptide YY (PYY) and glucagon like peptide-1 (GLP-1) secretion in humans, and reduce energy intake and weight gain in overweight adults. Design To investigate whether propionate promotes PYY and GLP-1 secretion, a primary cultured human colonic cell model was developed. To deliver propionate specifically to the colon, we developed a novel inulin-propionate ester. An acute randomised, controlled cross-over study was used to assess the effects of this inulin-propionate ester on energy intake and plasma PYY and GLP-1 concentrations. The long-term effects of inulin-propionate ester on weight gain were subsequently assessed in a randomised, controlled 24-week study involving 60 overweight adults. Results Propionate significantly stimulated the release of PYY and GLP-1 from human colonic cells. Acute ingestion of 10 g inulin-propionate ester significantly increased postprandial plasma PYY and GLP-1 and reduced energy intake. Over 24 weeks, 10 g/day inulin-propionate ester supplementation significantly reduced weight gain, intra-abdominal adipose tissue distribution, intrahepatocellular lipid content and prevented the deterioration in insulin sensitivity observed in the inulin-control group. Conclusions These data demonstrate for the first time that increasing colonic propionate prevents weight gain in overweight adult humans. Trial registration number NCT00750438. PMID:25500202

Sulfate addition as an effective method to improve methane fermentation performance and propionate degradation in thermophilic anaerobic co-digestion of coffee grounds, milk and waste activated sludge with AnMBR.

Science.gov (United States)

Li, Qian; Li, Yu-You; Qiao, Wei; Wang, Xiaochang; Takayanagi, Kazuyuki

2015-06-01

This study was conducted to investigate the effects of sulfate on propionate degradation and higher organic loading rate (OLR) achievement in a thermophilic AnMBR for 373days using coffee grounds, milk and waste activated sludge (WAS) as the co-substrate. Without the addition of sulfate, the anaerobic system failed at an OLR of 14.6g-COD/L/d, with propionate accumulating to above 2.23g-COD/L, and recovery by an alkalinity supplement was not successful. After sulfate was added into substrates at a COD/SO4(2-) ratio of 200:1 to 350:1, biogas production increased proportionally with OLR increasing from 4.06 to 15.2g-COD/L/d. Propionic acid was maintained at less than 100mg-COD/L due to the effective conversion of propionic acid to methane after the sulfate supplement was added. The long-term stable performance of the AnMBR indicated that adding sulfate was beneficial for the degradation of propionate and achieving a higher OLR under the thermophilic condition. Copyright © 2015 Elsevier Ltd. All rights reserved.

Monitoring and control of the biogas process based on propionate concentration using online VFA measurement

DEFF Research Database (Denmark)

Boe, Kanokwan; Steyer, J.P.; Angelidaki, Irini

2008-01-01

Simple logic control algorithms were tested for automatic control of a lab-scale CSTR manure digester. Using an online VFA monitoring system, propionate concentration in the reactor was used as parameter for control of the biogas process. The propionate concentration was kept below a threshold...

Determination of dissociation constants or propionic acid and lactic acid (2-hydroxypropionic acid) by potentiometry and conductometry

International Nuclear Information System (INIS)

Saeeduddin; Khanzada, A.W.K.

2004-01-01

Dissociation constants of propionic acid and 2-hydroxypropionic acid (lactic acid) have been studied at different temperatures between 25 to 50 deg. C interval. Propionic acid is analyzed by conductometry while 2-hydroxypropionic acid is analyzed by potentiometry. Both investigated compounds are symmetrical carboxylic acids having same length of carbon chain but are markedly different in ionic behavior. We were interested to see how the hydroxyl group (-OH) induction in propionic acid affects on pKa values of 2-hydroxypropionic acid. We observed that as temperature increases pKa values increase. The increase is observed for both the investigated compounds. PKa values of 2-hydroxypropionic acid are lower as compared to propionic acid because of electron withdrawing (-OH). (author)

Interactions of alfalfa hay and sodium propionate on dairy calf performance and rumen development.

Science.gov (United States)

Beiranvand, H; Ghorbani, G R; Khorvash, M; Nabipour, A; Dehghan-Banadaky, M; Homayouni, A; Kargar, S

2014-01-01

The objective of this experiment was to investigate the effects of different levels of alfalfa hay (AH) and sodium propionate (Pro) added to starter diets of Holstein calves on growth performance, rumen fermentation characteristics, and rumen development. Forty-two male Holstein calves (40±2kg of birth weight) were used in a complete randomized design with a 3×2 factorial arrangement of treatments. Dietary treatments were as follows: (1) control = concentrate only; (2) Pro = concentrate with 5% sodium propionate [dry matter (DM) basis]; (3) 5% AH = concentrate + 5% alfalfa hay (DM basis); (4) 5% AH + Pro = concentrate + 5% alfalfa hay + 5% sodium propionate (DM basis); (5) 10% AH = concentrate + 10% alfalfa hay (DM basis); and (6) 10% AH + Pro = concentrate + 10% alfalfa hay + 5% sodium propionate (DM basis). All calves were housed in individual pens bedded with sawdust until 10wk of age. They were given ad libitum access to water and starter throughout the experiment and were fed 2L of milk twice daily. Dry matter intake was recorded daily and body weight weekly. Calves from the control, 10% AH, and 10% AH + Pro treatments were euthanized after wk 10, and rumen wall samples were collected. Feeding of forage was found to increase overall dry matter intake, average daily gain, and final weight; supplementing sodium propionate had no effect on these parameters. Calves consuming forage had lower feed efficiency than those on the Pro diet. Rumen fluid in calves consuming forage had higher pH and greater concentrations of total volatile fatty acids and molar acetate. Morphometric parameters of the rumen wall substantiated the effect of AH supplementation, as plaque formation decreased macroscopically. Overall, the interaction between forage and sodium propionate did not affect calf performance parameters measured at the end of the experiment. Furthermore, inclusion of AH in starter diets positively enhanced the growth performance of male Holstein calves and influenced

Metabollic Engineering of Saccharomyces Cereviae a,omi acid metabolism for production of products of industrial interest

DEFF Research Database (Denmark)

Chen, Xiao

-based processes. This study has focused on metabolic engineering of the amino acid metabolism in S. cerevisiae for production of two types of chemicals of industrial interest. The first chemical is δ-(L-α-aminoadipyl)–L-cysteinyl–D-valine (LLD-ACV). ACV belongs to non-ribosomal peptides (NRPs), which......Saccharomyces cerevisiae is widely used in microbial production of chemicals, metabolites and proteins, mainly because genetic manipulation of S. cerevisiae is relatively easy and experiences from its wide application in the existing industrial fermentations directly benefit new S. cerevisiae...

Effects of supplemental calcium salts of palm oil and chromium-propionate on insulin sensitivity and productive and reproductive traits of mid- to late-lactating Holstein × Gir dairy cows consuming excessive energy.

Science.gov (United States)

Leiva, T; Cooke, R F; Brandão, A P; Bertin, R D; Colombo, E A; Miranda, V F B; Lourenço, L A C; Rodrigues, S M B; Vasconcelos, J L M

2018-01-01

This experiment compared insulin sensitivity, milk production, and reproductive outcomes in dairy cows consuming excessive energy during mid to late lactation and receiving in a 2 × 2 factorial design (1) concentrate based on ground corn (CRN; n = 20) or including 8% (DM basis) of Ca salts of palm oil (CSPO; n = 20), and (2) supplemented (n = 20) or not (n = 20) with 2.5 g/d of Cr-propionate. During the experiment (d 0-203), 40 multiparous, nonpregnant, lactating 3/4 Holstein × 1/4 Gir cows (initial days in milk = 81 ± 2; mean ± SE) were offered corn silage for ad libitum consumption, and individually received concentrate formulated to allow diets to provide 160% of their daily net energy for lactation requirements. From d -15 to 203, milk production was recorded daily, blood samples collected weekly, and cow body weight (BW) and body condition score (BCS) recorded on d 0 and 203. For dry matter intake evaluation, cows from both treatments were randomly divided in 5 groups of 8 cows each, and allocated to 8 individual feeding stations for 3 d. Intake was evaluated 6 times/group. Glucose tolerance tests (GTT; 0.5 g of glucose/kg of BW) were performed on d -3, 100, and 200. Follicle aspiration for in vitro embryo production was performed via transvaginal ovum pick-up on d -1, 98, and 198. Mean DMI, net energy for lactation intake, as well as BW and BCS change were similar across treatments. On average, cows gained 40 kg of BW and 0.49 BCS during the experiment. Within weekly blood samples, CRN cows had lower serum concentrations of glucose, insulin, fatty acids, and insulin-to-glucose ratio compared with CSPO cows, suggesting increased insulin sensitivity in CRN cows. During the GTT, insulin-sensitivity traits were also greater in CRN versus CSPO cows. Supplemental Cr-propionate resulted in lower serum insulin concentrations and insulin-to-glucose ratio within CRN cows only, indicating that Cr-propionate improved basal insulin sensitivity in CRN but not in CSPO

Decreased activity of a propionate degrading community in a UASB reactor fed with synthetic medium without molybdenum, tungsten and selenium

NARCIS (Netherlands)

Worm, P.; Fermoso, F.G.; Lens, P.N.L.; Plugge, C.M.

2009-01-01

The composition and dynamics of the propionate degrading community in a propionate-fed upflow anaerobic sludge bed (UASB) reactor with sludge originating from an alcohol distillery wastewater treating UASB reactor was studied. The rather stable propionate degrading microbial community comprised

75 FR 78243 - Propionic Acid and Salts, Urea Sulfate, Methidathion, and Methyl Parathion; Registration Review...

Science.gov (United States)

2010-12-15

... ENVIRONMENTAL PROTECTION AGENCY [EPA-HQ-OPP-2010-0650; FRL-8855-5] Propionic Acid and Salts, Urea.... 4078, urea sulfate, case no. 7213, methidathion, case no. 0034, and methyl parathion, case no. 0153... pesticides in the table below--propionic acid and salts, case 4078, urea sulfate, case no. 7213, methidathion...

Engineering yeast metabolism for production of fuels and chemicals

DEFF Research Database (Denmark)

Nielsen, Jens

2016-01-01

faster development of metabolically engineered strains that can be used for production of fuels and chemicals. The yeast Saccharomyces cerevisiae is widely used for production of fuels, chemicals, pharmaceuticals and materials. Through metabolic engineering of this yeast a number of novel industrial...... as for metabolic design. In this lecture it will be demonstrated how the Design-Build-Test cycle of metabolic engineering has allowed for development of yeast cell factories for production of a range of different fuels and chemicals. Some examples of different technologies will be presented together with examples......Metabolic engineering relies on the Design-Build-Test cycle. This cycle includes technologies like mathematical modeling of metabolism, genome editing and advanced tools for phenotypic characterization. In recent years there have been advances in several of these technologies, which has enabled...

[Isolation and identification of a lactate-utilizing, butyrate-producing bacterium and its primary metabolic characteristics].

Science.gov (United States)

Liu, Wei; Zhu, Wei-yun; Yao, Wen; Mao, Sheng-yong

2007-06-01

The distal mammalian gut harbors prodigiously abundant microbes, which provide unique metabolic traits to host. A lactate-utilizing, butyrate-producing bacterium, strain LB01, was isolated from adult swine feces by utilizing modified Hungate technique with rumen liquid-independent YCFA medium supplemented with lactate as the single carbon source. It was an obligate anaerobic, Gram positive bacterium, and could utilize glucose, fructose, maltose and lactate with a large amount of gas products. 16S rRNA sequence analysis revealed that it had the high similarity with members of the genus Megasphaera. The metabolic characteristics of strain LB01 was investigated by using in vitro fermentation system. Lactate at the concentration of 65 mmol/L in YCFA medium was rapidly consumed within 9 hours and was mainly converted to propionate and butyrate after 24h. As the level of acetate declined, the concentration of butyrate rose only in the presence of glucose, suggesting that butyrate could possibly be synthesized by the acetyl CoA: butyryl CoA transferase. When co-cultured with lactic acid bacteria strain K9, strain LB01 evidently reduced the concentration of lactate produced by strain K9 and decelerated the rapid pH drop, finally producing 12.11 mmol/L butyrate and 4.06 mmol/L propionate. The metabolic characteristics that strain LB01 efficiently converts toxic lactate and excessive acetate to butyrate can prevent lactate and acetate accumulation in the large intestine and maintain the slightly acidic environment of the large intestine, consequently revealing that stain LB01 could act as a potential probiotics.

Enrichment of Thermophilic Propionate-Oxidizing Bacteria in Syntrophy with Methanobacterium thermoautotrophicum or Methanobacterium thermoformicicum

OpenAIRE

Stams, Alfons J. M.; Grolle, Katja C. F.; Frijters, Carla T. M.; Van Lier, Jules B.

1992-01-01

Thermophilic propionate-oxidizing, proton-reducing bacteria were enriched from the granular methanogenic sludge of a bench-scale upflow anaerobic sludge bed reactor operated at 55°C with a mixture of volatile fatty acids as feed. Thermophilic hydrogenotrophic methanogens had a high decay rate. Therefore, stable, thermophilic propionate-oxidizing cultures could not be obtained by using the usual enrichment procedures. Stable and reproducible cultivation was possible by enrichment in hydrogen-p...

Hydrogen production and metabolic flux analysis of metabolically engineered Escherichia coli strains

Energy Technology Data Exchange (ETDEWEB)

Kim, Seohyoung; Seol, Eunhee; Park, Sunghoon [Department of Chemical and Biochemical Engineering, Pusan National University, Busan 609-735 (Korea); Oh, You-Kwan [Bioenergy Research Center, Korea Institute of Energy Research, Daejeon 305-543 (Korea); Wang, G.Y. [Department of Oceanography, University of Hawaii at Manoa Honolulu, HI 96822 (United States)

2009-09-15

Escherichia coli can produce H{sub 2} from glucose via formate hydrogen lyase (FHL). In order to improve the H{sub 2} production rate and yield, metabolically engineered E. coli strains, which included pathway alterations in their H{sub 2} production and central carbon metabolism, were developed and characterized by batch experiments and metabolic flux analysis. Deletion of hycA, a negative regulator for FHL, resulted in twofold increase of FHL activity. Deletion of two uptake hydrogenases (1 (hya) and hydrogenase 2 (hyb)) increased H{sub 2} production yield from 1.20 mol/mol glucose to 1.48 mol/mol glucose. Deletion of lactate dehydrogenase (ldhA) and fumarate reductase (frdAB) further improved the H{sub 2} yield; 1.80 mol/mol glucose under high H{sub 2} pressure or 2.11 mol/mol glucose under reduced H{sub 2} pressure. Several batch experiments at varying concentrations of glucose (2.5-10 g/L) and yeast extract (0.3 or 3.0 g/L) were conducted for the strain containing all these genetic alternations, and their carbon and energy balances were analyzed. The metabolic flux analysis revealed that deletion of ldhA and frdAB directed most of the carbons from glucose to the glycolytic pathway leading to H{sub 2} production by FHL, not to the pentose phosphate pathway. (author)

Modulation of Immunological Pathways in Autistic and Neurotypical Lymphoblastoid Cell Lines by the Enteric Microbiome Metabolite Propionic Acid.

Science.gov (United States)

Frye, Richard E; Nankova, Bistra; Bhattacharyya, Sudeepa; Rose, Shannon; Bennuri, Sirish C; MacFabe, Derrick F

2017-01-01

Propionic acid (PPA) is a ubiquitous short-chain fatty acid which is a fermentation product of the enteric microbiome and present or added to many foods. While PPA has beneficial effects, it is also associated with human disorders, including autism spectrum disorders (ASDs). We previously demonstrated that PPA modulates mitochondrial dysfunction differentially in subsets of lymphoblastoid cell lines (LCLs) derived from patients with ASD. Specifically, PPA significantly increases mitochondrial function in LCLs that have mitochondrial dysfunction at baseline [individuals with autistic disorder with atypical mitochondrial function (AD-A) LCLs] as compared to ASD LCLs with normal mitochondrial function [individuals with autistic disorder with normal mitochondrial function (AD-N) LCLs] and control (CNT) LCLs. PPA at 1 mM was found to have a minimal effect on expression of immune genes in CNT and AD-N LCLs. However, as hypothesized, Panther analysis demonstrated that 1 mM PPA exposure at 24 or 48 h resulted in significant activation of the immune system genes in AD-A LCLs. When the effect of PPA on ASD LCLs were compared to the CNT LCLs, both ASD groups demonstrated immune pathway activation, although the AD-A LCLs demonstrate a wider activation of immune genes. Ingenuity Pathway Analysis identified several immune-related pathways as key Canonical Pathways that were differentially regulated, specifically human leukocyte antigen expression and immunoglobulin production genes were upregulated. These data demonstrate that the enteric microbiome metabolite PPA can evoke atypical immune activation in LCLs with an underlying abnormal metabolic state. As PPA, as well as enteric bacteria which produce PPA, have been implicated in a wide variety of diseases which have components of immune dysfunction, including ASD, diabetes, obesity, and inflammatory diseases, insight into this metabolic modulator may have wide applications for both health and disease.

Impact of anti-acidification microbial consortium on carbohydrate metabolism of key microbes during food waste composting.

Science.gov (United States)

Song, Caihong; Li, Mingxiao; Qi, Hui; Zhang, Yali; Liu, Dongming; Xia, Xunfeng; Pan, Hongwei; Xi, Beidou

2018-07-01

This study investigated the effect of anti-acidification microbial consortium (AAMC), which act synergistically for rapid bioconversion of organic acids on carbohydrate metabolism of key microbes in the course of food waste (FW) composting by metaproteomics. AAMC was inoculated to the composting mass and compared with treatment with alkaline compounds and the control without any amendment. Inoculating AAMC could effectively accelerate carbohydrate degradation process and improve composting efficiency. Carbohydrate metabolic network profiles showed the inoculation with AAMC could increase significantly the types of enzymes catalysing the degradation of lignin, cellulose and hemicellulose. Furthermore, AAMC inoculum could increase not only diversities of microbes producing key enzymes in metabolism pathways of acetic and propionic acids, but also the amounts of these key enzymes. The increase of diversities of microbes could disperse the pressure from acidic adversity on microorganisms which were capable to degrade acetic and propionic acids. Copyright © 2018 Elsevier Ltd. All rights reserved.

Electrochemical reduction of Eu (III) in propionic media

International Nuclear Information System (INIS)

Brotto, M.E.; Rabockai, T.

1988-01-01

Some chronopotentiometric studies of Eu (III) electro-reducion in propionic media that suggests the presence of two parallel rections: Eu (III) → Eu (II) and Eu (III) → Eu (II) → Y are presented. Some experimental data, such Eu (III) reducion, electrolysis of solutions and ionic power of the system are discussed. (M.J.C.) [pt

Identification of Lactic Acid Bacteria and Propionic Acid Bacteria using FTIR Spectroscopy and Artificial Neural Networks

Directory of Open Access Journals (Sweden)

Beata Nalepa

2012-01-01

Full Text Available In the present study, lactic acid bacteria and propionic acid bacteria have been identified at the genus level with the use of artificial neural networks (ANNs and Fourier transform infrared spectroscopy (FTIR. Bacterial strains of the genera Lactobacillus, Lactococcus, Leuconostoc, Streptococcus and Propionibacterium were analyzed since they deliver health benefits and are routinely used in the food processing industry. The correctness of bacterial identification by ANNs and FTIR was evaluated at two stages. At first stage, ANNs were tested based on the spectra of 66 reference bacterial strains. At second stage, the evaluation involved 286 spectra of bacterial strains isolated from food products, deposited in our laboratory collection, and identified by genus-specific PCR. ANNs were developed based on the spectra and their first derivatives. The most satisfactory results were reported for the probabilistic neural network, which was built using a combination of W5W4W3 spectral ranges. This network correctly identified the genus of 95 % of the lactic acid bacteria and propionic acid bacteria strains analyzed.

Treatment of scalp psoriasis with clobetasol-17 propionate 0.05% shampoo: a study on daily clinical practice.

NARCIS (Netherlands)

Bovenschen, H.J.; Kerkhof, P.C.M. van de

2010-01-01

BACKGROUND: Safety and clinical effectiveness of clobetasol-17 propionate 0.05% shampoo have been shown in patients with scalp psoriasis. AIM: First, to evaluate treatment satisfaction, user convenience safety and effectiveness of clobetasol-17 propionate 0.05% shampoo treatment in daily clinical

Neuroprotective effect of creatine against propionic acid toxicity in ...

African Journals Online (AJOL)

With sufficient research and clinical trials in future, this could prove to be successful in treatment or management of autism as a neurodevelopmental disorder recently related to PA neurotoxicity. Keywords: Propionic acid, creatine, SH-SY5Y, comet assay, DNA fragmentation assay, apoptosis, neuroprotection. African Journal ...

Metabolic engineering of Clostridium autoethanogenum for selective alcohol production.

Science.gov (United States)

Liew, Fungmin; Henstra, Anne M; Kӧpke, Michael; Winzer, Klaus; Simpson, Sean D; Minton, Nigel P

2017-03-01

Gas fermentation using acetogenic bacteria such as Clostridium autoethanogenum offers an attractive route for production of fuel ethanol from industrial waste gases. Acetate reduction to acetaldehyde and further to ethanol via an aldehyde: ferredoxin oxidoreductase (AOR) and alcohol dehydrogenase has been postulated alongside the classic pathway of ethanol formation via a bi-functional aldehyde/alcohol dehydrogenase (AdhE). Here we demonstrate that AOR is critical to ethanol formation in acetogens and inactivation of AdhE led to consistently enhanced autotrophic ethanol production (up to 180%). Using ClosTron and allelic exchange mutagenesis, which was demonstrated for the first time in an acetogen, we generated single mutants as well as double mutants for both aor and adhE isoforms to confirm the role of each gene. The aor1+2 double knockout strain lost the ability to convert exogenous acetate, propionate and butyrate into the corresponding alcohols, further highlighting the role of these enzymes in catalyzing the thermodynamically unfavourable reduction of carboxylic acids into alcohols. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Biological hydrogen production from probiotic wastewater as substrate by selectively enriched anaerobic mixed microflora

Energy Technology Data Exchange (ETDEWEB)

Sivaramakrishna, D.; Sreekanth, D.; Himabindu, V. [Centre for Environment, Institute of Science and Technology, Jawaharlal Nehru Technological University, Kukatpally, Hyderabad 500072, Andhra Pradesh (India); Anjaneyulu, Y. [TLGVRC, JSU Box 18739, JSU, Jackson, MS 32917-0939 (United States)

2009-03-15

Biohydrogen production from probiotic wastewater using mixed anaerobic consortia is reported in this paper. Batch tests are carried out in a 5.0 L batch reactor under constant mesophillic temperature (37 C). The maximum hydrogen yield 1.8 mol-hydrogen/mol-carbohydrate is obtained at an optimum pH of 5.5 and substrate concentration 5 g/L. The maximum hydrogen production rate is 168 ml/h. The hydrogen content in the biogas is more than 65% and no significant methane is observed throughout the study. In addition to hydrogen, acetate, propionate, butyrate and ethanol are found to be the main by-products in the metabolism of hydrogen fermentation. (author)

Production of L-valine from metabolically engineered Corynebacterium glutamicum.

Science.gov (United States)

Wang, Xiaoyuan; Zhang, Hailing; Quinn, Peter J

2018-05-01

L-Valine is one of the three branched-chain amino acids (valine, leucine, and isoleucine) essential for animal health and important in metabolism; therefore, it is widely added in the products of food, medicine, and feed. L-Valine is predominantly produced through microbial fermentation, and the production efficiency largely depends on the quality of microorganisms. In recent years, continuing efforts have been made in revealing the mechanisms and regulation of L-valine biosynthesis in Corynebacterium glutamicum, the most utilitarian bacterium for amino acid production. Metabolic engineering based on the metabolic biosynthesis and regulation of L-valine provides an effective alternative to the traditional breeding for strain development. Industrially competitive L-valine-producing C. glutamicum strains have been constructed by genetically defined metabolic engineering. This article reviews the global metabolic and regulatory networks responsible for L-valine biosynthesis, the molecular mechanisms of regulation, and the strategies employed in C. glutamicum strain engineering.

Thermal decomposition of yttrium(III) propionate and butyrate

DEFF Research Database (Denmark)

Grivel, Jean-Claude

2013-01-01

The thermal decompositions of yttrium(III) propionate monohydrate (Y(C2H5CO2)3·H2O) and yttrium(III) butyrate dihydrate (Y(C3H7CO2)3·2H2O) were studied in argon by means of thermogravimetry, differential thermal analysis, IR-spectroscopy, X-ray diffraction and hot-stage microscopy. These two...

Neuroprotective effect of creatine against propionic acid toxicity in ...

African Journals Online (AJOL)

edoja

2013-07-31

Jul 31, 2013 ... Full Length Research Paper. Neuroprotective effect of creatine against propionic acid toxicity in neuroblastoma SH-SY5Y cells in culture. Afaf El-Ansary*, Ghada Abu-Shmais and Abeer Al-Dbass. Biochemistry Department, College of Science, King Saud University, P.O. Box 22452, Zip code 11495, Riyadh, ...

Anaerobic granule-based biofilms formation reduces propionate accumulation under high H2 partial pressure using conductive carbon felt particles.

Science.gov (United States)

Xu, Heng; Wang, Cuiping; Yan, Kun; Wu, Jing; Zuo, Jiane; Wang, Kaijun

2016-09-01

Syngas based co-digestion is not only more economically attractive than separate syngas methanation but also able to upgrade biogas and increase overall CH4 amount simultaneously. However, high H2 concentration in the syngas could inhibit syntrophic degradation of propionate, resulting in propionate accumulation and even failure of the co-digestion system. In an attempt to reduce propionate accumulation via enhancing both H2 interspecies transfer (HIT) and direct interspecies electron transfer (DIET) pathways, layered granule-based biofilms induced by conductive carbon felt particles (CCFP) was employed. The results showed that propionate accumulation was effectively reduced with influent COD load up to 7gL(-1)d(-1). Two types of granule-based biofilms, namely biofilm adhered to CCFP (B-CCFP) and granules formed by self-immobilization (B-SI) were formed in the reactor. Clostridium, Syntrophobacter, Methanospirillum were possibly involved in HIT and Clostridium, Geobacter, Anaerolineaceae, Methanosaeta in DIET, both of which might be responsible for the high-rate propionate degradation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of the ability to metabolize 1,2-propanediol by heterofermentative bacteria of the genus Lactobacillus

Directory of Open Access Journals (Sweden)

Krystyna Zielińska

2017-03-01

Conclusions: All tested isolates showed the ability to effectively metabolize 1,2-PD (in the presence of cobalamin and its conversion to propionic acid, which reveals that investigated bacteria meet the essential requirements of microorganisms with a potential application.

Multiple paths of electron flow to current in microbial electrolysis cells fed with low and high concentrations of propionate

KAUST Repository

Rao, Hari Ananda; Katuri, Krishna; Gorron, Eduardo; Logan, Bruce E.; Saikaly, Pascal

2016-01-01

Microbial electrolysis cells (MECs) provide a viable approach for bioenergy generation from fermentable substrates such as propionate. However, the paths of electron flow during propionate oxidation in the anode of MECs are unknown. Here, the paths

Short-Chain Fatty Acids Enhance the Lipid Accumulation of 3T3-L1 Cells by Modulating the Expression of Enzymes of Fatty Acid Metabolism.

Science.gov (United States)

Yu, Haining; Li, Ran; Huang, Haiyong; Yao, Ru; Shen, Shengrong

2018-01-01

Short-chain fatty acids (SCFA) such as acetic acid, propionic acid, and butyric acid are produced by fermentation by gut microbiota. In this paper, we investigate the effects of SCFA on 3T3-L1 cells and the underlying molecular mechanisms. The cells were treated with acetic acid, propionic acid, or butyric acid when cells were induced to differentiate into adipocytes. MTT assay was employed to detect the viability of 3T3-L1 cells. Oil Red O staining was used to visualize the lipid content in 3T3-L1 cells. A triglyceride assay kit was used to detect the triacylglycerol content in 3T3-L1 cells. qRT-PCR and Western blot were used to evaluate the expression of metabolic enzymes. MTT results showed that safe concentrations of acetic acid, propionic acid, and butyric acid were less than 6.4, 3.2, and 0.8 mM, respectively. Oil Red O staining and triacylglycerols detection results showed that treatment with acetic acid, propionic acid, and butyric acid accelerated the 3T3-L1 adipocyte differentiation. qRT-PCR and Western blot results showed that the expressions of lipoprotein lipase (LPL), adipocyte fatty acid binding protein 4 (FABP4), fatty acid transporter protein 4 (FATP4), and fatty acid synthase (FAS) were significantly increased by acetic acid, propionic acid, and butyric acid treatment during adipose differentiation (p fatty acid metabolism. © 2018 AOCS.

LIQUID-LIQUID EQUILIBRIA OF THE TERNARY SYSTEMS PROPIONIC ACID - WATER - SOLVENT (n-AMYL ALCOHOL AND n-AMYL ACETATE

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Dilek ÖZMEN

2005-02-01

Full Text Available The experimental liquid-liquid equilibrium (LLE data have been obtained at 25 oC for ternary systems propionic acid-water-n-amyl alcohol and propionic acid-water-n-amyl acetate. The reliability of the experimental tie line data are checked using the methods of Othmer-Tobias and Hand. The distribution coefficients and separation factors were obtained from experimental results and are also reported. The predicted tie line data obtained by UNIFAC method are compared with experimental data. It is concluded that n-amyl alcohol and n-amyl acetate are suitable separating agents for dilute aqueous propionic acid solutions.

Cyanobacterial metabolic engineering for biofuel and chemical production.

Science.gov (United States)

Oliver, Neal J; Rabinovitch-Deere, Christine A; Carroll, Austin L; Nozzi, Nicole E; Case, Anna E; Atsumi, Shota

2016-12-01

Rising levels of atmospheric CO 2 are contributing to the global greenhouse effect. Large scale use of atmospheric CO 2 may be a sustainable and renewable means of chemical and liquid fuel production to mitigate global climate change. Photosynthetic organisms are an ideal platform for efficient, natural CO 2 conversion to a broad range of chemicals. Cyanobacteria are especially attractive for these purposes, due to their genetic malleability and relatively fast growth rate. Recent years have yielded a range of work in the metabolic engineering of cyanobacteria and have led to greater knowledge of the host metabolism. Understanding of endogenous and heterologous carbon regulation mechanisms leads to the expansion of productive capacity and chemical variety. This review discusses the recent progress in metabolic engineering of cyanobacteria for biofuel and bulk chemical production since 2014. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synthesis of 1-[11c]methylpiperidin-4-yl propionate ([11c]pmp) for in vivo measurements of acetylcholinesterase activity

International Nuclear Information System (INIS)

Snyder, Scott E.; Tluczek, Louis; Jewett, Douglas M.; Nguyen, Thinh B.; Kuhl, David E.; Kilbourn, Michael R.

1998-01-01

Synthesis of 1-[ 11 C]methylpiperidin-4-yl propionate ([ 11 C]PMP), an in vivo substrate for acetylcholinesterase, is reported. An improved preparation of 4-piperidinyl propionate (PHP), the immediate precursor for radiolabeling, was accomplished in three steps from 4-hydroxypiperidine by (a) protection of the amine as the benzyl carbamate, (b) acylation with propionyl chloride, and (c) deprotection of the carbamate by catalytic hydrogenation. The final product was obtained in an overall 82% yield. Reaction of the free base form of PHP with [ 11 C]methyl trifluoromethanesulfonate at room temperature in N,N-dimethylformamide, followed by high performance liquid chromatography (HPLC) purification, provided [ 11 C]PMP in 57% radiochemical yield, >99% radiochemical purity, and >1500 Ci/mmol at the end of synthesis. The total synthesis time from end-of-bombardment was 35 min. [ 11 C]PMP can thus be reliably prepared for routine clinical studies of acetylcholinesterase in human brain using positron emission tomography

Production of amino acids - Genetic and metabolic engineering approaches.

Science.gov (United States)

Lee, Jin-Ho; Wendisch, Volker F

2017-12-01

The biotechnological production of amino acids occurs at the million-ton scale and annually about 6milliontons of l-glutamate and l-lysine are produced by Escherichia coli and Corynebacterium glutamicum strains. l-glutamate and l-lysine production from starch hydrolysates and molasses is very efficient and access to alternative carbon sources and new products has been enabled by metabolic engineering. This review focusses on genetic and metabolic engineering of amino acid producing strains. In particular, rational approaches involving modulation of transcriptional regulators, regulons, and attenuators will be discussed. To address current limitations of metabolic engineering, this article gives insights on recent systems metabolic engineering approaches based on functional tools and method such as genome reduction, amino acid sensors based on transcriptional regulators and riboswitches, CRISPR interference, small regulatory RNAs, DNA scaffolding, and optogenetic control, and discusses future prospects. Copyright © 2017 Elsevier Ltd. All rights reserved.

Budesonide and fluticasone propionate differentially affect the airway epithelial barrier

NARCIS (Netherlands)

Heijink, I. H.; Jonker, M.R.; Vries, de Maaike; van Oosterhout, A. J. M.; Telenga, E.; ten Hacken, N. H. T.; Postma, D. S.; van den Berge, M.

2016-01-01

Background: COPD patients have a higher risk of pneumonia when treated with fluticasone propionate (FP) than with placebo, and a lower risk with budesonide (BUD). We hypothesized that BUD and FP differentially affect the mucosal barrier in response to viral infection and/or cigarette smoke. Methods:

DIFFERENCES IN PROPIONATE-INDUCED INHIBITION OF CHOLESTEROL AND TRIACYLGLYCEROL SYNTHESIS BETWEEN HUMAN AND RAT HEPATOCYTES IN PRIMARY CULTURE

NARCIS (Netherlands)

LIN, YG; VONK, RJ; SLOOFF, MJH; KUIPERS, F; SMIT, MJ

Propionate is a short-chain fatty acid formed in the colon and supposedly involved in the cholesterol-lowering effect of soluble fibre. To explore the underlying mechanism(s) of this fibre action, we have used human hepatocytes in primary culture to study the effects of propionate on hepatic lipid

Regioselectively nucleus and/or side-chain fluorinated 2-(Phenanthryl)propionic acids by an effective combination of radical and organometallic chemistry.

Science.gov (United States)

Ricci, Giacomo; Ruzziconi, Renzo

2005-01-21

Regioselectively nucleus and/or side-chain fluorinated 2-(phenanthr-1-yl)- and 2-(phenanthr-2-yl)propionic acids 1-5 were prepared using phenanthren-1(2H)-ones 6a-c as key intermediates. Thus, ethyl 2-(fluorophenanthryl)propionates 11 were obtained in good yields by Reformatsky reaction of 6a-c with ethyl 2-bromopropionate followed by dehydratation and DDQ-promoted aromatization of the resulting beta-hydroxyesters. Side-chain alkyl 2-hydroxy-2-(phenanthr-1-yl)propionates 14 were obtained by bromine/lithium permutation of dihydrophenanthryl bromides 12a-c with butyllithium followed by quenching of the lithiated intermediates with methyl pyruvate or ethyl 3,3,3-trifluoropyruvate and subsequent DDQ-promoted aromatization. The alkyl 2-hydroxy-2-(phenanthr-1-yl)propionates 25 were prepared by reacting 8-bromo-1,3-difluorophenanthrene 24 with butyllithium for 10 seconds at -110 degrees C and subsequent addition of the suitable pyruvate to the lithiated intermediates. Alkyl 2-hydroxy-2-(phenanthr-2-yl)propionates 26 and 29 were suitably obtained by site-selective metalation of 1,3-difluorophenanthrene 28 and the bromophenanthrene 24, respectively, with LDA followed by quenching of the metalated intermediates with the suitable alkyl pyruvate. Fluorination of the above alpha-hydroxypropionates with DAST, followed by the alkaline hydrolysis, allowed the expected 2-(phenanthryl)propionic acids 1-5 to be obtained in satisfactory overall yields.

Synthesis of a cleavable heterobifunctional photolabelling reagent: ring-labelled 3-((4-azidophenyl)dithio)propionic acid- sup 14 C

Energy Technology Data Exchange (ETDEWEB)

Ramaswami, Varadarajan (Carnegie-Mellon Univ., Pittsburgh, PA (USA). Dept. of Chemistry); Tirrell, D.A. (Massachusetts Univ., Amherst, MA (USA). Dept. of Polymer Science and Engineering)

1989-08-01

An efficient synthesis of ring-labelled 3-((4-azidophenyl)dithio)propionic acid-{sup 14}C is described. Chlorosulfonation of uniformly ring-labelled acetanilide-{sup 14}C followed by reductive dimerization of the sulfonyl chloride with HI afforded 4-acetamidophenyl disulfide. Hydrolysis and diazotization then gave 4-azidophenyl disulfide, which was converted to the title compound via the sulfur transfer reagent N-(4-azidophenylthio)phthalimide. The overall yield of 3-((4-azidophenyl)dithio)propionic acid-{sup 14}C was 22%. 3-((4-Azidophenyl)dithio)propionic acid-{sup 14}C is a cleavable heterobifunctional photolabelling reagent of potential utility in studies of biomembrane structure and intermacromolecular interaction. (author).

Using clobetasol propionate in the form of a shampoo for the treatment of patients suffering from psoriasis localized in the scalp area

Directory of Open Access Journals (Sweden)

A. L. Bakulev

2016-01-01

Full Text Available The study involved 80 adult psoriatic patients with scalp affections at the dermatosis progressing stage. The authors compared scalp psoriasis topical treatment options such as using 0.05% clobetasol propionate in the form of a shampoo, and successive administration of the 2% salicylic acid ointment and aforesaid short-term topical product in patients with vulgar or exudative dermatoses using dynamic scores such as mPASI, DLQI and itching intensity degree. It was demonstrated that 0.05% clobetasol propionate used in the form of a shampoo is characterized by a high efficacy and safety profile for patients with vulgar or exudative psoriasis of the scalp. At the same time, in case of exudative dermatosis successive topical treatment with the use of the 2% salicylic acid ointment and 0.05% clobetasol propionate in the form of a shampoo contributes to the clearance of psoriatic foci from accumulated scales and enables a potent topical corticosteroid such as clobetasol to efficiently reduce principal clinical symptoms of scalp psoriasis such as erythema, infiltration, exfoliation and itching. Using the clobetasol shampoo reduces the scalp itching intensity as the key psoriatic symptom preventing an isomorphic reaction as a result of foci traumatization related to scratching.

The role of metabolic engineering in the production of secondary metabolites

DEFF Research Database (Denmark)

Nielsen, Jens Bredal

1998-01-01

In the production of secondary metabolites yield and productivity are the most important design parameters. The focus is therefore to direct the carbon fluxes towards the product of interest, and this can be obtained through metabolic engineering whereby directed genetic changes are introduced...... into the production strain. In this process it is, however, important to analyze the metabolic network through measurement of the intracellular metabolites and the flux distributions. Besides playing an important role in the optimization of existing processes, metabolic engineering also offers the possibility...

Late gestation under- and overnutrition have differential impacts when combined with a post-natal obesogenic diet on glucose-lactate-insulin adaptations during metabolic challenges in adolescent sheep

DEFF Research Database (Denmark)

Khanal, Prabhat; Axel, Anne Marie Dixen; Kongsted, Anna Hauntoft

2015-01-01

AIM: To determine whether late gestation under- and overnutrition programme metabolic plasticity in a similar way, and whether metabolic responses to an obesogenic diet in early post-natal life depend on the foetal nutrition history. METHODS: In a 3 × 2 factorial design, twin-pregnant ewes were......) or conventional (CONV; N = 35) diets from 3 days to 6 months of age (around puberty). Then intravenous glucose (GTT; overnight fasted), insulin (ITT; fed) and propionate (gluconeogenetic precursor; PTT; both fed and fasted) tolerance tests were conducted to evaluate (hepatic) metabolic plasticity. RESULTS......: Prenatal malnutrition differentially impacted adaptations of particularly plasma lactate followed by glucose, cholesterol and insulin. This was most clearly expressed during PTT in fasted lambs and much less during ITT and GTT. In fasted lambs, propionate induced more dramatic increases in lactate than...

THE EFFECT OF METHANOGENIC INHIBITOR FEED ON PROPIONIC ACID AND LAMB MEAT CHEMICAL QUALITY

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E. Suryanto

2012-09-01

Full Text Available This study aimed to determine the effect of medium chain fatty acids (MCFA on propionic acids and lamb meat chemical quality. The treatment given was R1: feed without medium chain fatty acids (MCFA, while R2 dan R3 were the feed contained 1.0% and 1.5% of MCFA, respectively. The twelve heads of lambs yearling weight of 16-17 kg were used as materials. Biological trial was done for three months and then was slaughtered. Before being slaughtered, the animal was taken rumen fluid to be analyzed for propionic acid. The carcass was sampled to be analyzed for chemical composition, cholesterol and fatty acids content. This study showed that methanogenic inhibitor feed with 1.0-1.5% MCFA could be used as sheep feed, and the results: the propionic acid content in rumen increased 29.59 – 36.11%. The cholesterol content decreased 7.14-10.06%. For the meat fatty acids composition, unsaturated fatty acids increased 9.05 – 17.96%. while saturated fatty acid decreased 6.59 – 11.88%.

Enhanced biological phosphorus removal in a sequencing batch reactor using propionate as the sole carbon source.

Science.gov (United States)

Pijuan, M; Saunders, A M; Guisasola, A; Baeza, J A; Casas, C; Blackall, L L

2004-01-05

An enhanced biological phosphorus removal (EBPR) system was developed in a sequencing batch reactor (SBR) using propionate as the sole carbon source. The microbial community was followed using fluorescence in situ hybridization (FISH) techniques and Candidatus 'Accumulibacter phosphatis' were quantified from the start up of the reactor until steady state. A series of SBR cycle studies was performed when 55% of the SBR biomass was Accumulibacter, a confirmed polyphosphate accumulating organism (PAO) and when Candidatus 'Competibacter phosphatis', a confirmed glycogen-accumulating organism (GAO), was essentially undetectable. These experiments evaluated two different carbon sources (propionate and acetate), and in every case, two different P-release rates were detected. The highest rate took place while there was volatile fatty acid (VFA) in the mixed liquor, and after the VFA was depleted a second P-release rate was observed. This second rate was very similar to the one detected in experiments performed without added VFA.A kinetic and stoichiometric model developed as a modification of Activated Sludge Model 2 (ASM2) including glycogen economy, was fitted to the experimental profiles. The validation and calibration of this model was carried out with the cycle study experiments performed using both VFAs. The effect of pH from 6.5 to 8.0 on anaerobic P-release and VFA-uptake and aerobic P-uptake was also studied using propionate. The optimal overall working pH was around 7.5. This is the first study of the microbial community involved in EBPR developed with propionate as a sole carbon source along with detailed process performance investigations of the propionate-utilizing PAOs. Copyright 2003 Wiley Periodicals, Inc.

Agglomerate behaviour of fluticasone propionate within dry powder inhaler formulations.

Science.gov (United States)

Le, V N P; Robins, E; Flament, M P

2012-04-01

Due to their small size, the respirable drug particles tend to form agglomerates which prevent flowing and aerosolisation. A carrier is used to be mixed with drug in one hand to facilitate the powder flow during manufacturing, in other hand to help the fluidisation upon patient inhalation. Depending on drug concentration, drug agglomerates can be formed in the mixture. The aim of this work was to study the agglomeration behaviour of fluticasone propionate (FP) within interactive mixtures for inhalation. The agglomerate phenomenon of fluticasone propionate after mixing with different fractions of lactose without fine particles of lactose (smaller than 32 μm) was demonstrated by the optical microscopy observation. A technique measuring the FP size in the mixture was developed, based on laser diffraction method. The FP agglomerate sizes were found to be in a linear correlation with the pore size of the carrier powder bed (R(2)=0.9382). The latter depends on the particle size distribution of carrier. This founding can explain the role of carrier size in de-agglomeration of drug particles in the mixture. Furthermore, it gives more structural information of interactive mixture for inhalation that can be used in the investigation of aerosolisation mechanism of powder. According to the manufacturing history, different batches of FP show different agglomeration intensities which can be detected by Spraytec, a new laser diffraction method for measuring aerodynamic size. After mixing with a carrier, Lactohale LH200, the most cohesive batch of FP, generates a lower fine particle fraction. It can be explained by the fact that agglomerates of fluticasone propionate with very large size was detected in the mixtures. By using silica-gel beads as ball-milling agent during the mixing process, the FP agglomerate size decreases accordingly to the quantity of mixing aid. The homogeneity and the aerodynamic performance of the mixtures are improved. The mixing aid based on ball

Propionic acid secreted from propionibacteria induces NKG2D ligand expression on human-activated T lymphocytes and cancer cells

DEFF Research Database (Denmark)

Andresen, Lars; Hansen, Karen Aagaard; Jensen, Helle

2009-01-01

We found that propionic acid secreted from propionibacteria induces expression of the NKG2D ligands MICA/B on activated T lymphocytes and different cancer cells, without affecting MICA/B expression on resting peripheral blood cells. Growth supernatant from propionibacteria or propionate alone cou...

Isolation of acetic, propionic and butyric acid-forming bacteria from biogas plants.

Science.gov (United States)

Cibis, Katharina Gabriela; Gneipel, Armin; König, Helmut

2016-02-20

In this study, acetic, propionic and butyric acid-forming bacteria were isolated from thermophilic and mesophilic biogas plants (BGP) located in Germany. The fermenters were fed with maize silage and cattle or swine manure. Furthermore, pressurized laboratory fermenters digesting maize silage were sampled. Enrichment cultures for the isolation of acid-forming bacteria were grown in minimal medium supplemented with one of the following carbon sources: Na(+)-dl-lactate, succinate, ethanol, glycerol, glucose or a mixture of amino acids. These substrates could be converted by the isolates to acetic, propionic or butyric acid. In total, 49 isolates were obtained, which belonged to the phyla Firmicutes, Tenericutes or Thermotogae. According to 16S rRNA gene sequences, most isolates were related to Clostridium sporosphaeroides, Defluviitoga tunisiensis and Dendrosporobacter quercicolus. Acetic, propionic or butyric acid were produced in cultures of isolates affiliated to Bacillus thermoamylovorans, Clostridium aminovalericum, Clostridium cochlearium/Clostridium tetani, C. sporosphaeroides, D. quercicolus, Proteiniborus ethanoligenes, Selenomonas bovis and Tepidanaerobacter sp. Isolates related to Thermoanaerobacterium thermosaccharolyticum produced acetic, butyric and lactic acid, and isolates related to D. tunisiensis formed acetic acid. Specific primer sets targeting 16S rRNA gene sequences were designed and used for real-time quantitative PCR (qPCR). The isolates were physiologically characterized and their role in BGP discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

Metabolic engineering of microalgal based biofuel production: prospects and challenges

Directory of Open Access Journals (Sweden)

Chiranjib eBanerjee

2016-03-01

Full Text Available The current scenario in renewable energy is focused on development of alternate and sustainable energy sources, amongst which microalgae stands as one of the promising feedstock for biofuel production. It is well known that microalgae generate much larger amounts of biofuels in a shorter time than other sources based on plant seeds. However, the greatest challenge in a transition to algae-based biofuel production is the various other complications involved in microalgal cultivation, its harvesting, concentration, drying and lipid extraction. Several green microalgae accumulate lipids, especially triacylglycerols (TAGs, which are main precursors in the production of lipid. The various aspects on metabolic pathway analysis of an oleaginous microalgae i.e. Chlamydomonas reinhardtii have elucidated some novel metabolically important genes and this enhances the lipid production in this microalgae. Adding to it, various other aspects in metabolic engineering using OptFlux and effectual bioprocess design also gives an interactive snapshot of enhancing lipid production which ultimately improvises the oil yield. This article reviews the current status of microalgal based technologies for biofuel production, bioreactor process design, flux analysis and it also provides various strategies to increase lipids accumulation via metabolic engineering.

Activation of Short and Long Chain Fatty Acid Sensing Machinery in the Ileum Lowers Glucose Production in Vivo.

Science.gov (United States)

Zadeh-Tahmasebi, Melika; Duca, Frank A; Rasmussen, Brittany A; Bauer, Paige V; Côté, Clémence D; Filippi, Beatrice M; Lam, Tony K T

2016-04-15

Evidence continues to emerge detailing the myriad of ways the gut microbiota influences host energy homeostasis. Among the potential mechanisms, short chain fatty acids (SCFAs), the byproducts of microbial fermentation of dietary fibers, exhibit correlative beneficial metabolic effects in humans and rodents, including improvements in glucose homeostasis. The underlying mechanisms, however, remain elusive. We here report that one of the main bacterially produced SCFAs, propionate, activates ileal mucosal free fatty acid receptor 2 to trigger a negative feedback pathway to lower hepatic glucose production in healthy rats in vivo We further demonstrate that an ileal glucagon-like peptide-1 receptor-dependent neuronal network is necessary for ileal propionate and long chain fatty acid sensing to regulate glucose homeostasis. These findings highlight the potential to manipulate fatty acid sensing machinery in the ileum to regulate glucose homeostasis. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Chromium supplementation alters both glucose and lipid metabolism in feedlot cattle during the receiving period

Science.gov (United States)

Crossbred steers (n = 20; 235 +/- 4 kg) were fed 53 days during a receiving period to determine if supplementing chromium (Cr; KemTRACE®brandChromium Propionate 0.04%, Kemin Industries) would alter the glucose or lipid metabolism of newly received cattle. Chromium premixes were supplemented to add 0...

Gastrointestinal Simulation Model TWIN-SHIME Shows Differences between Human Urolithin-Metabotypes in Gut Microbiota Composition, Pomegranate Polyphenol Metabolism, and Transport along the Intestinal Tract.

Science.gov (United States)

García-Villalba, Rocío; Vissenaekens, Hanne; Pitart, Judit; Romo-Vaquero, María; Espín, Juan C; Grootaert, Charlotte; Selma, María V; Raes, Katleen; Smagghe, Guy; Possemiers, Sam; Van Camp, John; Tomas-Barberan, Francisco A

2017-07-12

A TWIN-SHIME system was used to compare the metabolism of pomegranate polyphenols by the gut microbiota from two individuals with different urolithin metabotypes. Gut microbiota, ellagitannin metabolism, short-chain fatty acids (SCFA), transport of metabolites, and phase II metabolism using Caco-2 cells were explored. The simulation reproduced the in vivo metabolic profiles for each metabotype. The study shows for the first time that microbial composition, metabolism of ellagitannins, and SCFA differ between metabotypes and along the large intestine. The assay also showed that pomegranate phenolics preserved intestinal cell integrity. Pomegranate polyphenols enhanced urolithin and propionate production, as well as Akkermansia and Gordonibacter prevalence with the highest effect in the descending colon. The system provides an insight into the mechanisms of pomegranate polyphenol gut microbiota metabolism and absorption through intestinal cells. The results obtained by the combined SHIME/Caco-2 cell system are consistent with previous human and animal studies and show that although urolithin metabolites are present along the gastrointestinal tract due to enterohepatic circulation, they are predominantly produced in the distal colon region.

Changes in gut microbiota in rats fed a high fat diet correlate with obesity-associated metabolic parameters.

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Virginie Lecomte

Full Text Available The gut microbiota is emerging as a new factor in the development of obesity. Many studies have described changes in microbiota composition in response to obesity and high fat diet (HFD at the phylum level. In this study we used 16s RNA high throughput sequencing on faecal samples from rats chronically fed HFD or control chow (n = 10 per group, 16 weeks to investigate changes in gut microbiota composition at the species level. 53.17% dissimilarity between groups was observed at the species level. Lactobacillus intestinalis dominated the microbiota in rats under the chow diet. However this species was considerably less abundant in rats fed HFD (P<0.0001, this being compensated by an increase in abundance of propionate/acetate producing species. To further understand the influence of these species on the development of the obese phenotype, we correlated their abundance with metabolic parameters associated with obesity. Of the taxa contributing the most to dissimilarity between groups, 10 presented significant correlations with at least one of the tested parameters, three of them correlated positively with all metabolic parameters: Phascolarctobacterium, Proteus mirabilis and Veillonellaceae, all propionate/acetate producers. Lactobacillus intestinalis was the only species whose abundance was negatively correlated with change in body weight and fat mass. This species decreased drastically in response to HFD, favouring propionate/acetate producing bacterial species whose abundance was strongly correlated with adiposity and deterioration of metabolic factors. Our observations suggest that these species may play a key role in the development of obesity in response to a HFD.

Metabolic and microbial community dynamics during the hydrolytic and acidogenic fermentation in a leach-bed process

Energy Technology Data Exchange (ETDEWEB)

Straeuber, Heike; Kleinsteuber, Sabine [UFZ - Helmholtz Centre for Environmental Research, Leipzig (Germany). Dept. of Bioenergy; UFZ - Helmholtz Centre for Environmental Research, Leipzig (Germany). Dept. of Environmental Microbiology; Schroeder, Martina [UFZ - Helmholtz Centre for Environmental Research, Leipzig (Germany). Dept. of Bioenergy

2012-12-15

Biogas production from lignocellulosic feedstock not competing with food production can contribute to a sustainable bioenergy system. The hydrolysis is the rate-limiting step in the anaerobic digestion of solid substrates such as straw. Hence, a detailed understanding of the metabolic processes during the steps of hydrolysis and acidogenesis is required to improve process control strategies. The fermentation products formed during the acidogenic fermentation of maize silage as a model substrate in a leach-bed process were determined by gas and liquid chromatography. The bacterial community dynamics was monitored by terminal restriction fragment length polymorphism analysis. The community profiles were correlated with the process data using multivariate statistics. The batch process comprised three metabolic phases characterized by different fermentation products. The bacterial community dynamics correlated with the production of the respective metabolites. In phase 1, lactic and acetic acid fermentations dominated. Accordingly, bacteria of the genera Lactobacillus and Acetobacter were detected. In phase 2, the metabolic pathways shifted to butyric acid fermentation, accompanied by the production of hydrogen and carbon dioxide and a dominance of the genus Clostridium. In phase 3, phylotypes affiliated with Ruminococcaceae and Lachnospiraceae prevailed, accompanied by the formation of caproic and acetic acids, and a high gas production rate. A clostridial butyric type of fermentation was predominant in the acidogenic fermentation of maize silage, whereas propionic-type fermentation was marginal. As the metabolite composition resulting from acidogenesis affects the subsequent methanogenic performance, process control should focus on hydrolysis/acidogenesis when solid substrates are digested. (orig.)

Effects of hydrogen and formate on the degradation of propionate and butyrate in thermophilic granules from an upflow anaerobic sludge blanket reactor.

OpenAIRE

Schmidt, J E; Ahring, B K

1993-01-01

Degradation of propionate and butyrate in whole and disintegrated granules from a thermophilic (55 degrees C) upflow anaerobic sludge blanket reactor fed with acetate, propionate, and butyrate as substrates was examined. The propionate and butyrate degradation rates in whole granules were 1.16 and 4.0 mumol/min/g of volatile solids, respectively, and the rates decreased 35 and 25%, respectively, after disintegration of the granules. The effect of adding different hydrogen-oxidizing bacteria (...

Metabolic engineering of Escherichia coli for production of mixed-acid fermentation end products

Directory of Open Access Journals (Sweden)

Andreas Hartmut Förster

2014-05-01

Full Text Available Mixed-acid fermentation end products have numerous applications in biotechnology. This is probably the main driving force for the development of multiple strains that are supposed to produce individual end products with high yields. The process of engineering Escherichia coli strains for applied production of ethanol, lactate, succinate, or acetate was initiated several decades ago and is still ongoing. This review follows the path of strain development from the general characteristics of aerobic versus anaerobic metabolism over the regulatory machinery that enables the different metabolic routes. Thereafter, major improvements for broadening the substrate spectrum of Escherichia coli towards cheap carbon sources like molasses or lignocellulose are highlighted before major routes of strain development for the production of ethanol, acetate, lactate and succinate are presented.

Genome-scale metabolic analysis of Clostridium thermocellum for bioethanol production

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Brooks J Paul

2010-03-01

Full Text Available Abstract Background Microorganisms possess diverse metabolic capabilities that can potentially be leveraged for efficient production of biofuels. Clostridium thermocellum (ATCC 27405 is a thermophilic anaerobe that is both cellulolytic and ethanologenic, meaning that it can directly use the plant sugar, cellulose, and biochemically convert it to ethanol. A major challenge in using microorganisms for chemical production is the need to modify the organism to increase production efficiency. The process of properly engineering an organism is typically arduous. Results Here we present a genome-scale model of C. thermocellum metabolism, iSR432, for the purpose of establishing a computational tool to study the metabolic network of C. thermocellum and facilitate efforts to engineer C. thermocellum for biofuel production. The model consists of 577 reactions involving 525 intracellular metabolites, 432 genes, and a proteomic-based representation of a cellulosome. The process of constructing this metabolic model led to suggested annotation refinements for 27 genes and identification of areas of metabolism requiring further study. The accuracy of the iSR432 model was tested using experimental growth and by-product secretion data for growth on cellobiose and fructose. Analysis using this model captures the relationship between the reduction-oxidation state of the cell and ethanol secretion and allowed for prediction of gene deletions and environmental conditions that would increase ethanol production. Conclusions By incorporating genomic sequence data, network topology, and experimental measurements of enzyme activities and metabolite fluxes, we have generated a model that is reasonably accurate at predicting the cellular phenotype of C. thermocellum and establish a strong foundation for rational strain design. In addition, we are able to draw some important conclusions regarding the underlying metabolic mechanisms for observed behaviors of C. thermocellum

Synthesis of 1-[{sup 11}c]methylpiperidin-4-yl propionate ([{sup 11}c]pmp) for in vivo measurements of acetylcholinesterase activity

Energy Technology Data Exchange (ETDEWEB)

Snyder, Scott E. E-mail: snyderse@umich.edu; Tluczek, Louis; Jewett, Douglas M.; Nguyen, Thinh B.; Kuhl, David E.; Kilbourn, Michael R

1998-11-01

Synthesis of 1-[{sup 11}C]methylpiperidin-4-yl propionate ([{sup 11}C]PMP), an in vivo substrate for acetylcholinesterase, is reported. An improved preparation of 4-piperidinyl propionate (PHP), the immediate precursor for radiolabeling, was accomplished in three steps from 4-hydroxypiperidine by (a) protection of the amine as the benzyl carbamate, (b) acylation with propionyl chloride, and (c) deprotection of the carbamate by catalytic hydrogenation. The final product was obtained in an overall 82% yield. Reaction of the free base form of PHP with [{sup 11}C]methyl trifluoromethanesulfonate at room temperature in N,N-dimethylformamide, followed by high performance liquid chromatography (HPLC) purification, provided [{sup 11}C]PMP in 57% radiochemical yield, >99% radiochemical purity, and >1500 Ci/mmol at the end of synthesis. The total synthesis time from end-of-bombardment was 35 min. [{sup 11}C]PMP can thus be reliably prepared for routine clinical studies of acetylcholinesterase in human brain using positron emission tomography.

Syntrophic butyrate and propionate oxidation processes: from genomes to reaction mechanisms

NARCIS (Netherlands)

Müller, N.; Worm, P.; Schink, B.; Stams, A.J.M.; Plugge, C.M.

2010-01-01

In anoxic environments such as swamps, rice fields and sludge digestors, syntrophic microbial communities are important for decomposition of organic matter to CO2 and CH4. The most difficult step is the fermentative degradation of short-chain fatty acids such as propionate and butyrate. Conversion

Chromium supplementation alters the glucose and lipid metabolism of feedlot cattle during the receiving period

Science.gov (United States)

Crossbreed steers (n = 20; 235 ± 4 kg) were fed 53 d during a receiving period to determine if supplementing chromium (Cr; KemTRACE®brand Chromium Propionate 0.04%, Kemin Industries) would alter the glucose or lipid metabolism of newly received cattle. Chromium premixes were supplemented to add 0 (C...

Treatment of scalp psoriasis with clobetasol-17 propionate 0.05% shampoo: a study on daily clinical practice.

Science.gov (United States)

Bovenschen, H J; Van de Kerkhof, P C M

2010-04-01

Safety and clinical effectiveness of clobetasol-17 propionate 0.05% shampoo have been shown in patients with scalp psoriasis. First, to evaluate treatment satisfaction, user convenience safety and effectiveness of clobetasol-17 propionate 0.05% shampoo treatment in daily clinical practice. Second, to identify subgroup variables that may predict treatment success or failure. A total of 56 patients with scalp psoriasis were treated with short-contact clobetasol-17 propionate 0.05% shampoo once daily for 4 weeks. Data on treatment satisfaction, user convenience, safety and effectiveness were assessed on a 7-point Likert scale using postal questionnaires. Subgroup analyses were performed to identify variables that may predict treatment outcome. A total of 41 patients returned both questionnaires (73%). Positive treatment satisfaction and user convenience were reported by 66% and 79% of patients respectively. Patient-rated indicators for disease severity improved by 39-46% (P 0.05). Short-contact treatment with clobetasol-17 propionate 0.05% shampoo has high user convenience and patient satisfaction rates. Moreover, the treatment is well-tolerated and efficacious from patients' perspective. Subgroup analyses did not reveal factors predicting treatment outcome, although treatment success tended to be more evident in patients who had received fewer treatments previously.

Anaerobic Fermentation for Production of Carboxylic Acids as Bulk Chemicals from Renewable Biomass.

Science.gov (United States)

Wang, Jufang; Lin, Meng; Xu, Mengmeng; Yang, Shang-Tian

Biomass represents an abundant carbon-neutral renewable resource which can be converted to bulk chemicals to replace petrochemicals. Carboxylic acids have wide applications in the chemical, food, and pharmaceutical industries. This chapter provides an overview of recent advances and challenges in the industrial production of various types of carboxylic acids, including short-chain fatty acids (acetic, propionic, butyric), hydroxy acids (lactic, 3-hydroxypropionic), dicarboxylic acids (succinic, malic, fumaric, itaconic, adipic, muconic, glucaric), and others (acrylic, citric, gluconic, pyruvic) by anaerobic fermentation. For economic production of these carboxylic acids as bulk chemicals, the fermentation process must have a sufficiently high product titer, productivity and yield, and low impurity acid byproducts to compete with their petrochemical counterparts. System metabolic engineering offers the tools needed to develop novel strains that can meet these process requirements for converting biomass feedstock to the desirable product.

Quantification of in Vivo Colonic Short Chain Fatty Acid Production from Inulin.

Science.gov (United States)

Boets, Eef; Deroover, Lise; Houben, Els; Vermeulen, Karen; Gomand, Sara V; Delcour, Jan A; Verbeke, Kristin

2015-10-28

Short chain fatty acids (SCFA), including acetate, propionate, and butyrate, are produced during bacterial fermentation of undigested carbohydrates in the human colon. In this study, we applied a stable-isotope dilution method to quantify the in vivo colonic production of SCFA in healthy humans after consumption of inulin. Twelve healthy subjects performed a test day during which a primed continuous intravenous infusion with [1-(13)C]acetate, [1-(13)C]propionate and [1-(13)C]butyrate (12, 1.2 and 0.6 μmol·kg(-1)·min(-1), respectively) was applied. They consumed 15 g of inulin with a standard breakfast. Breath and blood samples were collected at regular times during the day over a 12 h period. The endogenous rate of appearance of acetate, propionate, and butyrate was 13.3 ± 4.8, 0.27 ± 0.09, and 0.28 ± 0.12 μmol·kg(-1)·min(-1), respectively. Colonic inulin fermentation was estimated to be 137 ± 75 mmol acetate, 11 ± 9 mmol propionate, and 20 ± 17 mmol butyrate over 12 h, assuming that 40%, 10%, and 5% of colonic derived acetate, propionate, and butyrate enter the systemic circulation. In conclusion, inulin is mainly fermented into acetate and, to lesser extents, into butyrate and propionate. Stable isotope technology allows quantifying the production of the three main SCFA in vivo and proved to be a practical tool to investigate the extent and pattern of SCFA production.

Lipid and fatty acid metabolism in Ralstonia eutropha: relevance for the biotechnological production of value-added products.

Science.gov (United States)

Riedel, Sebastian L; Lu, Jingnan; Stahl, Ulf; Brigham, Christopher J

2014-02-01

Lipid and fatty acid metabolism has been well studied in model microbial organisms like Escherichia coli and Bacillus subtilis. The major precursor of fatty acid biosynthesis is also the major product of fatty acid degradation (β-oxidation), acetyl-CoA, which is a key metabolite for all organisms. Controlling carbon flux to fatty acid biosynthesis and from β-oxidation allows for the biosynthesis of natural products of biotechnological importance. Ralstonia eutropha can utilize acetyl-CoA from fatty acid metabolism to produce intracellular polyhydroxyalkanoate (PHA). R. eutropha can also be engineered to utilize fatty acid metabolism intermediates to produce different PHA precursors. Metabolism of lipids and fatty acids can be rerouted to convert carbon into other value-added compounds like biofuels. This review discusses the lipid and fatty acid metabolic pathways in R. eutropha and how they can be used to construct reagents for the biosynthesis of products of industrial importance. Specifically, how the use of lipids or fatty acids as the sole carbon source in R. eutropha cultures adds value to these biotechnological products will be discussed here.

Inherited metabolic disorders in Thailand.

Science.gov (United States)

Wasant, Pornswan; Svasti, Jisnuson; Srisomsap, Chantragan; Liammongkolkul, Somporn

2002-08-01

The study of inborn errors of metabolism (IEM) in Thailand is in its infancy. The majority are clinically diagnosed since there are only a handful of clinicians and scientists with expertise in inherited metabolic disorders, shortage of well-equipped laboratory facilities and lack of governmental financial support. Genetic metabolic disorders are usually not considered a priority due to prevalence of infectious diseases and congenital infections. From a retrospective study at the Medical Genetics Unit, Department of Pediatrics, Siriraj Hospital; estimated pediatrics patients with suspected IEM were approximately 2-3 per cent of the total pediatric admissions of over 5,000 annually. After more than 10 years of research and accumulated clinical experiences, a genetic metabolic center is being established in collaboration with expert laboratories both in Bangkok (Chulabhorn Research Institute) and abroad (Japan and the United States). Numerous inherited metabolic disorders were identified--carbohydrate, amino acids, organic acids, mitochondrial fatty acid oxidation, peroxisomal, mucopolysaccharidoses etc. This report includes the establishment of genetic metabolic center in Thailand, research and pilot studies in newborn screening in Thailand and a multicenter study from 5 institutions (Children's National Center, King Chulalongkorn Memorial Hospital, Pramongkutklao Hospital, Ramathibodi and Siriraj Hospitals). Inherited metabolic disorders reported are fructose-1,6-bisphosphatase deficiency, phenylketonuria, homocystinuria, nonketotic hyperglycinemia, urea cycle defect (arginino succinate lyase deficiency, argininosuccinate synthetase deficiency), Menkes disease, propionic acidemia and mucopolysaccharidoses (Hurler, Hurler-Scheie).

Metabolic interactions in methanogenic and sulfate-reducing bioreactors.

Science.gov (United States)

Stams, A J M; Plugge, C M; de Bok, F A M; van Houten, B H G W; Lens, P; Dijkman, H; Weijma, J

2005-01-01

In environments where the amount of electron acceptors is insufficient for complete breakdown of organic matter, methane is formed as the major reduced end product. In such methanogenic environments organic acids are degraded by syntrophic consortia of acetogenic bacteria and methanogenic archaea. Hydrogen consumption by methanogens is essential for acetogenic bacteria to convert organic acids to acetate and hydrogen. Several syntrophic cocultures growing on propionate and butyrate have been described. These syntrophic fatty acid-degrading consortia are affected by the presence of sulfate. When sulfate is present sulfate-reducing bacteria compete with methanogenic archaea for hydrogen and acetate, and with acetogenic bacteria for propionate and butyrate. Sulfate-reducing bacteria easily outcompete methanogens for hydrogen, but the presence of acetate as carbon source may influence the outcome of the competition. By contrast, acetoclastic methanogens can compete reasonably well with acetate-degrading sulfate reducers. Sulfate-reducing bacteria grow much faster on propionate and butyrate than syntrophic consortia.

Modeling of fermentative hydrogen production from sweet sorghum extract based on modified ADM1

DEFF Research Database (Denmark)

Antonopoulou, Georgia; Gavala, Hariklia N.; Skiadas, Ioannis

2012-01-01

The Anaerobic digestion model 1 (ADM1) framework can be used to predict fermentative hydrogen production, since the latter is directly related to the acidogenic stage of the anaerobic digestion process. In this study, the ADM1 model framework was used to simulate and predict the process...... used for kinetic parameter validation. Since the ADM1 does not account for metabolic products such as lactic acid and ethanol that are crucial during the fermentative hydrogen production process, the structure of the model was modified to include lactate and ethanol among the metabolites and to improve...... of fermentative hydrogen production from the extractable sugars of sweet sorghum biomass. Kinetic parameters for sugars’ consumption and yield coefficients of acetic, propionic and butyric acid production were estimated using the experimental data obtained from the steady states of a CSTR. Batch experiments were...

Metabolic engineering approaches for production of biochemicals in food and medicinal plants.

Science.gov (United States)

Wilson, Sarah A; Roberts, Susan C

2014-04-01

Historically, plants are a vital source of nutrients and pharmaceuticals. Recent advances in metabolic engineering have made it possible to not only increase the concentration of desired compounds, but also introduce novel biosynthetic pathways to a variety of species, allowing for enhanced nutritional or commercial value. To improve metabolic engineering capabilities, new transformation techniques have been developed to allow for gene specific silencing strategies or stacking of multiple genes within the same region of the chromosome. The 'omics' era has provided a new resource for elucidation of uncharacterized biosynthetic pathways, enabling novel metabolic engineering approaches. These resources are now allowing for advanced metabolic engineering of plant production systems, as well as the synthesis of increasingly complex products in engineered microbial hosts. The status of current metabolic engineering efforts is highlighted for the in vitro production of paclitaxel and the in vivo production of β-carotene in Golden Rice and other food crops. Copyright © 2014 Elsevier Ltd. All rights reserved.

Improving lactate metabolism in an intensified CHO culture process: productivity and product quality considerations.

Science.gov (United States)

Xu, Sen; Hoshan, Linda; Chen, Hao

2016-11-01

In this study, we discussed the development and optimization of an intensified CHO culture process, highlighting medium and control strategies to improve lactate metabolism. A few strategies, including supplementing glucose with other sugars (fructose, maltose, and galactose), controlling glucose level at Productivity and product quality attributes differences between batch, fed-batch, and concentrated fed-batch cultures were discussed. The importance of process and cell metabolism understanding when adapting the existing process to a new operational mode was demonstrated in the study.

Metabolic engineering of biosynthetic pathway for production of renewable biofuels.

Science.gov (United States)

Singh, Vijai; Mani, Indra; Chaudhary, Dharmendra Kumar; Dhar, Pawan Kumar

2014-02-01

Metabolic engineering is an important area of research that involves editing genetic networks to overproduce a certain substance by the cells. Using a combination of genetic, metabolic, and modeling methods, useful substances have been synthesized in the past at industrial scale and in a cost-effective manner. Currently, metabolic engineering is being used to produce sufficient, economical, and eco-friendly biofuels. In the recent past, a number of efforts have been made towards engineering biosynthetic pathways for large scale and efficient production of biofuels from biomass. Given the adoption of metabolic engineering approaches by the biofuel industry, this paper reviews various approaches towards the production and enhancement of renewable biofuels such as ethanol, butanol, isopropanol, hydrogen, and biodiesel. We have also identified specific areas where more work needs to be done in the future.

Characterization of a bioflocculant produced by Citrobacter sp. TKF04 from acetic and propionic acids.

Science.gov (United States)

Fujita, M; Ike, M; Tachibana, S; Kitada, G; Kim, S M; Inoue, Z

2000-01-01

A bacterial strain, TKF04, capable of producing a bioflocculant from acetic and/or propionic acids was isolated from a biofilm formed in inside a kitchen drain. It was identified as a Citrobacter based on its morphological and physiological characteristics and the partial sequences of its 16S rRNA. TKF04 produced the bioflocculant during the logarithmic phase of growth, and the optimum temperature and pH for the bioflocculant production were 30 degrees C and 7.2-10.0, respectively. It could utilize some organic acids and sugars for its growth as the sole carbon sources when yeast extract was supplemented; however, only acetate and propionate were found to be good substrates for the bioflocculant production. The crude bioflocculant could be recovered from the supernatant of the culture broth by ethanol precipitation and dialysis against deionized water. It was found to be effective for flocculation of a kaolin suspension, when added at a final concentration of 1-10 mg/l, over a wide range of pHs (2-8) and temperatures (approximately 3-95 degrees C), while the co-presence of cations (Na+, K+, Ca2+, Mg2+, Fe2+, Al3+ or Fe3+) did not enhance the flocculating activity. It could efficiently flocculate a variety of inorganic and organic suspended particles, including kaolin, diatomite, bentonite, activated carbon, soil and activated sludge. It contained glucosamine as the major component, and the molecular weight was estimated to be between 232 and 440 kDa by gel filtration. The observation that the flocculating activity was completely lost following chitinase treatment and its analysis with a Fourier transform infrared spectrometer suggested that the bioflocculant is a biopolymer structurally-similar to chitin or chitosan.

Production of L-carnitine by secondary metabolism of bacteria

Directory of Open Access Journals (Sweden)

Iborra José L

2007-10-01

Full Text Available Abstract The increasing commercial demand for L-carnitine has led to a multiplication of efforts to improve its production with bacteria. The use of different cell environments, such as growing, resting, permeabilized, dried, osmotically stressed, freely suspended and immobilized cells, to maintain enzymes sufficiently active for L-carnitine production is discussed in the text. The different cell states of enterobacteria, such as Escherichia coli and Proteus sp., which can be used to produce L-carnitine from crotonobetaine or D-carnitine as substrate, are analyzed. Moreover, the combined application of both bioprocess and metabolic engineering has allowed a deeper understanding of the main factors controlling the production process, such as energy depletion and the alteration of the acetyl-CoA/CoA ratio which are coupled to the end of the biotransformation. Furthermore, the profiles of key central metabolic activities such as the TCA cycle, the glyoxylate shunt and the acetate metabolism are seen to be closely interrelated and affect the biotransformation efficiency. Although genetically modified strains have been obtained, new strain improvement strategies are still needed, especially in Escherichia coli as a model organism for molecular biology studies. This review aims to summarize and update the state of the art in L-carnitine production using E. coli and Proteus sp, emphasizing the importance of proper reactor design and operation strategies, together with metabolic engineering aspects and the need for feed-back between wet and in silico work to optimize this biotransformation.

Automated Screening for Three Inborn Metabolic Disorders: A Pilot Study

Directory of Open Access Journals (Sweden)

Kavitha S

2006-12-01

Full Text Available Background: Inborn metabolic disorders (IMDs form a large group of rare, but often serious, metabolic disorders. Aims: Our objective was to construct a decision tree, based on classification algorithm for the data on three metabolic disorders, enabling us to take decisions on the screening and clinical diagnosis of a patient. Settings and Design: A non-incremental concept learning classification algorithm was applied to a set of patient data and the procedure followed to obtain a decision on a patient’s disorder. Materials and Methods: Initially a training set containing 13 cases was investigated for three inborn errors of metabolism. Results: A total of thirty test cases were investigated for the three inborn errors of metabolism. The program identified 10 cases with galactosemia, another 10 cases with fructosemia and the remaining 10 with propionic acidemia. The program successfully identified all the 30 cases. Conclusions: This kind of decision support systems can help the healthcare delivery personnel immensely for early screening of IMDs.

The development and microbiology of bioprocesses for the production of hydrogen and ethanol by dark fermentation

Energy Technology Data Exchange (ETDEWEB)

Koskinen, P.

2008-07-01

This work investigated the production of hydrogen and ethanol from carbohydrates by bacterial dark fermentation. Meso and thermophilic fermenters were enriched from the environment, and their H{sub 2} and/or ethanol production in batch determined. Continuous biofilm, suspended-cell and granular-cell processes for H{sub 2} or ethanol+H{sub 2} production from glucose were developed and studied. Dynamics of microbial communities in processes were determined based on the 16S rRNA gene sequence analyses. Mesophilic enrichment, obtained from anaerobic digester sludge, produced 1.24 mol-H{sub 2} mol-glucose-1 in batch assays. Hydrogen production by the enrichment in a mesophilic fluidized-bed bioreactor (FBR) was found to be unstable - prompt onset of H{sub 2} production along with butyrate-acetate was followed by rapid decrease and cease associated with propionate-acetate production. Intermittent batch (semi-continuous) operation allowed a momentary recovery of H{sub 2} production in the FBR. The highest H{sub 2} production rate (HPR) observed in FBR was 28.8 mmol h-1 L-1, which corresponded to a relatively high hydrogen yield (HY) of 1.90 mol-H{sub 2} mol-glucose-1. Mesophilic, completely-mixed column reactor (CMCR), with a similar inoculum and feed as used in the FBR, provided a prolonged H{sub 2} production for 5 months. Highest HPR observed in the CMCR was 18.8 mmol h-1 L-1 (HY of 1.70 mol-H{sub 2} mol-glucose-1), while it in general remained between 1 and 6 mmol h-1 L-1. Hydrogen production in the CMCR was decreased by shifts in microbial community metabolism from initial butyrate-acetate metabolism, first to ethanol-acetate, followed by acetate-dominated metabolism, and finally to propionate-acetate metabolism, which ceased H{sub 2} production. The transitions of dominant metabolisms were successfully detected and visualized by self-organizing maps (SOMs). Developed Clustering hybrid regression (CHR) model, performed well in modeling the HPR based on the data on

Quantification of in Vivo Colonic Short Chain Fatty Acid Production from Inulin

Directory of Open Access Journals (Sweden)

Eef Boets

2015-10-01

Full Text Available Short chain fatty acids (SCFA, including acetate, propionate, and butyrate, are produced during bacterial fermentation of undigested carbohydrates in the human colon. In this study, we applied a stable-isotope dilution method to quantify the in vivo colonic production of SCFA in healthy humans after consumption of inulin. Twelve healthy subjects performed a test day during which a primed continuous intravenous infusion with [1-13C]acetate, [1-13C]propionate and [1-13C]butyrate (12, 1.2 and 0.6 μmol·kg−1·min−1, respectively was applied. They consumed 15 g of inulin with a standard breakfast. Breath and blood samples were collected at regular times during the day over a 12 h period. The endogenous rate of appearance of acetate, propionate, and butyrate was 13.3 ± 4.8, 0.27 ± 0.09, and 0.28 ± 0.12 μmol·kg−1·min−1, respectively. Colonic inulin fermentation was estimated to be 137 ± 75 mmol acetate, 11 ± 9 mmol propionate, and 20 ± 17 mmol butyrate over 12 h, assuming that 40%, 10%, and 5% of colonic derived acetate, propionate, and butyrate enter the systemic circulation. In conclusion, inulin is mainly fermented into acetate and, to lesser extents, into butyrate and propionate. Stable isotope technology allows quantifying the production of the three main SCFA in vivo and proved to be a practical tool to investigate the extent and pattern of SCFA production.

Induction of the p75NTR by Aryl Propionic Acids in Prostate Cancer Cells

National Research Council Canada - National Science Library

Quann, Emily

2007-01-01

.... I have found that treatment of prostate cancer cells with the aryl propionic acids R-flurbiprofen and ibuprofen induces reexpression of p75NTR, decreases cell survival, and increases apoptosis...

Synthesis of nanocrystalline ceria thin films by low-temperature thermal decomposition of Ce-propionate

International Nuclear Information System (INIS)

Roura, P.; Farjas, J.; Ricart, S.; Aklalouch, M.; Guzman, R.; Arbiol, J.; Puig, T.; Calleja, A.; Peña-Rodríguez, O.; Garriga, M.; Obradors, X.

2012-01-01

Thin films of Ce-propionate (thickness below 20 nm) have been deposited by spin coating and pyrolysed into ceria at temperatures below 200 °C. After 1 h of thermal treatment, no signature of the vibrational modes of Ce-propionate is detected by infrared spectroscopy, indicating that decomposition has been completed. The resulting ceria films are nanocrystalline as revealed by X-ray diffraction (average grain size of 2–2.5 nm) and confirmed by microscopy. They are transparent in the visible region and show the characteristic band gap absorption below 400 nm. A direct band gap energy of 3.50 ± 0.05 eV has been deduced irrespective of the pyrolysis temperature (160, 180 and 200 °C).

The effect of inhaled fluticasone propionate in the treatment of young asthmatic children

DEFF Research Database (Denmark)

Bisgaard, H; Gillies, J; Groenewald, M

1999-01-01

The response in asthmatic young children to inhaled steroids within the usual pediatric dose range is unknown. We therefore evaluated the dose-related response in young children with moderate asthma to inhaled fluticasone propionate (FP) (delivered via the Babyhaler spacer device) within the pedi......The response in asthmatic young children to inhaled steroids within the usual pediatric dose range is unknown. We therefore evaluated the dose-related response in young children with moderate asthma to inhaled fluticasone propionate (FP) (delivered via the Babyhaler spacer device) within...... the pediatric dose range. A total of 237 children (mean age 28 mo, range 12 to 47) with moderate asthmatic symptoms were studied in this multicenter, randomized, double-blind, parallel group, placebo-controlled study of 12 wk treatment following a 4-wk run-in period. The median use of rescue medication was 1...

Comparison of the effect of acetic, propionic and butyric acids on ...

African Journals Online (AJOL)

番茄花园

2011-05-23

May 23, 2011 ... Graded levels of mixed VFA sodium salt (the molar proportion of acetate, propionate, and butyrate was 65:25:10), i.e. 0, 5, ... be more associated with the VFA energy level (Ma and. Zhao, 2010) and mediated by IGF-I, insulin ..... Influence of nutrition and bovine growth hormone (GH) on hepatic GH binding, ...

Metabolic engineering of cyanobacteria for the synthesis of commodity products

NARCIS (Netherlands)

Angermayr, S.A.; Gorchs Rovira, A.; Hellingwerf, K.J.

2015-01-01

Through metabolic engineering cyanobacteria can be employed in biotechnology. Combining the capacity for oxygenic photosynthesis and carbon fixation with an engineered metabolic pathway allows carbon-based product formation from CO2, light, and water directly. Such cyanobacterial 'cell factories'

Physical-chemical properties of the surface of B2O3-P2O5-MeOx/SiO2 catalysts and its effect on the parameters of the process of aldol condensation of propionic acid with formaldehyde

International Nuclear Information System (INIS)

Yivasyiv, V.V.; Pyikh, Z.G.; Zhiznevs'kij, V.M.; Nebesnij, R.V.

2011-01-01

Effect of catalyst B 2 O 3 -P 2 O 5 -MeO x /SiO 2 composition on its physical-chemical properties has been investigated. Relations between physical-chemical and catalytic properties of catalysts in the gas-phase reaction of propionic acid with formaldehyde to methacrylic acid have been found. Effect of the specific surface area and the specific surface acidity on the propionic acid conversion has been determined. Effect of the acidic active site's strength on the selectivity of reaction products has been determined. It has been pointed that methacrylic acid is formed on the moderate strength acidic active sites, whereas the by-product (diethyl ketone) - on the strong acidic active sites of the catalyst.

High-temperature unimolecular decomposition of ethyl propionate

KAUST Repository

Giri, Binod

2016-10-09

This work reports rate coefficients of the thermal unimolecular decomposition reaction of ethyl propionate (EP) behind reflected shock waves over the temperature range of 976–1300 K and pressures of 825–1875 Torr. The reaction progress was monitored by detecting CH near 10.532 μm using CO gas laser absorption. In addition, G3//MP2/aug-cc-pVDZ and master equation calculations were performed to assess the pressure- and temperature-dependence of the reaction. Our calculations revealed that CH elimination occurs via a six-centered retro-ene transition state. Our measured rate data are close to the high-pressure limit and showed no discernable temperature fall off.

Arabinoxylo-Oligosaccharides and Inulin Impact Inter-Individual Variation on Microbial Metabolism and Composition, Which Immunomodulates Human Cells.

Science.gov (United States)

Van den Abbeele, Pieter; Taminiau, Bernard; Pinheiro, Iris; Duysburgh, Cindy; Jacobs, Heidi; Pijls, Loek; Marzorati, Massimo

2018-02-07

Fecal batch fermentations coupled to cocultures of epithelial cells and macrophages were used to compare how arabinoxylo-oligosaccharides (AXOS) and inulin modulate gut microbial activity and composition of three different human donors and subsequently the epithelial permeability and immune response. Both inulin and AXOS decreased the pH during incubation (-1.5 pH units), leading to increased productions of acetate, propionate, and butyrate. Differences in terms of metabolites production could be linked to specific microbial alterations at genus level upon inulin/AXOS supplementation (i.e., Bifidobacterium, Bacteroides, Prevotella and unclassified Erysipelotrichaceae), as shown by 16S-targeted Illumina sequencing. Both products stimulated gut barrier and immune function with increases in TEER, NF-KB, IL-10, and IL-6. Ingredients with different structures selectively modulate the microbiota of a specific donor leading to differential changes at metabolic level. The extent of this effect is donor specific and is linked to a final specific modulation of the host's immune system.

Conductive iron oxides accelerate thermophilic methanogenesis from acetate and propionate.

Science.gov (United States)

Yamada, Chihaya; Kato, Souichiro; Ueno, Yoshiyuki; Ishii, Masaharu; Igarashi, Yasuo

2015-06-01

Anaerobic digester is one of the attractive technologies for treatment of organic wastes and wastewater, while continuous development and improvements on their stable operation with efficient organic removal are required. Particles of conductive iron oxides (e.g., magnetite) are known to facilitate microbial interspecies electron transfer (termed as electric syntrophy). Electric syntrophy has been reported to enhance methanogenic degradation of organic acids by mesophilic communities in soil and anaerobic digester. Here we investigated the effects of supplementation of conductive iron oxides (magnetite) on thermophilic methanogenic microbial communities derived from a thermophilic anaerobic digester. Supplementation of magnetite accelerated methanogenesis from acetate and propionate under thermophilic conditions, while supplementation of ferrihydrite also accelerated methanogenesis from propionate. Microbial community analysis revealed that supplementation of magnetite drastically changed bacterial populations in the methanogenic acetate-degrading cultures, in which Tepidoanaerobacter sp. and Coprothermobacter sp. dominated. These results suggest that supplementation of magnetite induce electric syntrophy between organic acid-oxidizing bacteria and methanogenic archaea and accelerate methanogenesis even under thermophilic conditions. Findings from this study would provide a possibility for the achievement of stably operating thermophilic anaerobic digestion systems with high efficiency for removal of organics and generation of CH4. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Improved Triacylglycerol Production in Acinetobacter baylyi ADP1 by Metabolic Engineering

Directory of Open Access Journals (Sweden)

Karp Matti

2011-05-01

Full Text Available Abstract Background Triacylglycerols are used in various purposes including food applications, cosmetics, oleochemicals and biofuels. Currently the main sources for triacylglycerol are vegetable oils, and microbial triacylglycerol has been suggested as an alternative for these. Due to the low production rates and yields of microbial processes, the role of metabolic engineering has become more significant. As a robust model organism for genetic and metabolic studies, and for the natural capability to produce triacylglycerol, Acinetobacter baylyi ADP1 serves as an excellent organism for modelling the effects of metabolic engineering for energy molecule biosynthesis. Results Beneficial gene deletions regarding triacylglycerol production were screened by computational means exploiting the metabolic model of ADP1. Four deletions, acr1, poxB, dgkA, and a triacylglycerol lipase were chosen to be studied experimentally both separately and concurrently by constructing a knock-out strain (MT with three of the deletions. Improvements in triacylglycerol production were observed: the strain MT produced 5.6 fold more triacylglycerol (mg/g cell dry weight compared to the wild type strain, and the proportion of triacylglycerol in total lipids was increased by 8-fold. Conclusions In silico predictions of beneficial gene deletions were verified experimentally. The chosen single and multiple gene deletions affected beneficially the natural triacylglycerol metabolism of A. baylyi ADP1. This study demonstrates the importance of single gene deletions in triacylglycerol metabolism, and proposes Acinetobacter sp. ADP1 as a model system for bioenergetic studies regarding metabolic engineering.

Metabolic engineering of Agrobacterium sp. ATCC31749 for curdlan production from cellobiose.

Science.gov (United States)

Shin, Hyun-Dong; Liu, Long; Kim, Mi-Kyoung; Park, Yong-Il; Chen, Rachel

2016-09-01

Curdlan is a commercial polysaccharide made by fermentation of Agrobacterium sp. Its anticipated expansion to larger volume markets demands improvement in its production efficiency. Metabolic engineering for strain improvement has so far been limited due to the lack of genetic tools. This research aimed to identify strong promoters and to engineer a strain that converts cellobiose efficiently to curdlan. Three strong promoters were identified and were used to install an energy-efficient cellobiose phosphorolysis mechanism in a curdlan-producing strain. The engineered strains were shown with enhanced ability to utilize cellobiose, resulting in a 2.5-fold increase in titer. The availability of metabolically engineered strain capable of producing β-glucan from cellobiose paves the way for its production from cellulose. The identified native promoters from Agrobacterium open up opportunities for further metabolic engineering for improved production of curdlan and other products. The success shown here marks the first such metabolic engineering effort in this microbe.

2-Amino-3-(3-hydroxy-1,2,5-thiadiazol-4-yl)propionic acid

DEFF Research Database (Denmark)

Johansen, Tommy N; Janin, Yves L; Nielsen, Birgitte

2002-01-01

In order to identify new subtype-selective (S)-glutamate (Glu) receptor ligands we have synthesized (RS)-2-amino-3-(3-hydroxy-1,2,5-thiadiazol-4-yl)propionic acid [(RS)-TDPA]. Resolution of (RS)-TDPA by chiral chromatography was performed using a Crownpac CR(+) column affording (R)- and (S......)-TDPA of high enantiomeric purity (enantiomeric excess=99.9%). An X-ray crystallographic analysis revealed that the early eluting enantiomer has R-configuration. Both enantiomers showed high affinity as well as high agonist activity at (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA...... a remarkably low AMPA receptor stereoselectivity, (S)-TDPA showing the highest affinity and (R)-TDPA the most potent agonist activity. In addition, (S)-TDPA was shown to interact with synaptosomal Glu uptake sites displacing [(3)H](R)-aspartic acid (IC(50 ) approximately 390 microM). An enantiospecific...

The preparation of highly absorbing cellulosic copolymers -the cellulose acetate/propionate-g.co-acrylic acid system

International Nuclear Information System (INIS)

Bilgin, V.; Guthrie, J.T.

1990-01-01

A series of copolymers based on the cellulose acetate/propionate-g.co-acrylic acid system has been prepared under radiation-induced control. These copolymers have been assessed for their water-retention capacity both in an unmodified state and after ''decrystallization'' or ''neutralization'' treatments. The grafting of acrylic acid onto the cellulose acetate/propionate had little effect on the water retention power of the cellulose acetate/propionate. However, improvements to the water retentivity was obtained after ''decrystallization'' procedures had been carried out on the copolymers using selected alkali metal salts with methanol as the continuous medium. The water-retentivity of the copolymers increased with increase in the extent of grafting, though the effect is less pronounced at high graft levels. Neutralization of the functional groups of the grafted branches provided a route to obtaining a marked increase in the level of water retentivity. Excessive salt concentrations gave reduced levels of water retentivity. Cesium carbonate and sodium carbonate have been shown to be effective in providing marked improvements in the water-retaining capacity of the copolymers. Maxima in performance are shown with respect to the treatment conditions. (author)

Growth performance, rumen fermentation, nutrient utilization, and metabolic profile of dairy heifers limit-fed distillers dried grains with ad libitum forage.

Science.gov (United States)

Manthey, A K; Anderson, J L

2018-01-01

The objective of this study was to determine the effects of feeding a corn- and soybean-product-based concentrate mix or distillers dried grains with solubles concentrate mix with ad libitum grass hay to dairy heifers. A 16-wk randomized complete block design study was conducted using 24 heifers [18 Holstein and 6 Brown Swiss; 219 ± 2 d of age (±standard deviation); 230 ± 4 kg of body weight] to evaluate the effect of diet on dry matter intake (DMI), growth performance, rumen fermentation, metabolic profile, and nutrient digestibility. Treatments were (1) corn and soybean product concentrate mix, and (2) distillers-dried-grains-with-solubles-based concentrate mix (DDG). Both concentrate mixes were limit-fed at 0.8% of body weight and grass hay was offered ad libitum. Heifers were individually fed using Calan gates and orts were recorded daily at feeding. Heifers were weighed every 2 wk and ration concentrate mix offered was adjusted accordingly. Frame measurements and body condition score were recorded every 2 wk. Rumen fluid was collected via esophageal tubing during wk 12 and 16 for pH, ammonia N, and volatile fatty acid analysis. Jugular blood samples were collected every 4 wk for metabolite and metabolic hormone analysis. Total-tract digestibility of nutrients was evaluated during wk 16 by fecal grab sampling. No treatment by week interactions were observed for any of the growth measurements and growth measurements and DMI did not differ between treatments. A treatment by time interaction was observed for rumen butyrate percentage with heifers fed DDG having a greater percentage. Total volatile fatty acid concentration, acetate molar percentage, and acetate:propionate decreased with the DDG treatment, whereas propionate molar percentage increased. No treatment by week interactions were observed for any of the metabolites or metabolic hormones measured. A tendency was observed for glucose and plasma urea nitrogen concentration to decrease with DDG. Plasma

Metabolic engineering of yeast for lignocellulosic biofuel production.

Science.gov (United States)

Jin, Yong-Su; Cate, Jamie Hd

2017-12-01

Production of biofuels from lignocellulosic biomass remains an unsolved challenge in industrial biotechnology. Efforts to use yeast for conversion face the question of which host organism to use, counterbalancing the ease of genetic manipulation with the promise of robust industrial phenotypes. Saccharomyces cerevisiae remains the premier host for metabolic engineering of biofuel pathways, due to its many genetic, systems and synthetic biology tools. Numerous engineering strategies for expanding substrate ranges and diversifying products of S. cerevisiae have been developed. Other yeasts generally lack these tools, yet harbor superior phenotypes that could be exploited in the harsh processes required for lignocellulosic biofuel production. These include thermotolerance, resistance to toxic compounds generated during plant biomass deconstruction, and wider carbon consumption capabilities. Although promising, these yeasts have yet to be widely exploited. By contrast, oleaginous yeasts such as Yarrowia lipolytica capable of producing high titers of lipids are rapidly advancing in terms of the tools available for their metabolic manipulation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Randomised clinical study: inulin short-chain fatty acid esters for targeted delivery of short-chain fatty acids to the human colon.

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Polyviou, T; MacDougall, K; Chambers, E S; Viardot, A; Psichas, A; Jawaid, S; Harris, H C; Edwards, C A; Simpson, L; Murphy, K G; Zac-Varghese, S E K; Blundell, J E; Dhillo, W S; Bloom, S R; Frost, G S; Preston, T; Tedford, M C; Morrison, D J

2016-10-01

Short-chain fatty acids (SCFA) produced through fermentation of nondigestible carbohydrates by the gut microbiota are associated with positive metabolic effects. However, well-controlled trials are limited in humans. To develop a methodology to deliver SCFA directly to the colon, and to optimise colonic propionate delivery in humans, to determine its role in appetite regulation and food intake. Inulin SCFA esters were developed and tested as site-specific delivery vehicles for SCFA to the proximal colon. Inulin propionate esters containing 0-61 wt% (IPE-0-IPE-61) propionate were assessed in vitro using batch faecal fermentations. In a randomised, controlled, crossover study, with inulin as control, ad libitum food intake (kcal) was compared after 7 days on IPE-27 or IPE-54 (10 g/day all treatments). Propionate release was determined using (13) C-labelled IPE variants. In vitro, IPE-27-IPE-54 wt% propionate resulted in a sevenfold increase in propionate production compared with inulin (P inulin (439.5 vs. 703.9 kcal, P = 0.025) and IPE-54 (439.5 vs. 659.3 kcal, P = 0.025), whereas IPE-54 was not significantly different from inulin control. IPE-27 significantly reduced food intake suggesting colonic propionate plays a role in appetite regulation. Inulin short-chain fatty acid esters provide a novel tool for probing the diet-gut microbiome-host metabolism axis in humans. © 2016 The Authors. Alimentary Pharmacology & Therapeutics Published by John Wiley & Sons Ltd.

Involvement of a bacterial microcompartment in the metabolism of fucose and rhamnose by Clostridium phytofermentans.

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Elsa Petit

Full Text Available Clostridium phytofermentans, an anaerobic soil bacterium, can directly convert plant biomass into biofuels. The genome of C. phytofermentans contains three loci with genes encoding shell proteins of bacterial microcompartments (BMC, organelles composed entirely of proteins.One of the BMC loci has homology to a BMC-encoding locus implicated in the conversion of fucose to propanol and propionate in a human gut commensal, Roseburia inulinivorans. We hypothesized that it had a similar role in C. phytofermentans. When C. phytofermentans was grown on fucose, the major products identified were ethanol, propanol and propionate. Transmission electron microscopy of fucose- and rhamnose-grown cultures revealed polyhedral structures, presumably BMCs. Microarray analysis indicated that during growth on fucose, operons coding for the BMC locus, fucose dissimilatory enzymes, and an ATP-binding cassette transporter became the dominant transcripts. These data are consistent with fucose fermentation producing a 1,2-propanediol intermediate that is further metabolized in the microcompartment encoded in the BMC locus. Growth on another deoxyhexose sugar, rhamnose, resulted in the expression of the same BMC locus and similar fermentation products. However, a different set of dissimilatory enzymes and transport system genes were induced. Quite surprisingly, growth on fucose or rhamnose also led to the expression of a diverse array of complex plant polysaccharide-degrading enzymes.Based on physiological, genomic, and microarray analyses, we propose a model for the fermentation of fucose and rhamnose in C. phytofermentans that includes enzymes encoded in the same BMC locus. Comparative genomic analysis suggests that this BMC may be present in other clostridial species.

Adjuvant activity of peptidoglycan monomer and its metabolic products.

Science.gov (United States)

Halassy, Beata; Krstanović, Marina; Frkanec, Ruza; Tomasić, Jelka

2003-02-14

Peptidoglycan monomer (PGM) is a natural compound of bacterial origin. It is a non-toxic, non-pyrogenic, water-soluble immunostimulator potentiating humoral immune response to ovalbumin (OVA) in mice. It is fast degraded and its metabolic products-the pentapeptide (PP) and the disaccharide (DS)-are excreted from the mammalian organism upon parenteral administration. The present study investigates: (a). whether PGM could influence the long-living memory generation; (b). whether metabolic products retain adjuvant properties of the parent compound and contribute to its adjuvanticity. We report now that mice immunised twice with OVA+PGM had significantly higher anti-OVA IgG levels upon challenge with antigen alone 6 months later in comparison to control group immunised with OVA only. PP and DS were prepared enzymatically in vitro as apyrogenic and chemically pure compounds. When mice were immunised with OVA plus PP and DS, respectively, the level of anti-OVA IgGs in sera was not higher than in mice immunised with OVA alone, while PGM raised the level of specific antibodies. Results implicate that the adjuvant active molecule, capable of enhancing long-living memory generation, is PGM itself, and none of its metabolic products.

Metabolic engineering of Corynebacterium glutamicum for fermentative production of chemicals in biorefinery.

Science.gov (United States)

Baritugo, Kei-Anne; Kim, Hee Taek; David, Yokimiko; Choi, Jong-Il; Hong, Soon Ho; Jeong, Ki Jun; Choi, Jong Hyun; Joo, Jeong Chan; Park, Si Jae

2018-05-01

Bio-based production of industrially important chemicals provides an eco-friendly alternative to current petrochemical-based processes. Because of the limited supply of fossil fuel reserves, various technologies utilizing microbial host strains for the sustainable production of platform chemicals from renewable biomass have been developed. Corynebacterium glutamicum is a non-pathogenic industrial microbial species traditionally used for L-glutamate and L-lysine production. It is a promising species for industrial production of bio-based chemicals because of its flexible metabolism that allows the utilization of a broad spectrum of carbon sources and the production of various amino acids. Classical breeding, systems, synthetic biology, and metabolic engineering approaches have been used to improve its applications, ranging from traditional amino-acid production to modern biorefinery systems for production of value-added platform chemicals. This review describes recent advances in the development of genetic engineering tools and techniques for the establishment and optimization of metabolic pathways for bio-based production of major C2-C6 platform chemicals using recombinant C. glutamicum.

Metabolic-flux analysis of hydrogen production pathway in Citrobacter amalonaticus Y19

Energy Technology Data Exchange (ETDEWEB)

Oh, You-Kwan; Kim, Mi-Sun [Bioenergy Research Center, Korea Institute of Energy Research, Daejeon 305-343 (Korea); Kim, Heung-Joo; Park, Sunghoon [Department of Chemical and Biochemical Engineering and Institute for Environmental Technology and Industry, Pusan National University, Busan 609-735 (Korea); Ryu, Dewey D.Y. [Biochemical Engineering Program, Department of Chemical Engineering and Material Science, University of California, Davis, CA 95616 (United States)

2008-03-15

For the newly isolated chemoheterotrophic bacterium Citrobacter amalonaticus Y19, anaerobic glucose metabolism and hydrogen (H{sub 2}) production pathway were studied using batch cultivation and an in silico metabolic-flux analysis. Batch cultivation was conducted under varying initial glucose concentration between 1.5 and 9.5 g/L with quantitative measurement of major metabolites to obtain accurate carbon material balance. The metabolic flux of Y19 was analyzed using a metabolic-pathway model which was constructed from 81 biochemical reactions. The linear optimization program MetaFluxNet was employed for the analysis. When the specific growth rate of cells was chosen as an objective function, the model described the batch culture characteristics of Ci. amalonaticus Y19 reasonably well. When the specific H{sub 2} production rate was selected as an objective function, on the other hand, the achievable maximal H{sub 2} production yield (8.7molH{sub 2}/mol glucose) and the metabolic pathway enabling the high H{sub 2} yield were identified. The pathway involved non-native NAD(P)-linked hydrogenase and H{sub 2} production from NAD(P)H which were supplied at a high rate from glucose degradation through the pentose phosphate pathway. (author)

PREPARATION AND CHARACTERIZATION OF CO-PROCESSED EXCIPIENT-PREGELATINIZED CASSAVA STARCH PROPIONATE AS A MATRIX IN THE GASTRORETENTIVE DOSAGE FORM

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Junaedi

2011-11-01

Full Text Available The gastroretentive dosage form is designed to prolong the gastric residence time of the drug delivery system whichalso results in the development of an appropriate excipient. The purpose of this study is to develop and characterize coprocessedexcipient made from carrageenan (kappa-iota = 1:1 and pregelatinized cassava starch propionate (PCSP inratios of 1:1, 1:2, and 1:3. PCSP was prepared with propionic anhydride in an aqueous medium. The product was mixedwith carrageenan (kappa-iota = 1:1, as well as characterized physicochemical and functional properties. The coprocessedexcipient was then used as a mucoadhesive granule and floating tablet. The USP Basket was selected toperform the dissolution test of the granules in HCl buffer (pH 1.2 and distilled water for 8 hours each. Mucoadhesiveproperties were evaluated using bioadhesive through a vitro test and wash-off test. As for the floating tablet, the USPPaddle was selected to perform the dissolution test of the tablets in 0.1 N HCl for 10 hours. The floating lag time andfloating time were tested in 0.1 N HCl for 24 hours. The result of these studies indicated that co-processed excipientcarrageenan-PCSP can retard dosage form in gastric and drug controlled release, thus making it a suitable material forthe gastroretentive dosage form.

Metabolic engineering of Candida glabrata for diacetyl production.

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Xiang Gao

Full Text Available In this study, Candida glabrata, an efficient pyruvate-producing strain, was metabolically engineered for the production of the food ingredient diacetyl. A diacetyl biosynthetic pathway was reconstructed based on genetic modifications and medium optimization. The former included (i channeling carbon flux into the diacetyl biosynthetic pathway by amplification of acetolactate synthase, (ii elimination of the branched pathway of α-acetolactate by deleting the ILV5 gene, and (iii restriction of diacetyl degradation by deleting the BDH gene. The resultant strain showed an almost 1∶1 co-production of α-acetolactate and diacetyl (0.95 g L(-1. Furthermore, addition of Fe3+ to the medium enhanced the conversion of α-acetolactate to diacetyl and resulted in a two-fold increase in diacetyl production (2.1 g L(-1. In addition, increased carbon flux was further channeled into diacetyl biosynthetic pathway and a titer of 4.7 g L(-1 of diacetyl was achieved by altering the vitamin level in the flask culture. Thus, this study illustrates that C. glabrata could be tailored as an attractive platform for enhanced biosynthesis of beneficial products from pyruvate by metabolic engineering strategies.

Microbial Community Pathways for the Production of Volatile Fatty Acids From CO2 and Electricity

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Jorge Wenzel

2018-04-01

Full Text Available This study aims at elucidating the metabolic pathways involved in the production of volatile fatty acids from CO2 and electricity. Two bioelectrochemical systems (BES were fed with pure CO2 (cells A and B. The cathode potential was first poised at −574 mV vs. standard hydrogen electrode (SHE and then at −756 mV vs. SHE in order to ensure the required reducing power. Despite applying similar operation conditions to both BES, they responded differently. A mixture of organic compounds (1.87 mM acetic acid, 2.30 mM formic acid, 0.43 mM propionic acid, 0.15 mM butyric acid, 0.55 mM valeric acid, and 0.62 mM ethanol was produced in cell A while mainly 1.82 mM acetic acid and 0.23 mM propionic acid were produced in cell B. The microbial community analysis performed by 16S rRNA gene pyrosequencing showed a predominance of Clostridium sp. and Serratia sp. in cell A whereas Burkholderia sp. and Xanthobacter sp. predominated in cell B. The coexistence of three metabolic pathways involved in carbon fixation was predicted. Calvin cycle was predicted in both cells during the whole experiment while Wood-Ljungdahl and Arnon-Buchanan pathways predominated in the period with higher coulombic efficiency. Metabolic pathways which transform organic acids into anabolic intermediaries were also predicted, indicating the occurrence of complex trophic interactions. These results further complicate the understanding of these mixed culture microbial processes but also expand the expectation of compounds that could potentially be produced with this technology.

Systems metabolic engineering design: fatty acid production as an emerging case study.

Science.gov (United States)

Tee, Ting Wei; Chowdhury, Anupam; Maranas, Costas D; Shanks, Jacqueline V

2014-05-01

Increasing demand for petroleum has stimulated industry to develop sustainable production of chemicals and biofuels using microbial cell factories. Fatty acids of chain lengths from C6 to C16 are propitious intermediates for the catalytic synthesis of industrial chemicals and diesel-like biofuels. The abundance of genetic information available for Escherichia coli and specifically, fatty acid metabolism in E. coli, supports this bacterium as a promising host for engineering a biocatalyst for the microbial production of fatty acids. Recent successes rooted in different features of systems metabolic engineering in the strain design of high-yielding medium chain fatty acid producing E. coli strains provide an emerging case study of design methods for effective strain design. Classical metabolic engineering and synthetic biology approaches enabled different and distinct design paths towards a high-yielding strain. Here we highlight a rational strain design process in systems biology, an integrated computational and experimental approach for carboxylic acid production, as an alternative method. Additional challenges inherent in achieving an optimal strain for commercialization of medium chain-length fatty acids will likely require a collection of strategies from systems metabolic engineering. Not only will the continued advancement in systems metabolic engineering result in these highly productive strains more quickly, this knowledge will extend more rapidly the carboxylic acid platform to the microbial production of carboxylic acids with alternate chain-lengths and functionalities. © 2014 Wiley Periodicals, Inc.

Engineering the fatty acid metabolic pathway in Saccharomyces cerevisiae for advanced biofuel production

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Xiaoling Tang

2015-12-01

Full Text Available Fatty acid-derived fuels and chemicals have attracted a great deal of attention in recent decades, due to their following properties of high compatibility to gasoline-based fuels and existing infrastructure for their direct utilization, storage and distribution. The yeast Saccharomyces cerevisiae is the ideal biofuel producing candidate, based on the wealth of available genetic information and versatile tools designed to manipulate its metabolic pathways. Engineering the fatty acid metabolic pathways in S. cerevisiae is an effective strategy to increase its fatty acid biosynthesis and provide more pathway precursors for production of targeted products. This review summarizes the recent progress in metabolic engineering of yeast cells for fatty acids and fatty acid derivatives production, including the regulation of acetyl-CoA biosynthesis, NADPH production, fatty acid elongation, and the accumulation of activated precursors of fatty acids for converting enzymes. By introducing specific enzymes in the engineered strains, a powerful platform with a scalable, controllable and economic route for advanced biofuel production has been established. Keywords: Metabolic engineering, Fatty acid biosynthesis, Fatty acid derivatives, Saccharomyces cerevisiae

Subdermal penetration of topically applied clobetasol propionate in ointment base through intact human skin

DEFF Research Database (Denmark)

Petersen, Lars Jelstrup; Sindrup, J H; Kristensen, J K

1992-01-01

Some data have demonstrated a substantial subdermal accumulation of topically applied drugs in animals. The aim of this study was to evaluate a possible effect of epicutaneously applied clobetasol propionate on blood flow in human subcutaneous adipose tissue. Nine healthy subjects were studied...

Programming Saposin-Mediated Compensatory Metabolic Sinks for Enhanced Ubiquinone Production.

Science.gov (United States)

Xu, Wen; Yuan, Jifeng; Yang, Shuiyun; Ching, Chi-Bun; Liu, Jiankang

2016-12-16

Microbial synthesis of ubiquinone by fermentation processes has been emerging in recent years. However, as ubiquinone is a primary metabolite that is tightly regulated by the host central metabolism, tweaking the individual pathway components could only result in a marginal improvement on the ubiquinone production. Given that ubiquinone is stored in the lipid bilayer, we hypothesized that introducing additional metabolic sink for storing ubiquinone might improve the CoQ 10 production. As human lipid binding/transfer protein saposin B (hSapB) was reported to extract ubiquinone from the lipid bilayer and form the water-soluble complex, hSapB was chosen to build a compensatory metabolic sink for the ubiquinone storage. As a proof-of-concept, hSapB-mediated metabolic sink systems were devised and systematically investigated in the model organism of Escherichia coli. The hSapB-mediated periplasmic sink resulted in more than 200% improvement of CoQ 8 over the wild type strain. Further investigation revealed that hSapB-mediated sink systems could also improve the CoQ 10 production in a CoQ 10 -hyperproducing E. coli strain obtained by a modular pathway rewiring approach. As the design principles and the engineering strategies reported here are generalizable to other microbes, compensatory sink systems will be a method of significant interest to the synthetic biology community.

Effect of Applying Molasses and Propionic Acid on Fermentation Quality and Aerobic Stability of Total Mixed Ration Silage Prepared with Whole-plant Corn in Tibet

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Lei Chen

2014-03-01

Full Text Available The objective of this study was to evaluate the effects of molasses and propionic acid on the fermentation quality and aerobic stability of total mixed ration (TMR silages prepared with whole-plant corn in Tibet. TMR (354 g/kg DM was ensiled with four different treatments: no additive (control, molasses (M, propionic acid (P, and molasses+propionic acid (PM, in laboratory silos (250 mL and fermented for 45 d. Silos were opened and silages were subjected to an aerobic stability test for 12 days, in which chemical and microbiological parameters of TMR silages were measured to determined the aerobic deterioration. After 45 d of ensiling, the four TMR silages were of good quality with low pH value and ammonia/total N (AN, and high lactic acid (LA content and V-scores. M silage showed the highest (p105 cfu/g FM, however, it appeared to be more stable as indicated by a delayed pH value increase. P and PM silages showed fewer yeasts (<105 cfu/g FM (p<0.05 and were more stable than the control and M silages during aerobic exposure. It was concluded that M application increased LA content and improved aerobic stability of TMR silage prepared with whole-plant corn in Tibet. P application inhibited lactic acid production during ensiling, and apparently preserved available sugars which stimulated large increases in lactic acid during aerobic exposure stage, which resulted in greater aerobic stability of TMR silage.

Biobased organic acids production by metabolically engineered microorganisms

DEFF Research Database (Denmark)

Chen, Yun; Nielsen, Jens

2016-01-01

Bio-based production of organic acids via microbial fermentation has been traditionally used in food industry. With the recent desire to develop more sustainable bioprocesses for production of fuels, chemicals and materials, the market for microbial production of organic acids has been further...... expanded as organic acids constitute a key group among top building block chemicals that can be produced from renewable resources. Here we review the current status for production of citric acid and lactic acid, and we highlight the use of modern metabolic engineering technologies to develop high...... performance microbes for production of succinic acid and 3-hydroxypropionic acid. Also, the key limitations and challenges in microbial organic acids production are discussed...

Growth and characterization of organic NLO material: Clobetasol propionate

Science.gov (United States)

Purusothaman, R.; Rajesh, P.; Ramasamy, P.

2015-06-01

Single crystals of clobetasol propionate (CP) have been grown by slow evaporation solution technique using mixed solvent of methanol-acetone. The grown crystals were subjected to single crystal X-ray diffraction analysis to confirm their lattice parameter and space group. The powder X-ray diffraction pattern of the grown CP has been indexed. Thermal analysis was performed to study the thermal stability of the grown crystals. Photoluminescence spectrum shows broad emission peak observed at 421 nm. Nonlinear optical studies were carried out for the grown crystal and second harmonic generation (SHG) efficiency was found in the crystal.

Biobased production of alkanes and alkenes through metabolic engineering of microorganisms

DEFF Research Database (Denmark)

Kang, Min Kyoung; Nielsen, Jens

2017-01-01

Advancement in metabolic engineering of microorganisms has enabled bio-based production of a range of chemicals, and such engineered microorganism can be used for sustainable production leading to reduced carbon dioxide emission there. One area that has attained much interest is microbial...... hydrocarbon biosynthesis, and in particular, alkanes and alkenes are important high-value chemicals as they can be utilized for a broad range of industrial purposes as well as ‘drop-in’ biofuels. Some microorganisms have the ability to biosynthesize alkanes and alkenes naturally, but their production level...... is extremely low. Therefore, there have been various attempts to recruit other microbial cell factories for production of alkanes and alkenes by applying metabolic engineering strategies. Here we review different pathways and involved enzymes for alkane and alkene production and discuss bottlenecks...

Engineering microorganisms to increase ethanol production by metabolic redirection

Science.gov (United States)

Deng, Yu; Olson, Daniel G.; van Dijken, Johannes Pieter; Shaw, IV, Arthur J.; Argyros, Aaron; Barrett, Trisha; Caiazza, Nicky; Herring, Christopher D.; Rogers, Stephen R.; Agbogbo, Frank

2017-10-31

The present invention provides for the manipulation of carbon flux in a recombinant host cell to increase the formation of desirable products. The invention relates to cellulose-digesting organisms that have been genetically modified to allow the production of ethanol at a high yield by redirecting carbon flux at key steps of central metabolism.

Changes in gut microbiota in rats fed a high fat diet correlate with obesity-associated metabolic parameters.

Science.gov (United States)

Lecomte, Virginie; Kaakoush, Nadeem O; Maloney, Christopher A; Raipuria, Mukesh; Huinao, Karina D; Mitchell, Hazel M; Morris, Margaret J

2015-01-01

The gut microbiota is emerging as a new factor in the development of obesity. Many studies have described changes in microbiota composition in response to obesity and high fat diet (HFD) at the phylum level. In this study we used 16s RNA high throughput sequencing on faecal samples from rats chronically fed HFD or control chow (n = 10 per group, 16 weeks) to investigate changes in gut microbiota composition at the species level. 53.17% dissimilarity between groups was observed at the species level. Lactobacillus intestinalis dominated the microbiota in rats under the chow diet. However this species was considerably less abundant in rats fed HFD (Pdevelopment of the obese phenotype, we correlated their abundance with metabolic parameters associated with obesity. Of the taxa contributing the most to dissimilarity between groups, 10 presented significant correlations with at least one of the tested parameters, three of them correlated positively with all metabolic parameters: Phascolarctobacterium, Proteus mirabilis and Veillonellaceae, all propionate/acetate producers. Lactobacillus intestinalis was the only species whose abundance was negatively correlated with change in body weight and fat mass. This species decreased drastically in response to HFD, favouring propionate/acetate producing bacterial species whose abundance was strongly correlated with adiposity and deterioration of metabolic factors. Our observations suggest that these species may play a key role in the development of obesity in response to a HFD.

A Systematic Analysis of the Sensitivity of Plasma Pharmacokinetics to Detect Differences in the Pulmonary Performance of Inhaled Fluticasone Propionate Products Using a Model-Based Simulation Approach.

Science.gov (United States)

Weber, Benjamin; Hochhaus, Guenther

2015-07-01

The role of plasma pharmacokinetics (PK) for assessing bioequivalence at the target site, the lung, for orally inhaled drugs remains unclear. A validated semi-mechanistic model, considering the presence of mucociliary clearance in central lung regions, was expanded for quantifying the sensitivity of PK studies in detecting differences in the pulmonary performance (total lung deposition, central-to-peripheral lung deposition ratio, and pulmonary dissolution characteristics) between test (T) and reference (R) inhaled fluticasone propionate (FP) products. PK bioequivalence trials for inhaled FP were simulated based on this PK model for a varying number of subjects and T products. The statistical power to conclude bioequivalence when T and R products are identical was demonstrated to be 90% for approximately 50 subjects. Furthermore, the simulations demonstrated that PK metrics (area under the concentration time curve (AUC) and C max) are capable of detecting differences between T and R formulations of inhaled FP products when the products differ by more than 20%, 30%, and 25% for total lung deposition, central-to-peripheral lung deposition ratio, and pulmonary dissolution characteristics, respectively. These results were derived using a rather conservative risk assessment approach with an error rate of <10%. The simulations thus indicated that PK studies might be a viable alternative to clinical studies comparing pulmonary efficacy biomarkers for slowly dissolving inhaled drugs. PK trials for pulmonary efficacy equivalence testing should be complemented by in vitro studies to avoid false positive bioequivalence assessments that are theoretically possible for some specific scenarios. Moreover, a user-friendly web application for simulating such PK equivalence trials with inhaled FP is provided.

An unusual insertion/deletion in the gene encoding the β-subunit of propionyl-CoA carboxylase is a frequent mutation in Caucasian propionic acidemia

International Nuclear Information System (INIS)

Tahara, T.; Kraus, J.P.; Rosenberg, L.E.

1990-01-01

Propionic acidemia is an inherited disorder of organic acid metabolism that is caused by deficiency of propionly-CoA carboxylase. Affected patients fall into two complementation groups, pccA and pccBC (subgroups B, C, and BC), resulting from deficiency of the nonidentical α and β subunits of PCC, respectively. The authors have detected an unusual insertion/deletion in the DNA of patients from the pccBC and pccC subgroups that replaces 14 nucleotides in the coding sequence of the β subunit with 12 nucleotides unrelated to this region of the gene. Among 14 unrelated Caucasian patients in the pccBc complementation group, this unique mutation was found in 8 of 28 mutant alleles examined. Mutant allele-specific oligonucleotide hybridization to amplified genomic DNAs revealed that the inserted 12 nucleotides do not originate in an ∼1000-bp region around the mutation. In the course of the investigation, they identified another mutation in the same exon: a 3-bp in-frame deletion that eliminates one of two isoleucine codons immediately preceding the Msp I site. Two unrelated patients were compound heterozygotes for this single-codon deletion and for the insertion/deletion described above. They conclude that either there is a propensity for the PCC β-subunit gene to undergo mutations of this sort at this position or, more likely, the mutations in all of the involved Caucasian patients have a common origin in preceding generations

Purification of Peptide Components including Melittin from Bee Venom using gel filtration chromatography and propionic acid/urea polyacrylamide gel electrophoresis

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Young Chon Choi

2006-06-01

Full Text Available Objectives : This study was conducted to carry out Purification of Melittin and other peptide components from Bee Venom using gel filtration chromatography and propionic acid/urea polyacrylamide gel electrophoresis Methods : Melittin and other peptide components were separated from bee venom by using gel filtration chromatography on Sephadex G-50 column in 0.05M ammonium acetate buffer. Results : Melittin and other peptide components were separated from bee venom by using gel filtration chromatography on Sephadex G-50 column in 0.05M ammonium acetate buffer. The fractions obtained from gel filtration chromatography was analyzed by using SDS-PAGE and propionic acid/urea polyacrylamide gel electrophoresis. The melittin obtained from the gel filtration contained residual amount of phospholipase A2 and a protein with molecular weight of 6,000. The contaminating proteins were removed by the second gel filtration chromatography. Conclusion : Gel filtration chromatography and propionic acid/urea polyacrylamide gel electrophoresis are useful to separate peptide components including melittin from bee venom.

Suitability of combination of calcium propionate and chitosan for preserving minimally processed banana quality.

Science.gov (United States)

Mirshekari, Amin; Madani, Babak; Golding, John B

2017-08-01

The marketability of fresh-cut banana slices is limited by the rapid rate of fruit softening and browning. However, there is no scientific literature available about the role of postharvest calcium propionate and chitosan treatment on the quality attributes of fresh-cut banana. Therefore, the aim of the present study was to investigate these effects. The application of calcium propionate plus chitosan (CaP+Chit) retained higher firmness, higher ascorbic acid content, higher total antioxidant activity and higher total phenolic compounds, along with lower browning, lower polyphenol oxidase, lower peroxidase, lower polygalacturonase and lower pectin methyl esterase activities and microbial growth, compared to control banana slices after 5 days of cold storage. The results of the present study show that CaP+Chit could be used to slow the loss of quality at the same time as maintaining quality and inhibiting microbial loads. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Aspects of anaerobic metabolism in Anodonta cygnea L.

NARCIS (Netherlands)

Holwerda, Dirk A.; Veenhof, P.R.

1984-01-01

1. After 6 days of anoxia A. cygnea had produced 1.0 µmole succinate, 2.7 µmole propionate and 1.7 µmole acetate/g of total soft tissue (wet). In addition, 0.35 µmole glutamate had disappeared. No other changes were detectable. 2. Concentrations of anaerobic end products and of amino acids

Temporal Microbial Community Dynamics in Microbial Electrolysis Cells – Influence of Acetate and Propionate Concentration

KAUST Repository

Rao, Hari Ananda; Venkidusamy, Krishnaveni; Katuri, Krishna; Bagchi, Samik; Saikaly, Pascal

2017-01-01

at low (0.5 g COD/L) and high (4 g COD/L) concentrations of acetate or propionate, which are important intermediates of fermentation of municipal wastewaters and sludge. The results showed that acetate-fed reactors exhibited higher performance in terms

In vitro metabolism of radiolabeled carbohydrates by protective cecal anaerobic bacteria.

Science.gov (United States)

Hume, M E; Beier, R C; Hinton, A; Scanlan, C M; Corrier, D E; Peterson, D V; DeLoach, J R

1993-12-01

Cecal anaerobic bacteria from adult broilers were cultured in media containing .25% glucose or .25% lactose. Media also contained either [14C]-labeled lactose, glucose, galactose, or lactic acid as metabolic tracers. Cultures were analyzed at 4, 8, and 12 h for pH, radiolabeled and unlabeled volatile fatty acids, and lactic acid. The pH values of cultures containing .25% lactose were significantly (P galactose, lactose > glucose. The volatile fatty acids in which radiolabel was most concentrated were acetic acid, propionic acid, or butyric acid.

Detection, phylogeny and population dynamics of syntrophic propionate - oxidizing bacteria in anaerobic granular sludge

NARCIS (Netherlands)

Harmsen, H.J.M.

1996-01-01

The research described this thesis concerns the diversity and phylogeny of syntrophic propionate-oxidizing bacteria and their ecology in granular sludge, from which they were obtained. 16S rRNA was used as a molecular marker to study both the phylogeny and the ecology of these bacteria.

Metabolic Engineering of Oleaginous Yeasts for Production of Fuels and Chemicals

Directory of Open Access Journals (Sweden)

Shuobo Shi

2017-11-01

Full Text Available Oleaginous yeasts have been increasingly explored for production of chemicals and fuels via metabolic engineering. Particularly, there is a growing interest in using oleaginous yeasts for the synthesis of lipid-related products due to their high lipogenesis capability, robustness, and ability to utilize a variety of substrates. Most of the metabolic engineering studies in oleaginous yeasts focused on Yarrowia that already has plenty of genetic engineering tools. However, recent advances in systems biology and synthetic biology have provided new strategies and tools to engineer those oleaginous yeasts that have naturally high lipid accumulation but lack genetic tools, such as Rhodosporidium, Trichosporon, and Lipomyces. This review highlights recent accomplishments in metabolic engineering of oleaginous yeasts and recent advances in the development of genetic engineering tools in oleaginous yeasts within the last 3 years.

Production of vanillin by metabolically engineered Escherichia coli.

Science.gov (United States)

Yoon, Sang-Hwal; Li, Cui; Kim, Ju-Eun; Lee, Sook-Hee; Yoon, Ji-Young; Choi, Myung-Suk; Seo, Weon-Taek; Yang, Jae-Kyung; Kim, Jae-Yeon; Kim, Seon-Won

2005-11-01

E. coli was metabolically engineered to produce vanillin by expression of the fcs and ech genes from Amycolatopsis sp. encoding feruloyl-CoA synthetase and enoyl-CoA hydratase/aldolase, respectively. Vanillin production was optimized by leaky expression of the genes, under the IPTG-inducible trc promoter, in complex 2YT medium. Supplementation with glucose, fructose, galactose, arabinose or glycerol severely decreased vanillin production. The highest vanillin production of 1.1 g l(-1) was obtained with cultivation for 48 h in 2YT medium with 0.2% (w/v) ferulate, without IPTG and no supplementation of carbon sources.

Mini-review: In vitro Metabolic Engineering for Biomanufacturing of High-value Products

Directory of Open Access Journals (Sweden)

Weihua Guo

Full Text Available With the breakthroughs in biomolecular engineering and synthetic biology, many valuable biologically active compound and commodity chemicals have been successfully manufactured using cell-based approaches in the past decade. However, because of the high complexity of cell metabolism, the identification and optimization of rate-limiting metabolic pathways for improving the product yield is often difficult, which represents a significant and unavoidable barrier of traditional in vivo metabolic engineering. Recently, some in vitro engineering approaches were proposed as alternative strategies to solve this problem. In brief, by reconstituting a biosynthetic pathway in a cell-free environment with the supplement of cofactors and substrates, the performance of each biosynthetic pathway could be evaluated and optimized systematically. Several value-added products, including chemicals, nutraceuticals, and drug precursors, have been biosynthesized as proof-of-concept demonstrations of in vitro metabolic engineering. This mini-review summarizes the recent progresses on the emerging topic of in vitro metabolic engineering and comments on the potential application of cell-free technology to speed up the “design-build-test” cycles of biomanufacturing. Keywords: Cell-free, Biosynthesis, Metabolic pathways, Design-build-test cycle

Interspecies Electron Transfer during Propionate and Butyrate Degradation in Mesophilic, Granular Sludge

OpenAIRE

Schmidt, J. E.; Ahring, B. K.

1995-01-01

Granules from a mesophilic upflow anaerobic sludge blanket reactor were disintegrated, and bacteria utilizing only hydrogen or formate or both hydrogen and formate were added to investigate the role of interspecies electron transfer during degradation of propionate and butyrate. The data indicate that the major electron transfer occurred via interspecies hydrogen transfer, while interspecies formate transfer may not be essential for interspecies electron transfer in this system during degrada...

Fumaric acid production in Saccharomyces cerevisiae by in silico aided metabolic engineering.

Directory of Open Access Journals (Sweden)

Guoqiang Xu

Full Text Available Fumaric acid (FA is a promising biomass-derived building-block chemical. Bio-based FA production from renewable feedstock is a promising and sustainable alternative to petroleum-based chemical synthesis. Here we report on FA production by direct fermentation using metabolically engineered Saccharomyces cerevisiae with the aid of in silico analysis of a genome-scale metabolic model. First, FUM1 was selected as the target gene on the basis of extensive literature mining. Flux balance analysis (FBA revealed that FUM1 deletion can lead to FA production and slightly lower growth of S. cerevisiae. The engineered S. cerevisiae strain obtained by deleting FUM1 can produce FA up to a concentration of 610±31 mg L(-1 without any apparent change in growth in fed-batch culture. FT-IR and (1H and (13C NMR spectra confirmed that FA was synthesized by the engineered S. cerevisiae strain. FBA identified pyruvate carboxylase as one of the factors limiting higher FA production. When the RoPYC gene was introduced, S. cerevisiae produced 1134±48 mg L(-1 FA. Furthermore, the final engineered S. cerevisiae strain was able to produce 1675±52 mg L(-1 FA in batch culture when the SFC1 gene encoding a succinate-fumarate transporter was introduced. These results demonstrate that the model shows great predictive capability for metabolic engineering. Moreover, FA production in S. cerevisiae can be efficiently developed with the aid of in silico metabolic engineering.

Comparative study of hop-containing products on human cytochrome p450-mediated metabolism.

Science.gov (United States)

Foster, Brian C; Kearns, Nikia; Arnason, John T; Saleem, Ammar; Ogrodowczyk, Carolina; Desjardins, Suzanne

2009-06-10

Thirty-five national and international brands of beer were examined for their potential to affect human cytochrome P450 (CYP)-mediated metabolism. They represented the two main categories of beer, ales and lagers, and included a number of specialty products including bitter (porter, stout), coffee, ice, wheat, Pilsner, and hemp seed. Aliquots were examined for nonvolatile soluble solids, effect on CYP metabolism and P-glycoprotein (Pgp) transport, and major alpha- and beta-hop acids. Wide variance was detected in contents of alcohol, nonvolatile suspended solids, and hop acids and in the potential to affect CYP-mediated metabolism and Pgp-mediated efflux transport. Many of the products affected CYP2C9-mediated metabolism, and only two (NRP 306 and 307) markedly affected CYP3A4; hence, some products have the capacity to affect drug safety. CYP3A4, CYP3A5, CYP3A7, and CYP19 (aromatase) inhibition to the log concentration of beta-acid content was significant with r(2) > 0.37, suggesting that these components can account for some of the variation in inhibition of CYP metabolism.

Postprandial glucose metabolism and SCFA after consuming wholegrain rye bread and wheat bread enriched with bioprocessed rye bran in individuals with mild gastrointestinal symptoms

DEFF Research Database (Denmark)

Lappi, J; Mykkänen, H; Knudsen, Knud Erik Bach

2014-01-01

BackgroundRye bread benefits glucose metabolism. It is unknown whether the same effect is achieved by rye bran-enriched wheat bread. We tested whether white wheat bread enriched with bioprocessed rye bran (BRB + WW) and sourdough wholegrain rye bread (WGR) have similar effects on glucose metabolism...... and plasma level of short chain fatty acids (SCFAs).  MethodsTwenty-one (12 women) of 23 recruited subjects completed an intervention with a four-week run-in and two four-week test periods in cross-over design. White wheat bread (WW; 3% fibre) was consumed during the run-in, and WGR and BRB + WW (10% fibre.......05) and propionate (p = 0.009) at 30 min increased during both rye bread periods.ConclusionsBeneficial effects of WGR over white wheat bread on glucose and SCFA production were confirmed. The enrichment of the white wheat bread with bioprocessed rye bran (BRB + WW) yielded similar but not as pronounced effects than...

Production of anthocyanins in metabolically engineered microorganisms: Current status and perspectives

Directory of Open Access Journals (Sweden)

Jian Zha

2017-12-01

Full Text Available Microbial production of plant-derived natural products by engineered microorganisms has achieved great success thanks to large extend to metabolic engineering and synthetic biology. Anthocyanins, the water-soluble colored pigments found in terrestrial plants that are responsible for the red, blue and purple coloration of many flowers and fruits, are extensively used in food and cosmetics industry; however, their current supply heavily relies on complex extraction from plant-based materials. A promising alternative is their sustainable production in metabolically engineered microbes. Here, we review the recent progress on anthocyanin biosynthesis in engineered bacteria, with a special focus on the systematic engineering modifications such as selection and engineering of biosynthetic enzymes, engineering of transportation, regulation of UDP-glucose supply, as well as process optimization. These promising engineering strategies will facilitate successful microbial production of anthocyanins in industry in the near future.

Metabolic engineering with systems biology tools to optimize production of prokaryotic secondary metabolites

DEFF Research Database (Denmark)

Kim, Hyun Uk; Charusanti, Pep; Lee, Sang Yup

2016-01-01

Metabolic engineering using systems biology tools is increasingly applied to overproduce secondary metabolites for their potential industrial production. In this Highlight, recent relevant metabolic engineering studies are analyzed with emphasis on host selection and engineering approaches...... for the optimal production of various prokaryotic secondary metabolites: native versus heterologous hosts (e.g., Escherichia coli) and rational versus random approaches. This comparative analysis is followed by discussions on systems biology tools deployed in optimizing the production of secondary metabolites....... The potential contributions of additional systems biology tools are also discussed in the context of current challenges encountered during optimization of secondary metabolite production....

Metabolic Engineering of Microorganisms for the Production of Higher Alcohols

Science.gov (United States)

Choi, Yong Jun; Lee, Joungmin; Jang, Yu-Sin

2014-01-01

ABSTRACT Due to the increasing concerns about limited fossil resources and environmental problems, there has been much interest in developing biofuels from renewable biomass. Ethanol is currently used as a major biofuel, as it can be easily produced by existing fermentation technology, but it is not the best biofuel due to its low energy density, high vapor pressure, hygroscopy, and incompatibility with current infrastructure. Higher alcohols, including 1-propanol, 1-butanol, isobutanol, 2-methyl-1-butanol, and 3-methyl-1-butanol, which possess fuel properties more similar to those of petroleum-based fuel, have attracted particular interest as alternatives to ethanol. Since microorganisms isolated from nature do not allow production of these alcohols at high enough efficiencies, metabolic engineering has been employed to enhance their production. Here, we review recent advances in metabolic engineering of microorganisms for the production of higher alcohols. PMID:25182323

Desulfomusa hansenii gen. nov., sp. nov., a novel marine propionate-degrading, sulfate-reducing bacterium isolated from Zostera marina roots.

Science.gov (United States)

Finster, K; Thomsen, T R; Ramsing, N B

2001-11-01

The physiology and phylogeny of a novel sulfate-reducing bacterium, isolated from surface-sterilized roots of the marine macrophyte Zostera marina, are presented. The strain, designated P1T, was enriched and isolated in defined oxygen-free, bicarbonate-buffered, iron-reduced seawater medium with propionate as sole carbon source and electron donor and sulfate as electron acceptor. Strain P1T had a rod-shaped, slightly curved cell morphology and was motile by means of a single polar flagellum. Cells generally aggregated in clumps throughout the growth phase. High CaCl2 (10 mM) and MgCl2 (50 mM) concentrations were required for optimum growth. In addition to propionate, strain P1T utilized fumarate, succinate, pyruvate, ethanol, butanol and alanine. Oxidation of propionate was incomplete and acetate was formed in stoichiometric amounts. Strain P1T thus resembles members of the sulfate-reducing genera Desulfobulbus and Desulforhopalus, which both oxidize propionate incompletely and form acetate in addition to CO2. However, sequence analysis of the small-subunit rDNA and the dissimilatory sulfite reductase gene revealed that strain P1T was unrelated to the incomplete oxidizers Desulfobulbus and Desulforhopalus and that it constitutes a novel lineage affiliated with the genera Desulfococcus, Desulfosarcina, Desulfonema and 'Desulfobotulus'. Members of this branch, with the exception of 'Desulfobotulus sapovorans', oxidize a variety of substrates completely to CO2. Strain P1T (= DSM 12642T = ATCC 700811T) is therefore proposed as Desulfomusa hansenii gen. nov., sp. nov. Strain p1T thus illustrates the difficulty of extrapolating rRNA similarities to physiology and/or ecological function.

Yeast cell metabolism investigated by CO{_2} production and soft X-ray irradiation

Science.gov (United States)

Masini, A.; Batani, D.; Previdi, F.; Milani, M.; Pozzi, A.; Turcu, E.; Huntington, S.; Takeyasu, H.

1999-01-01

Results obtained using a new technique for studying cell metabolism are presented. The technique, consisting in CO2 production monitoring, has been applied to Saccharomyces cerevisiae yeast cells. Also the cells were irradiated using the soft X-ray laser-plasma source at Rutherford Appleton Laboratory with the aim of producing a damage of metabolic processes at the wall level, responsible for fermentation, without great interference with respiration, taking place in mitochondria, and DNA activity. The source was calibrated with PIN diodes and X-ray spectrometers and used Teflon stripes as target, emitting X-rays at about 0.9 keV, with a very low penetration in biological material. X-ray doses delivered to the different cell compartments were calculated following a Lambert-Bouguet-Beer law. Immediately after irradiation, the damage to metabolic activity was measured again by monitoring CO2 production. Results showed a general reduction in gas production by irradiated samples, together with non-linear and non-monotone response to dose. There was also evidence of oscillations in cell metabolic activity and of X-ray induced changes in oscillation frequency.

Anaerobic treatment of cassava stillage for hydrogen and methane production in continuously stirred tank reactor (CSTR) under high organic loading rate (OLR)

Energy Technology Data Exchange (ETDEWEB)

Luo, Gang; Xie, Li; Zou, Zhonghai; Wang, Wen; Zhou, Qi [Key Laboratory of Yangtze River Water Environment, Ministry of Education (Tongji University), UNEP-Tongji, Tongji University, Siping Road No. 1239, Shanghai 200092 (China); Shim, Hojae [Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau SAR 999078 (China)

2010-11-15

Anaerobic hydrogen and methane production from cassava stillage in continuously stirred tank reactor (CSTR) were investigated in this study. Results showed that the heat-pretreatment of inoculum did not enhance hydrogen yield compared to raw inoculum under mesophilic condition after continuous operation. However, the hydrogen yield increased from about 14 ml H{sub 2}/gVS under mesophilic condition to 69.6 ml H{sub 2}/gVS under thermophilic condition due to the decrease of propionate concentration and inhibition of homoacetogens. Therefore, temperature was demonstrated to be more important than pretreatment of inoculum to enhance the hydrogen production. Under high organic loading rate (OLR) (>10 gVS/(L.d)), the two-phase thermophilic CSTR for hydrogen and methane production was stable with hydrogen and methane yields of 56.6 mlH{sub 2}/gVS and 249 mlCH{sub 4}/gVS. The one-phase thermophilic CSTR for methane production failed due to the accumulation of both acetate and propionate, leading to the pH lower than 6. Instead of propionate alone, the accumulations of both acetate and propionate were found to be related to the breakdown of methane reactor. (author)

Effect of feeding a by-product feed-based silage on nutrients intake, apparent digestibility, and nitrogen balance in sheep.

Science.gov (United States)

Seok, J S; Kim, Y I; Lee, Y H; Choi, D Y; Kwak, W S

2016-01-01

Literature is lacking on the effects of feeding by-product feed (BF)-based silage on rumen fermentation parameters, nutrient digestion and nitrogen (N) retention in sheep. Therefore, this study was conducted to determine the effect of replacing rye straw with BF-based silage as a roughage source on ruminal parameters, total-tract apparent nutrient digestibility, and N balance in sheep. The by-product feed silage was composed of spent mushroom substrate (SMS) (45 %), recycled poultry bedding (RPB) (21 %), rye straw (11 %), rice bran (10.8 %), corn taffy residue (10 %), protected fat (1.0 %), bentonite (0.6 %), and mixed microbial additive (0.6 %). Six sheep were assigned randomly to either the control (concentrate mix + rye straw) or a treatment diet (concentrate mix + BF-based silage). Compared with the control diet, feeding a BF-based silage diet resulted in similar ruminal characteristics (pH, acetate, propionate, and butyrate concentrations, and acetate: propionate ratio), higher (p < 0.05) ruminal NH3-N, higher (p < 0.05) ether extract digestibility, similar crude protein digestibility, lower (p < 0.05) dry matter, fiber, and crude ash digestibilities, and higher (p < 0.05) N retention (g/d). The BF-based silage showed similar energy value, higher protein metabolism and utilization, and lower fiber digestion in sheep compared to the control diet containing rye straw.

Defect states and room temperature ferromagnetism in cerium oxide nanopowders prepared by decomposition of Ce-propionate

DEFF Research Database (Denmark)

Mihalache, V.; Grivel, J. C.; Secu, M.

2018-01-01

. An improvement of ferromagnetism and intensity of defect-related PL emission was observed when annealing the products in which nanocrystalline cerium oxide coexists with Ce - oxicarbonate traces, Ce2O2CO3. The experimental results were explained based on the following considerations: room temperature......Four batches of cerium oxide powders (with nanocrystallite size of 6.9 nm–572 nm) were prepared from four precursor nanopowders by thermal decomposition of Ce-propionate and annealing in air between 250 °C–1200 °C for 10 min–240 min. Ceria formation reactions, structure, vibrational, luminescence...... and magnetic properties were investigated by differential scanning calorimetry, x-ray diffraction, electron microscopy, infrared spectroscopy, photoluminescence and SQUID. All the samples exhibit room temperature ferromagnetism, RTFM, (with coercivity, Hc, of 8 Oe - 121 Oe and saturation magnetization, Ms...

Metabolic engineering in chemolithoautotrophic hosts for the production of fuels and chemicals.

Science.gov (United States)

Nybo, S Eric; Khan, Nymul E; Woolston, Benjamin M; Curtis, Wayne R

2015-07-01

The ability of autotrophic organisms to fix CO2 presents an opportunity to utilize this 'greenhouse gas' as an inexpensive substrate for biochemical production. Unlike conventional heterotrophic microorganisms that consume carbohydrates and amino acids, prokaryotic chemolithoautotrophs have evolved the capacity to utilize reduced chemical compounds to fix CO2 and drive metabolic processes. The use of chemolithoautotrophic hosts as production platforms has been renewed by the prospect of metabolically engineered commodity chemicals and fuels. Efforts such as the ARPA-E electrofuels program highlight both the potential and obstacles that chemolithoautotrophic biosynthetic platforms provide. This review surveys the numerous advances that have been made in chemolithoautotrophic metabolic engineering with a focus on hydrogen oxidizing bacteria such as the model chemolithoautotrophic organism (Ralstonia), the purple photosynthetic bacteria (Rhodobacter), and anaerobic acetogens. Two alternative strategies of microbial chassis development are considered: (1) introducing or enhancing autotrophic capabilities (carbon fixation, hydrogen utilization) in model heterotrophic organisms, or (2) improving tools for pathway engineering (transformation methods, promoters, vectors etc.) in native autotrophic organisms. Unique characteristics of autotrophic growth as they relate to bioreactor design and process development are also discussed in the context of challenges and opportunities for genetic manipulation of organisms as production platforms. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Temporal Microbial Community Dynamics in Microbial Electrolysis Cells – Influence of Acetate and Propionate Concentration

KAUST Repository

Rao, Hari Ananda

2017-07-20

Microbial electrolysis cells (MECs) are widely considered as a next generation wastewater treatment system. However, fundamental insight on the temporal dynamics of microbial communities associated with MEC performance under different organic types with varied loading concentrations is still unknown, nevertheless this knowledge is essential for optimizing this technology for real-scale applications. Here, the temporal dynamics of anodic microbial communities associated with MEC performance was examined at low (0.5 g COD/L) and high (4 g COD/L) concentrations of acetate or propionate, which are important intermediates of fermentation of municipal wastewaters and sludge. The results showed that acetate-fed reactors exhibited higher performance in terms of maximum current density (I: 4.25 ± 0.23 A/m), coulombic efficiency (CE: 95 ± 8%), and substrate degradation rate (98.8 ± 1.2%) than propionate-fed reactors (I: 2.7 ± 0.28 A/m; CE: 68 ± 9.5%; substrate degradation rate: 84 ± 13%) irrespective of the concentrations tested. Despite of the repeated sampling of the anodic biofilm over time, the high-concentration reactors demonstrated lower and stable performance in terms of current density (I: 1.1 ± 0.14 to 4.2 ± 0.21 A/m), coulombic efficiency (CE: 44 ± 4.1 to 103 ± 7.2%) and substrate degradation rate (64.9 ± 6.3 to 99.7 ± 0.5%), while the low-concentration reactors produced higher and dynamic performance (I: 1.1 ± 0.12 to 4.6 ± 0.1 A/m; CE: 52 ± 2.5 to 105 ± 2.7%; substrate degradation rate: 87.2 ± 0.2 to 99.9 ± 0.06%) with the different substrates tested. Correlating reactor\\'s performance with temporal dynamics of microbial communities showed that relatively similar anodic microbial community composition but with varying relative abundances was observed in all the reactors despite differences in the substrate and concentrations tested. Particularly, Geobacter was the predominant bacteria on the anode biofilm of all MECs over time suggesting its

Central carbon metabolism influences cellulase production in Bacillus licheniformis.

Science.gov (United States)

Wang, J; Liu, S; Li, Y; Wang, H; Xiao, S; Li, C; Liu, B

2018-01-01

Bacillus licheniformis that can produce cellulase including endo glucanase and glucosidase is an important industrial microbe for cellulose degradation. The purpose of this research was to assess the effect of endo glucanase gene bglC and glucosidase gene bglH on the central metabolic flux in B. licheniformis. bglC and bglH were knocked out using homologous recombination method, respectively, and the corresponding knockout strains were obtained for 13 C metabolic flux analysis. A significant change was observed in metabolic fluxes after 13 C metabolic flux ratio analysis. In both of the knockout strains, the increased fluxes of the pentose phosphate pathway and malic enzyme reaction enabled an elevated supply of NADPH which provided enough reducing power for the in vivo synthesis reactions. The fluxes through tricarboxylic acid cycle and anaplerotic reactions increased fast in the two knockout strains, which meant more energy generated. The changed fluxes in central carbon metabolism provided a holistic view of the physiological status in B. licheniformis and possible targets for further strain engineering. Cellulase is very important in the field of agriculture and bioenergy because of its degrading effect on cellulosic biomass. This study presented the effect of central carbon metabolism on cellulase production in Bacillus licheniformis. The study also provided a holistic view of the physiological status in B. licheniformis. The shifted metabolism provided a quantitative evaluation of the biosynthesis of cellulase and a priority ranked target list for further strain engineering. © 2017 The Society for Applied Microbiology.

A bacterial population analysis of granular sludge from an anaerobic digester treating a maize-processing waste

Energy Technology Data Exchange (ETDEWEB)

Howgrave-Graham, A.R.; Wallis, F.M. (Natal Univ., Pietermaritzburg (ZA). Dept. of Microbiology and Plant Pathology); Steyn, P.L. (Pretoria Univ. (South Africa))

1991-01-01

Microbial population studies were conducted on a dense granular sludge, with excellent settling, thickening and nutrient removal properties, from a South African clarigester treating effluent from a factory producing glucose and other carbohydrates from maize. The bacterial population comprised a heterogeneous group including acetogens, enterobacteria, sulphate-reducers, spirochaetes, heterofermentative lactobacilli and methanogens. The presence of these bacteria and lack of propionic acid and butyric acid bacteria suggests that the microbial activity of this anaerobic digester involved acetate and lactate metabolism rather than propionate or butyrate catabolism as a source of precursors for methane production. (author).

Neurotransmitter alteration in a testosterone propionate-induced polycystic ovarian syndrome rat model.

Science.gov (United States)

Chaudhari, Nirja K; Nampoothiri, Laxmipriya P

2017-02-01

Polycystic ovarian syndrome (PCOS), one of the leading causes of infertility seen in women, is characterized by anovulation and hyperandrogenism, resulting in ovarian dysfunction. In addition, associations of several metabolic complications like insulin resistance, obesity, dyslipidemia and psychological co-morbidities are well known in PCOS. One of the major factors influencing mood and the emotional state of mind is neurotransmitters. Also, these neurotransmitters are very crucial for GnRH release. Hence, the current study investigates the status of neurotransmitters in PCOS. A PCOS rat model was developed using testosterone. Twenty-one-day-old rats were subcutaneously injected with 10 mg/kg body weight of testosterone propionate (TP) for 35 days. The animals were validated for PCOS characteristics by monitoring estrus cyclicity, serum testosterone and estradiol levels and by histological examination of ovarian sections. Neurotransmitter estimation was carried out using fluorometric and spectrophotometric methods. TP-treated animals demonstrated increased serum testosterone levels with unaltered estradiol content, disturbed estrus cyclicity and many peripheral cysts in the ovary compared to control rats mimicking human PCOS. Norepinephrine (NE), dopamine, serotonin, γ-amino butyric acid (GABA) and epinephrine levels were significantly low in TP-induced PCOS rats compared to control ones, whereas the activity of acetylcholinesterase in the PCOS brain was markedly elevated. Neurotransmitter alteration could be one of the reasons for disturbed gonadotropin-releasing hormone (GnRH) release, consequently directing the ovarian dysfunction in PCOS. Also, decrease in neurotransmitters, mainly NE, serotonin and dopamine (DA) attributes to mood disorders like depression and anxiety in PCOS.

Set anode potentials affect the electron fluxes and microbial community structure in propionate-fed microbial electrolysis cells

KAUST Repository

Rao, Hari Ananda; Katuri, Krishna; Logan, Bruce E.; Saikaly, Pascal

2016-01-01

, but their relative abundance varied among the tested SAPs. Microbial community analysis implies that complete degradation of propionate in all the tested SAPs was facilitated by syntrophic interactions between fermenters and Geobacter at the anode and ferementers

Impact of temperature and substrate concentration on degradation rates of acetate, propionate and hydrogen and their links to microbial community structure.

Science.gov (United States)

Zhao, Jing; Westerholm, Maria; Qiao, Wei; Yin, Dongmin; Bi, Shaojie; Jiang, Mengmeng; Dong, Renjie

2018-05-01

The present study investigates the conversion of acetate, propionate and hydrogen consumption linked to the microbial community structure and related to temperature and substrate concentration. Biogas reactors were continuously fed with coffee powder (20 g-COD/L) or acetate (20, 40, and 60 g-COD/L) and operated for 193 days at 37 °C or 55 °C conditions. Starting HRT was 23 days which was then reduced to 7 days. The kinetics of acetate and propionate degradation and hydrogen consumption rates were measured in batch assays. At HRT 7 days, the degradation rate of propionate was higher in thermophilic batches, while acetate degradation rate was higher at mesophilic conditions. The gaseous hydrogen consumption in acetate reactors increased proportionally with temperature and substrate concentration, while the dissolved hydrogen was not affected. The relative high abundance of hydrogentrophic methanogens indicated that the methanogenesis was directed towards the syntrophic acetate oxidation pathway at high acetate concentration and high temperature. Copyright © 2018 Elsevier Ltd. All rights reserved.

The Genome-Based Metabolic Systems Engineering to Boost Levan Production in a Halophilic Bacterial Model.

Science.gov (United States)

Aydin, Busra; Ozer, Tugba; Oner, Ebru Toksoy; Arga, Kazim Yalcin

2018-03-01

Metabolic systems engineering is being used to redirect microbial metabolism for the overproduction of chemicals of interest with the aim of transforming microbial hosts into cellular factories. In this study, a genome-based metabolic systems engineering approach was designed and performed to improve biopolymer biosynthesis capability of a moderately halophilic bacterium Halomonas smyrnensis AAD6 T producing levan, which is a fructose homopolymer with many potential uses in various industries and medicine. For this purpose, the genome-scale metabolic model for AAD6 T was used to characterize the metabolic resource allocation, specifically to design metabolic engineering strategies for engineered bacteria with enhanced levan production capability. Simulations were performed in silico to determine optimal gene knockout strategies to develop new strains with enhanced levan production capability. The majority of the gene knockout strategies emphasized the vital role of the fructose uptake mechanism, and pointed out the fructose-specific phosphotransferase system (PTS fru ) as the most promising target for further metabolic engineering studies. Therefore, the PTS fru of AAD6 T was restructured with insertional mutagenesis and triparental mating techniques to construct a novel, engineered H. smyrnensis strain, BMA14. Fermentation experiments were carried out to demonstrate the high efficiency of the mutant strain BMA14 in terms of final levan concentration, sucrose consumption rate, and sucrose conversion efficiency, when compared to the AAD6 T . The genome-based metabolic systems engineering approach presented in this study might be considered an efficient framework to redirect microbial metabolism for the overproduction of chemicals of interest, and the novel strain BMA14 might be considered a potential microbial cell factory for further studies aimed to design levan production processes with lower production costs.

The composition and metabolism of faecal microbiota is specifically modulated by different dietary polysaccharides and mucin: an isothermal microcalorimetry study.

Science.gov (United States)

Adamberg, K; Kolk, K; Jaagura, M; Vilu, R; Adamberg, S

2018-01-29

The metabolic activity of colon microbiota is specifically affected by fibres with various monomer compositions, degree of polymerisation and branching. The supply of a variety of dietary fibres assures the diversity of gut microbial communities considered important for the well-being of the host. The aim of this study was to compare the impact of different oligo- and polysaccharides (galacto- and fructooligosaccharides, resistant starch, levan, inulin, arabinogalactan, xylan, pectin and chitin), and a glycoprotein mucin on the growth and metabolism of faecal microbiota in vitro by using isothermal microcalorimetry (IMC). Faecal samples from healthy donors were incubated in a phosphate-buffered defined medium with or without supplementation of a single substrate. The generation of heat was followed on-line, microbiota composition (V3-V4 region of the 16S rRNA using Illumina MiSeq v2) and concentrations of metabolites (HPLC) were determined at the end of growth. The multiauxic power-time curves obtained were substrate-specific. More than 70% of all substrates except chitin were fermented by faecal microbiota with total heat generation of up to 8 J/ml. The final metabolite patterns were in accordance with the microbiota changes. For arabinogalactan, xylan and levan, the fibre-affected distribution of bacterial taxa showed clear similarities (e.g. increase of Bacteroides ovatus and decrease of Bifidobacterium adolescentis). The formation of propionic acid, an important colon metabolite, was enhanced by arabinogalactan, xylan and mucin but not by galacto- and fructooligosaccharides or inulin. Mucin fermentation resulted in acetate, propionate and butyrate production in ratios previously observed for faecal samples, indicating that mucins may serve as major substrates for colon microbial population. IMC combined with analytical methods was shown to be an effective method for screening the impact of specific dietary fibres on functional changes in faecal microbiota.

Computational metabolic engineering strategies for growth-coupled biofuel production by Synechocystis

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Kiyan Shabestary

2016-12-01

Full Text Available Chemical and fuel production by photosynthetic cyanobacteria is a promising technology but to date has not reached competitive rates and titers. Genome-scale metabolic modeling can reveal limitations in cyanobacteria metabolism and guide genetic engineering strategies to increase chemical production. Here, we used constraint-based modeling and optimization algorithms on a genome-scale model of Synechocystis PCC6803 to find ways to improve productivity of fermentative, fatty-acid, and terpene-derived fuels. OptGene and MOMA were used to find heuristics for knockout strategies that could increase biofuel productivity. OptKnock was used to find a set of knockouts that led to coupling between biofuel and growth. Our results show that high productivity of fermentation or reversed beta-oxidation derived alcohols such as 1-butanol requires elimination of NADH sinks, while terpenes and fatty-acid based fuels require creating imbalances in intracellular ATP and NADPH production and consumption. The FBA-predicted productivities of these fuels are at least 10-fold higher than those reported so far in the literature. We also discuss the physiological and practical feasibility of implementing these knockouts. This work gives insight into how cyanobacteria could be engineered to reach competitive biofuel productivities. Keywords: Cyanobacteria, Modeling, Flux balance analysis, Biofuel, MOMA, OptFlux, OptKnock

Impact of synthetic biology and metabolic engineering on industrial production of fine chemicals

DEFF Research Database (Denmark)

Jullesson, David; David, Florian; Pfleger, Brian

2015-01-01

Industrial bio-processes for fine chemical production are increasingly relying on cell factories developed through metabolic engineering and synthetic biology. The use of high throughput techniques and automation for the design of cell factories, and especially platform strains, has played...... chemicals that have reached the market, key metabolic engineering tools that have allowed this to happen and some of the companies that are currently utilizing these technologies for developing industrial production processes....... an important role in the transition from laboratory research to industrial production. Model organisms such as Saccharomyces cerevisiae and Escherichia coli remain widely used host strains for industrial production due to their robust and desirable traits. This review describes some of the bio-based fine...

Specific substrate-driven changes in human faecal microbiota composition contrast with functional redundancy in short-chain fatty acid production.

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Reichardt, Nicole; Vollmer, Maren; Holtrop, Grietje; Farquharson, Freda M; Wefers, Daniel; Bunzel, Mirko; Duncan, Sylvia H; Drew, Janice E; Williams, Lynda M; Milligan, Graeme; Preston, Thomas; Morrison, Douglas; Flint, Harry J; Louis, Petra

2018-02-01

The diet provides carbohydrates that are non-digestible in the upper gut and are major carbon and energy sources for the microbial community in the lower intestine, supporting a complex metabolic network. Fermentation produces the short-chain fatty acids (SCFAs) acetate, propionate and butyrate, which have health-promoting effects for the human host. Here we investigated microbial community changes and SCFA production during in vitro batch incubations of 15 different non-digestible carbohydrates, at two initial pH values with faecal microbiota from three different human donors. To investigate temporal stability and reproducibility, a further experiment was performed 1 year later with four of the carbohydrates. The lower pH (5.5) led to higher butyrate and the higher pH (6.5) to more propionate production. The strongest propionigenic effect was found with rhamnose, followed by galactomannans, whereas fructans and several α- and β-glucans led to higher butyrate production. 16S ribosomal RNA gene-based quantitative PCR analysis of 22 different microbial groups together with 454 sequencing revealed significant stimulation of specific bacteria in response to particular carbohydrates. Some changes were ascribed to metabolite cross-feeding, for example, utilisation by Eubacterium hallii of 1,2-propanediol produced from fermentation of rhamnose by Blautia spp. Despite marked inter-individual differences in microbiota composition, SCFA production was surprisingly reproducible for different carbohydrates, indicating a level of functional redundancy. Interestingly, butyrate formation was influenced not only by the overall % butyrate-producing bacteria in the community but also by the initial pH, consistent with a pH-dependent shift in the stoichiometry of butyrate production.

Metabolic changes during B cell differentiation for the production of intestinal IgA antibody.

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Kunisawa, Jun

2017-04-01

To sustain the bio-energetic demands of growth, proliferation, and effector functions, the metabolism of immune cells changes dramatically in response to immunologic stimuli. In this review, I focus on B cell metabolism, especially regarding the production of intestinal IgA antibody. Accumulating evidence has implicated not only host-derived factors (e.g., cytokines) but also gut environmental factors, including the possible involvement of commensal bacteria and diet, in the control of B cell metabolism during intestinal IgA antibody production. These findings yield new insights into the regulation of immunosurveillance and homeostasis in the gut.

Resolution, configurational assignment, and enantiopharmacology at glutamate receptors of 2-amino-3-(3-carboxy-5-methyl-4-isoxazolyl)propionic acid (ACPA) and demethyl-ACPA

DEFF Research Database (Denmark)

Johansen, T N; Stensbøl, T B; Nielsen, B

2001-01-01

We have previously described (RS)-2-amino-3-(3-carboxy-5-methyl-4-isoxazolyl)propionic acid (ACPA) as a potent agonist at the (RS)-2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid (AMPA) receptor subtype of (S)-glutamic acid (Glu) receptors. We now report the chromatographic resolution...... of ACPA and (RS)-2-amino-3-(3-carboxy-4-isoxazolyl)propionic acid (demethyl-ACPA) using a Sumichiral OA-5000 column. The configuration of the enantiomers of both compounds have been assigned based on X-ray crystallographic analyses, supported by circular dichroism spectra and elution orders on chiral HPLC...... columns. Furthermore, the enantiopharmacology of ACPA and demethyl-ACPA was investigated using radioligand binding and cortical wedge electrophysiological assay systems and cloned metabotropic Glu receptors. (S)-ACPA showed high affinity in AMPA binding (IC(50) = 0.025 microM), low affinity in kainic acid...

Metabolic flux profiling of MDCK cells during growth and canine adenovirus vector production.

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Carinhas, Nuno; Pais, Daniel A M; Koshkin, Alexey; Fernandes, Paulo; Coroadinha, Ana S; Carrondo, Manuel J T; Alves, Paula M; Teixeira, Ana P

2016-03-23

Canine adenovirus vector type 2 (CAV2) represents an alternative to human adenovirus vectors for certain gene therapy applications, particularly neurodegenerative diseases. However, more efficient production processes, assisted by a greater understanding of the effect of infection on producer cells, are required. Combining [1,2-(13)C]glucose and [U-(13)C]glutamine, we apply for the first time (13)C-Metabolic flux analysis ((13)C-MFA) to study E1-transformed Madin-Darby Canine Kidney (MDCK) cells metabolism during growth and CAV2 production. MDCK cells displayed a marked glycolytic and ammoniagenic metabolism, and (13)C data revealed a large fraction of glutamine-derived labelling in TCA cycle intermediates, emphasizing the role of glutamine anaplerosis. (13)C-MFA demonstrated the importance of pyruvate cycling in balancing glycolytic and TCA cycle activities, as well as occurrence of reductive alphaketoglutarate (AKG) carboxylation. By turn, CAV2 infection significantly upregulated fluxes through most central metabolism, including glycolysis, pentose-phosphate pathway, glutamine anaplerosis and, more prominently, reductive AKG carboxylation and cytosolic acetyl-coenzyme A formation, suggestive of increased lipogenesis. Based on these results, we suggest culture supplementation strategies to stimulate nucleic acid and lipid biosynthesis for improved canine adenoviral vector production.

Effects of ionophores and antibiotics on in vitro hydrogen sulfide production, dry matter disappearance, and total gas production in cultures with a steam-flaked corn-based substrate with or without added sulfur.

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Quinn, M J; May, M L; Hales, K E; DiLorenzo, N; Leibovich, J; Smith, D R; Galyean, M L

2009-05-01

Effects of 3 ionophores and 2 antibiotics on in vitro H(2)S production, IVDMD, total gas production, and VFA profile with or without added S were examined. In Exp. 1, ruminal fluid from 2 ruminally cannulated steers fed a steam-flaked corn-based diet (75% concentrate) without ionophore and antibiotics for 28 d before collection was used to inoculate in vitro cultures. Treatments were control (no ionophore or antibiotic), 3 ionophores (lasalocid sodium and monensin sodium at 5 mg/L or laidlomycin propionate at 1.65 mg/L), and 2 antibiotics (chlortetracycline hydrochloride at 5 mg/L and tylosin tartarate at 1.25 mg/L). Cultures also had 0 or 1.75 mg of S/L (from sodium sulfate). No S x ionophore-antibiotic treatment interactions were noted (P > 0.53) for IVDMD, total gas production, and H(2)S production. Hydrogen sulfide (mumol/g of fermentable DM) was increased (P production tended (P = 0.09) to be increased with additional S; however, IVDMD was not affected by added S (P = 0.90). Production of H(2)S was not affected by ionophores or antibiotics (P > 0.18). On average, IVDMD (P = 0.05) was greater for ionophores than for antibiotics, whereas total gas production was less for ionophores than for control (P antibiotics (P 0.20) in acetate, propionate, or acetate:propionate between ionophores and control (S x treatment interaction, P = 0.03). In Exp. 2, the effects of ionophore-antibiotic combinations with added S were examined using the same procedures as in Exp. 1. Treatments were control, monensin plus tylosin (MT), and lasalocid plus chlortetracycline (LCTC), with concentrations of the ionophores and antibiotics as in Exp. 1. No differences were observed among treatments for H(2)S production (P > 0.55). Treatments MT and LCTC tended (P = 0.06) to increase IVDMD and decreased (P = 0.02) gas production vs. control. Proportion of acetate (P = 0.01) and acetate:propionate (P antibiotics we evaluated did not affect production of H(2)S gas in an in vitro rumen culture

Regulation of metabolic products and gene expression in Fusarium asiaticum by agmatine addition.

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Suzuki, Tadahiro; Kim, Young-Kyung; Yoshioka, Hifumi; Iwahashi, Yumiko

2013-05-01

The metabolic products resulting from the cultivation of F. asiaticum in agmatine were identified using capillary electrophoresis-time of flight mass spectrometry. Glyoxylic acid was detected from fungal cultures grown in agmatine, while it was absent in control cells. The abundance of other metabolic products of the glycolytic pathway also increased because of agmatine; however, there was no increase in the amounts of pyruvic acid or metabolites from the tricarboxylic acid cycle. Moreover, gene expression levels within Fusarium asiaticum exposed to agmatine were analyzed by DNA microarray. Changes in gene expression levels directed the changes in metabolic products. Our results suggest that acetyl coenzyme A, which is a starting substrate for the biosynthesis of deoxynivalenol (DON), was simultaneously produced by activated β-oxidation. Furthermore, the content of 4-aminobutyrate (GABA) was increased in the agmatine addition culture medium. GABA can be synthesized from agmatine through putrescine and might influence the regulation of DON-related genes.

Impact of synthetic biology and metabolic engineering on industrial production of fine chemicals.

Science.gov (United States)

Jullesson, David; David, Florian; Pfleger, Brian; Nielsen, Jens

2015-11-15

Industrial bio-processes for fine chemical production are increasingly relying on cell factories developed through metabolic engineering and synthetic biology. The use of high throughput techniques and automation for the design of cell factories, and especially platform strains, has played an important role in the transition from laboratory research to industrial production. Model organisms such as Saccharomyces cerevisiae and Escherichia coli remain widely used host strains for industrial production due to their robust and desirable traits. This review describes some of the bio-based fine chemicals that have reached the market, key metabolic engineering tools that have allowed this to happen and some of the companies that are currently utilizing these technologies for developing industrial production processes. Copyright © 2015 Elsevier Inc. All rights reserved.

Fructose increases corticosterone production in association with NADPH metabolism alterations in rat epididymal white adipose tissue.

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Prince, Paula D; Santander, Yanina A; Gerez, Estefania M; Höcht, Christian; Polizio, Ariel H; Mayer, Marcos A; Taira, Carlos A; Fraga, Cesar G; Galleano, Monica; Carranza, Andrea

2017-08-01

Metabolic syndrome is an array of closely metabolic disorders that includes glucose intolerance/insulin resistance, central obesity, dyslipidemia, and hypertension. Fructose, a highly lipogenic sugar, has profound metabolic effects in adipose tissue, and has been associated with the etiopathology of many components of the metabolic syndrome. In adipocytes, the enzyme 11 β-HSD1 amplifies local glucocorticoid production, being a key player in the pathogenesis of central obesity and metabolic syndrome. 11 β-HSD1 reductase activity is dependent on NADPH, a cofactor generated by H6PD inside the endoplasmic reticulum. Our focus was to explore the effect of fructose overload on epididymal white adipose tissue (EWAT) machinery involved in glucocorticoid production and NADPH and oxidants metabolism. Male Sprague-Dawley rats fed with a fructose solution (10% (w/v) in tap water) during 9 weeks developed some characteristic features of metabolic syndrome, such as hypertriglyceridemia, and hypertension. In addition, high levels of plasma and EWAT corticosterone were detected. Activities and expressions of H6PD and 11 β-HSD1, NAPDH content, superoxide anion production, expression of NADPH oxidase 2 subunits, and indicators of oxidative metabolism were measured. Fructose overloaded rats showed an increased potential in oxidant production respect to control rats. In parallel, in EWAT from fructose overloaded rats we found higher expression/activity of H6PD and 11 β-HSD1, and NADPH/NADP + ratio. Our in vivo results support that fructose overload installs in EWAT conditions favoring glucocorticoid production through higher H6PD expression/activity supplying NADPH for enhanced 11 β-HSD1 expression/activity, becoming this tissue a potential extra-adrenal source of corticosterone under these experimental conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

Homogeneous preparation of cellulose acetate propionate (CAP) and cellulose acetate butyrate (CAB) from sugarcane bagasse cellulose in ionic liquid.

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Huang, Kelin; Wang, Ben; Cao, Yan; Li, Huiquan; Wang, Jinshu; Lin, Weijiang; Mu, Chaoshi; Liao, Dankui

2011-05-25

Cellulose acetate butyrate (CAB) and cellulose acetate propionate (CAP) were prepared homogeneously in a 1-allyl-3-methylimidazolium chloride (AmimCl) ionic liquid system from sugarcane bagasse (SB). The reaction temperature, reaction time, and molar ratio of butyric (propionic) anhydride/anhydroglucose units in the cellulose affect the butyryl (B) or propionyl (P) content of CAB or CAP samples. The (13)C NMR data revealed the distribution of the substituents of CAB and CAP. The thermal stability of sugar cane bagasse cellulose was found by thermogravimetric analysis to have decreased after chemical modification. After reaction, the ionic liquid was effectively recycled and reused. This study provides a new way for high-value-added utilization of SB and realizing the objective of turning waste into wealth.

Metabolic Engineering for Production of Biorenewable Fuels and Chemicals: Contributions of Synthetic Biology

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Laura R. Jarboe

2010-01-01

Full Text Available Production of fuels and chemicals through microbial fermentation of plant material is a desirable alternative to petrochemical-based production. Fermentative production of biorenewable fuels and chemicals requires the engineering of biocatalysts that can quickly and efficiently convert sugars to target products at a cost that is competitive with existing petrochemical-based processes. It is also important that biocatalysts be robust to extreme fermentation conditions, biomass-derived inhibitors, and their target products. Traditional metabolic engineering has made great advances in this area, but synthetic biology has contributed and will continue to contribute to this field, particularly with next-generation biofuels. This work reviews the use of metabolic engineering and synthetic biology in biocatalyst engineering for biorenewable fuels and chemicals production, such as ethanol, butanol, acetate, lactate, succinate, alanine, and xylitol. We also examine the existing challenges in this area and discuss strategies for improving biocatalyst tolerance to chemical inhibitors.

Advances in Metabolic Engineering of Cyanobacteria for Photosynthetic Biochemical Production

OpenAIRE

Lai, Martin C.; Lan, Ethan I.

2015-01-01

Engineering cyanobacteria into photosynthetic microbial cell factories for the production of biochemicals and biofuels is a promising approach toward sustainability. Cyanobacteria naturally grow on light and carbon dioxide, bypassing the need of fermentable plant biomass and arable land. By tapping into the central metabolism and rerouting carbon flux towards desirable compound production, cyanobacteria are engineered to directly convert CO2 into various chemicals. This review discusses the d...

Enhanced transdermal bioavailability of testosterone propionate via surfactant-modified ethosomes

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Meng S

2013-08-01

Full Text Available Shu Meng,1 Zaixing Chen,2 Liqun Yang,1 Wei Zhang,1 Danhua Liu,1 Jing Guo,1 Yanmin Guan,1 Jianxin Li11Liaoning Research Institute of Family Planning, Shenyang, Liaoning Province, People's Republic of China; 2School of Pharmacy, China Medical University, Shenyang, Liaoning Province, People's Republic of ChinaAbstract: The current investigation aimed to evaluate the transdermal potential of novel testosterone propionate (TP ethosomes and liposomes prepared by surfactant modification. The effect of hexadecyl trimethyl ammonium bromide and cremophor EL-35 on the particle size and zeta potential of the prepared vesicles was investigated. The entrapment efficiency and stability, as well as in vitro and in vivo skin permeation, were studied with the various techniques, such as differential scanning calorimetry, confocal laser scanning microscopy, transmission electron microscopy, dynamic light scattering, and so on. The results indicated that the ethosomes were defined as spherical, unilamellar structures with low polydispersity (0.100 ± 0.015 and nanometric size (156.5 ± 3.5 nm. The entrapment efficiency of TP in ethosomal and liposomal carriers was 92.7% ± 3.7% and 64.7% ± 2.1%, respectively. The stability profile of the prepared TP ethosomal system assessed for 120 days revealed very low aggregation and very low growth in vesicular size. TP ethosomes also provided an enhanced transdermal flux of 37.85 ± 2.8 µg/cm2/hour and a decreased lag time of 0.18 hours across mouse skin. The skin permeation efficiency of the TP ethosomes as further assessed by confocal laser scanning microscopy revealed enhanced permeation of rhodamine red-loaded formulations to the deeper layers of the skin (260 µm than that of the liposomal formation (120 µm.Keywords: testosterone propionate, surfactant-modified ethosomes, liposomes, confocal laser scanning microscopy

Phenotypic characteristics of nitrate and 3-nitro-1-propionate-respiring enzymes of the obligate respiratory anaerobe Denitrobacterium detoxificans

Science.gov (United States)

Anaerobic respiration consumes reducing equivalents generated during fermentation thereby contributing to the maintenance of hydrogen homoeostasis in gut ecosystems. Nitrate and 3-nitro-1-propionate (NPA) are acceptors used by the nonfermentative, rumen anaerobe, Denitrobacterium detoxificans, whic...

The use of in vitro gas production technique to evaluate molasses supplementation to mulberry (morus alba and rice straw mixed diets

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Dwi Yulistiani

2007-12-01

Full Text Available Mulberry foliages have high nutritive value (protein content, digestibility and degradability, therefore it is potential to be used as a supplement to poor quality roughages. The objective of this experiment was to evaluate the effect of addition of fermentable energy in the mixed of mulberry and rice straw basal diet. A control diet consisted of either rice straw (RS or urea treated rice straw mixed with mulberry foliage (URS with ratio of 60 : 40%. Treatment was formulated by supplementation of control diet with molasses (as sources of fermentable energy at 3 levels (5, 10 and 15%. The study was conducted in a 2 x 4 factorial experiment, consisted of 2 levels rice straw (untreated and urea treated and 4 levels molasses supplementation (control and 3 levels for molasses. Diets were evaluated using in vitro gas production. The fermentation kinetics was determined from the incubation of 200 mg sample during 96 hours. The calculation of the kinetics based on exponential equation P = A+ B (1-e-ct. A shorter gas production test was carried out to determine truly degradable fermented substrates (in vitro true organic matter degradability/IVTOMD by incubating 500 mg of samples 24 hours. The result showed that there was no significant interaction between rice straw treatment and molasses supplementation on fermentation characteristics, in vitro true dry matter digestibility, fermented substrate and total volatile fatty acid (VFA production. However there was a significant interaction between rice straw treatment on partitioning factor (PF, gas produced, propionic acid production and ratio between acetic acid and propionic acid. Molasses supplementation significantly (P<0.05 decreased gas production and ratio of acetic to propionic acid, and increase PF, propionic acid production in untreated rice straw mulberry (RSM basal diet. It is concluded that molasses supplementation to RSM diet decreased gas production and ratio of C2/C3, and increased PF and

Microbial production of antioxidant food ingredients via metabolic engineering.

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Lin, Yuheng; Jain, Rachit; Yan, Yajun

2014-04-01

Antioxidants are biological molecules with the ability to protect vital metabolites from harmful oxidation. Due to this fascinating role, their beneficial effects on human health are of paramount importance. Traditional approaches using solvent-based extraction from food/non-food sources and chemical synthesis are often expensive, exhaustive, and detrimental to the environment. With the advent of metabolic engineering tools, the successful reconstitution of heterologous pathways in Escherichia coli and other microorganisms provides a more exciting and amenable alternative to meet the increasing demand of natural antioxidants. In this review, we elucidate the recent progress in metabolic engineering efforts for the microbial production of antioxidant food ingredients - polyphenols, carotenoids, and antioxidant vitamins. Copyright © 2013 Elsevier Ltd. All rights reserved.

Progress of succinic acid production from renewable resources: Metabolic and fermentative strategies.

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Jiang, Min; Ma, Jiangfeng; Wu, Mingke; Liu, Rongming; Liang, Liya; Xin, Fengxue; Zhang, Wenming; Jia, Honghua; Dong, Weiliang

2017-12-01

Succinic acid is a four-carbon dicarboxylic acid, which has attracted much interest due to its abroad usage as a precursor of many industrially important chemicals in the food, chemicals, and pharmaceutical industries. Facing the shortage of crude oil supply and demand of sustainable development, biological production of succinic acid from renewable resources has become a topic of worldwide interest. In recent decades, robust producing strain selection, metabolic engineering of model strains, and process optimization for succinic acid production have been developed. This review provides an overview of succinic acid producers and cultivation technology, highlight some of the successful metabolic engineering approaches. Copyright © 2017 Elsevier Ltd. All rights reserved.

Understanding the Representative Gut Microbiota Dysbiosis in Metformin-Treated Type 2 Diabetes Patients Using Genome-Scale Metabolic Modeling

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Dorines Rosario

2018-06-01

Full Text Available Dysbiosis in the gut microbiome composition may be promoted by therapeutic drugs such as metformin, the world’s most prescribed antidiabetic drug. Under metformin treatment, disturbances of the intestinal microbes lead to increased abundance of Escherichia spp., Akkermansia muciniphila, Subdoligranulum variabile and decreased abundance of Intestinibacter bartlettii. This alteration may potentially lead to adverse effects on the host metabolism, with the depletion of butyrate producer genus. However, an increased production of butyrate and propionate was verified in metformin-treated Type 2 diabetes (T2D patients. The mechanisms underlying these nutritional alterations and their relation with gut microbiota dysbiosis remain unclear. Here, we used Genome-scale Metabolic Models of the representative gut bacteria Escherichia spp., I. bartlettii, A. muciniphila, and S. variabile to elucidate their bacterial metabolism and its effect on intestinal nutrient pool, including macronutrients (e.g., amino acids and short chain fatty acids, minerals and chemical elements (e.g., iron and oxygen. We applied flux balance analysis (FBA coupled with synthetic lethality analysis interactions to identify combinations of reactions and extracellular nutrients whose absence prevents growth. Our analyses suggest that Escherichia sp. is the bacteria least vulnerable to nutrient availability. We have also examined bacterial contribution to extracellular nutrients including short chain fatty acids, amino acids, and gasses. For instance, Escherichia sp. and S. variabile may contribute to the production of important short chain fatty acids (e.g., acetate and butyrate, respectively involved in the host physiology under aerobic and anaerobic conditions. We have also identified pathway susceptibility to nutrient availability and reaction changes among the four bacteria using both FBA and flux variability analysis. For instance, lipopolysaccharide synthesis, nucleotide sugar

A state of the art of metabolic networks of unicellular microalgae and cyanobacteria for biofuel production.

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Baroukh, Caroline; Muñoz-Tamayo, Rafael; Steyer, Jean-Philippe; Bernard, Olivier

2015-07-01

The most promising and yet challenging application of microalgae and cyanobacteria is the production of renewable energy: biodiesel from microalgae triacylglycerols and bioethanol from cyanobacteria carbohydrates. A thorough understanding of microalgal and cyanobacterial metabolism is necessary to master and optimize biofuel production yields. To this end, systems biology and metabolic modeling have proven to be very efficient tools if supported by an accurate knowledge of the metabolic network. However, unlike heterotrophic microorganisms that utilize the same substrate for energy and as carbon source, microalgae and cyanobacteria require light for energy and inorganic carbon (CO2 or bicarbonate) as carbon source. This double specificity, together with the complex mechanisms of light capture, makes the representation of metabolic network nonstandard. Here, we review the existing metabolic networks of photoautotrophic microalgae and cyanobacteria. We highlight how these networks have been useful for gaining insight on photoautotrophic metabolism. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Growth of Highly Epitaxial YBa2Cu3O7-δ Films from a Simple Propionate-Based Solution

DEFF Research Database (Denmark)

Yue, Zhao; Torres, Pol; Tang, Xiao

2015-01-01

Intensive investigations have been conducted to develop epitaxial oxide thin films with superior electromagnetic performance by low-cost chemical solution deposition routes. In this paper, a novel propionate-based precursor solution without involving any other additive was proposed and employed...... to grow superconducting YBa2Cu3O7-δ (YBCO) films on LaAlO3 (LAO) single crystals. The precursor solutions are stable with a long shelf life of up to several months. Since the primary compositions are propionates after evaporating the solvent, the toxic reagents and evolved gases during solution synthesis...... and heat treatment can be eliminated completely. In this process, rapid pyrolysis and high conversation rate can also be achieved during growth of YBCO films in comparison with the conventional trifluoroacetate metal organic deposition routes. Remarkably, a 210 nm YBCO film exhibits high superconducting...

Nutrition and metabolism of parasitized and non-parasitized ruminants. Some approaches for studying the mode of action of parasites

International Nuclear Information System (INIS)

Leng, R.A.

1981-01-01

The effects of helminth infections on ruminant digestive function and metabolism are discussed against the background of current information on the mechanisms controlling feed intake and utilization in normal animals. Although parasites reduce productivity by impairing appetite and utilization of nutrients, few studies have been conducted on the function of the digestive tract and the metabolism of parasitized animals. Those areas which warrant further investigation are described, and the techniques which could be usefully applied are outlined. It is concluded that more emphasis should be given to the diet available to parasitized animals, and that by using diets of different digestibility and protein content, valuable information could be obtained as to the relative importance of reduced appetite and reduced efficiency of feed utilization. Central to all studies is a proper delineation of the fate of proteins in the small intestine of parasitized animals, and characterization of the types of bacteria in the gut and their effects on endogenous protein losses. The application of 15 N is mentioned. The potential usefulness of 14 C (eg. to measure the flow of digesta, to the lower digestive tract; clearance of 14 C-propionate from blood; etc.) is described

Comparative study of hops-containing products on human cytochrome P450-mediated metabolism.

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Foster, Brian C; Arnason, John T; Saleem, Ammar; Tam, Teresa W; Liu, Rui; Mao, Jingqin; Desjardins, Suzanne

2011-05-11

The potential for 15 different ales (6), ciders (2 apple and 1 pear), and porters (6) and 2 non-alcoholic products to affect cytochrome P450 (CYP)-mediated biotransformation and P-glycoprotein-mediated efflux of rhodamine was examined. As in our previous study, a wide range of recovered nonvolatile suspended solids dry weights were noted. Aliquots were also found to have varying effects on biotransformation and efflux. Distinct differences in product ability to affect the safety and efficacy of therapeutic products confirmed our initial findings that some porters (stouts) have a potential to affect the safety and efficacy of health products metabolized by CYP2D6 and CYP3A4 isozymes. Most products, except 2 of the ciders and the 2 non-alcoholic products, also have the potential to affect the safety of CYP2C9 metabolized medications and supplements. Further studies are required to determine the clinical significance of these findings.

The first dairy product exclusively fermented by Propionibacterium freudenreichii: a new vector to study probiotic potentialities in vivo.

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Cousin, Fabien J; Louesdon, Séverine; Maillard, Marie-Bernadette; Parayre, Sandrine; Falentin, Hélène; Deutsch, Stéphanie-Marie; Boudry, Gaëlle; Jan, Gwénaël

2012-10-01

Dairy propionibacteria display probiotic properties which require high populations of live and metabolically active propionibacteria in the colon. In this context, the probiotic vector determines probiotic efficiency. Fermented dairy products protect propionibacteria against digestive stresses and generally contain a complex mixture of lactic and propionic acid bacteria. This does not allow the identification of dairy propionibacteria specific beneficial effects. The aim of this study was to develop a dairy product exclusively fermented by dairy propionibacteria. As they grow poorly in milk, we determined their nutritional requirements concerning carbon and nitrogen by supplementing milk ultrafiltrate (UF) with different concentrations of lactate and casein hydrolysate. Milk or UF supplemented with 50 mM lactate and 5 g L(-1) casein hydrolysate allowed growth of all dairy propionibacteria studied. In these new fermented dairy products, dairy propionibacteria remained viable and stress-tolerant in vitro during minimum 15 days at 4 °C. The efficiency of milk fermented by the most tolerant Propionibacterium freudenreichii strain was evaluated in piglets. Viability and SCFA content in the colon evidenced survival and metabolic activity of P. freudenreichii. This work results in the design of a new food grade vector, which will allow preclinical and clinical trials. Copyright © 2012 Elsevier Ltd. All rights reserved.

Transcriptomic Changes in Response to Putrescine Production in Metabolically Engineered Corynebacterium glutamicum

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Zhen Li

2017-10-01

Full Text Available Putrescine is widely used in industrial production of bioplastics, pharmaceuticals, agrochemicals, and surfactants. Although engineered Corynebacterium glutamicum has been successfully used to produce high levels of putrescine, the overall cellular physiological and metabolic changes caused by overproduction of putrescine remains unclear. To reveal the transcriptional changes that occur in response to putrescine production in an engineered C. glutamicum strain, a comparative transcriptomic analysis was carried out. Overproduction of putrescine resulted in transcriptional downregulation of genes involved in glycolysis; the TCA cycle, pyruvate degradation, biosynthesis of some amino acids, oxidative phosphorylation; vitamin biosynthesis (thiamine and vitamin 6, metabolism of purine, pyrimidine and sulfur, and ATP-, NAD-, and NADPH-consuming enzymes. The transcriptional levels of genes involved in ornithine biosynthesis and NADPH-forming related enzymes were significantly upregulated in the putrescine producing C. glutamicum strain PUT-ALE. Comparative transcriptomic analysis provided some genetic modification strategies to further improve putrescine production. Repressing ATP- and NADPH-consuming enzyme coding gene expression via CRISPRi enhanced putrescine production.

Transcriptomic Changes in Response to Putrescine Production in Metabolically Engineered Corynebacterium glutamicum

Science.gov (United States)

Li, Zhen; Liu, Jian-Zhong

2017-01-01

Putrescine is widely used in industrial production of bioplastics, pharmaceuticals, agrochemicals, and surfactants. Although engineered Corynebacterium glutamicum has been successfully used to produce high levels of putrescine, the overall cellular physiological and metabolic changes caused by overproduction of putrescine remains unclear. To reveal the transcriptional changes that occur in response to putrescine production in an engineered C. glutamicum strain, a comparative transcriptomic analysis was carried out. Overproduction of putrescine resulted in transcriptional downregulation of genes involved in glycolysis; the TCA cycle, pyruvate degradation, biosynthesis of some amino acids, oxidative phosphorylation; vitamin biosynthesis (thiamine and vitamin 6), metabolism of purine, pyrimidine and sulfur, and ATP-, NAD-, and NADPH-consuming enzymes. The transcriptional levels of genes involved in ornithine biosynthesis and NADPH-forming related enzymes were significantly upregulated in the putrescine producing C. glutamicum strain PUT-ALE. Comparative transcriptomic analysis provided some genetic modification strategies to further improve putrescine production. Repressing ATP- and NADPH-consuming enzyme coding gene expression via CRISPRi enhanced putrescine production. PMID:29089930

Calorimetric study on human erythrocyte glycolysis. Heat production in various metabolic conditions.

Science.gov (United States)

Minakami, S; de Verdier, C H

1976-06-01

The heat production of human erythrocytes was measured on a flow microcalorimeter with simultaneous analyses of lactate and other metabolites. The heat production connected with the lactate formation was about 17 kcal (71 kJ) per mol lactate formed which corresponded to the sum of heat production due to the formation of lactate from glucose and the heat production due to neutralization. The heat production rate increased as the pH of the suspension increased, corresponding to the increase in lactate formation. Glycolytic inhibitors such as fluoride and monoiodoacetate caused a decrease in the rate of heat production, whereas arsenate induced a large transient increase in heat production associated with a transient increase in lactate formation. Decrease in pyruvate concentration was usually associated with increase in heat production, although the decreased pyruvate concentration was coupled with formation of 2,3-bisphosphoglycerate. When inosine, dihydroxyacetone or D-glyceraldehyde was used as a substrate, an increase in the heat production rate was observed. Addition of methylene blue caused an oxygen uptake which was accompanied by a remarkable increase in heat production rate corresponding to about 160 kcal (670 kJ) per mol oxygen consumed. The value for heat production in red cells in the above-mentioned metabolic conditions was considered in relation to earlier known data on free energy and enthalpy changes of the different metabolic steps in the glycolytic pathway.

INTAKE, DIGESTIBILITY, RUMEN METABOLISM AND GROWTH PERFORMANCE OF GOAT KIDS RAISED UNDER DIFFERENT PRODUCTION SYSTEMS

Directory of Open Access Journals (Sweden)

Sandra G. Solaiman

2009-06-01

Full Text Available Forty-five wether goat kids (BW of 21.76 + 0.76 were randomly assigned to one of three production systems for 14 weeks to evaluate intake, digestibility and goat performance. Production systems were: 1 feedlot (FL, housed in individual pens and fed 40% protein pellets, 40% soybean hulls and 20% bermudagrass hay; 2 grazing continuously on 1 hectare bahiagrass pasture (BP supplemented daily with 150 g of protein pellets/hd; and 3 browsing rotationally on 4, 0.5 hectare mimosa (MB supplemented daily with 100 g cracked corn/hd. Body weights were recorded every two weeks. Feed intake and digestibility were measured on eight goats from each treatment groups. Goats were fitted with canvas fecal collection bags, allowed for 3 days of adjustments followed by 5 days of fecal collection. Feces, feed offered, pasture and browse samples were analyzed for acid insoluble ash to determine digestibility and predict intake. Rumen fluid and blood samples were collected to measure volatile fatty acids and blood urea nitrogen (BUN. Total feed and medication costs also were recorded. Goats on FL system gained faster (P 0.10 in butyrate and valerate. However, acetate: propionate was lower (P 0.10 BUN. Numerically, browse system was most cost effective and bahaigrass pasture was most expensive in terms of animal production.

Recent advances in microbial production of fuels and chemicals using tools and strategies of systems metabolic engineering

DEFF Research Database (Denmark)

Cho, Changhee; Choi, So Young; Luo, Zi Wei

2015-01-01

The advent of various systems metabolic engineering tools and strategies has enabled more sophisticated engineering of microorganisms for the production of industrially useful fuels and chemicals. Advances in systems metabolic engineering have been made in overproducing natural chemicals...... and producing novel non-natural chemicals. In this paper, we review the tools and strategies of systems metabolic engineering employed for the development of microorganisms for the production of various industrially useful chemicals belonging to fuels, building block chemicals, and specialty chemicals......, in particular focusing on those reported in the last three years. It was aimed at providing the current landscape of systems metabolic engineering and suggesting directions to address future challenges towards successfully establishing processes for the bio-based production of fuels and chemicals from renewable...

Metabolic inhibitors as stimulating factors for citric acid production

International Nuclear Information System (INIS)

Adham, N.Z.; Ahmed, E.M.; Refai, H.A.E.

2008-01-01

The effect of some metabolic inhibitors on citric acid (CA) production by Aspergillus niger in cane molasses medium was investigated. Addition of 0.01-0.1 mM iodoacetic acid and sodium arsenate, 0.05-1.0 mM sodium malonate, 0.01 mM sodium azide, 0.01-0.05 mM sodium fluoride, 0.1-1.0 mM EDTA stimulated CA production (5-49%). Higher concentrations (10 mM) of iodoacetic acid, sodium malonate and 0.5 mM sodium azide caused a complete inhibition of fungal growth, Iodoacetic acid, sodium arsenate and sodium fluoride (0.2 mM) caused a remarkable inhibition of CA production. The implications of those preliminary functions was discussed. (author)

Magnetic Vinylphenyl Boronic Acid Microparticles for Surface Catalytic Performance in Esterification of Propionic Acid with Methanol

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Ali Kara

2016-12-01

Full Text Available Magnetic vinylphenyl boronic acid microparticles, poly(ethylene glycol dimethacrylate-vinylphenyl boronic acid [m-poly(EGDMA-VPBA], produced by suspension polymerization, was found to be efficient solid acid catalyst for the esterification of methanol and propionic acid. Characterization techniques such as FT-IR, Elemental analyses, ICP-AES, ESR, SEM and N2 sorption showed that both of Fe3O4 and H2SO4 are bonded to the polymer successfully. Esterification was studied for different molar percentages of H2SO4 at temperature range of 50-70 oC. The apparent activation energy was found to be 27.7 kj.mol-1 for 10% H2SO4 doped m-poly(EGDMA-VPBA. Combining of strong acid H2SO4 with m-poly(EGDMA-VPBA, leads to materials with different functional properties. In addition, H2SO4 species could be introduced into the structure as acid centers, therefore this micro-dimensional catalyst has potential candidate for applications in the catalytic esterifications such as propionic acid with methanol.

Metabolic engineering of microorganisms for biofuels production: from bugs to synthetic biology to fuels

Energy Technology Data Exchange (ETDEWEB)

Kuk Lee, Sung; Chou, Howard; Ham, Timothy S.; Soon Lee, Taek; Keasling, Jay D.

2009-12-02

The ability to generate microorganisms that can produce biofuels similar to petroleum-based transportation fuels would allow the use of existing engines and infrastructure and would save an enormous amount of capital required for replacing the current infrastructure to accommodate biofuels that have properties significantly different from petroleum-based fuels. Several groups have demonstrated the feasibility of manipulating microbes to produce molecules similar to petroleum-derived products, albeit at relatively low productivity (e.g. maximum butanol production is around 20 g/L). For cost-effective production of biofuels, the fuel-producing hosts and pathways must be engineered and optimized. Advances in metabolic engineering and synthetic biology will provide new tools for metabolic engineers to better understand how to rewire the cell in order to create the desired phenotypes for the production of economically viable biofuels.

Metabolic engineering of Escherichia coli for the production of riboflavin

OpenAIRE

Lin, Zhenquan; Xu, Zhibo; Li, Yifan; Wang, Zhiwen; Chen, Tao; Zhao, Xueming

2014-01-01

Background Riboflavin (vitamin B2), the precursor of the flavin cofactors flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), is used commercially as an animal feed supplement and food colorant. E. coli is a robust host for various genetic manipulations and has been employed for efficient production of biofuels, polymers, amino acids, and bulk chemicals. Thus, the aim of this study was to understand the metabolic capacity of E. coli for the riboflavin production by modification...

Metabolic heat production by human and animal populations in cities

Science.gov (United States)

Stewart, Iain D.; Kennedy, Chris A.

2017-07-01

Anthropogenic heating from building energy use, vehicle fuel consumption, and human metabolism is a key term in the urban energy budget equation. Heating from human metabolism, however, is often excluded from urban energy budgets because it is widely observed to be negligible. Few reports for low-latitude cities are available to support this observation, and no reports exist on the contribution of domestic animals to urban heat budgets. To provide a more comprehensive view of metabolic heating in cities, we quantified all terms of the anthropogenic heat budget at metropolitan scale for the world's 26 largest cities, using a top-down statistical approach. Results show that metabolic heat release from human populations in mid-latitude cities (e.g. London, Tokyo, New York) accounts for 4-8% of annual anthropogenic heating, compared to 10-45% in high-density tropical cities (e.g. Cairo, Dhaka, Kolkata). Heat release from animal populations amounts to <1% of anthropogenic heating in all cities. Heat flux density from human and animal metabolism combined is highest in Mumbai—the world's most densely populated megacity—at 6.5 W m-2, surpassing heat production by electricity use in buildings (5.8 W m-2) and fuel combustion in vehicles (3.9 W m-2). These findings, along with recent output from global climate models, suggest that in the world's largest and most crowded cities, heat emissions from human metabolism alone can force measurable change in mean annual temperature at regional scale.

Metabolic heat production by human and animal populations in cities.

Science.gov (United States)

Stewart, Iain D; Kennedy, Chris A

2017-07-01

Anthropogenic heating from building energy use, vehicle fuel consumption, and human metabolism is a key term in the urban energy budget equation. Heating from human metabolism, however, is often excluded from urban energy budgets because it is widely observed to be negligible. Few reports for low-latitude cities are available to support this observation, and no reports exist on the contribution of domestic animals to urban heat budgets. To provide a more comprehensive view of metabolic heating in cities, we quantified all terms of the anthropogenic heat budget at metropolitan scale for the world's 26 largest cities, using a top-down statistical approach. Results show that metabolic heat release from human populations in mid-latitude cities (e.g. London, Tokyo, New York) accounts for 4-8% of annual anthropogenic heating, compared to 10-45% in high-density tropical cities (e.g. Cairo, Dhaka, Kolkata). Heat release from animal populations amounts to heating in all cities. Heat flux density from human and animal metabolism combined is highest in Mumbai-the world's most densely populated megacity-at 6.5 W m -2 , surpassing heat production by electricity use in buildings (5.8 W m -2 ) and fuel combustion in vehicles (3.9 W m -2 ). These findings, along with recent output from global climate models, suggest that in the world's largest and most crowded cities, heat emissions from human metabolism alone can force measurable change in mean annual temperature at regional scale.

From pathways to genomes and beyond. The metabolic engineering toolbox and its place in biofuels production

Energy Technology Data Exchange (ETDEWEB)

Liu, Leqian; Reed, Ben; Alper, Hal [Texas Univ., Austin, TX (United States). Dept. of Chemical Engineering

2011-07-01

Concerns about the availability of petroleum-derived fuels and chemicals have led to the exploration of metabolically engineered organisms as novel hosts for biofuels and chemicals production. However, the complexity inherent in metabolic and regulatory networks makes this undertaking a complex task. To address these limitations, metabolic engineering has adapted a wide-variety of tools for altering phenotypes. In this review, we will highlight traditional and recent metabolic engineering tools for optimizing cells including pathway-based, global, and genomic-enabled approaches. Specifically, we describe these tools as well as provide demonstrations of their effectiveness in optimizing biofuels production. However, each of these tools provides stepping stones towards the grand goal of biofuels production. Thus, developing methods for large-scale cellular optimization and integrative approaches are invaluable for further cell optimization. This review highlights the challenges that still must be met to accomplish this goal. (orig.)

Valence-delocalization of the mixed-valence oxo-centered trinuclear iron propionates [FeIII2FeIIO(C2H5CO2)6(py)3[npy; n = 0, 1.5

International Nuclear Information System (INIS)

Nakamoto, Tadahiro; Katada, Motomi; Kawata, Satoshi; Kitagawa, Susumu; Sano, Hirotoshi; Konno, Michiko

1994-01-01

Mixed-valence trinuclear iron propionates [Fe III 2 Fe II O(C 2 H 5 CO 2 ) 6 (py) 3 [npy, where n = 0, 1.5, were synthesized and the structure of the pyridine-solvated complex was determined by single-crystal X-ray diffraction. Moessbauer spectra of the solvated propionate complex showed a temperature-dependent mixed-valence state related to phase transitions, reaching an almost delocalized valence state at room temperature. On the other hand, the non-solvated propionate showed a remarkable change of the spectral shape related to a phase transition, remaining in a localized valence state at higher temperatures up to room temperature. (orig.)

Quantitative Metabolomics and Instationary 13C-Metabolic Flux Analysis Reveals Impact of Recombinant Protein Production on Trehalose and Energy Metabolism in Pichia pastoris

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Joel Jordà

2014-05-01

Full Text Available Pichia pastoris has been recognized as an effective host for recombinant protein production. In this work, we combine metabolomics and instationary 13C metabolic flux analysis (INST 13C-MFA using GC-MS and LC-MS/MS to evaluate the potential impact of the production of a Rhizopus oryzae lipase (Rol on P. pastoris central carbon metabolism. Higher oxygen uptake and CO2 production rates and slightly reduced biomass yield suggest an increased energy demand for the producing strain. This observation is further confirmed by 13C-based metabolic flux analysis. In particular, the flux through the methanol oxidation pathway and the TCA cycle was increased in the Rol-producing strain compared to the reference strain. Next to changes in the flux distribution, significant variations in intracellular metabolite concentrations were observed. Most notably, the pools of trehalose, which is related to cellular stress response, and xylose, which is linked to methanol assimilation, were significantly increased in the recombinant strain.

Gene expression profiling in psoriatic scalp hair follicles: clobetasol propionate shampoo 0.05% normalizes psoriasis disease markers.

Science.gov (United States)

Aubert, J; Reiniche, P; Fogel, P; Poulin, Y; Lui, H; Lynde, C; Shapiro, J; Villemagne, H; Soto, P; Voegel, J J

2010-11-01

Clobetasol propionate shampoo is effective and safe in treatment of scalp psoriasis (SP). Gene expression profiling of psoriatic skin biopsies led to the identification of numerous disease-related genes. However, it remained unknown whether the gene expression profile of hair follicles of SP patients was also affected. To determine whether psoriasis-related genes are differentially regulated in the hair follicles of SP patients and whether the modulation of these genes can be correlated with clinical severity scores. A single arm, open study was conducted in three centres. SP patients received daily treatment with clobetasol propionate shampoo. At Baseline, Weeks 2 and 4, investigators assessed clinical severity parameters and collected scalp hair follicles in anagen phase. Total RNA extracted from hair follicles was used to determine the expression level of 44 genes, which were reported previously to be upregulated in the skin of psoriasis patients. RNA of good quality and sufficient quantity was obtained from hair follicles of psoriasis patients and healthy volunteers (HV). The expression level of 10 inflammation-related genes was significantly increased in psoriatic hair follicles. The patient's exploratory transcriptomic score, defined as the mean fold modulation of these 10 genes compared with HV, correlated with clinical severity scores. Clobetasol propionate shampoo was effective in decreasing both the exploratory transcriptomics and the clinical severity scores. Hair follicles of SP patients are affected by the inflammatory process. The change in the expression level of inflammation-related genes correlates with the severity of the disease. © 2010 Galderma R&D. Journal of the European Academy of Dermatology and Venereology © 2010 European Academy of Dermatology and Venereology.

Intake, digestion, and digestive characteristics of Neotyphodium coenophialum-infected and uninfected fescue by heifers offered hay diets supplemented with Aspergillus oryzae fermentation extract or laidlomycin propionate.

Science.gov (United States)

Humphry, J B; Coffey, K P; Moyert, J L; Brazle, F K; Lomas, L W

2002-01-01

Tarentaise heifers fitted with a rumen cannula (539 +/- 7.5 and 487 +/- 15.7 kg avg initial BW in Exp. 1 and 2, respectively) were used in two Latin square metabolism experiments having 2 x 2 factorial treatment arrangements to determine the effects of supplementation with Aspergillus oryzae fermentation extract (AO) or laidlomycin propionate (LP) on intake, digestion, and digestive characteristics of Neotyphodium coenophialum-infected (IF) or uninfected (FF) tall fescue (Festuca arundinacea) hay diets consumed ad libitum. Heifers were housed in individual stanchions in a metabolism facility with ambient temperatures controlled to range between 26.7 and 32.2 degrees C daily. Total feces and urine were collected for 5 d following a 21-d dietary adaptation period. In situ DM and NDF disappearance and ruminal fermentation characteristics were also determined. In Exp. 1, DMI was 24% greater (P or = 0.42). In Exp. 2, DMI was 18.9% greater (P < 0.01) by heifers offered FF than by those offered IF (6.6 vs 5.5 kg/d). Heifers fed LP (50 mg/d) consumed 10.6% less (P < 0.05) DM than those not fed LP (5.7 vs 6/5 kg/d). Digestibility of NDF tended to be greater (P = 0.08) and digestibility of ADF was greater (P < 0.05) from FF than from IF. Conversely, apparent N absorption (%) was greater (P < 0.05) from IF than from FF. Heifers fed LP had lower (P < 0.05) ADF digestibility than those not fed LP. In situ degradable DM and NDF fractions were greater (P < 0.01) from IF than from FF. Diets supplemented with LP had higher (P < 0.01) indigestible DM and NDF fractions than those without LP. Propionic acid and total VFA concentrations were greater (P < 0.05) from heifers offered FF than from those offered IF and from heifers fed LP than from those not fed LP. Therefore, it appears the major effect of N. coenophialum was a reduction in forage intake and total-tract fiber digestibility in certain situations. Response to the feed additives was similar whether heifers were offered IF or

Recent advances in microbial production of fuels and chemicals using tools and strategies of systems metabolic engineering.

Science.gov (United States)

Cho, Changhee; Choi, So Young; Luo, Zi Wei; Lee, Sang Yup

2015-11-15

The advent of various systems metabolic engineering tools and strategies has enabled more sophisticated engineering of microorganisms for the production of industrially useful fuels and chemicals. Advances in systems metabolic engineering have been made in overproducing natural chemicals and producing novel non-natural chemicals. In this paper, we review the tools and strategies of systems metabolic engineering employed for the development of microorganisms for the production of various industrially useful chemicals belonging to fuels, building block chemicals, and specialty chemicals, in particular focusing on those reported in the last three years. It was aimed at providing the current landscape of systems metabolic engineering and suggesting directions to address future challenges towards successfully establishing processes for the bio-based production of fuels and chemicals from renewable resources. Copyright © 2014 Elsevier Inc. All rights reserved.

Ruminant Nutrition Symposium: ruminant production and metabolic responses to heat stress.

Science.gov (United States)

Baumgard, L H; Rhoads, R P

2012-06-01

Heat stress compromises efficient animal production by marginalizing nutrition, management, and genetic selection efforts to maximize performance endpoints. Modifying farm infrastructure has yielded modest success in mitigating heat stress-related losses, yet poor production during the summer remains arguably the costliest issue facing livestock producers. Reduced output (e.g., milk yield and muscle growth) during heat stress was traditionally thought to result from decreased nutrient intake (i.e., a classic biological response shared by all animals during environmental-induced hyperthermia). Our recent observations have begun to challenge this belief and indicate heat-stressed animals employ novel homeorhetic strategies to direct metabolic and fuel selection priorities independently of nutrient intake or energy balance. Alterations in systemic physiology support a shift in carbohydrate metabolism, evident by increased basal and stimulated circulating insulin concentrations. Perhaps most intriguing given the energetic shortfall of the heat-stressed animal is the apparent lack of basal adipose tissue mobilization coupled with a reduced responsiveness to lipolytic stimuli. Thus, the heat stress response markedly alters postabsorptive carbohydrate, lipid, and protein metabolism independently of reduced feed intake through coordinated changes in fuel supply and utilization by multiple tissues. Interestingly, the systemic, cellular, and molecular changes appear conserved amongst different species and physiological states. Ultimately, these changes result in the reprioritization of fuel selection during heat stress, which appears to be primarily responsible for reduced ruminant animal productivity during the warm summer months.

Whole-body CO2 production as an index of the metabolic response to sepsis

Science.gov (United States)

Whole-body carbon dioxide (CO2) production (RaCO2) is an index of substrate oxidation and energy expenditure; therefore, it may provide information about the metabolic response to sepsis. Using stable isotope techniques, we determined RaCO2 and its relationship to protein and glucose metabolism in m...

Production of biopharmaceutical proteins by yeast: Advances through metabolic engineering

DEFF Research Database (Denmark)

Nielsen, Jens

2013-01-01

Production of recombinant proteins for use as pharmaceuticals, so-called biopharmaceuticals, is a multi-billion dollar industry. Many different cell factories are used for the production of biopharmaceuticals, but the yeast Saccharomyces cerevisiae is an important cell factory as it is used for p...... production. The involvement of directed metabolic engineering through the integration of tools from genetic engineering, systems biology and mathematical modeling, is also discussed....... by yeast are human serum albumin, hepatitis vaccines and virus like particles used for vaccination against human papillomavirus. Here is given a brief overview of biopharmaceutical production by yeast and it is discussed how the secretory pathway can be engineered to ensure more efficient protein...

Effects of a propionic-acid based preservative on storage characteristics of alfalfa-orchardgrass hay in large-rectangular bales

Science.gov (United States)

For many years, various formulations of organic acids have been marketed as preservatives, most specifically for use on hays that could not be field-dried to moisture concentrations low enough to reduce or eliminate spontaneous heating during storage. These preservatives are often propionic-acid-bas...

Effects of volatile fatty acids in biohydrogen effluent on biohythane production from palm oil mill effluent under thermophilic condition

Directory of Open Access Journals (Sweden)

Chonticha Mamimin

2017-09-01

Conclusion: Preventing the high concentration of butyric acid, and propionic acid in the hydrogenic effluent could enhance methane production in two-stage anaerobic digestion for biohythane production.

Toward systems metabolic engineering of Aspergillus and Pichia species for the production of chemicals and biofuels

DEFF Research Database (Denmark)

Caspeta, Luis; Nielsen, Jens

2013-01-01

trends in systems biology of Aspergillus and Pichia species, highlighting the relevance of these developments for systems metabolic engineering of these organisms for the production of hydrolytic enzymes, biofuels and chemicals from biomass. Metabolic engineering is moving from traditional methods...... for the production of hydrolytic enzymes, biofuels and chemicals from biomass. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim....

The microbiome of professional athletes differs from that of more sedentary subjects in composition and particularly at the functional metabolic level.

Science.gov (United States)

Barton, Wiley; Penney, Nicholas C; Cronin, Owen; Garcia-Perez, Isabel; Molloy, Michael G; Holmes, Elaine; Shanahan, Fergus; Cotter, Paul D; O'Sullivan, Orla

2018-04-01

It is evident that the gut microbiota and factors that influence its composition and activity effect human metabolic, immunological and developmental processes. We previously reported that extreme physical activity with associated dietary adaptations, such as that pursued by professional athletes, is associated with changes in faecal microbial diversity and composition relative to that of individuals with a more sedentary lifestyle. Here we address the impact of these factors on the functionality/metabolic activity of the microbiota which reveals even greater separation between exercise and a more sedentary state. Metabolic phenotyping and functional metagenomic analysis of the gut microbiome of professional international rugby union players (n=40) and controls (n=46) was carried out and results were correlated with lifestyle parameters and clinical measurements (eg, dietary habit and serum creatine kinase, respectively). Athletes had relative increases in pathways (eg, amino acid and antibiotic biosynthesis and carbohydrate metabolism) and faecal metabolites (eg, microbial produced short-chain fatty acids (SCFAs) acetate, propionate and butyrate) associated with enhanced muscle turnover (fitness) and overall health when compared with control groups. Differences in faecal microbiota between athletes and sedentary controls show even greater separation at the metagenomic and metabolomic than at compositional levels and provide added insight into the diet-exercise-gut microbiota paradigm. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Worldwide research productivity in the field of endocrinology and metabolism--a bibliometric analysis.

Science.gov (United States)

Zhao, Xiyan; Ye, Ru; Zhao, Linhua; Lin, Yiqun; Huang, Wenjing; He, Xinhui; Lian, Fengmei; Tong, Xiaolin

2015-01-01

Recently, significant contributions to the study of endocrinology and metabolism have been made. The national contribution, however, has not been reported. The aim of this study was to assess national efforts in the field of endocrinology and metabolism. A Web of Science search was performed using subject categories "endocrinology & metabolism" to identify articles published from 2010 to 2014. The total and per capita numbers of articles and citations were analysed for different countries. A total of 79,394 articles were published on endocrinology and metabolism from 2010 to 2014. Most were published in North America, East Asia, and Europe. The majority (82.28%) were reported by authors in high-income countries, 17.64% were published in middle-income countries, and only 0.08% were published in low-income countries. Authors in the United States published the most articles (27.38%), followed by China (7.22%), Italy (5.70%), the United Kingdom (5.6%), and Japan (5.54%). Articles published by authors in the United States had the most citations (260,934). A positive correlation was found between the number of publications and population/gross domestic product (GDP; p endocrinology and metabolism articles were published by authors from high-income countries with few from low-income countries. The United States was the most productive country. However, when population size and GDP were considered, some European countries were ranked higher.

A metabolic derivation of tritium transfer factors in animal products

International Nuclear Information System (INIS)

Galeriu, D.; Melintescu, A.; Crout, N. M. J.; Bersford, N. A.; Peterson, S. R.; Hess, M. van

2001-01-01

Tritium is a potentially important environmental contaminant arising from the nuclear industry. Because tritium is an isotope of hydrogen, its behaviour in the environment is controlled by the behaviour of hydrogen. Chronic releases of tritium to the atmosphere, in particular, will result in tritium-to-hydrogen (T/H) ratios in plants and animals that are more or less in equilibrium with T/H ratios in the air moisture. Tritium is thus a potentially important contaminant of plant and animal food products. The transfer of tritium from air moisture to plants is quite well understood. In contrast, although a number of regulatory agencies have published transfer coefficient values for diet tritium transfer for a limited number of animal products, a fresh evaluation of these transfers needs to be made In this paper we present an approach for the derivation of tritium transfer coefficients which is based on the metabolism of hydrogen in animals in conjunction with experimental data on tritium transfer. The derived transfer coefficients separately account for transfer to and from free (i.e. water) and organically bound tritium. The predicted transfer coefficients are compared to available data independent of model development. Agreement is good, with the exception of the transfer coefficient for transfer from tritiated water to organically bound tritium in ruminants, which may be attributable to the particular characteristics of ruminant digestion. We show that transfer coefficients will vary in response to the metabolic status of an animal (e.g. stage of lactation, digestibility of diet, etc.) and that the use of a single transfer coefficient from diet to animal product is not appropriate for tritium. It is possible to derive concentration ratio values which relate the concentration of tritiated water and organically bound tritium in an animal product to the corresponding concentrations in the animals diet. These concentration ratios are shown to be less subject to

In vitro activities of inulin fermentation products to HCT-116 cells enhanced by the cooperation between exogenous strains and adult faecal microbiota.

Science.gov (United States)

Yin, Dan-Ting; Fu, Yu; Zhao, Xin-Huai

2018-01-10

Inulin was fermented by adult faecal microbiota and 10 exogenous strains for 24 or 48 h. The contents of acetate, propionate, butyrate and lactate were quantified in the fermented products, and the growth-inhibitory and apoptosis-inducing effects on a human colon cell line (HCT-116 cells) were assessed. Most of these strains increased contents of acetate, propionate and butyrate, and promoted lactate conversion. Correlation analysis suggested that butyrate and lactate in the fermentation products were positively and negatively correlated with the measured inhibition ratios (p inulin fermentation products with higher anti-colon cancer activity.

Metabolic engineering of Ustilago trichophora TZ1 for improved malic acid production

Directory of Open Access Journals (Sweden)

Thiemo Zambanini

2017-06-01

These results open up a wide range of possibilities for further optimization, especially combinatorial metabolic engineering to increase the flux from pyruvate to malic acid and to reduce by-product formation.

Enhancing microbial production of biofuels by expanding microbial metabolic pathways.

Science.gov (United States)

Yu, Ping; Chen, Xingge; Li, Peng

2017-09-01

Fatty acid, isoprenoid, and alcohol pathways have been successfully engineered to produce biofuels. By introducing three genes, atfA, adhE, and pdc, into Escherichia coli to expand fatty acid pathway, up to 1.28 g/L of fatty acid ethyl esters can be achieved. The isoprenoid pathway can be expanded to produce bisabolene with a high titer of 900 mg/L in Saccharomyces cerevisiae. Short- and long-chain alcohols can also be effectively biosynthesized by extending the carbon chain of ketoacids with an engineered "+1" alcohol pathway. Thus, it can be concluded that expanding microbial metabolic pathways has enormous potential for enhancing microbial production of biofuels for future industrial applications. However, some major challenges for microbial production of biofuels should be overcome to compete with traditional fossil fuels: lowering production costs, reducing the time required to construct genetic elements and to increase their predictability and reliability, and creating reusable parts with useful and predictable behavior. To address these challenges, several aspects should be further considered in future: mining and transformation of genetic elements related to metabolic pathways, assembling biofuel elements and coordinating their functions, enhancing the tolerance of host cells to biofuels, and creating modular subpathways that can be easily interconnected. © 2016 International Union of Biochemistry and Molecular Biology, Inc.

Conjugated fatty acids and methane production by rumen microbes when incubated with linseed oil alone or mixed with fish oil and/or malate.

Science.gov (United States)

Li, Xiang Z; Gao, Qing S; Yan, Chang G; Choi, Seong H; Shin, Jong S; Song, Man K

2015-08-01

We hypothesized that manipulating metabolism with fish oil and malate as a hydrogen acceptor would affect the biohydrogenation process of α-linolenic acid by rumen microbes. This study was to examine the effect of fish oil and/or malate on the production of conjugated fatty acids and methane (CH4 ) by rumen microbes when incubated with linseed oil. Linseed oil (LO), LO with fish oil (LO-FO), LO with malate (LO-MA), or LO with fish oil and malate (LO-FO-MA) was added to diluted rumen fluid, respectively. The LO-MA and LO-FO-MA increased pH and propionate concentration compared to the other treatments. LO-MA and LO-FO-MA reduced CH4 production compared to LO. LO-MA and LO-FO-MA increased the contents of c9,t11-conjugated linoleic acid (CLA) and c9,t11,c15-conjugated linolenic acid (CLnA) compared to LO. The content of malate was rapidly reduced while that of lactate was reduced in LO-MA and LO-FO-MA from 3 h incubation time. The fold change of the quantity of methanogen related to total bacteria was decreased at both 3 h and 6 h incubation times in all treatments compared to the control. Overall data indicate that supplementation of combined malate and/or fish oil when incubated with linseed oil, could depress methane generation and increase production of propionate, CLA and CLnA under the conditions of the current in vitro study. © 2015 Japanese Society of Animal Science.

Production of the sesquiterpenoid (+)-nootkatone by metabolic engineering of Pichia pastoris.

Science.gov (United States)

Wriessnegger, Tamara; Augustin, Peter; Engleder, Matthias; Leitner, Erich; Müller, Monika; Kaluzna, Iwona; Schürmann, Martin; Mink, Daniel; Zellnig, Günther; Schwab, Helmut; Pichler, Harald

2014-07-01

The sesquiterpenoid (+)-nootkatone is a highly demanded and highly valued aroma compound naturally found in grapefruit, pummelo or Nootka cypress tree. Extraction of (+)-nootkatone from plant material or its production by chemical synthesis suffers from low yields and the use of environmentally harmful methods, respectively. Lately, major attention has been paid to biotechnological approaches, using cell extracts or whole-cell systems for the production of (+)-nootkatone. In our study, the yeast Pichia pastoris initially was applied as whole-cell biocatalyst for the production of (+)-nootkatone from (+)-valencene, the abundant aroma compound of oranges. Therefore, we generated a strain co-expressing the premnaspirodiene oxygenase of Hyoscyamus muticus (HPO) and the Arabidopsis thaliana cytochrome P450 reductase (CPR) that hydroxylated extracellularly added (+)-valencene. Intracellular production of (+)-valencene by co-expression of valencene synthase from Callitropsis nootkatensis resolved the phase-transfer issues of (+)-valencene. Bi-phasic cultivations of P. pastoris resulted in the production of trans-nootkatol, which was oxidized to (+)-nootkatone by an intrinsic P. pastoris activity. Additional overexpression of a P. pastoris alcohol dehydrogenase and truncated hydroxy-methylglutaryl-CoA reductase (tHmg1p) significantly enhanced the (+)-nootkatone yield to 208mg L(-1) cell culture in bioreactor cultivations. Thus, metabolically engineered yeast P. pastoris represents a valuable, whole-cell system for high-level production of (+)-nootkatone from simple carbon sources. Copyright © 2014 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Effect of weak acid preservatives on growth of bakery product spoilage fungi at different water activities and pH values

DEFF Research Database (Denmark)

Suhr, Karin Isabel; Nielsen, Per Væggemose

2004-01-01

moisture sponge cake types (a(w) 0.80-0.95, pH 4.7-7.4). Initially, rye bread conditions (a(w) 0.94-0.97 and pH 4.4-4.8) in combination with calcium propionate were investigated. Results showed that the highest concentration of propionate (0.3%) at all conditions apart from high a(w) (0.97) and high pH (4...... enhanced at high water activity levels. The effect of propionate on production of secondary metabolites (mycophenolic acid, rugulovasine, echinulin, flavoglaucin) was also studied, and variable or isolate dependent results were found. Subsequently, a screening experiment representing a wider range...

Control of fluxes towards antibiotics and the role of primary metabolism in production of antibiotics

DEFF Research Database (Denmark)

Gunnarsson, Nina; Eliasson Lantz, Anna; Nielsen, Jacob

2004-01-01

Yield improvements in antibiotic-producing strains have classically been obtained through random mutagenesis and screening. An attractive alternative to this strategy is the rational design of producer strains via metabolic engineering, an approach that offers the possibility to increase yields...... in the metabolic network. Here we describe and discuss available methods for identification of these steps, both in antibiotic biosynthesis pathways and in the primary metabolism, which serves as the supplier of precursors and cofactors for the secondary metabolism. Finally, the importance of precursor...... and cofactor supply from primary metabolism in the biosynthesis of different types of antibiotics is discussed and recent developments in metabolic engineering towards increased product yields in antibiotic producing strains are reviewed....

Effects of dietary inulin on bacterial growth, short-chain fatty acid production and hepatic lipid metabolism in gnotobiotic mice.

Science.gov (United States)

Weitkunat, Karolin; Schumann, Sara; Petzke, Klaus Jürgen; Blaut, Michael; Loh, Gunnar; Klaus, Susanne

2015-09-01

In literature, contradictory effects of dietary fibers and their fermentation products, short-chain fatty acids (SCFA), are described: On one hand, they increase satiety, but on the other hand, they provide additional energy and promote obesity development. We aimed to answer this paradox by investigating the effects of fermentable and non-fermentable fibers on obesity induced by high-fat diet in gnotobiotic C3H/HeOuJ mice colonized with a simplified human microbiota. Mice were fed a high-fat diet supplemented either with 10% cellulose (non-fermentable) or inulin (fermentable) for 6 weeks. Feeding the inulin diet resulted in an increased diet digestibility and reduced feces energy, compared to the cellulose diet with no differences in food intake, suggesting an increased intestinal energy extraction from inulin. However, we observed no increase in body fat/weight. The additional energy provided by the inulin diet led to an increased bacterial proliferation in this group. Supplementation of inulin resulted further in significantly elevated concentrations of total SCFA in cecum and portal vein plasma, with a reduced cecal acetate:propionate ratio. Hepatic expression of genes involved in lipogenesis (Fasn, Gpam) and fatty acid elongation/desaturation (Scd1, Elovl3, Elovl6, Elovl5, Fads1 and Fads2) were decreased in inulin-fed animals. Accordingly, plasma and liver phospholipid composition were changed between the different feeding groups. Concentrations of omega-3 and odd-chain fatty acids were increased in inulin-fed mice, whereas omega-6 fatty acids were reduced. Taken together, these data indicate that, during this short-term feeding, inulin has mainly positive effects on the lipid metabolism, which could cause beneficial effects during obesity development in long-term studies. Copyright © 2015 Elsevier Inc. All rights reserved.

Role of glycolytic intermediate in regulation: Improving lycopene production in Escherichia coli by engineering metabolic control

Energy Technology Data Exchange (ETDEWEB)

Farmer, W.R.; Liao, J.C.

2001-06-01

Metabolic engineering in the postgenomic era is expected to benefit from a full understanding of the biosynthetic capability of microorganisms as a result of the progress being made in bioinformatics and functional genomics. The immediate advantage of such information is to allow the rational design of novel pathways and the elimination of native reactions that are detrimental or unnecessary for the desired purpose. However, with the ability to manipulate metabolic pathways becoming more effective, metabolic engineering will need to face a new challenge: the reengineering of the regulatory hierarchy that controls gene expression in those pathways. In addition to constructing the genetic composition of a metabolic pathway, they propose that it will become just as important to consider the dynamics of pathways gene expression. It has been widely observed that high-level induction of a recombinant protein or pathway leads to growth retardation and reduced metabolic activity. These phenotypic characteristics result from the fact that the constant demands of production placed upon the cell interfere with its changing requirements for growth. They believe that this common situation in metabolic engineering can be alleviated by designing a dynamic controller that is able to sense the metabolic state of the cell and regulate the expression of the recombinant pathway accordingly. This approach, which is termed metabolic control engineering, involves redesigning the native regulatory circuits and applying them to the recombinant pathway. The general goal of such an effort will be to control the flux to the recombinant pathway adaptively according to the cell's metabolic state. The dynamically controlled recombinant pathway can potentially lead to enhanced production, minimized growth retardation, and reduced toxic by-product formation. The regulation of gene expression in response to the physiological state is also essential to the success of gene therapy. Here they

Selective Hydrodeoxygenation of Alkyl Lactates to Alkyl Propionates with Fe-based Bimetallic Supported Catalysts.

Science.gov (United States)

Khokarale, Santosh Govind; He, Jian; Schill, Leonhard; Yang, Song; Riisager, Anders; Saravanamurugan, Shunmugavel

2018-02-22

Hydrodeoxygenation (HDO) of methyl lactate (ML) to methyl propionate (MP) was performed with various base-metal supported catalysts. A high yield of 77 % MP was obtained with bimetallic Fe-Ni/ZrO 2 in methanol at 220 °C and 50 bar H 2 . A synergistic effect of Ni increased the yield of MP significantly when using Fe-Ni/ZrO 2 instead of Fe/ZrO 2 alone. Moreover, the ZrO 2 support contributed to improve the yield as a phase transition of ZrO 2 from tetragonal to monoclinic occurred after metal doping giving rise to fine dispersion of the Fe and Ni on the ZrO 2 , resulting in a higher catalytic activity of the material. Interestingly, it was observed that Fe-Ni/ZrO 2 also effectively catalyzed methanol reforming to produce H 2 in situ, followed by HDO of ML, yielding 60 % MP at 220 °C with 50 bar N 2 instead of H 2 . Fe-Ni/ZrO 2 also catalyzed HDO of other short-chain alkyl lactates to the corresponding alkyl propionates in high yields around 70 %. No loss of activity of Fe-Ni/ZrO 2 occurred in five consecutive reaction runs demonstrating the high durability of the catalyst system. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

SYNTHESIS AND STUDY OF ANTIOXIDANT ACTIVITY OF [(1-ARYL-5-FORMYL-1H-IMIDAZOLE-4-ILTHIO]PROPIONIC ACIDS

Directory of Open Access Journals (Sweden)

A. O. Palamar

2014-12-01

Full Text Available Introduction. Derivatives of imidazole belong to the promising group of compounds for antioxidant activity study, due to the series of recent publications. This is defined by special features of their structure, specific reactivity and significant potential of pharmacological action. Earlier during process of looking for new antioxidants we studied significant amount of imidazole derivatives, among which the [(1-aryl-5-formylimidazole-4-ilthio]acetic acids structurally modified by the formyl group and thioacetic acid fragment, are especially worth noting. The purpose of the study. Synthesis of [(1-aryl-5-formylimidazole-4-ilthio]propionic acids and comparison of their antioxidant effect with [(1-aryl-5-formylimidazole-4-ilthio]acetic acids with to identify prospects of in-depth study of the most active compounds as antioxidants. Materials and methods. The method based on interaction of available 4-chloro-5-formylimidazoles with thiopropionic acid was proposed for the synthesis of [(1-aryl-5-formylimidazole-4-ilthio]propionic acids. The reaction takes place in ethanol in presence of potassium hydroxide and leads to the target compounds with yields of 81-86%. The study of antioxidant activity of synthesized compounds was conducted in vitro by speed inhibition value of rats’ liver endogenous lipids ascorbate-dependent peroxide oxidation. It was determined by concentration of one of the final products of free radical oxidation of lipids (FROL – maleic aldehyde (MA in the investigated sample. Concentrations of synthesized compounds were chosen within concentrations which were studied for thiotriazolin (manufactured by corporation “Arterium”, Ukraine, solution for injection, 25 mg/ml. The results of the study and their discussion. Preparative method for the synthesis of [(1-aryl-5-formylimidazole-4-ilthio]propionic acids has been designed. Imidazolylthiopropionic acids have been synthesized; they are crystalline compounds, of light

L-rhamnose as a source of colonic propionate inhibits insulin secretion but does not influence measures of appetite or food intake.

Science.gov (United States)

Darzi, Julia; Frost, Gary S; Swann, Jonathan R; Costabile, Adele; Robertson, M Denise

2016-03-01

Activation of free fatty acid receptor (FFAR)2 and FFAR3 via colonic short-chain fatty acids, particularly propionate, are postulated to explain observed inverse associations between dietary fiber intake and body weight. Propionate is reported as the predominant colonic fermentation product from l-rhamnose, a natural monosaccharide that resists digestion and absorption reaching the colon intact, while effects of long-chain inulin on appetite have not been extensively investigated. In this single-blind randomized crossover study, healthy unrestrained eaters (n = 13) ingested 25.5 g/d l-rhamnose, 22.4 g/d inulin or no supplement (control) alongside a standardized breakfast and lunch, following a 6-d run-in to investigate if appetite was inhibited. Postprandial qualitative appetite, breath hydrogen, and plasma glucose, insulin, triglycerides and non-esterified fatty acids were assessed for 420 min, then an ad libitum meal was provided. Significant treatment x time effects were found for postprandial insulin (P = 0.009) and non-esterified fatty acids (P = 0.046) with a significantly lower insulin response for l-rhamnose (P = 0.023) than control. No differences between treatments were found for quantitative and qualitative appetite measures, although significant treatment x time effects for meal desire (P = 0.008) and desire to eat sweet (P = 0.036) were found. Breath hydrogen was significantly higher with inulin (P = 0.001) and l-rhamnose (P = 0.009) than control, indicating colonic fermentation. These findings suggest l-rhamnose may inhibit postprandial insulin secretion, however neither l-rhamnose or inulin influenced appetite. Copyright © 2015 Elsevier Ltd. All rights reserved.

Biobased production of alkanes and alkenes through metabolic engineering of microorganisms

OpenAIRE

Kang, Min Kyoung; Nielsen, Jens

2017-01-01

Advancement in metabolic engineering of microorganisms has enabled bio-based production of a range of chemicals, and such engineered microorganism can be used for sustainable production leading to reduced carbon dioxide emission there. One area that has attained much interest is microbial hydrocarbon biosynthesis, and in particular, alkanes and alkenes are important high-value chemicals as they can be utilized for a broad range of industrial purposes as well as ?drop-in? biofuels. Some microo...

A20 modulates lipid metabolism and energy production to promote liver regeneration.

Directory of Open Access Journals (Sweden)

Scott M Damrauer

2011-03-01

Full Text Available Liver regeneration is clinically of major importance in the setting of liver injury, resection or transplantation. We have demonstrated that the NF-κB inhibitory protein A20 significantly improves recovery of liver function and mass following extended liver resection (LR in mice. In this study, we explored the Systems Biology modulated by A20 following extended LR in mice.We performed transcriptional profiling using Affymetrix-Mouse 430.2 arrays on liver mRNA retrieved from recombinant adenovirus A20 (rAd.A20 and rAd.βgalactosidase treated livers, before and 24 hours after 78% LR. A20 overexpression impacted 1595 genes that were enriched for biological processes related to inflammatory and immune responses, cellular proliferation, energy production, oxidoreductase activity, and lipid and fatty acid metabolism. These pathways were modulated by A20 in a manner that favored decreased inflammation, heightened proliferation, and optimized metabolic control and energy production. Promoter analysis identified several transcriptional factors that implemented the effects of A20, including NF-κB, CEBPA, OCT-1, OCT-4 and EGR1. Interactive scale-free network analysis captured the key genes that delivered the specific functions of A20. Most of these genes were affected at basal level and after resection. We validated a number of A20's target genes by real-time PCR, including p21, the mitochondrial solute carriers SLC25a10 and SLC25a13, and the fatty acid metabolism regulator, peroxisome proliferator activated receptor alpha. This resulted in greater energy production in A20-expressing livers following LR, as demonstrated by increased enzymatic activity of cytochrome c oxidase, or mitochondrial complex IV.This Systems Biology-based analysis unravels novel mechanisms supporting the pro-regenerative function of A20 in the liver, by optimizing energy production through improved lipid/fatty acid metabolism, and down-regulated inflammation. These findings

Shikimic acid production in Escherichia coli: From classical metabolic engineering strategies to omics applied to improve its production

Directory of Open Access Journals (Sweden)

Juan Andrés Martínez

2015-09-01

Full Text Available Shikimic acid (SA is an intermediate of the SA pathway that is present in bacteria and plants. SA has gained great interest because it is a precursor in the synthesis of the drug oseltamivir phosphate (OSF, an efficient inhibitor of the neuraminidase enzyme of diverse seasonal influenza viruses, the avian influenza virus H5N1, and the human influenza virus H1N1. For the purposes of OSF production, SA is extracted from the pods of Chinese star anise plants (Illicium spp., yielding up to 17% of SA (dry basis content. The high demand for OSF necessary to manage a major influenza outbreak is not adequately met by industrial production using SA from plants sources. As the SA pathway is present in the model bacteria Escherichia coli, several intuitive metabolically engineered strains have been applied for its successful overproduction by biotechnological processes, resulting in strains producing up to 71 g/L of SA, with high conversion yields of up to 0.42 (mol SA/mol Glc, in both batch and fed-batch cultures using complex fermentation broths, including glucose as a carbon source and yeast extract. Global transcriptomic analyses have been performed in SA producing strains, resulting in the identification of possible key target genes for the design of a rational strain improvement strategy. Because possible target genes are involved in the transport, catabolism and interconversion of different carbon sources and metabolic intermediates outside the central carbon metabolism and SA pathways, as genes involved in diverse cellular stress responses, the development of rational cellular strain improvement strategies based on omics data constitutes a challenging task to improve SA production in currently overproducing engineered strains. In this review, we discuss the main metabolic engineering strategies that have been applied for the development of efficient SA producing strains, as the perspective of omics analysis has focused on further strain improvement

Global metabolic rewiring for improved CO2 fixation and chemical production in cyanobacteria

Science.gov (United States)

Kanno, Masahiro; Carroll, Austin L.; Atsumi, Shota

2017-03-01

Cyanobacteria have attracted much attention as hosts to recycle CO2 into valuable chemicals. Although cyanobacteria have been engineered to produce various compounds, production efficiencies are too low for commercialization. Here we engineer the carbon metabolism of Synechococcus elongatus PCC 7942 to improve glucose utilization, enhance CO2 fixation and increase chemical production. We introduce modifications in glycolytic pathways and the Calvin Benson cycle to increase carbon flux and redirect it towards carbon fixation. The engineered strain efficiently uses both CO2 and glucose, and produces 12.6 g l-1 of 2,3-butanediol with a rate of 1.1 g l-1 d-1 under continuous light conditions. Removal of native regulation enables carbon fixation and 2,3-butanediol production in the absence of light. This represents a significant step towards industrial viability and an excellent example of carbon metabolism plasticity.

Metabolic engineering of carbon overflow metabolism of Bacillus subtilis for improved N-acetyl-glucosamine production.

Science.gov (United States)

Ma, Wenlong; Liu, Yanfeng; Shin, Hyun-Dong; Li, Jianghua; Chen, Jian; Du, Guocheng; Liu, Long

2018-02-01

Bacillus subtilis is widely used as cell factories for the production of important industrial biochemicals. Although many studies have demonstrated the effects of organic acidic byproducts, such as acetate, on microbial fermentation, little is known about the effects of blocking the neutral byproduct overflow, such as acetoin, on bioproduction. In this study, we focused on the influences of modulating overflow metabolism on the production of N-acetyl-d-glucosamine (GlcNAc) in engineered B. subtilis. We found that acetoin overflow competes with GlcNAc production, and blocking acetoin overflow increased GlcNAc titer and yield by 1.38- and 1.39-fold, reaching 48.9 g/L and 0.32 g GlcNAc/g glucose, respectively. Further blocking acetate overflow inhibited cell growth and GlcNAc production may be induced by inhibiting glucose uptake. Taken together, our results show that blocking acetoin overflow is a promising strategy for enhancing GlcNAc production. The strategies developed in this work may be useful for engineering strains of B. subtilis for producing other important biochemicals. Copyright © 2017. Published by Elsevier Ltd.

The impact of obesity, sex, and diet on hepatic glucose production in cats.

Science.gov (United States)

Kley, Saskia; Hoenig, Margarethe; Glushka, John; Jin, Eunsook S; Burgess, Shawn C; Waldron, Mark; Jordan, Erin T; Prestegard, James H; Ferguson, Duncan C; Wu, Shaoxiong; Olson, Darin E

2009-04-01

Obesity is a risk factor for type 2 diabetes in cats. The risk of developing diabetes is severalfold greater for male cats than for females, even after having been neutered early in life. The purpose of this study was to investigate the role of different metabolic pathways in the regulation of endogenous glucose production (EGP) during the fasted state considering these risk factors. A triple tracer protocol using (2)H(2)O, [U-(13)C(3)]propionate, and [3,4-(13)C(2)]glucose was applied in overnight-fasted cats (12 lean and 12 obese; equal sex distribution) fed three different diets. Compared with lean cats, obese cats had higher insulin (P mass index, and girth correlated negatively with EGP (P lean cats and are still capable of maintaining fasting euglycemia, despite the well-documented existence of peripheral insulin resistance in obese cats. Our data further suggest that sex-related differences exist in the regulation of hepatic glucose metabolism in obese cats, suggesting that pyruvate cycling acts as a controlling mechanism to modulate EGP. Increased pyruvate cycling could therefore be an important factor in modulating the diabetes risk in female cats.

Metabolism of pharmaceutical and personal care products by carrot cell cultures.

Science.gov (United States)

Wu, Xiaoqin; Fu, Qiuguo; Gan, Jay

2016-04-01

With the increasing use of treated wastewater and biosolids in agriculture, residues of pharmaceutical and personal care products (PPCPs) in these reused resources may contaminate food produce via plant uptake, constituting a route for human exposure. Although various PPCPs have been reported to be taken up by plants in laboratories or under field conditions, at present little information is available on their metabolism in plants. In this study, we applied carrot cell cultures to investigate the plant metabolism of PPCPs. Five phase I metabolites of carbamazepine were identified and the potential metabolism pathways of carbamazepine were proposed. We also used the carrot cell cultures as a rapid screening tool to initially assess the metabolism potentials of 18 PPCPs. Eleven PPCPs, including acetaminophen, caffeine, meprobamate, primidone, atenolol, trimethoprim, DEET, carbamazepine, dilantin, diazepam, and triclocarban, were found to be recalcitrant to metabolism. The other 7 PPCPs, including triclosan, naproxen, diclofenac, ibuprofen, gemfibrozil, sulfamethoxazole, and atorvastatin, displayed rapid metabolism, with 0.4-47.3% remaining in the culture at the end of the experiment. Further investigation using glycosidase hydrolysis showed that 1.3-20.6% of initially spiked naproxen, diclofenac, ibuprofen, and gemfibrozil were transformed into glycoside conjugates. Results from this study showed that plant cell cultures may be a useful tool for initially exploring the potential metabolites of PPCPs in plants as well as for rapidly screening the metabolism potentials of a variety of PPCPs or other emerging contaminants, and therefore may be used for prioritizing compounds for further comprehensive evaluations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparison of Lipid Accumulation Product Index with Body Mass Index and Waist Circumference as a Predictor of Metabolic Syndrome in Indian Population.

Science.gov (United States)

Ray, Lopamudra; Ravichandran, Kandasamy; Nanda, Sunil Kumar

2018-06-01

Metabolic syndrome (MetS), which confers a high risk for cardiovascular diseases, needs early diagnosis and treatment to reduce morbidity and mortality. Lipid accumulation product index has been reported to be an inexpensive marker of visceral fat and metabolic syndrome. This study aimed to evaluate lipid accumulation product index as a marker for metabolic syndrome in the Indian population where the prevalence of the condition is steadily increasing. A hospital-based, case-control study was conducted with 72 diagnosed cases of metabolic syndrome and 79 control subjects. In all the participants, body mass index (BMI) and lipid accumulation product index were calculated. The difference between cases and controls in BMI, waist circumference (WC), and lipid accumulation product index was assessed by Mann-Whitney U test/unpaired t-test. Associations of BMI, WC, and lipid accumulation product index with metabolic syndrome were compared by multiple logistic regression analysis and receiver operating characteristic analysis. BMI, WC, and lipid accumulation product index were significantly higher in metabolic syndrome (P product index had the highest prediction accuracy. The parameter also had a high area under curve of 0.901 (95% confidence interval 0.85-0.95) and a high sensitivity (76.4%), specificity (91.1%), positive predictive value (88.7%), and negative predictive value (80.9%) for detection of metabolic syndrome. In the Indian population, lipid accumulation product index is a better predictor of metabolic syndrome compared to BMI and WC and should be incorporated in laboratory reports as early, accurate, and inexpensive indicator of metabolic syndrome.

Central Venous Catheter-Related Bloodstream Infection with Kocuria kristinae in a Patient with Propionic Acidemia

OpenAIRE

Kimura, Masato; Kawai, Eichiro; Yaoita, Hisao; Ichinoi, Natsuko; Sakamoto, Osamu; Kure, Shigeo

2017-01-01

Kocuria kristinae is a catalase-positive, coagulase-negative, Gram-positive coccus found in the environment and in normal skin and mucosa in humans; however, it is rarely isolated from clinical specimens and is considered a nonpathogenic bacterium. We describe a case of catheter-related bacteremia due to K. kristinae in a young adult with propionic acidemia undergoing periodic hemodialysis. The patient had a central venous catheter implanted for total parenteral nutrition approximately 6 mont...

The relationship of metabolic burden to productivity levels in CHO cell lines.

Science.gov (United States)

Zou, Wu; Edros, Raihana; Al-Rubeai, Mohamed

2018-03-01

The growing demand for recombinant therapeutics has driven biotechnologists to develop new production strategies. One such strategy for increasing the expression of heterologous proteins has focused on enhancing cell-specific productivity through environmental perturbations. In this work, the effects of hypothermia, hyperosmolarity, high shear stress, and sodium butyrate treatment on growth and productivity were studied using three (low, medium, and high producing) CHO cell lines that differed in their specific productivities of monoclonal antibody. In all three cell lines, the inhibitory effect of these parameters on proliferation was demonstrated. Additionally, compared to the control, specific productivity was enhanced under all conditions and exhibited a consistent cell line specific pattern, with maximum increases (50-290%) in the low producer, and minimum increases (7-20%) in the high producer. Thus, the high-producing cell line was less responsive to environmental perturbations than the low-producing cell line. We hypothesize that this difference is most likely due to the bottleneck associated with a higher metabolic burden caused by higher antibody expression. Increased recombinant mRNA levels and pyruvate carboxylase activities due to low temperature and hyperosmotic stress were found to be positively associated with the metabolic burden. © 2017 International Union of Biochemistry and Molecular Biology, Inc.

Patchoulol Production with Metabolically Engineered Corynebacterium glutamicum

Directory of Open Access Journals (Sweden)

Nadja A. Henke

2018-04-01

Full Text Available Patchoulol is a sesquiterpene alcohol and an important natural product for the perfume industry. Corynebacterium glutamicum is the prominent host for the fermentative production of amino acids with an average annual production volume of ~6 million tons. Due to its robustness and well established large-scale fermentation, C. glutamicum has been engineered for the production of a number of value-added compounds including terpenoids. Both C40 and C50 carotenoids, including the industrially relevant astaxanthin, and short-chain terpenes such as the sesquiterpene valencene can be produced with this organism. In this study, systematic metabolic engineering enabled construction of a patchoulol producing C. glutamicum strain by applying the following strategies: (i construction of a farnesyl pyrophosphate-producing platform strain by combining genomic deletions with heterologous expression of ispA from Escherichia coli; (ii prevention of carotenoid-like byproduct formation; (iii overproduction of limiting enzymes from the 2-c-methyl-d-erythritol 4-phosphate (MEP-pathway to increase precursor supply; and (iv heterologous expression of the plant patchoulol synthase gene PcPS from Pogostemon cablin. Additionally, a proof of principle liter-scale fermentation with a two-phase organic overlay-culture medium system for terpenoid capture was performed. To the best of our knowledge, the patchoulol titers demonstrated here are the highest reported to date with up to 60 mg L−1 and volumetric productivities of up to 18 mg L−1 d−1.

Advances in cyanobacterial polyhydroxyalkanoates production.

Science.gov (United States)

Singh, Akhilesh Kumar; Mallick, Nirupama

2017-11-01

Polyhydroxyalkanoates (PHAs) have received much attention in the current scenario due to their attractive material properties, namely biodegradability, biocompatibility, thermoplasticity, hydrophobicity, piezoelectricity and stereospecificity. All these properties make them highly competitive for various industrial applications similar to non-degradable conventional plastics. In PHA biosynthesis, PHA synthase acts as a natural catalyst for PHA polymerization process using the (R)-hydroxyacyl-CoA as substrate. Cyanobacteria can accumulate PHAs under photoautotrophic and/or mixotrophic growth conditions with organic substrates such as acetate, glucose, propionate, valerate, and so on. The natural incidence of PHA accumulation by the cyanobacteria is known since 1966. Nevertheless, PHA accumulation in cyanobacteria based on the cell biomass and volumetric productivity is critically lower than the heterotrophic bacteria. Consequently, cyanobacteria are nowadays not considered for commercial production of PHAs. Thus, strain improvements by genetic modification, new cultivation and harvesting techniques, advanced photobioreactor development, efficient and sustainable downstream processes, alternate economical carbon sources and usage of various metabolic inhibitors are suggested for enhancing cyanobacterial PHA accumulation. In addition, identification of transcriptional regulators like RNA polymerase sigma factor (SigE) and a response regulator (Rre37) together with the recent major scientific breakthrough on the existence of complete Krebs cycle in cyanobacteria would be helpful in taking PHA production from cyanobacteria to a new-fangled height in near future. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Metabolism of pharmaceutical and personal care products by carrot cell cultures

International Nuclear Information System (INIS)

Wu, Xiaoqin; Fu, Qiuguo; Gan, Jay

2016-01-01

With the increasing use of treated wastewater and biosolids in agriculture, residues of pharmaceutical and personal care products (PPCPs) in these reused resources may contaminate food produce via plant uptake, constituting a route for human exposure. Although various PPCPs have been reported to be taken up by plants in laboratories or under field conditions, at present little information is available on their metabolism in plants. In this study, we applied carrot cell cultures to investigate the plant metabolism of PPCPs. Five phase I metabolites of carbamazepine were identified and the potential metabolism pathways of carbamazepine were proposed. We also used the carrot cell cultures as a rapid screening tool to initially assess the metabolism potentials of 18 PPCPs. Eleven PPCPs, including acetaminophen, caffeine, meprobamate, primidone, atenolol, trimethoprim, DEET, carbamazepine, dilantin, diazepam, and triclocarban, were found to be recalcitrant to metabolism. The other 7 PPCPs, including triclosan, naproxen, diclofenac, ibuprofen, gemfibrozil, sulfamethoxazole, and atorvastatin, displayed rapid metabolism, with 0.4–47.3% remaining in the culture at the end of the experiment. Further investigation using glycosidase hydrolysis showed that 1.3–20.6% of initially spiked naproxen, diclofenac, ibuprofen, and gemfibrozil were transformed into glycoside conjugates. Results from this study showed that plant cell cultures may be a useful tool for initially exploring the potential metabolites of PPCPs in plants as well as for rapidly screening the metabolism potentials of a variety of PPCPs or other emerging contaminants, and therefore may be used for prioritizing compounds for further comprehensive evaluations. - Highlights: • Five phase I metabolites of carbamazepine were identified in carrot cell cultures. • The metabolism potentials of 18 PPCPs were evaluated using carrot cell cultures. • Four PPCPs may partially form glycoside conjugates as phase II

Effect of some metabolic inhibitors on citric acid production Aspergillus niger

Energy Technology Data Exchange (ETDEWEB)

Agrawal, P.K.; Bhatt, C.S.; Viswanathan, L.

1983-09-01

Stationary cultures of Aspergillus niger grown on a synthetic medium have been used to study the effect of some metabolic inhibitors on citric acid production. Addition of 0.05 to 1 mM sodium malonate or 0.01 to 0.1 mM potassium ferricyanide, iodoacetate, sodium azide, soldium arsenate or sodium fluoride stimulated citric acid production (3.6 to 45%), but not total titratable acids. Addition of higher concentrations (0.2 to 10 mM) of later inhibitors caused a marked inhibition of fungal growth and citric acid production. The implications of these preliminary findings are discussed. (Refs. 25).

Cellulose acetate propionate coated titanium: characterization and biotechnological application

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Guilherme da Silva Gomes

2007-12-01

Full Text Available Surfaces of pure titanium and Ti coated with cellulose acetate propionate (CAP have been characterized by means of scanning electron microscopy X ray coupled with elemental microanalysis (SEM-EDS, ellipsometry, atomic force microscopy (AFM and contact angle measurements. Coating Ti surfaces with CAP ultrathin films reduced original surface roughness. Surface energy and wettability of CAP covered Ti surfaces pure Ti surfaces were similar. The adsorption of lysozyme (LYZ, an antibacterial protein, onto Ti and CAP-coated Ti surfaces has been studied by means of ellipsometry and atomic force microscopy (AFM. The adsorption of LYZ was mainly driven by hydrophobic interaction between protein hydrophobic residues and CAP propyl groups. Pure Ti and CAP coated Ti surfaces presented no cytotoxicity effect and proved to be adequate substrates for cell adhesion. The biocompatibility of CAP coated Ti surfaces was attributed to the surface enrichment in glucopyranosyl residues and short alkyl side groups.

Low-dose aspartame consumption differentially affects gut microbiota-host metabolic interactions in the diet-induced obese rat.

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Palmnäs, Marie S A; Cowan, Theresa E; Bomhof, Marc R; Su, Juliet; Reimer, Raylene A; Vogel, Hans J; Hittel, Dustin S; Shearer, Jane

2014-01-01

Aspartame consumption is implicated in the development of obesity and metabolic disease despite the intention of limiting caloric intake. The mechanisms responsible for this association remain unclear, but may involve circulating metabolites and the gut microbiota. Aims were to examine the impact of chronic low-dose aspartame consumption on anthropometric, metabolic and microbial parameters in a diet-induced obese model. Male Sprague-Dawley rats were randomized into a standard chow diet (CH, 12% kcal fat) or high fat (HF, 60% kcal fat) and further into ad libitum water control (W) or low-dose aspartame (A, 5-7 mg/kg/d in drinking water) treatments for 8 week (n = 10-12 animals/treatment). Animals on aspartame consumed fewer calories, gained less weight and had a more favorable body composition when challenged with HF compared to animals consuming water. Despite this, aspartame elevated fasting glucose levels and an insulin tolerance test showed aspartame to impair insulin-stimulated glucose disposal in both CH and HF, independently of body composition. Fecal analysis of gut bacterial composition showed aspartame to increase total bacteria, the abundance of Enterobacteriaceae and Clostridium leptum. An interaction between HF and aspartame was also observed for Roseburia ssp wherein HF-A was higher than HF-W (Paspartame attenuated the typical HF-induced increase in the Firmicutes:Bacteroidetes ratio. Serum metabolomics analysis revealed aspartame to be rapidly metabolized and to be associated with elevations in the short chain fatty acid propionate, a bacterial end product and highly gluconeogenic substrate, potentially explaining its negative affects on insulin tolerance. How aspartame influences gut microbial composition and the implications of these changes on the development of metabolic disease require further investigation.

Adiposity indicators lipid accumulation product and triglyceride-glucose index as alternate criteria for the diagnosis of metabolic obesity in adult

OpenAIRE

Mariya Tabassum; Md. Matiur Rahman; Miliva Mozaffor

2018-01-01

Metabolic obesity refers to the state of having metabolic syndrome irrespective of one’s BMI. This study was aimed to elucidate the lipid accumulation product and triglyceride-glucose index as simple and alternate criteria for the detecting metabolic obesity in adult. The study was conducted in 200 adult (age range: 19-45 years). According to lipid accumulation product and Triglyceride-glucose index, the prevalence of metabolic obesity was 54.0% and 53.5% respectively. With a cutoff value of ...

Salmeterol and fluticasone propionate and survival in chronic obstructive pulmonary disease

DEFF Research Database (Denmark)

Calverley, PM; Anderson, JA; Celli, B

2007-01-01

-therapy group and 18.3% in the fluticasone group) than in the placebo group (12.3%, Plevel of statistical...... group, and 16.0% in the fluticasone group. The hazard ratio for death in the combination-therapy group, as compared with the placebo group, was 0.825 (95% confidence interval [CI], 0.681 to 1.002; P=0.052, adjusted for the interim analyses), corresponding to a difference of 2.6 percentage points...... or a reduction in the risk of death of 17.5%. The mortality rate for salmeterol alone or fluticasone propionate alone did not differ significantly from that for placebo. As compared with placebo, the combination regimen reduced the annual rate of exacerbations from 1.13 to 0.85 and improved health status...

A review on the bioenergetics of anaerobic microbial metabolism close to the thermodynamic limits and its implications for digestion applications.

Science.gov (United States)

Leng, Ling; Yang, Peixian; Singh, Shubham; Zhuang, Huichuan; Xu, Linji; Chen, Wen-Hsing; Dolfing, Jan; Li, Dong; Zhang, Yan; Zeng, Huiping; Chu, Wei; Lee, Po-Heng

2018-01-01

The exploration of the energetics of anaerobic digestion systems can reveal how microorganisms cooperate efficiently for cell growth and methane production, especially under low-substrate conditions. The establishment of a thermodynamically interdependent partnership, called anaerobic syntrophy, allows unfavorable reactions to proceed. Interspecies electron transfer and the concentrations of electron carriers are crucial for maintaining this mutualistic activity. This critical review summarizes the functional microorganisms and syntroph partners, particularly in the metabolic pathways and energy conservation of syntrophs. The kinetics and thermodynamics of propionate degradation to methane, reversibility of the acetate oxidation process, and estimation of microbial growth are summarized. The various routes of interspecies electron transfer, reverse electron transfer, and Poly-β-hydroxyalkanoate formation in the syntrophic community are also reviewed. Finally, promising and critical directions of future research are proposed. Fundamental insight in the activities and interactions involved in AD systems could serve as a guidance for engineered systems optimization and upgrade. Copyright © 2017 Elsevier Ltd. All rights reserved.

Role of Age-Related Shifts in Rumen Bacteria and Methanogens in Methane Production in Cattle

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Chong Liu

2017-08-01

Full Text Available Rumen microbiota are essential for maintaining digestive and metabolic functions, producing methane as a byproduct. Dairy heifers produce large amounts of methane based on fermentation of digested organic matter, with adverse consequences for feed efficiency and the environment. It is therefore important to understand the influence of host age on the relationship between microbiota and methane production. This study explored the age effect on the relationship between microbial communities and enteric methane production in dairy cows and heifers using high-throughput sequencing. Methane production and volatile fatty acid concentrations were age-related. Heifers (9–10 months had lower methane production but higher methane production per dry matter intake (DMI. The acetate:propionate ratio decreased significantly with increasing age. Age-related microbiota changes in the rumen were reflected by a significant shift in bacterial taxa, but relatively stable archaeal taxa. Prevotella, Ruminococcus, Flavonifractor, Succinivibrio, and Methanobrevibacter were affected by age. This study revealed different associations between predominant bacterial phylotypes and Methanobrevibacter with increasing age. Prevotella was strongly correlated with Methanobrevibacter in heifers; howerver, in older cows (96–120 months this association was replaced by a correlation between Succinivibrio and Methanobrevibacter. This shift may account for the age-related difference in rumen fermentation and methane production per DMI.

TetR Family Transcriptional Regulator PccD Negatively Controls Propionyl Coenzyme A Assimilation in Saccharopolyspora erythraea.

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Xu, Zhen; Wang, Miaomiao; Ye, Bang-Ce

2017-10-15

Propanol stimulates erythromycin biosynthesis by increasing the supply of propionyl coenzyme A (propionyl-CoA), a starter unit of erythromycin production in Saccharopolyspora erythraea Propionyl-CoA is assimilated via propionyl-CoA carboxylase to methylmalonyl-CoA, an extender unit of erythromycin. We found that the addition of n -propanol or propionate caused a 4- to 16-fold increase in the transcriptional levels of the SACE_3398-3400 locus encoding propionyl-CoA carboxylase, a key enzyme in propionate metabolism. The regulator PccD was proved to be directly involved in the transcription regulation of the SACE_3398-3400 locus by EMSA and DNase I footprint analysis. The transcriptional levels of SACE_3398-3400 were upregulated 15- to 37-fold in the pccD gene deletion strain (Δ pccD ) and downregulated 3-fold in the pccD overexpression strain (WT/pIB- pccD ), indicating that PccD was a negative transcriptional regulator of SACE_3398-3400. The Δ pccD strain has a higher growth rate than that of the wild-type strain (WT) on Evans medium with propionate as the sole carbon source, whereas the growth of the WT/pIB- pccD strain was repressed. As a possible metabolite of propionate metabolism, methylmalonic acid was identified as an effector molecule of PccD and repressed its regulatory activity. A higher level of erythromycin in the Δ pccD strain was observed compared with that in the wild-type strain. Our study reveals a regulatory mechanism in propionate metabolism and suggests new possibilities for designing metabolic engineering to increase erythromycin yield. IMPORTANCE Our work has identified the novel regulator PccD that controls the expression of the gene for propionyl-CoA carboxylase, a key enzyme in propionyl-CoA assimilation in S. erythraea PccD represses the generation of methylmalonyl-CoA through carboxylation of propionyl-CoA and reveals an effect on biosynthesis of erythromycin. This finding provides novel insight into propionyl-CoA assimilation, and

Precipitation of fluticasone propionate microparticles using supercritical antisolvent

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A Vatanara

2009-03-01

Full Text Available ABSTRACT Background: The ability of supercritical fluids (SCFs, such as carbon dioxide, to dissolve and expand or extract organic solvents and as result lower their solvation power, makes it possible the use of SCFs for the precipitation of solids from organic solutions. The process could be the injection of a solution of the substrate in an organic solvent into a vessel which is swept by a supercritical fluid. The aim of this study was to ascertain the feasibility of supercritical processing to prepare different particulate forms of fluticasone propionate (FP, and to evaluate the influence of different liquid solvents and precipitation temperatures on the morphology, size and crystal habit of particles. Method: The solution of FP in organic solvents, was precipitated by supercritical carbon dioxide (SCCO2 at two pressure and temperature levels. Effects of process parameters on the physicochemical characteristics of harvested microparticles were evaluated. Results: Particle formation was observed only at the lower selected pressure, whilst at the higher pressure, no precipitation of particles was occurred due to dissolution of FP in supercritical antisolvent. The micrographs of the produced particles showed different morphologies for FP obtained from different conditions. The results of thermal analysis of the resulted particles showed that changes in the processing conditions didn't influence thermal behavior of the precipitated particles. Evaluation of the effect of temperature on the size distribution of particles showed that increase in the temperature from 40 oC to 50 oC, resulted in reduction of the mean particle size from about 30 µm to about 12 μm. ‍Conclusion: From the results of this study it may be concluded that, processing of FP by supercritical antisolvent could be an approach for production of diverse forms of the drug and drastic changes in the physical characteristics of microparticles could be achieved by changing the

Metabolic and mineral conditions of retained placenta in highly productive dairy cows: pathogenesis, diagnostics and prevention – a review

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Ryszard Mordak

2017-01-01

Full Text Available The time around calving in highly productive dairy cows is a critical period in terms of their metabolism, which is connected with high demands of the foetus as well as with the onset of lactation. Retained placenta in cows may have multifactorial aetiology, but in herds which are free from infectious diseases, the most important reasons are; periparturient metabolic changes and disturbances to the internal balance and stress. During the periparturient period, the most important factor causing immune suppression and hypotony of uterus in cows is metabolic stress due to hormonal and nutritional factors, including metabolic fluctuations, negative energy balance, as well as shortage of proteins, minerals, vitamins and antioxidants. This metabolic stress as a result of an imbalance in the internal metabolic homeostasis activates the hypothalamic-pituitary-adrenocortical axis (HPA and increases serum corticosterid (cortisol concentration, especially on the day of calving. Cortisol is a powerful immune suppressive factor that causes depression of leukocyte proliferation and their functions. The periparturient metabolic stress may also stimulate the production of catecholamines, especially adrenalin. Elevated levels of adrenalin activate adrenoreceptors of the myometrium, which in turn cause hypotony or atony of the uterus at calving in cows. Elevated levels of cortisol and adrenalin may significantly inhibit the rejection and expulsion of foetal membranes in cows, resulting in an increased incidence of their retention. These important mechanisms for placental retention in highly productive dairy cows often have primary nutritional metabolic aetiology, but they also occur during secondary metabolic disturbances and metabolic stress during calving. This metabolic and immunological aetiology and pathogenesis of retained placenta usually occur in highly productive periparturient cows on dairy farms in the absence of bovine infectious diseases, which can

Therapeutic potency of bee pollen against biochemical autistic features induced through acute and sub-acute neurotoxicity of orally administered propionic acid.

Science.gov (United States)

Al-Salem, Huda S; Bhat, Ramesa Shafi; Al-Ayadhi, Laila; El-Ansary, Afaf

2016-04-23

It is now well documented that postnatal exposure to certain chemicals has been reported to increase the risk of autism spectrum disorder. Propionic acid (PA), as a metabolic product of gut microbiotaandas a commonly used food additive, has been reported to mediate the effects of autism. Results from animal studies may help to identify environmental neurotoxic agents and drugs that can ameliorate neurotoxicity and may thereby aid in the treatment of autism. The present study investigated the ameliorative effects of natural bee pollen against acute and sub-acute brain intoxication induced by (PA) in rats. Twenty-four young male Western Albino ratswere enrolled in the present study. They were classified into four equal groups, eachwith6 rats. The control group received only phosphate buffered saline; the oral buffered PA-treated groups (II and III) received a neurotoxic dose of 750 mg/kg body weight divided in 3 dose of 250 mg/kg body weight/day serving asthe acute group and 750 mg/kg body weight divided in 10 equal dose of 75 mg/kg body weight/day as the sub-acute group. The fourth group received 50 mg bee pollen for 30 days after PA-acute intoxication. The obtained data showed that the PA-treated groups demonstrated multiple signs of brain toxicity, as indicated by a depletion of serotonin (5HT), dopamine and nor-adrenaline, together withan increase in IFN-γ and caspase 3. Bee pollen was effective in ameliorating the neurotoxic effect of PA. All measured parameters demonstrated minimal alteration in comparison with thecontrol animal than did those of acute and sub-acute PA-treated animals. In conclusion, bee pollen demonstrates anti-inflammatory and anti-apoptotic effects while ameliorating the impaired neurochemistry of PA-intoxicated rats.

Hydrogen peroxide production and myo-inositol metabolism as important traits for virulence of Mycoplasma hyopneumoniae.

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Ferrarini, M G; Mucha, S G; Parrot, D; Meiffren, G; Bachega, J F R; Comte, G; Zaha, A; Sagot, M F

2018-04-06

Mycoplasma hyopneumoniae is the causative agent of enzootic pneumonia. In our previous work, we reconstructed the metabolic models of this species along with two other mycoplasmas from the respiratory tract of swine: Mycoplasma hyorhinis, considered less pathogenic but which nonetheless causes disease and Mycoplasma flocculare, a commensal bacterium. We identified metabolic differences that partially explained their different levels of pathogenicity. One important trait was the production of hydrogen peroxide from the glycerol metabolism only in the pathogenic species. Another important feature was a pathway for the metabolism of myo-inositol in M. hyopneumoniae. Here, we tested these traits to understand their relation to the different levels of pathogenicity, comparing not only the species but also pathogenic and attenuated strains of M. hyopneumoniae. Regarding the myo-inositol metabolism, we show that only M. hyopneumoniae assimilated this carbohydrate and remained viable when myo-inositol was the primary energy source. Strikingly, only the two pathogenic strains of M. hyopneumoniae produced hydrogen peroxide in complex medium. We also show that this production was dependent on the presence of glycerol. Although further functional tests are needed, we present in this work two interesting metabolic traits of M. hyopneumoniae that might be directly related to its enhanced virulence. This article is protected by copyright. All rights reserved. © 2018 John Wiley & Sons Ltd.

Solar photocatalytic oxidation of recalcitrant natural metabolic by-products of amoxicillin biodegradation.

Science.gov (United States)

Pereira, João H O S; Reis, Ana C; Homem, Vera; Silva, José A; Alves, Arminda; Borges, Maria T; Boaventura, Rui A R; Vilar, Vítor J P; Nunes, Olga C

2014-11-15

The contamination of the aquatic environment by non-metabolized and metabolized antibiotic residues has brought the necessity of alternative treatment steps to current water decontamination technologies. This work assessed the feasibility of using a multistage treatment system for amoxicillin (AMX) spiked solutions combining: i) a biological treatment process using an enriched culture to metabolize AMX, with ii) a solar photocatalytic system to achieve the removal of the metabolized transformation products (TPs) identified via LC-MS, recalcitrant to further biological degradation. Firstly, a mixed culture (MC) was obtained through the enrichment of an activated sludge sample collected in an urban wastewater treatment plant (WWTP). Secondly, different aqueous matrices spiked with AMX were treated with the MC and the metabolic transformation products were identified. Thirdly, the efficiency of two solar assisted photocatalytic processes (TiO2/UV or Fe(3+)/Oxalate/H2O2/UV-Vis) was assessed in the degradation of the obtained TPs using a lab-scale prototype photoreactor equipped with a compound parabolic collector (CPC). Highest AMX specific biodegradation rates were obtained in buffer and urban wastewater (WW) media (0.10 ± 0.01 and 0.13 ± 0.07 g(AMX) g(biomass)(-1) h(-1), respectively). The resulting TPs, which no longer presented antibacterial activity, were identified as amoxicilloic acid (m/z = 384). The performance of the Fe(3+)/Oxalate/H2O2/UV-Vis system in the removal of the TPs from WW medium was superior to the TiO2/UV process (TPs no longer detected after 40 min (QUV = 2.6 kJ L(-1)), against incomplete TPs removal after 240 min (QUV = 14.9 kJ L(-1)), respectively). Copyright © 2014 Elsevier Ltd. All rights reserved.

Metabolic and Kinetic analyses of influenza production in perfusion HEK293 cell culture

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Lohr Verena

2011-09-01

Full Text Available Abstract Background Cell culture-based production of influenza vaccine remains an attractive alternative to egg-based production. Short response time and high production yields are the key success factors for the broader adoption of cell culture technology for industrial manufacturing of pandemic and seasonal influenza vaccines. Recently, HEK293SF cells have been successfully used to produce influenza viruses, achieving hemagglutinin (HA and infectious viral particle (IVP titers in the highest ranges reported to date. In the same study, it was suggested that beyond 4 × 106 cells/mL, viral production was limited by a lack of nutrients or an accumulation of toxic products. Results To further improve viral titers at high cell densities, perfusion culture mode was evaluated. Productivities of both perfusion and batch culture modes were compared at an infection cell density of 6 × 106 cells/mL. The metabolism, including glycolysis, glutaminolysis and amino acids utilization as well as physiological indicators such as viability and apoptosis were extensively documented for the two modes of culture before and after viral infection to identify potential metabolic limitations. A 3 L bioreactor with a perfusion rate of 0.5 vol/day allowed us to reach maximal titers of 3.3 × 1011 IVP/mL and 4.0 logHA units/mL, corresponding to a total production of 1.0 × 1015 IVP and 7.8 logHA units after 3 days post-infection. Overall, perfusion mode titers were higher by almost one order of magnitude over the batch culture mode of production. This improvement was associated with an activation of the cell metabolism as seen by a 1.5-fold and 4-fold higher consumption rates of glucose and glutamine respectively. A shift in the viral production kinetics was also observed leading to an accumulation of more viable cells with a higher specific production and causing an increase in the total volumetric production of infectious influenza particles. Conclusions These results

The Metabolic Properties of the Fission Products and Actinide Elements

Energy Technology Data Exchange (ETDEWEB)

Hamilton M.D., J.G.

1948-03-01

An investigation of the assimilation, distribution, retention, an excretion of the fission products and actinide elements in the rat has been conducted at the Crocker Radiation Laboratory, University of California, Berkeley, California. These studies were initiated October 15, 1942, and are continuing at the present time. An extensive survey has been made of the metabolism of twenty-two different radio elements in the rat.

Metabolic engineering of riboflavin production in Ashbya gossypii through pathway optimization.

Science.gov (United States)

Ledesma-Amaro, Rodrigo; Serrano-Amatriain, Cristina; Jiménez, Alberto; Revuelta, José Luis

2015-10-14

The industrial production of riboflavin mostly relies on the microbial fermentation of flavinogenic microorganisms and Ashbya gossypii is the main industrial producer of the vitamin. Accordingly, bioengineering strategies aimed at increasing riboflavin production in A. gossypii are highly valuable for industry. We analyze the contribution of all the RIB genes to the production of riboflavin in A. gossypii. Two important metabolic rate-limiting steps that limit the overproduction of riboflavin have been found: first, low mRNA levels of the RIB genes hindered the overproduction of riboflavin; second, the competition of the AMP branch for purinogenic precursors also represents a limitation for riboflavin overproduction. Thus, overexpression of the RIB genes resulted in a significant increase in riboflavin yield. Moreover, both the inactivation and the underexpression of the ADE12 gene, which controls the first step of the AMP branch, also proved to have a positive effect on riboflavin production. Accordingly, a strain that combines both the overexpression of the RIB genes and the underexpression of the ADE12 gene was engineered. This strain produced 523 mg/L of riboflavin (5.4-fold higher than the wild-type), which is the highest titer of riboflavin obtained by metabolic engineering in A. gossypii so far. Riboflavin production in A. gossypii is limited by a low transcription activity of the RIB genes. Flux limitation towards AMP provides committed substrate GTP for riboflavin overproduction without detrimental effects on biomass formation. A multiple-engineered Ashbya strain that produces up to 523 mg/L of riboflavin was generated.

Clobetasol propionate shampoo 0.05% is efficacious and safe for long-term control of scalp psoriasis.

Science.gov (United States)

Poulin, Yves; Papp, Kim; Bissonnette, Robert; Guenther, Lyn; Tan, Jerry; Lynde, Charles; Kerrouche, Nabil; Villemagne, Hervé

2010-01-01

Clobetasol propionate (CP) shampoo 0.05% is an efficacious and safe treatment for scalp psoriasis. The aim of this double-blind, randomized, placebo-controlled study was to determine if CP shampoo is suitable for long-term disease control. Participants with moderate to severe scalp psoriasis (global severity score [GSS] of 3 or 4 on a scale of 0 [clear] to 5 [very severe]) first received once daily CP shampoo treatment for up to 4 weeks. Responders were subsequently randomized to receive the CP shampoo or vehicle twice weekly maintenance regimen for up to 6 months. When relapse occurred (defined as GSS > 2), participants resumed once daily CP shampoo treatment; when symptoms diminished (GSS shampoo did not relapse compared with participants treated with vehicle (P shampoo group. After 6 months 31.1% (33/106) of participants in the CP shampoo group were still relapse free versus 8.1% (9/111) of participants in the vehicle group. There was no greater incidence of skin atrophy, telangiectasia, or hypothalamic-pituitary-adrenal (HPA) axis suppression in the CP shampoo group compared with the vehicle group. Clobetasol propionate shampoo is efficacious and safe for acute management and long-term maintenance of moderate to severe scalp psoriasis.

Flux Balance Analysis Inspired Bioprocess Upgrading for Lycopene Production by a Metabolically Engineered Strain of Yarrowia lipolytica

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Komi Nambou

2015-12-01

Full Text Available Genome-scale metabolic models embody a significant advantage of systems biology since their applications as metabolic flux simulation models enable predictions for the production of industrially-interesting metabolites. The biotechnological production of lycopene from Yarrowia lipolytica is an emerging scope that has not been fully scrutinized, especially for what concerns cultivation conditions of newly generated engineered strains. In this study, by combining flux balance analysis (FBA and Plackett-Burman design, we screened chemicals for lycopene production from a metabolically engineered strain of Y. lipolytica. Lycopene concentrations of 126 and 242 mg/L were achieved correspondingly from the FBA-independent and the FBA-assisted designed media in fed-batch cultivation mode. Transcriptional studies revealed upregulations of heterologous genes in media designed according to FBA, thus implying the efficiency of model predictions. Our study will potentially support upgraded lycopene and other terpenoids production from existing or prospect bioengineered strains of Y. lipolytica and/or closely related yeast species.

Regulatory effect of dietary intake of chromium propionate on the response of monocyte-derived macrophages from Holstein cows in mid lactation.

Science.gov (United States)

Garcia, M; Qu, Y; Scholte, C M; O'Connor, D; Rounds, W; Moyes, K M

2017-08-01

Chromium (Cr) has been reported to enhance immune function and improve insulin sensitivity and performance in beef and dairy cattle. However, its effect on bovine macrophage inflammatory and metabolic response is unknown. The objective of this study was to characterize the effect of dietary Cr on the inflammatory and metabolic response of polarized macrophages ex vivo. Twelve primiparous and 16 multiparous healthy Holstein cows in mid lactation (143 ± 37 d in milk) were enrolled in this study. Cows were fed a common total mixed ration once per day that was top-dressed with 200 g of ground corn containing 1 of 2 dietary treatments: control (CTL, no Cr supplementation) or Cr propionate (CrP, 8 mg of Cr/cow per day) for 35 d. At d 1, 17, and 35 of treatment, blood monocytes were isolated and cultured to obtain 3 monocyte-derived macrophage (MDM) phenotypes: M0 (non-polarized), M1 (pro-inflammatory; IFN-γ polarized) and M2 (anti-inflammatory; IL-4 polarized). The experiment was set in a randomized complete block design. Neither dry matter intake nor milk yield was affected by treatment. Plasma concentrations of metabolites and the metabolic and inflammatory response of MDM in spent media were not affected by treatment. Neither the whole blood cell population nor the specific proportion of leukocytes was affected by the main effect of treatment. However, we did observe a trend for fewer circulating neutrophils in cows fed CrP than in cows fed CTL for 35 d, which may be partly attributable to a greater influx of neutrophils into peripheral tissues, a reduced pro-inflammatory response during disease, or both; this warrants future study. Expression of IGFI was increased in MDM-M0, and expression of CXCL11 tended to increase in MDM-M2 from cows fed CrP compared with cows fed CTL. Expression of SLC2A3 also tended to increase in MDM-M2 from cows fed CrP compared with cows fed CTL at 17 d. Our results suggest that CrP has minimal effect on the inflammatory and metabolic

Changes in energetic metabolism of Biomphalaria glabrata (Mollusca, Planorbidae in response to exogenous calcium

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L. D. Silva

Full Text Available Abstract Calcium is considered an essential element for the metabolism of aquatic snail Biomphalaria glabrata (Say, 1818, intermediate host of Schistosoma mansoni Sambon, 1907 in Brazil, and represents a limiting factor to its distribution and adaptation to the environment. This study investigated the effect of different concentrations of exogenous CaCO3 on the energetic metabolism of B. glabrata for better understanding the physiological interference of chemical elements dissolved in the environment with the physiology of this species. Sixty-day-old snails were distributed into six groups, five exposed to different concentrations of CaCO3 (20, 40, 60, 80 and 100 mg/L and a control group. The exposure to CaCO3 was assessed over time, with analysis of 15 snails of each group in the following intervals: 1, 14, 21 or 30 days for hemolymph extraction. Concentrations of calcium and glucose in the hemolymph were determined by commercial kits, and organic acids were extracted using an ion exchange column and analyzed by high-performance liquid chromatography. Concentration of calcium in the hemolymph showed no significant difference (p>0.05 from the control group and between the concentrations tested. Concentration of glucose decreased (p<0.05 in the treatments of exposure to 20 and 40 mg/L and increased when exposed to 80 and 100 mg/L CaCO3 compared to control and to other concentrations tested over 30 days. The organic acids pyruvate, oxaloacetate, citrate, succinate, fumarate, beta-hydroxybutyrate and lactate presented increased concentrations, while propionate and acetoacetate, decreased concentrations, when exposed to CaCO3 compared to control. Considering the influence of different periods of exposure to CaCO3, on the 14th day, there were stronger alterations in the metabolism of B. glabrata. In conclusion, exposure to CaCO3 reduced the concentration of glucose, which is metabolized into pyruvate, the final product of glycolysis, and also

Thermodynamic Driving Force of Hydrogen on Rumen Microbial Metabolism: A Theoretical Investigation.

Science.gov (United States)

van Lingen, Henk J; Plugge, Caroline M; Fadel, James G; Kebreab, Ermias; Bannink, André; Dijkstra, Jan

2016-01-01

Hydrogen is a key product of rumen fermentation and has been suggested to thermodynamically control the production of the various volatile fatty acids (VFA). Previous studies, however, have not accounted for the fact that only thermodynamic near-equilibrium conditions control the magnitude of reaction rate. Furthermore, the role of NAD, which is affected by hydrogen partial pressure (PH2), has often not been considered. The aim of this study was to quantify the control of PH2 on reaction rates of specific fermentation pathways, methanogenesis and NADH oxidation in rumen microbes. The control of PH2 was quantified using the thermodynamic potential factor (FT), which is a dimensionless factor that corrects a predicted kinetic reaction rate for the thermodynamic control exerted. Unity FT was calculated for all glucose fermentation pathways considered, indicating no inhibition of PH2 on the production of a specific type of VFA (e.g., acetate, propionate and butyrate) in the rumen. For NADH oxidation without ferredoxin oxidation, increasing PH2 within the rumen physiological range decreased FT from unity to zero for different NAD+ to NADH ratios and pH of 6.2 and 7.0, which indicates thermodynamic control of PH2. For NADH oxidation with ferredoxin oxidation, increasing PH2 within the rumen physiological range decreased FT from unity at pH of 7.0 only. For the acetate to propionate conversion, FT increased from 0.65 to unity with increasing PH2, which indicates thermodynamic control. For propionate to acetate and butyrate to acetate conversions, FT decreased to zero below the rumen range of PH2, indicating full thermodynamic suppression. For methanogenesis by archaea without cytochromes, FT differed from unity only below the rumen range of PH2, indicating no thermodynamic control. This theoretical investigation shows that thermodynamic control of PH2 on individual VFA produced and associated yield of hydrogen and methane cannot be explained without considering NADH

Thermodynamic Driving Force of Hydrogen on Rumen Microbial Metabolism: A Theoretical Investigation.

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Henk J van Lingen

Full Text Available Hydrogen is a key product of rumen fermentation and has been suggested to thermodynamically control the production of the various volatile fatty acids (VFA. Previous studies, however, have not accounted for the fact that only thermodynamic near-equilibrium conditions control the magnitude of reaction rate. Furthermore, the role of NAD, which is affected by hydrogen partial pressure (PH2, has often not been considered. The aim of this study was to quantify the control of PH2 on reaction rates of specific fermentation pathways, methanogenesis and NADH oxidation in rumen microbes. The control of PH2 was quantified using the thermodynamic potential factor (FT, which is a dimensionless factor that corrects a predicted kinetic reaction rate for the thermodynamic control exerted. Unity FT was calculated for all glucose fermentation pathways considered, indicating no inhibition of PH2 on the production of a specific type of VFA (e.g., acetate, propionate and butyrate in the rumen. For NADH oxidation without ferredoxin oxidation, increasing PH2 within the rumen physiological range decreased FT from unity to zero for different NAD+ to NADH ratios and pH of 6.2 and 7.0, which indicates thermodynamic control of PH2. For NADH oxidation with ferredoxin oxidation, increasing PH2 within the rumen physiological range decreased FT from unity at pH of 7.0 only. For the acetate to propionate conversion, FT increased from 0.65 to unity with increasing PH2, which indicates thermodynamic control. For propionate to acetate and butyrate to acetate conversions, FT decreased to zero below the rumen range of PH2, indicating full thermodynamic suppression. For methanogenesis by archaea without cytochromes, FT differed from unity only below the rumen range of PH2, indicating no thermodynamic control. This theoretical investigation shows that thermodynamic control of PH2 on individual VFA produced and associated yield of hydrogen and methane cannot be explained without

Metabolic Signatures of Kidney Yang Deficiency Syndrome and Protective Effects of Two Herbal Extracts in Rats Using GC/TOF MS

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Linjing Zhao

2013-01-01

Full Text Available Kidney Yang Deficiency Syndrome (KDS-Yang, a typical condition in Chinese medicine, shares similar clinical signs of the glucocorticoid withdrawal syndrome. To date, the underlying mechanism of KDS-Yang has been remained unclear, especially at the metabolic level. In this study, we report a metabolomic profiling study on a classical model of KDS-Yang in rats induced by hydrocortisone injection to characterize the metabolic transformation using gas chromatography/time-of-flight mass spectrometry. WKY1, a polysaccharide extract from Astragalus membranaceus and Lycium barbarum, and WKY2, an aqueous extract from a similar formula containing Astragalus membranaceus, Lycium barbarum, Morinda officinalis, Taraxacum mongolicum, and Cinnamomum cassia presl, were used separately for protective treatments of KDS-Yang. The changes of serum metabolic profiles indicated that significant alterations of key metabolic pathways in response to abrupt hydrocortisone perturbation, including decreased energy metabolism (lactic acid, acetylcarnitine, lipid metabolism (free fatty acids, 1-monolinoleoylglycerol, and cholesterol, gut microbiota metabolism (indole-3-propionic acid, biosynthesis of catecholamine (norepinephrine, and elevated alanine metabolism, were attenuated or normalized with different degrees by the pretreatment of WKY1 or WKY2, which is consistent with the observations in which the two herbal agents could ameliorate biochemical markers of serum cortisone, adrenocorticotropic (ACTH, and urine 17-hydroxycorticosteroids (17-OHCS.

Perspectives in metabolic engineering: understanding cellular regulation towards the control of metabolic routes.

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Zadran, Sohila; Levine, Raphael D

2013-01-01

Metabolic engineering seeks to redirect metabolic pathways through the modification of specific biochemical reactions or the introduction of new ones with the use of recombinant technology. Many of the chemicals synthesized via introduction of product-specific enzymes or the reconstruction of entire metabolic pathways into engineered hosts that can sustain production and can synthesize high yields of the desired product as yields of natural product-derived compounds are frequently low, and chemical processes can be both energy and material expensive; current endeavors have focused on using biologically derived processes as alternatives to chemical synthesis. Such economically favorable manufacturing processes pursue goals related to sustainable development and "green chemistry". Metabolic engineering is a multidisciplinary approach, involving chemical engineering, molecular biology, biochemistry, and analytical chemistry. Recent advances in molecular biology, genome-scale models, theoretical understanding, and kinetic modeling has increased interest in using metabolic engineering to redirect metabolic fluxes for industrial and therapeutic purposes. The use of metabolic engineering has increased the productivity of industrially pertinent small molecules, alcohol-based biofuels, and biodiesel. Here, we highlight developments in the practical and theoretical strategies and technologies available for the metabolic engineering of simple systems and address current limitations.

Engineering Cellular Metabolism

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Nielsen, Jens; Keasling, Jay

2016-01-01

Metabolic engineering is the science of rewiring the metabolism of cells to enhance production of native metabolites or to endow cells with the ability to produce new products. The potential applications of such efforts are wide ranging, including the generation of fuels, chemicals, foods, feeds...... of metabolic engineering and will discuss how new technologies can enable metabolic engineering to be scaled up to the industrial level, either by cutting off the lines of control for endogenous metabolism or by infiltrating the system with disruptive, heterologous pathways that overcome cellular regulation....

Oxidative metabolism of 5-o-caffeoylquinic acid (chlorogenic acid), a bioactive natural product, by metalloporphyrin and rat liver mitochondria.

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dos Santos, Michel D; Martins, Patrícia R; dos Santos, Pierre A; Bortocan, Renato; Iamamoto, Y; Lopes, Norberto P

2005-09-01

Synthetic metalloporphyrins, in the presence of monooxygen donors, are known to mimic the various reactions of cytochrome P450 enzymes systems in the oxidation and oxygenation of various drugs and biologically active compounds. This paper reports an HPLC-MS-MS investigation of chlorogenic acid (CGA) oxidation by iodosylbenzene using iron(III) tetraphenylporphyrin chloride as catalyst. The oxidation products have been detected by sequential MS analyses. In addition, CGA was submitted to an in vitro metabolism assay employing isolated rat liver mitochondria. The single oxidized product obtained from mitochondrial metabolism corresponds to the major product formed by the metalloporphyrin-catalyzed reaction. These results indicate that biomimetic oxidation reactions, in addition to in vitro metabolism assays employing isolated organs/organelles, could replace some in vivo metabolism studies, thus minimizing the problems related to the use of a large number of living animals in experimental research.

In vivo effects of Faizol Ubat Batuk, a herbal product on aminopyrine metabolism in rat hepatocytes

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Abas Hj Hussin

2011-09-01

Full Text Available Traditional medicines, in particular herbal products, have been used abundantly over the years in curing several diseases. Pharmacological interactions of herbal products with modern drugs, however, remain to some extent unknown. Herein, we examined whether co-administration of Faizol Ubat Batuk (FUB, a mixture of aqueous extract of different plants, modifies the metabolism of aminopyrine, a conventional analgesic drug, in rat liver. We used rat hepatocytes outfitted by collagenase perfusion technique. Determination of aminopyrine n-demethylase activity was performed using the Nash colorimetric method, by measuring the amount of formaldehyde produced. Compared to control treatment, FUB significantly increased the hepatic metabolism of aminopyrine in healthy adult male rats. In contrast, the hepatic metabolism of aminopyrine in adult female rats was decreased. Besides, a biphasic effect in n-demethylase activity was observed in young male rats treated with FUB. In a subsequent experiment, FUB did not change the metabolism of aminopyrine in streptozotocin (STZ-diabetic adult male rats. In conclusion, administration of FUB could affect phase I aminopyrine metabolism in rat heptocytes. In addition, the effects of FUB on hepatic n-demethylase activity were gender and disease dependent.

Metabolic pathway analysis and kinetic studies for production of nattokinase in Bacillus subtilis.

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Unrean, Pornkamol; Nguyen, Nhung H A

2013-01-01

We have constructed a reaction network model of Bacillus subtilis. The model was analyzed using a pathway analysis tool called elementary mode analysis (EMA). The analysis tool was used to study the network capabilities and the possible effects of altered culturing conditions on the production of a fibrinolytic enzyme, nattokinase (NK) by B. subtilis. Based on all existing metabolic pathways, the maximum theoretical yield for NK synthesis in B. subtilis under different substrates and oxygen availability was predicted and the optimal culturing condition for NK production was identified. To confirm model predictions, experiments were conducted by testing these culture conditions for their influence on NK activity. The optimal culturing conditions were then applied to batch fermentation, resulting in high NK activity. The EMA approach was also applied for engineering B. subtilis metabolism towards the most efficient pathway for NK synthesis by identifying target genes for deletion and overexpression that enable the cell to produce NK at the maximum theoretical yield. The consistency between experiments and model predictions proves the feasibility of EMA being used to rationally design culture conditions and genetic manipulations for the efficient production of desired products.

Genome Sequencing of Streptomyces atratus SCSIOZH16 and Activation Production of Nocardamine via Metabolic Engineering

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Yan Li

2018-06-01

Full Text Available The Actinomycetes are metabolically flexible microorganisms capable of producing a wide range of interesting compounds, including but by no means limited to, siderophores which have high affinity for ferric iron. In this study, we report the complete genome sequence of marine-derived Streptomyces atratus ZH16 and the activation of an embedded siderophore gene cluster via the application of metabolic engineering methods. The S. atratus ZH16 genome reveals that this strain has the potential to produce 26 categories of natural products (NPs barring the ilamycins. Our activation studies revealed S. atratus SCSIO ZH16 to be a promising source of the production of nocardamine-type (desferrioxamine compounds which are important in treating acute iron intoxication and performing ecological remediation. We conclude that metabolic engineering provides a highly effective strategy by which to discover drug-like compounds and new NPs in the genomic era.

Effect of co-substrate on production of poly-β- hydroxybutyrate (PHB and copolymer PHBV from newly identified mutant Rhodobacter sphaeroides U7 cultivated under aerobic-dark condition

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Kemarajt Kemavongse

2007-07-01

Full Text Available Photosynthetic bacterial mutant strain U7 was identified using both classical and molecular (16S rDNA techniques to be Rhodobacter sphaeroides. The glutamate-acetate (GA medium containing sodium acetate and sodium glutamate as carbon and nitrogen sources was used for production of poly-β-hydroxybutyrate (PHB from R. sphaeroides U7 cultivated under aerobic-dark condition (200 rpm at 37oC. Effect of auxiliary carbon sources (propionate and valerate and concentrations (molar ratio of 40/0, 40/20, 40/40 and 40/80 on copolymer production were studied. Both combinations of acetate with valerate and acetate with propionate were found to induce the accumulation of poly-β-hydroxybutyrate-co-β-hydroxyvalerate (PHBV within the cell. Acetate with propionate in the molar ratio of 40/40 gave the highest poly-β-hydroxyalkanoates (PHA content (77.68%, followed by acetate with valerate at the same molar ratio (77.42%. Although their polymer contents were similar, the presence of 40 mM valerate gave more than 4 times higher hydroxyvalerate (HV fraction (84.77% than in the presence of 40 mM propionate (19.12% HV fraction.

A study of the prebiotic-like effects of tomato juice consumption in rats with diet-induced non-alcoholic fatty liver disease (NAFLD).

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García-Alonso, F J; González-Barrio, R; Martín-Pozuelo, G; Hidalgo, N; Navarro-González, I; Masuero, D; Soini, E; Vrhovsek, U; Periago, M J

2017-10-18

Gut microbiota may play a role in the pathogenesis of NAFLD. We investigated whether tomato juice consumption for 5 weeks could ameliorate high-fat diet-induced alterations in certain intestinal bacterial groups and products arising from their metabolism (short-chain fatty acids and microbial phenolic catabolites). For this, we used a rat model with NAFLD induced by a high-fat diet, involving four experimental groups: NA (standard diet and water), NL (standard diet and tomato juice), HA (high-fat diet and water) and HL (high-fat diet and tomato juice). The onset of NAFLD impacted the gut microbiota profile, reducing the abundance of Bifidobacterium and Lactobacillus and increasing that of Enterobacteriaceae. Also, reduced concentrations of propionate, butyrate and phenolic catabolites and an increased acetate to propionate (Ac : Pr) ratio were observed. Tomato juice intake partially ameliorated high-fat diet-induced disturbances, particularly by increasing Lactobacillus abundance and diminishing the Ac : Pr ratio, suggesting a potential improvement of the metabolic pattern of NAFLD.

Systematic metabolic engineering of Methylomicrobium alcaliphilum 20Z for 2,3-butanediol production from methane.

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Nguyen, Anh Duc; Hwang, In Yeub; Lee, Ok Kyung; Kim, Donghyuk; Kalyuzhnaya, Marina G; Mariyana, Rina; Hadiyati, Susila; Kim, Min Sik; Lee, Eun Yeol

2018-04-16

Methane is considered a next-generation feedstock, and methanotrophic cell-based biorefinery is attractive for production of a variety of high-value compounds from methane. In this work, we have metabolically engineered Methylomicrobium alcaliphilum 20Z for 2,3-butanediol (2,3-BDO) production from methane. The engineered strain 20Z/pBudK.p, harboring the 2,3-BDO synthesis gene cluster (budABC) from Klebsiella pneumoniae, accumulated 2,3-BDO in methane-fed shake flask cultures with a titer of 35.66 mg/L. Expression of the most efficient gene cluster was optimized using selection of promoters, translation initiation rates (TIR), and the combination of 2,3-BDO synthesis genes from different sources. A higher 2,3-BDO titer of 57.7 mg/L was measured in the 20Z/pNBM-Re strain with budA of K. pneumoniae and budB of Bacillus subtilis under the control of the Tac promoter. The genome-scale metabolic network reconstruction of M. alcaliphilum 20Z enabled in silico gene knockout predictions using an evolutionary programming method to couple growth and 2,3-BDO production. The ldh, ack, and mdh genes in M. alcaliphilum 20Z were identified as potential knockout targets. Pursuing these targets, a triple-mutant strain ∆ldh ∆ack ∆mdh was constructed, resulting in a further increase of the 2,3-BDO titer to 68.8 mg/L. The productivity of this optimized strain was then tested in a fed-batch stirred tank bioreactor, where final product concentrations of up to 86.2 mg/L with a yield of 0.0318 g-(2,3-BDO) /g-CH 4 were obtained under O 2 -limited conditions. This study first demonstrates the strategy of in silico simulation-guided metabolic engineering and represents a proof-of-concept for the production of value-added compounds using systematic approaches from engineered methanotrophs. Copyright © 2018 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Understanding the interplay of carbon and nitrogen supply for ectoines production and metabolic overflow in high density cultures of Chromohalobacter salexigens.

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Salar-García, María J; Bernal, Vicente; Pastor, José M; Salvador, Manuel; Argandoña, Montserrat; Nieto, Joaquín J; Vargas, Carmen; Cánovas, Manuel

2017-02-08

The halophilic bacterium Chromohalobacter salexigens has been proposed as promising cell factory for the production of the compatible solutes ectoine and hydroxyectoine. This bacterium has evolved metabolic adaptations to efficiently grow under high salt concentrations by accumulating ectoines as compatible solutes. However, metabolic overflow, which is a major drawback for the efficient conversion of biological feedstocks, occurs as a result of metabolic unbalances during growth and ectoines production. Optimal production of ectoines is conditioned by the interplay of carbon and nitrogen metabolisms. In this work, we set out to determine how nitrogen supply affects the production of ectoines. Chromohalobacter salexigens was challenged to grow in media with unbalanced carbon/nitrogen ratio. In C. salexigens, overflow metabolism and ectoines production are a function of medium composition. At low ammonium conditions, the growth rate decreased importantly, up to 80%. Shifts in overflow metabolism were observed when changing the C/N ratio in the culture medium. 13 C-NMR analysis of ectoines labelling revealed a high metabolic rigidity, with almost constant flux ratios in all conditions assayed. Unbalanced C/N ratio led to pyruvate accumulation, especially upon N-limitation. Analysis of an ect - mutant demonstrated the link between metabolic overflow and ectoine biosynthesis. Under non ectoine synthesizing conditions, glucose uptake and metabolic overflow decreased importantly. Finally, in fed-batch cultures, biomass yield was affected by the feeding scheme chosen. High growth (up to 42.4 g L -1 ) and volumetric ectoine yields (up to 4.21 g L -1 ) were obtained by minimizing metabolite overflow and nutrient accumulation in high density cultures in a low nitrogen fed-batch culture. Moreover, the yield coefficient calculated for the transformation of glucose into biomass was 30% higher in fed-batch than in the batch culture, demonstrating that the metabolic

Taenia crassiceps: fatty acids oxidation and alternative energy source in in vitro cysticerci exposed to anthelminthic drugs.

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Vinaud, Marina Clare; Ferreira, Cirlane Silva; Lino Junior, Ruy de Souza; Bezerra, José Clecildo Barreto

2009-07-01

Cysticerci metabolic studies demonstrate alternative pathways responsible for its survival, such as energy sources, fatty acids oxidation and excretion of beta-hydroxybutyrate, which indicates the capability of energy production from proteins. The aim of this study was to detect alternative metabolic pathways for energy production and its end products in Taenia crassiceps cysticerci in vitro exposed to praziquantel and albendazole, in sub-lethal doses. Spectrophotometer and chromatographic analysis were performed to detect: propionate, acetate, beta-hydroxybutyrate, total proteins, urea and creatinine, SE by cysticerci in vitro exposed to praziquantel and albendazole. The drugs influenced the metabolism by inducing the creatinine phosphate phosphorylation as an alternative energy source, inhibiting the use of proteins and amino acids in the acid nucleic synthesis; and preventing the budding and replication of the cysticerci. This study also highlights the description of urea excretion, which is an important metabolic pathway to excrete toxic products such as ammonia, and the fatty acid oxidation as an alternative energy source in cysticerci exposed to anthelmintic drugs.

The RNA chaperone Hfq impacts growth, metabolism and production of virulence factors in Yersinia enterocolitica.

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Tamara Kakoschke

Full Text Available To adapt to changes in environmental conditions, bacteria regulate their gene expression at the transcriptional but also at the post-transcriptional level, e.g. by small RNAs (sRNAs which modulate mRNA stability and translation. The conserved RNA chaperone Hfq mediates the interaction of many sRNAs with their target mRNAs, thereby playing a global role in fine-tuning protein production. In this study, we investigated the significance of Hfq for the enteropathogen Yersina enterocolitica serotype O:8. Hfq facilitated optimal growth in complex and minimal media. Our comparative protein analysis of parental and hfq-negative strains suggested that Hfq promotes lipid metabolism and transport, cell redox homeostasis, mRNA translation and ATP synthesis, and negatively affects carbon and nitrogen metabolism, transport of siderophore and peptides and tRNA synthesis. Accordingly, biochemical tests indicated that Hfq represses ornithine decarboxylase activity, indole production and utilization of glucose, mannitol, inositol and 1,2-propanediol. Moreover, Hfq repressed production of the siderophore yersiniabactin and its outer membrane receptor FyuA. In contrast, hfq mutants exhibited reduced urease production. Finally, strains lacking hfq were more susceptible to acidic pH and oxidative stress. Unlike previous reports in other Gram-negative bacteria, Hfq was dispensable for type III secretion encoded by the virulence plasmid. Using a chromosomally encoded FLAG-tagged Hfq, we observed increased production of Hfq-FLAG in late exponential and stationary phases. Overall, Hfq has a profound effect on metabolism, resistance to stress and modulates the production of two virulence factors in Y. enterocolitica, namely urease and yersiniabactin.

Ginkgo fruit extract as an additive to modify rumen microbiota and fermentation and to mitigate methane production.

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Oh, S; Shintani, R; Koike, S; Kobayashi, Y

2017-03-01

Ginkgo fruit, an unused byproduct of the ginkgo nut industry, contains antimicrobial compounds known as anacardic acids. Two major cultivars of ginkgo, Kyuju (K) and Tokuro (T), were evaluated for their potential as a feed additive for ruminants. In batch culture, we incubated a mixture of hay and concentrate in diluted rumen fluid with or without 1.6% (fruit equivalent) ginkgo fruit extract. We conducted another series of batch culture studies to determine the dose response of fermentation. We also conducted continuous culture using the rumen simulation technique (RUSITEC) with cultivar K and carried out a pure culture study to monitor the sensitivity of 17 representative rumen bacterial species to ginkgo extract and component phenolics. Although both K and T extracts led to decreased methane and increased propionate production, changes were more apparent with K extract, and were dose-dependent. Total gas production was depressed at doses ≥3.2%, suggesting that 1.6% was the optimal supplementation level. In RUSITEC fermentation supplemented with 1.6% ginkgo K, methane decreased by 53% without affecting total gas or total VFA production, but with decreased acetate and increased propionate. Disappearance of dry matter, neutral detergent fiber, and acid detergent fiber were not affected by ginkgo, but ammonia levels were decreased. Quantitative PCR indicated that the abundance of protozoa, fungi, methanogens, and bacteria related to hydrogen and formate production decreased, but the abundance of bacteria related to propionate production increased. MiSeq analysis (Illumina Inc., San Diego, CA) confirmed these bacterial changes and identified archaeal community changes, including a decrease in Methanobrevibacter and Methanomassiliicoccaceae and an increase in Methanoplanus. Pure culture study results supported the findings for the above bacterial community changes. These results demonstrate that ginkgo fruit can modulate rumen fermentation toward methane mitigation

Systems-wide metabolic pathway engineering in Corynebacterium glutamicum for bio-based production of diaminopentane.

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Kind, Stefanie; Jeong, Weol Kyu; Schröder, Hartwig; Wittmann, Christoph

2010-07-01

In the present work the Gram-positive bacterium Corynebacterium glutamicum was engineered into an efficient, tailor-made production strain for diaminopentane (cadaverine), a highly attractive building block for bio-based polyamides. The engineering comprised expression of lysine decarboxylase (ldcC) from Escherichia coli, catalyzing the conversion of lysine into diaminopentane, and systems-wide metabolic engineering of central supporting pathways. Substantially re-designing the metabolism yielded superior strains with desirable properties such as (i) the release from unwanted feedback regulation at the level of aspartokinase and pyruvate carboxylase by introducing the point mutations lysC311 and pycA458, (ii) an optimized supply of the key precursor oxaloacetate by amplifying the anaplerotic enzyme, pyruvate carboxylase, and deleting phosphoenolpyruvate carboxykinase which otherwise removes oxaloacetate, (iii) enhanced biosynthetic flux via combined amplification of aspartokinase, dihydrodipicolinate reductase, diaminopimelate dehydrogenase and diaminopimelate decarboxylase, and (iv) attenuated flux into the threonine pathway competing with production by the leaky mutation hom59 in the homoserine dehydrogenase gene. Lysine decarboxylase proved to be a bottleneck for efficient production, since its in vitro activity and in vivo flux were closely correlated. To achieve an optimal strain having only stable genomic modifications, the combination of the strong constitutive C. glutamicum tuf promoter and optimized codon usage allowed efficient genome-based ldcC expression and resulted in a high diaminopentane yield of 200 mmol mol(-1). By supplementing the medium with 1 mgL(-1) pyridoxal, the cofactor of lysine decarboxylase, the yield was increased to 300 mmol mol(-1). In the production strain obtained, lysine secretion was almost completely abolished. Metabolic analysis, however, revealed substantial formation of an as yet unknown by-product. It was identified as an

Precision metabolic engineering: The design of responsive, selective, and controllable metabolic systems.

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McNerney, Monica P; Watstein, Daniel M; Styczynski, Mark P

2015-09-01

Metabolic engineering is generally focused on static optimization of cells to maximize production of a desired product, though recently dynamic metabolic engineering has explored how metabolic programs can be varied over time to improve titer. However, these are not the only types of applications where metabolic engineering could make a significant impact. Here, we discuss a new conceptual framework, termed "precision metabolic engineering," involving the design and engineering of systems that make different products in response to different signals. Rather than focusing on maximizing titer, these types of applications typically have three hallmarks: sensing signals that determine the desired metabolic target, completely directing metabolic flux in response to those signals, and producing sharp responses at specific signal thresholds. In this review, we will first discuss and provide examples of precision metabolic engineering. We will then discuss each of these hallmarks and identify which existing metabolic engineering methods can be applied to accomplish those tasks, as well as some of their shortcomings. Ultimately, precise control of metabolic systems has the potential to enable a host of new metabolic engineering and synthetic biology applications for any problem where flexibility of response to an external signal could be useful. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Metabolic engineering of strains: from industrial-scale to lab-scale chemical production.

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Sun, Jie; Alper, Hal S

2015-03-01

A plethora of successful metabolic engineering case studies have been published over the past several decades. Here, we highlight a collection of microbially produced chemicals using a historical framework, starting with titers ranging from industrial scale (more than 50 g/L), to medium-scale (5-50 g/L), and lab-scale (0-5 g/L). Although engineered Escherichia coli and Saccharomyces cerevisiae emerge as prominent hosts in the literature as a result of well-developed genetic engineering tools, several novel native-producing strains are gaining attention. This review catalogs the current progress of metabolic engineering towards production of compounds such as acids, alcohols, amino acids, natural organic compounds, and others.

Low-dose aspartame consumption differentially affects gut microbiota-host metabolic interactions in the diet-induced obese rat.

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Marie S A Palmnäs

Full Text Available Aspartame consumption is implicated in the development of obesity and metabolic disease despite the intention of limiting caloric intake. The mechanisms responsible for this association remain unclear, but may involve circulating metabolites and the gut microbiota. Aims were to examine the impact of chronic low-dose aspartame consumption on anthropometric, metabolic and microbial parameters in a diet-induced obese model. Male Sprague-Dawley rats were randomized into a standard chow diet (CH, 12% kcal fat or high fat (HF, 60% kcal fat and further into ad libitum water control (W or low-dose aspartame (A, 5-7 mg/kg/d in drinking water treatments for 8 week (n = 10-12 animals/treatment. Animals on aspartame consumed fewer calories, gained less weight and had a more favorable body composition when challenged with HF compared to animals consuming water. Despite this, aspartame elevated fasting glucose levels and an insulin tolerance test showed aspartame to impair insulin-stimulated glucose disposal in both CH and HF, independently of body composition. Fecal analysis of gut bacterial composition showed aspartame to increase total bacteria, the abundance of Enterobacteriaceae and Clostridium leptum. An interaction between HF and aspartame was also observed for Roseburia ssp wherein HF-A was higher than HF-W (P<0.05. Within HF, aspartame attenuated the typical HF-induced increase in the Firmicutes:Bacteroidetes ratio. Serum metabolomics analysis revealed aspartame to be rapidly metabolized and to be associated with elevations in the short chain fatty acid propionate, a bacterial end product and highly gluconeogenic substrate, potentially explaining its negative affects on insulin tolerance. How aspartame influences gut microbial composition and the implications of these changes on the development of metabolic disease require further investigation.

The production of (14C) oxalate during the metabolism of (14C) carbohydrates in isolated rat hepatocytes.

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Rofe, A M; James, H M; Bais, R; Edwards, J B; Conyers, R A

1980-04-01

Oxalate (14C) was produced during the metabolism of (U-14C) carbohydrates in hepatocytes isolated from normal rats. At 10 mM, the order of oxalate production was fructose > glycerol > xylitol > sorbitol greater than or equal to glucose in the ratio 10 : 4 : 3 : 1 : 1. This difference between oxalate production from fructose and glucose was reflected in their rates of utilisation, glucose being poorly metabolised in hepatocytes from fasted rats. Fructose was rapidly metabolised, producing glucose, lactate and pyruvate as the major metabolites. Glycerol, xylitol and sorbitol were metabolised at half the rate of fructose, the major metabolites being glucose, lactate and glycerophosphate. The marked similarity in the pattern of intermediary metabolites produced by these polyols was not, however, reflected in the rates of oxalate production. Hepatic polyol metabolism resulted in high levels of cytosolic NADH, as indicated by elevated lactate : pyruvate and glycerophosphate : dihydroxyacetone phosphate ratios. The artificial electron acceptor, phenazine methosulphate (PMS) stimulated oxalate production from the polyols, particularly xylitol. In the presence of PMS, the order of oxalate production was fructose greater than or equal to xylitol > glycerol > sorbitol in the ratio 10 : 10 : 6 : 2. The production of glucose, lactate and pyruvate from the polyols was also stimulated by PMS, whereas the general metabolism of fructose, including oxalate production, was little affected. Oxalate (14C) was produced from (1-14C), (2-14C) and (6-14C) but not (3,4-14C) glucose in hepatocytes isolated from non-fasted, pyridoxine-deficient rats. Whilst this labelling pattern is consistent with oxalate being produced by a number of pathways, it is suggested that metabolism via hydroxypyruvate is a major route for oxalate production from various carbohydrates, with perhaps the exception of xylitol, which appears to have an alternative mechanism for oxalate production. The observation that

Efficient protein production by yeast requires global tuning of metabolism

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Huang, Mingtao; Bao, Jichen; Hallstrom, Bjorn M.

2017-01-01

The biotech industry relies on cell factories for production of pharmaceutical proteins, of which several are among the top-selling medicines. There is, therefore, considerable interest in improving the efficiency of protein production by cell factories. Protein secretion involves numerous...... intracellular processes with many underlying mechanisms still remaining unclear. Here, we use RNA-seq to study the genome-wide transcriptional response to protein secretion in mutant yeast strains. We find that many cellular processes have to be attuned to support efficient protein secretion. In particular...... that by tuning metabolism cells are able to efficiently secrete recombinant proteins. Our findings provide increased understanding of which cellular regulations and pathways are associated with efficient protein secretion....

Redirection of Metabolic Hydrogen by Inhibiting Methanogenesis in the Rumen Simulation Technique (RUSITEC)

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Guyader, Jessie; Ungerfeld, Emilio M.; Beauchemin, Karen A.

2017-01-01

A decrease in methanogenesis is expected to improve ruminant performance by allocating rumen metabolic hydrogen ([2H]) to more energy-rendering fermentation pathways for the animal. However, decreases in methane (CH4) emissions of up to 30% are not always linked with greater performance. Therefore, the aim of this study was to understand the fate of [2H] when CH4 production in the rumen is inhibited by known methanogenesis inhibitors (nitrate, NIT; 3-nitrooxypropanol, NOP; anthraquinone, AQ) in comparison with a control treatment (CON) with the Rumen Simulation Technique (RUSITEC). Measurements started after 1 week adaptation. Substrate disappearance was not modified by methanogenesis inhibitors. Nitrate mostly seemed to decrease [2H] availability by acting as an electron acceptor competing with methanogenesis. As a consequence, NIT decreased CH4 production (−75%), dissolved dihydrogen (H2) concentration (−30%) and the percentages of reduced volatile fatty acids (butyrate, isobutyrate, valerate, isovalerate, caproate and heptanoate) except propionate, but increased acetate molar percentage, ethanol concentration and the efficiency of microbial nitrogen synthesis (+14%) without affecting gaseous H2. Nitrooxypropanol decreased methanogenesis (−75%) while increasing both gaseous and dissolved H2 concentrations (+81% and +24%, respectively). Moreover, NOP decreased acetate and isovalerate molar percentages and increased butyrate, valerate, caproate and heptanoate molar percentages as well as n-propanol and ammonium concentrations. Methanogenesis inhibition with AQ (−26%) was associated with higher gaseous H2 production (+70%) but lower dissolved H2 concentration (−76%), evidencing a lack of relationship between the two H2 forms. Anthraquinone increased ammonium concentration, caproate and heptanoate molar percentages but decreased acetate and isobutyrate molar percentages, total microbial nitrogen production and efficiency of microbial protein synthesis (�

Towards a sustainable bio-based economy: Redirecting primary metabolism to new products with plant synthetic biology.

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Shih, Patrick M

2018-08-01

Humans have domesticated many plant species as indispensable sources of food, materials, and medicines. The dawning era of synthetic biology represents a means to further refine, redesign, and engineer crops to meet various societal and industrial needs. Current and future endeavors will utilize plants as the foundation of a bio-based economy through the photosynthetic production of carbohydrate feedstocks for the microbial fermentation of biofuels and bioproducts, with the end goal of decreasing our dependence on petrochemicals. As our technological capabilities improve, metabolic engineering efforts may expand the utility of plants beyond sugar feedstocks through the direct production of target compounds, including pharmaceuticals, renewable fuels, and commodity chemicals. However, relatively little work has been done to fully realize the potential in redirecting central carbon metabolism in plants for the engineering of novel bioproducts. Although our ability to rationally engineer and manipulate plant metabolism is in its infancy, I highlight some of the opportunities and challenges in applying synthetic biology towards engineering plant primary metabolism. Copyright © 2018 Elsevier B.V. All rights reserved.

Ethylene production in relation to nitrogen metabolism in Saccharomyces cerevisiae.

Science.gov (United States)

Johansson, Nina; Persson, Karl O; Quehl, Paul; Norbeck, Joakim; Larsson, Christer

2014-11-01

We have previously shown that ethylene production in Saccharomyces cerevisiae expressing the ethylene-forming enzyme (EFE) from Pseudomonas syringae is strongly influenced by variations in the mode of cultivation as well as the choice of nitrogen source. Here, we have studied the influence of nitrogen metabolism on the production of ethylene further. Using ammonium, glutamate, glutamate/arginine, and arginine as nitrogen sources, it was found that glutamate (with or without arginine) correlates with a high ethylene production, most likely linked to an observed increase in 2-oxoglutarate levels. Arginine as a sole nitrogen source caused a reduced ethylene production. A reduction of arginine levels, accomplished using an arginine auxotrophic ARG4-deletion strain in the presence of limiting amounts of arginine or through CAR1 overexpression, did however not correlate with an increased ethylene production. As expected, arginine was necessary for ethylene production as ethylene production in the ARG4-deletion strain ceased at the time when arginine was depleted. In conclusion, our data suggest that high levels of 2-oxoglutarate and a limited amount of arginine are required for successful ethylene production in yeast. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Spatial separation of photosynthesis and ethanol production by cell type-specific metabolic engineering of filamentous cyanobacteria.

Science.gov (United States)

Ehira, Shigeki; Takeuchi, Takuto; Higo, Akiyoshi

2018-02-01

Cyanobacteria, which perform oxygenic photosynthesis, have drawn attention as hosts for the direct production of biofuels and commodity chemicals from CO 2 and H 2 O using light energy. Although cyanobacteria capable of producing diverse chemicals have been generated by metabolic engineering, anaerobic non-photosynthetic culture conditions are often necessary for their production. In this study, we conducted cell type-specific metabolic engineering of the filamentous cyanobacterium Anabaena sp. PCC 7120, which forms a terminally differentiated cell called a heterocyst with a semi-regular spacing of 10-15 cells. Because heterocysts are specialized cells for nitrogen fixation, the intracellular oxygen level of heterocysts is maintained very low even when adjacent cells perform oxygenic photosynthesis. Pyruvate decarboxylase of Zymomonas mobilis and alcohol dehydrogenase of Synechocystis sp. PCC 6803 were exclusively expressed in heterocysts. Ethanol production was concomitant with nitrogen fixation in genetically engineered Anabaena sp. PCC 7120. Engineering of carbon metabolism in heterocysts improved ethanol production, and strain ET14, with an extra copy of the invB gene expressed from a heterocyst-specific promoter, produced 130.9 mg L -1 of ethanol after 9 days. ET14 produced 1681.9 mg L -1 of ethanol by increasing the CO 2 supply. Ethanol production per heterocyst cell was approximately threefold higher than that per cell of unicellular cyanobacterium. This study demonstrates the potential of heterocysts for anaerobic production of biofuels and commodity chemicals under oxygenic photosynthetic conditions.

Deletion of Type I glutamine synthetase deregulates nitrogen metabolism and increases ethanol production in Clostridium thermocellum

Energy Technology Data Exchange (ETDEWEB)

Rydzak, Thomas [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division, BioEnergy Science Center; Garcia, David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division, BioEnergy Science Center; Stevenson, David M. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Bacteriology; Sladek, Margaret [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division, BioEnergy Science Center; Klingeman, Dawn M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division, BioEnergy Science Center; Holwerda, Evert K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division; Dartmouth College, Hanover, NH (United States). Thayer School of Engineering; Amador-Noguez, Daniel [Univ. of Wisconsin, Madison, WI (United States). Dept. of Bacteriology; Brown, Steven D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division, BioEnergy Science Center; Guss, Adam M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division, BioEnergy Science Center

2017-05-01

Clostridium thermocellum rapidly deconstructs cellulose and ferments resulting hydrolysis products into ethanol and other products, and is thus a promising platform organism for the development of cellulosic biofuel production via consolidated bioprocessing. And while recent metabolic engineering strategies have targeted eliminating canonical fermentation products (acetate, lactate, formate, and H₂), C. thermocellum also secretes amino acids, which has limited ethanol yields in engineered strains to approximately 70% of the theoretical maximum. To decrease amino acid secretion, we attempted to reduce ammonium assimilation by deleting the Type I glutamine synthetase (glnA) in C. thermocellum. Deletion of glnA reduced levels of secreted valine and total amino acids by 53% and 44% respectively, and increased ethanol yields by 53%. RNA-seq analysis revealed that genes encoding the RNF-complex were more highly expressed in ΔglnA and may have a role in improving NADH-availability for ethanol production. While a significant up-regulation of genes involved in nitrogen assimilation and urea uptake suggested that deletion of glnA induces a nitrogen starvation response, metabolomic analysis showed an increase in intracellular glutamine and α-ketoglutarate levels indicative of nitrogen-rich conditions. Here, we propose that deletion of glnA causes deregulation of nitrogen metabolism, leading to overexpression of nitrogen metabolism genes and, in turn, elevated glutamine/α-ketoglutarate levels. Here we demonstrate that perturbation of nitrogen assimilation is a promising strategy to redirect flux from the production of nitrogenous compounds toward biofuels in C. thermocellum.

Metabolic Engineering of Oleaginous Yeasts for Fatty Alcohol Production

Energy Technology Data Exchange (ETDEWEB)

Wang, Wei; Wei, Hui; Knoshaug, Eric; Van Wychen, Stefanie; Xu, Qi; Himmel, Michael E.; Zhang, Min

2016-04-25

To develop pathways for advanced biological upgrading of sugars to hydrocarbons, we are seeking biological approaches to produce high carbon efficiency intermediates amenable to separations and catalytic upgrading to hydrocarbon fuels. In this study, we successfully demonstrated fatty alcohol production by oleaginous yeasts Yarrowia lipolytica and Lipomyces starkeyi by expressing a bacteria-derived fatty acyl-CoA reductase (FAR). Moreover, we find higher extracellular distribution of fatty alcohols produced by FAR-expressing L. starkeyi strain as compared to Y. lipolytica strain, which would benefit the downstream product recovery process. In both oleaginous yeasts, long chain length saturated fatty alcohols were predominant, accounting for more than 85% of the total fatty alcohols produced. To the best of our knowledge, this is the first report of fatty alcohol production in L. starkeyi. Taken together, our work demonstrates that in addition to Y. lipolytica, L. starkeyi can also serve as a platform organism for production of fatty acid-derived biofuels and bioproducts via metabolic engineering. We believe strain and process development both will significantly contribute to our goal of producing scalable and cost-effective fatty alcohols from renewable biomass.

Metabolic engineering of Dunaliella salina for production of ketocarotenoids.

Science.gov (United States)

Anila, N; Simon, Daris P; Chandrashekar, Arun; Ravishankar, G A; Sarada, R

2016-03-01

Dunaliella is a commercially important marine alga producing high amount of β-carotene. The use of Dunaliella as a potential transgenic system for the production of recombinant proteins has been recently recognized. The present study reports for the first time the metabolic engineering of carotenoid biosynthesis in Dunaliella salina for ketocarotenoid production. The pathway modification included the introduction of a bkt gene from H. pluvialis encoding β-carotene ketolase (4,4'β-oxygenase) along with chloroplast targeting for the production of ketocarotenoids. The bkt under the control of Dunaliella Rubisco smaller subunit promoter along with its transit peptide sequence was introduced into the alga through standardized Agrobacterium-mediated transformation procedure. The selected transformants were confirmed using GFP and GUS expression, PCR and southern blot analysis. A notable upregulation of the endogenous hydroxylase level of transformants was observed where the BKT expression was higher in nutrient-limiting conditions. Carotenoid analysis of the transformants through HPLC and MS analysis showed the presence of astaxanthin and canthaxanthin with maximum content of 3.5 and 1.9 µg/g DW, respectively. The present study reports the feasibility of using D. salina for the production of ketocarotenoids including astaxanthin.

Hepatic metabolism of anaesthetized growing pigs during acute portal infusion of volatile fatty acids and hydroxy-methyl butyrate

DEFF Research Database (Denmark)

Theil, Peter Kappel; Larsen, Uffe Krogh; Bjerre-Harpøth, Vibeke

2016-01-01

ABSTRACT: The objective of the experiment was to study hepatic metabolism during infusion of volatile fatty acids (VFA) differing in amounts and composition or infusion of HMB. Three fasted (20 h) pigs (mean BW ± SE; 58 kg ± 1) were fitted with indwelling catheters in the portal vein, hepatic vein......, respectively, for Inf2 and Inf3, or 65%, 20%, and 10% of acetate, propionate, and butyrate, respectively, for Inf4 and Inf5. In addition, for Inf5, HMB was infused at 2 mmol/h. Statistical analysis included fixed effects of infusion and interaction between infusion and samplings within infusion while...

Recent advances in engineering propionyl-CoA metabolism for microbial production of value-added chemicals and biofuels.

Science.gov (United States)

Srirangan, Kajan; Bruder, Mark; Akawi, Lamees; Miscevic, Dragan; Kilpatrick, Shane; Moo-Young, Murray; Chou, C Perry

2017-09-01

Diminishing fossil fuel reserves and mounting environmental concerns associated with petrochemical manufacturing practices have generated significant interests in developing whole-cell biocatalytic systems for the production of value-added chemicals and biofuels. Although acetyl-CoA is a common natural biogenic precursor for the biosynthesis of numerous metabolites, propionyl-CoA is unpopular and non-native to most organisms. Nevertheless, with its C3-acyl moiety as a discrete building block, propionyl-CoA can serve as another key biogenic precursor to several biological products of industrial importance. As a result, engineering propionyl-CoA metabolism, particularly in genetically tractable hosts with the use of inexpensive feedstocks, has paved an avenue for novel biomanufacturing. Herein, we present a systematic review on manipulation of propionyl-CoA metabolism as well as relevant genetic and metabolic engineering strategies for microbial production of value-added chemicals and biofuels, including odd-chain alcohols and organic acids, bio(co)polymers and polyketides. [Formula: see text].

Multi-omic profiling of EPO-producing CHO cell panel reveals metabolic adaptation to heterologous protein production

DEFF Research Database (Denmark)

Ley, Daniel; Kazemi Seresht, Ali; Engmark, Mikael

The Chinese hamster ovary (CHO) cell line is the predominant mammalian cell factory for production of therapeutic glycoproteins. In this work, we aimed to study bottlenecks in the secretory pathway associated with the production of human erythropoietin (EPO) in CHO cells. In connection to this, we...... discovered indications of metabolic adaptation of the amino acid catabolism in favor of heterologous protein production. We established a panel of stably EPO expressing CHO-K1 clones spanning a 25-fold productivity range and characterized the clones in batch and chemostat cultures. For this, we employed...... a multi-omic physiological characterization including metabolic foot printing of amino acids, metabolite fingerprinting of glycolytic intermediates, NAD(P)H-/NAD(P)+ and adenosine nucleotide phosphates. We used qPCR, qRT-PCR, western blots and Affymetrix CHO microarrays to assess EPO gene copy numbers...

Biofuel production in Escherichia coli. The role of metabolic engineering and synthetic biology

Energy Technology Data Exchange (ETDEWEB)

Clomburg, James M. [Rice Univ., Houston, TX (United States). Dept. of Chemical and Biomolecular Engineering; Gonzalez, Ramon [Rice Univ., Houston, TX (United States). Dept. of Chemical and Biomolecular Engineering; Rice Univ., Houston, TX (United States). Dept. of Bioengineering

2010-03-15

The microbial production of biofuels is a promising avenue for the development of viable processes for the generation of fuels from sustainable resources. In order to become cost and energy effective, these processes must utilize organisms that can be optimized to efficiently produce candidate fuels from a variety of feedstocks. Escherichia coli has become a promising host organism for the microbial production of biofuels in part due to the ease at which this organism can be manipulated. Advancements in metabolic engineering and synthetic biology have led to the ability to efficiently engineer E. coli as a biocatalyst for the production of a wide variety of potential biofuels from several biomass constituents. This review focuses on recent efforts devoted to engineering E. coli for the production of biofuels, with emphasis on the key aspects of both the utilization of a variety of substrates as well as the synthesis of several promising biofuels. Strategies for the efficient utilization of carbohydrates, carbohydrate mixtures, and noncarbohydrate carbon sources will be discussed along with engineering efforts for the exploitation of both fermentative and nonfermentative pathways for the production of candidate biofuels such as alcohols and higher carbon biofuels derived from fatty acid and isoprenoid pathways. Continued advancements in metabolic engineering and synthetic biology will help improve not only the titers, yields, and productivities of biofuels discussed herein, but also increase the potential range of compounds that can be produced. (orig.)

The glutamate receptor GluR5 agonist (S)-2-amino-3-(3-hydroxy-7,8-dihydro-6H-cyclohepta[d]isoxazol-4-yl)propionic acid and the 8-methyl analogue

DEFF Research Database (Denmark)

Clausen, Rasmus Prætorius; Naur, Peter; Kristensen, Anders Skov

2009-01-01

The design, synthesis, and pharmacological characterization of a highly potent and selective glutamate GluR5 agonist is reported. (S)-2-Amino-3-((RS)-3-hydroxy-8-methyl-7,8-dihydro-6H-cyclohepta[d]isoxazol-4-yl)propionic acid (5) is the 8-methyl analogue of (S)-2-amino-3-(3-hydroxy-7,8-dihydro-6H......-cyclohepta[d]isoxazol-4-yl)propionic acid ((S)-4-AHCP, 4). Compound 5 displays an improved selectivity profile compared to 4. A versatile stereoselective synthetic route for this class of compounds is presented along with the characterization of the binding affinity of 5 to ionotropic glutamate receptors (i......GluRs). Functional characterization of 5 at cloned iGluRs using a calcium imaging assay and voltage-clamp recordings show a different activation of GluR5 compared to (S)-glutamic acid (Glu), kainic acid (KA, 1), and (S)-2-amino-3-(3-hydroxy-5-tert-butyl-4-isoxazolyl)propionic acid ((S)-ATPA, 3) as previously...

Metabolic engineering of ethanol production in Thermoanaerobacter mathranii

Energy Technology Data Exchange (ETDEWEB)

Shou Yao

2010-11-15

Strain BG1 is a xylanolytic, thermophilic, anaerobic, Gram-positive bacterium originally isolated from an Icelandic hot spring. The strain belongs to the species Thermoanaerobacter mathranii. The strain ferments glucose, xylose, arabinose, galactose and mannose simultaneously and produces ethanol, acetate, lactate, CO{sub 2}, and H2 as fermentation end-products. As a potential ethanol producer from lignocellulosic biomass, tailor-made BG1 strain with the metabolism redirected to produce ethanol is needed. Metabolic engineering of T. mathranii BG1 is therefore necessary to improve ethanol production. Strain BG1 contains four alcohol dehydrogenase (ADH) encoding genes. They are adhA, adhB, bdhA and adhE encoding primary alcohol dehydrogenase, secondary alcohol dehydrogenase, butanol dehydrogenase and bifunctional alcohol/acetaldehyde dehydrogenase, respectively. The presence in an organism of multiple alcohol dehydrogenases with overlapping specificities makes the determination of the specific role of each ADH difficult. Deletion of each individual adh gene in the strain revealed that the adhE deficient mutant strain fails to produce ethanol as the fermentation product. The bifunctional alcohol/acetaldehyde dehydrogenase, AdhE, is therefore proposed responsible for ethanol production in T. mathranii BG1, by catalyzing sequential NADH-dependent reductions of acetyl-CoA to acetaldehyde and then to ethanol under fermentative conditions. Moreover, AdhE was conditionally expressed from a xylose-induced promoter in a recombinant strain (BG1E1) with a concomitant deletion of a lactate dehydrogenase. Over-expression of AdhE in strain BG1E1 with xylose as a substrate facilitates the production of ethanol at an increased yield. With a cofactor-dependent ethanol production pathway in T. mathranii BG1, it may become crucial to regenerate cofactor to increase the ethanol yield. Feeding the cells with a more reduced carbon source, such as mannitol, was shown to increase ethanol

Distribution of Rhodium in Mice Submitted to Treatment With the Adduct of Rhodium Propionate and Sodium Isonicotinate

OpenAIRE

de Souza, Aparecido Ribeiro; Najjar, Renato; de Oliveira, Elizabeth; Zyngier, Szulim Ber

1997-01-01

The distribution of rhodium in Balb/c mice following intraperitoneal (ip) administration of a solution of adduct of rhodium propionate and sodium isonicotinate has been investigated. The metal concentration was determined in blood and in the following organ tissues: brain, heart, lung, liver, spleen, kidney, testes, and uterus/ovary, and the rhodium concentration was obtained by Inductively Coupled Argon Atomic Emission Spectroscopy (ICP-AES). The metal was detected in all organ tissues exami...

Study on substrate metabolism process of saline waste sludge and its biological hydrogen production potential.

Science.gov (United States)

Zhang, Zengshuai; Guo, Liang; Li, Qianqian; Zhao, Yangguo; Gao, Mengchun; She, Zonglian

2017-07-01

With the increasing of high saline waste sludge production, the treatment and utilization of saline waste sludge attracted more and more attention. In this study, the biological hydrogen production from saline waste sludge after heating pretreatment was studied. The substrate metabolism process at different salinity condition was analyzed by the changes of soluble chemical oxygen demand (SCOD), carbohydrate and protein in extracellular polymeric substances (EPS), and dissolved organic matters (DOM). The excitation-emission matrix (EEM) with fluorescence regional integration (FRI) was also used to investigate the effect of salinity on EPS and DOM composition during hydrogen fermentation. The highest hydrogen yield of 23.6 mL H 2 /g VSS and hydrogen content of 77.6% were obtained at 0.0% salinity condition. The salinity could influence the hydrogen production and substrate metabolism of waste sludge.

Engineering yeast metabolism for production of terpenoids for use as perfume ingredients, pharmaceuticals and biofuels.

Science.gov (United States)

Zhang, Yueping; Nielsen, Jens; Liu, Zihe

2017-12-01

Terpenoids represent a large class of natural products with significant commercial applications. These chemicals are currently mainly obtained through extraction from plants and microbes or through chemical synthesis. However, these sources often face challenges of unsustainability and low productivity. In order to address these issues, Escherichia coli and yeast have been metabolic engineered to produce non-native terpenoids. With recent reports of engineering yeast metabolism to produce several terpenoids at high yields, it has become possible to establish commercial yeast production of terpenoids that find applications as perfume ingredients, pharmaceuticals and advanced biofuels. In this review, we describe the strategies to rewire the yeast pathway for terpenoid biosynthesis. Recent advances will be discussed together with challenges and perspectives of yeast as a cell factory to produce different terpenoids. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Kinetic modeling of cell metabolism for microbial production.

Science.gov (United States)

Costa, Rafael S; Hartmann, Andras; Vinga, Susana

2016-02-10

Kinetic models of cellular metabolism are important tools for the rational design of metabolic engineering strategies and to explain properties of complex biological systems. The recent developments in high-throughput experimental data are leading to new computational approaches for building kinetic models of metabolism. Herein, we briefly survey the available databases, standards and software tools that can be applied for kinetic models of metabolism. In addition, we give an overview about recently developed ordinary differential equations (ODE)-based kinetic models of metabolism and some of the main applications of such models are illustrated in guiding metabolic engineering design. Finally, we review the kinetic modeling approaches of large-scale networks that are emerging, discussing their main advantages, challenges and limitations. Copyright © 2015 Elsevier B.V. All rights reserved.

Metabolic network model guided engineering ethylmalonyl-CoA pathway to improve ascomycin production in Streptomyces hygroscopicus var. ascomyceticus.

Science.gov (United States)

Wang, Junhua; Wang, Cheng; Song, Kejing; Wen, Jianping

2017-10-03

Ascomycin is a 23-membered polyketide macrolide with high immunosuppressant and antifungal activity. As the lower production in bio-fermentation, global metabolic analysis is required to further explore its biosynthetic network and determine the key limiting steps for rationally engineering. To achieve this goal, an engineering approach guided by a metabolic network model was implemented to better understand ascomycin biosynthesis and improve its production. The metabolic conservation of Streptomyces species was first investigated by comparing the metabolic enzymes of Streptomyces coelicolor A3(2) with those of 31 Streptomyces strains, the results showed that more than 72% of the examined proteins had high sequence similarity with counterparts in every surveyed strain. And it was found that metabolic reactions are more highly conserved than the enzymes themselves because of its lower diversity of metabolic functions than that of genes. The main source of the observed metabolic differences was from the diversity of secondary metabolism. According to the high conservation of primary metabolic reactions in Streptomyces species, the metabolic network model of Streptomyces hygroscopicus var. ascomyceticus was constructed based on the latest reported metabolic model of S. coelicolor A3(2) and validated experimentally. By coupling with flux balance analysis and using minimization of metabolic adjustment algorithm, potential targets for ascomycin overproduction were predicted. Since several of the preferred targets were highly associated with ethylmalonyl-CoA biosynthesis, two target genes hcd (encoding 3-hydroxybutyryl-CoA dehydrogenase) and ccr (encoding crotonyl-CoA carboxylase/reductase) were selected for overexpression in S. hygroscopicus var. ascomyceticus FS35. Both the mutants HA-Hcd and HA-Ccr showed higher ascomycin titer, which was consistent with the model predictions. Furthermore, the combined effects of the two genes were evaluated and the strain HA

Digestibility by lambs offered alfalfa hay treated with a propionic acid hay preservative and baled at different concentrations of moisture

Science.gov (United States)

Eighteen crossbred wether lambs (76.1 ± 8.18 lb initial BW) were used for a 2 period digestion study to evaluate the effect of hay preservative concentration (0, 0.56, or 0.98% buffered propionic acid) and hay moisture concentration at baling (19.6, 23.8, or 27.4% moisture) on digestibility of alfal...

Disruption of quercetin metabolism by fungicide affects energy production in honey bees (Apis mellifera).

Science.gov (United States)

Mao, Wenfu; Schuler, Mary A; Berenbaum, May R

2017-03-07

Cytochrome P450 monooxygenases (P450) in the honey bee, Apis mellifera , detoxify phytochemicals in honey and pollen. The flavonol quercetin is found ubiquitously and abundantly in pollen and frequently at lower concentrations in honey. Worker jelly consumed during the first 3 d of larval development typically contains flavonols at very low levels, however. RNA-Seq analysis of gene expression in neonates reared for three days on diets with and without quercetin revealed that, in addition to up-regulating multiple detoxifying P450 genes, quercetin is a negative transcriptional regulator of mitochondrion-related nuclear genes and genes encoding subunits of complexes I, III, IV, and V in the oxidative phosphorylation pathway. Thus, a consequence of inefficient metabolism of this phytochemical may be compromised energy production. Several P450s metabolize quercetin in adult workers. Docking in silico of 121 pesticide contaminants of American hives into the active pocket of CYP9Q1, a broadly substrate-specific P450 with high quercetin-metabolizing activity, identified six triazole fungicides, all fungal P450 inhibitors, that dock in the catalytic site. In adults fed combinations of quercetin and the triazole myclobutanil, the expression of five of six mitochondrion-related nuclear genes was down-regulated. Midgut metabolism assays verified that adult bees consuming quercetin with myclobutanil metabolized less quercetin and produced less thoracic ATP, the energy source for flight muscles. Although fungicides lack acute toxicity, they may influence bee health by interfering with quercetin detoxification, thereby compromising mitochondrial regeneration and ATP production. Thus, agricultural use of triazole fungicides may put bees at risk of being unable to extract sufficient energy from their natural food.

Reconstruction of a metabolic regulatory network in Escherichia coli for purposeful switching from cell growth mode to production mode in direct GABA fermentation from glucose.

Science.gov (United States)

Soma, Yuki; Fujiwara, Yuri; Nakagawa, Takuya; Tsuruno, Keigo; Hanai, Taizo

2017-09-01

γ-aminobutyric acid (GABA) is a drug and functional food additive and is used as a monomer for producing the biodegradable plastic, polyamide 4. Recently, direct GABA fermentation from glucose has been developed as an alternative to glutamate-based whole cell bioconversion. Although total productivity in fermentation is determined by the specific productivity and cell amount responsible for GABA production, the optimal metabolic state for GABA production conflicts with that for bacterial cell growth. Herein, we demonstrated metabolic state switching from the cell growth mode based on the metabolic pathways of the wild type strain to a GABA production mode based on a synthetic metabolic pathway in Escherichia coli through rewriting of the metabolic regulatory network and pathway engineering. The GABA production mode was achieved by multiple strategies such as conditional interruption of the TCA and glyoxylate cycles, engineering of GABA production pathway including a bypass for precursor metabolite supply, and upregulation of GABA transporter. As a result, we achieved 3-fold improvement in total GABA production titer and yield (4.8g/L, 49.2% (mol/mol glucose)) in batch fermentation compared to the case without metabolic state switching (1.6g/L, 16.4% (mol/mol glucose)). This study reports the highest GABA production performance among previous reports on GABA fermentation from glucose using engineered E. coli. Copyright © 2017 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

(13)C-metabolic flux analysis in S-adenosyl-L-methionine production by Saccharomyces cerevisiae.

Science.gov (United States)

Hayakawa, Kenshi; Kajihata, Shuichi; Matsuda, Fumio; Shimizu, Hiroshi

2015-11-01

S-Adenosyl-L-methionine (SAM) is a major biological methyl group donor, and is used as a nutritional supplement and prescription drug. Yeast is used for the industrial production of SAM owing to its high intracellular SAM concentrations. To determine the regulation mechanisms responsible for such high SAM production, (13)C-metabolic flux analysis ((13)C-MFA) was conducted to compare the flux distributions in the central metabolism between Kyokai no. 6 (high SAM-producing) and S288C (control) strains. (13)C-MFA showed that the levels of tricarboxylic acid (TCA) cycle flux in SAM-overproducing strain were considerably increased compared to those in the S228C strain. Analysis of ATP balance also showed that a larger amount of excess ATP was produced in the Kyokai 6 strain because of increased oxidative phosphorylation. These results suggest that high SAM production in Kyokai 6 strains could be attributed to enhanced ATP regeneration with high TCA cycle fluxes and respiration activity. Thus, maintaining high respiration efficiency during cultivation is important for improving SAM production. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Seasonal Oxygen Dynamics in a Warm Temperate Estuary: Effects of Hydrologic Variability on Measurements of Primary Production, Respiration, and Net Metabolism

Science.gov (United States)

Seasonal responses in estuarine metabolism (primary production, respiration, and net metabolism) were examined using two complementary approaches. Total ecosystem metabolism rates were calculated from dissolved oxygen time series using Odum’s open water method. Water column rates...

Causality Assessment of Olfactory and Gustatory Dysfunction Associated with Intranasal Fluticasone Propionate: Application of the Bradford Hill Criteria

OpenAIRE

Muganurmath, Chandrashekhar S.; Curry, Amy L.; Schindzielorz, Andrew H.

2018-01-01

Causality assessment is crucial to post-marketing pharmacovigilance and helps optimize safe and appropriate use of medicines by patients in the real world. Self-reported olfactory and gustatory dysfunction are common in the general population as well as in patients with allergic rhinitis and nasal polyposis. Intranasal corticosteroids, including intranasal fluticasone propionate (INFP), are amongst the most effective drugs indicated in the treatment of allergic rhinitis and nasal polyposis. W...

Easy method for the preparation of L (+) 2-amino 3-sulfino propionic acid (cysteine sulfinic acid)

International Nuclear Information System (INIS)

Emiliozzi, Romeo; Pichat, Louis

1960-01-01

Description of a new method of preparing cystine disulphoxide by oxidising cystine hydrochloride with a mixture of formic acid and hydrogen peroxide. Yield; 85 per cent. The disproportionation of cystine disulphoxide by ammonia gives 2-amino 3-sulfino propionic acid with a yield of 93 per cent. The method had been applied to the preparation of 35 S DL cysteine sulfinic acid. Reprint of a paper published in Bulletin de la Societe Chimique de France, no. 2653, 4. quarter 1959, p. 1887-1888 [fr

Deletion of Type I glutamine synthetase deregulates nitrogen metabolism and increases ethanol production in Clostridium thermocellum.

Science.gov (United States)

Rydzak, Thomas; Garcia, David; Stevenson, David M; Sladek, Margaret; Klingeman, Dawn M; Holwerda, Evert K; Amador-Noguez, Daniel; Brown, Steven D; Guss, Adam M

2017-05-01

Clostridium thermocellum rapidly deconstructs cellulose and ferments resulting hydrolysis products into ethanol and other products, and is thus a promising platform organism for the development of cellulosic biofuel production via consolidated bioprocessing. While recent metabolic engineering strategies have targeted eliminating canonical fermentation products (acetate, lactate, formate, and H 2 ), C. thermocellum also secretes amino acids, which has limited ethanol yields in engineered strains to approximately 70% of the theoretical maximum. To investigate approaches to decrease amino acid secretion, we attempted to reduce ammonium assimilation by deleting the Type I glutamine synthetase (glnA) in an essentially wild type strain of C. thermocellum. Deletion of glnA reduced levels of secreted valine and total amino acids by 53% and 44% respectively, and increased ethanol yields by 53%. RNA-seq analysis revealed that genes encoding the RNF-complex were more highly expressed in ΔglnA and may have a role in improving NADH-availability for ethanol production. While a significant up-regulation of genes involved in nitrogen assimilation and urea uptake suggested that deletion of glnA induces a nitrogen starvation response, metabolomic analysis showed an increase in intracellular glutamine levels indicative of nitrogen-rich conditions. We propose that deletion of glnA causes deregulation of nitrogen metabolism, leading to overexpression of nitrogen metabolism genes and, in turn, elevated glutamine levels. Here we demonstrate that perturbation of nitrogen assimilation is a promising strategy to redirect flux from the production of nitrogenous compounds toward biofuels in C. thermocellum. Copyright © 2017. Published by Elsevier Inc.

Metabolic engineering of Escherichia coli for limonene and perillyl alcohol production.

Science.gov (United States)

Alonso-Gutierrez, Jorge; Chan, Rossana; Batth, Tanveer S; Adams, Paul D; Keasling, Jay D; Petzold, Christopher J; Lee, Taek Soon

2013-09-01

Limonene is a valuable monoterpene used in the production of several commodity chemicals and medicinal compounds. Among them, perillyl alcohol (POH) is a promising anti-cancer agent that can be produced by hydroxylation of limonene. We engineered E. coli with a heterologous mevalonate pathway and limonene synthase for production of limonene followed by coupling with a cytochrome P450, which specifically hydroxylates limonene to produce POH. A strain containing all mevalonate pathway genes in a single plasmid produced limonene at titers over 400mg/L from glucose, substantially higher than has been achieved in the past. Incorporation of a cytochrome P450 to hydroxylate limonene yielded approximately 100mg/L of POH. Further metabolic engineering of the pathway and in situ product recovery using anion exchange resins would make this engineered E. coli a potential production platform for any valuable limonene derivative. © 2013 Elsevier Inc. All rights reserved.

Metabolic engineering for the microbial production of isoprenoids: Carotenoids and isoprenoid-based biofuels

Directory of Open Access Journals (Sweden)

Fu-Xing Niu

2017-09-01

Full Text Available Isoprenoids are the most abundant and highly diverse group of natural products. Many isoprenoids have been used for pharmaceuticals, nutraceuticals, flavors, cosmetics, food additives and biofuels. Carotenoids and isoprenoid-based biofuels are two classes of important isoprenoids. These isoprenoids have been produced microbially through metabolic engineering and synthetic biology efforts. Herein, we briefly review the engineered biosynthetic pathways in well-characterized microbial systems for the production of carotenoids and several isoprenoid-based biofuels.

Advances in metabolic engineering of yeast Saccharomyces cerevisiae for production of chemicals.

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Borodina, Irina; Nielsen, Jens

2014-05-01

Yeast Saccharomyces cerevisiae is an important industrial host for production of enzymes, pharmaceutical and nutraceutical ingredients and recently also commodity chemicals and biofuels. Here, we review the advances in modeling and synthetic biology tools and how these tools can speed up the development of yeast cell factories. We also present an overview of metabolic engineering strategies for developing yeast strains for production of polymer monomers: lactic, succinic, and cis,cis-muconic acids. S. cerevisiae has already firmly established itself as a cell factory in industrial biotechnology and the advances in yeast strain engineering will stimulate development of novel yeast-based processes for chemicals production. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Differential proteomic analysis reveals novel links between primary metabolism and antibiotic production in Amycolatopsis balhimycina

DEFF Research Database (Denmark)

Gallo, G.; Renzone, G.; Alduina, R.

2010-01-01

A differential proteomic analysis, based on 2-DE and MS procedures, was performed on Amycolatopsis balhimycina DSM5908, the actinomycete producing the vancomycin-like antibiotic balhimycin. A comparison of proteomic profiles before and during balhimycin production characterized differentially...... available over the World Wide Web as interactive web pages (http://www.unipa.it/ampuglia/Abal-proteome-maps). Functional clustering analysis revealed that differentially expressed proteins belong to functional groups involved in central carbon metabolism, amino acid metabolism and protein biosynthesis...... intermediates, were upregulated during antibiotic production. qRT-PCR analysis revealed that 8 out of 14 upregulated genes showed a positive correlation between changes at translational and transcriptional expression level. Furthermore, proteomic analysis of two nonproducing mutants, restricted to a sub...

Live Cells Decreased Methane Production in Intestinal Content of Pigs

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Y. L. Gong

2013-06-01

Full Text Available An in vitro gas production technique was used in this study to elucidate the effect of two strains of active live yeast on methane (CH4 production in the large intestinal content of pigs to provide an insight to whether active live yeast could suppress CH4 production in the hindgut of pigs. Treatments used in this study include blank (no substrate and no live yeast cells, control (no live yeast cells and yeast (YST supplementation groups (supplemented with live yeast cells, YST1 or YST2. The yeast cultures contained 1.8×1010 cells per g, which were added at the rates of 0.2 mg and 0.4 mg per ml of the fermented inoculum. Large intestinal contents were collected from 2 Duroc×Landrace×Yorkshire pigs, mixed with a phosphate buffer (1:2, and incubated anaerobically at 39°C for 24 h using 500 mg substrate (dry matter (DM basis. Total gas and CH4 production decreased (p<0.05 with supplementation of yeast. The methane production reduction potential (MRP was calculated by assuming net methane concentration for the control as 100%. The MRP of yeast 2 was more than 25%. Compared with the control group, in vitro DM digestibility (IVDMD and total volatile fatty acids (VFA concentration increased (p<0.05 in 0.4 mg/ml YST1 and 0.2 mg/ml YST2 supplementation groups. Proportion of propionate, butyrate and valerate increased (p<0.05, but that of acetate decreased (p<0.05, which led to a decreased (p<0.05 acetate: propionate (A: P ratio in the both YST2 treatments and the 0.4 mg/ml YST 1 supplementation groups. Hydrogen recovery decreased (p<0.05 with yeast supplementation. Quantity of methanogenic archaea per milliliter of inoculum decreased (p<0.05 with yeast supplementation after 24 h of incubation. Our results suggest that live yeast cells suppressed in vitro CH4 production when inoculated into the large intestinal contents of pigs and shifted the fermentation pattern to favor propionate production together with an increased population of acetogenic

Excitatory amino acid receptor ligands: resolution, absolute stereochemistry, and enantiopharmacology of 2-amino-3-(4-butyl-3-hydroxyisoxazol-5-yl)propionic acid

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Johansen, T N; Ebert, B; Bräuner-Osborne, Hans

1998-01-01

(RS)-2-Amino-3-(4-butyl-3-hydroxyisoxazol-5-yl)propionic acid (Bu-HIBO, 6) has previously been shown to be an agonist at (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) receptors and an inhibitor of CaCl2-dependent [3H]-(S)-glutamic acid binding (J. Med. Chem. 1992, 35, 3512......-3519). To elucidate the pharmacological significance of this latter binding affinity, which is also shown by quisqualic acid (3) but not by AMPA, we have now resolved Bu-HIBO via diastereomeric salt formation using the diprotected Bu-HIBO derivative 11 and the enantiomers of 1-phenylethylamine (PEA). The absolute...... equipotent as inhibitors of CaCl2-dependent [3H]-(S)-glutamic acid binding, neither enantiomer showed significant affinity for the synaptosomal (S)-glutamic acid uptake system(s). AMPA receptor affinity (IC50 = 0.48 microM) and agonism (EC50 = 17 microM) were shown to reside exclusively in the S...

The effect of dietary supplementation of salts of organic acid on production performance of laying hens

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Ravinder Dahiya

2016-12-01

Full Text Available Aim: An experiment was conducted to evaluate the effect of supplementing different levels of salts of organic acid in the laying hen’s diet on their production performance and egg quality parameters during a period of 16-week. Materials and Methods: A total of 140 white leghorn laying hens at 24 weeks of age were randomly distributed to seven dietary treatment groups, i.e. T1 (control, T2 (0.5% sodium-butyrate, T3 (1.0% sodium-butyrate, T4 (1.5% sodium-butyrate, T5 (0.5% calcium-propionate, T6 (1.0% calcium-propionate and T7 (1.5% calcium-propionate consisting of 5 replications of 4 birds each in each treatment and housed in individual cages from 24 to 40 weeks of age. Feed intake, percent hen-day egg production, egg weight, egg mass production, feed conversion ratio (FCR, and economics of supplementation of salts of organic acids in layers’ ration were evaluated. Results: The dietary supplementation of salts of organic acids did not significantly affect the feed intake (g/day/hen and body weight gain (g. Different levels of supplementation significantly (p<0.05 improved production performance (percent hen-day egg production and egg mass production as compared to control group. FCR in terms of feed intake (kg per dozen eggs was lowest (1.83±0.05 in T4 and feed intake (kg per kg egg mass was lowest (2.87±0.05 in T5 as comparison to control (T1 group. Salts of organic acids supplementation resulted in significant (p<0.05 improvement in FCR. Egg weight was significantly (p<0.05 increased at 0.5% level of salts of organic acids in the diet. The cumulative mean values of feed cost per dozen egg production were Rs. 44.14, 42.40, 42.85, 43.26, 42.57, 43.29 and 43.56 in treatment groups T1, T2, T3, T4, T5, T6 and T7, respectively, and reduction in feed cost per kg egg mass production for Rs. 0.52 and 0.99 in groups T2 and T5, respectively, in comparison to T1 group. Conclusions: It can be concluded that supplementation of salts of organic acids

Combining metabolic engineering and biocompatible chemistry for high-yield production of homo-diacetyl and homo-(S,S)-2,3-butanediol.

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Liu, Jianming; Chan, Siu Hung Joshua; Brock-Nannestad, Theis; Chen, Jun; Lee, Sang Yup; Solem, Christian; Jensen, Peter Ruhdal

2016-07-01

Biocompatible chemistry is gaining increasing attention because of its potential within biotechnology for expanding the repertoire of biological transformations carried out by enzymes. Here we demonstrate how biocompatible chemistry can be used for synthesizing valuable compounds as well as for linking metabolic pathways to achieve redox balance and rescued growth. By comprehensive rerouting of metabolism, activation of respiration, and finally metal ion catalysis, we successfully managed to convert the homolactic bacterium Lactococcus lactis into a homo-diacetyl producer with high titer (95mM or 8.2g/L) and high yield (87% of the theoretical maximum). Subsequently, the pathway was extended to (S,S)-2,3-butanediol (S-BDO) through efficiently linking two metabolic pathways via chemical catalysis. This resulted in efficient homo-S-BDO production with a titer of 74mM (6.7g/L) S-BDO and a yield of 82%. The diacetyl and S-BDO production rates and yields obtained are the highest ever reported, demonstrating the promising combination of metabolic engineering and biocompatible chemistry as well as the great potential of L. lactis as a new production platform. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Metabolic engineering of Escherichia coli for the production of riboflavin

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2014-01-01

Background Riboflavin (vitamin B2), the precursor of the flavin cofactors flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), is used commercially as an animal feed supplement and food colorant. E. coli is a robust host for various genetic manipulations and has been employed for efficient production of biofuels, polymers, amino acids, and bulk chemicals. Thus, the aim of this study was to understand the metabolic capacity of E. coli for the riboflavin production by modification of central metabolism, riboflavin biosynthesis pathway and optimization of the fermentation conditions. Results The basic producer RF01S, in which the riboflavin biosynthesis genes ribABDEC from E. coli were overexpressed under the control of the inducible trc promoter, could accumulate 229.1 mg/L of riboflavin. Further engineering was performed by examining the impact of expression of zwf (encodes glucose 6-phosphate dehydrogenase) and gnd (encodes 6-phosphogluconate dehydrogenase) from Corynebacterium glutamicum and pgl (encodes 6-phosphogluconolactonase) from E. coli on riboflavin production. Deleting pgi (encodes glucose-6-phosphate isomerase) and genes of Entner-Doudoroff (ED) pathway successfully redirected the carbon flux into the oxidative pentose phosphate pathway, and overexpressing the acs (encodes acetyl-CoA synthetase) reduced the acetate accumulation. These modifications increased riboflavin production to 585.2 mg/L. By further modulating the expression of ribF (encodes riboflavin kinase) for reducing the conversion of riboflavin to FMN in RF05S, the final engineering strain RF05S-M40 could produce 1036.1 mg/L riboflavin in LB medium at 37°C. After optimizing the fermentation conditions, strain RF05S-M40 produced 2702.8 mg/L riboflavin in the optimized semi-defined medium, which was a value nearly 12-fold higher than that of RF01S, with a yield of 137.5 mg riboflavin/g glucose. Conclusions The engineered strain RF05S-M40 has the highest yield among all

Metabolic engineering of Escherichia coli for the production of riboflavin.

Science.gov (United States)

Lin, Zhenquan; Xu, Zhibo; Li, Yifan; Wang, Zhiwen; Chen, Tao; Zhao, Xueming

2014-07-16

Riboflavin (vitamin B2), the precursor of the flavin cofactors flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), is used commercially as an animal feed supplement and food colorant. E. coli is a robust host for various genetic manipulations and has been employed for efficient production of biofuels, polymers, amino acids, and bulk chemicals. Thus, the aim of this study was to understand the metabolic capacity of E. coli for the riboflavin production by modification of central metabolism, riboflavin biosynthesis pathway and optimization of the fermentation conditions. The basic producer RF01S, in which the riboflavin biosynthesis genes ribABDEC from E. coli were overexpressed under the control of the inducible trc promoter, could accumulate 229.1 mg/L of riboflavin. Further engineering was performed by examining the impact of expression of zwf (encodes glucose 6-phosphate dehydrogenase) and gnd (encodes 6-phosphogluconate dehydrogenase) from Corynebacterium glutamicum and pgl (encodes 6-phosphogluconolactonase) from E. coli on riboflavin production. Deleting pgi (encodes glucose-6-phosphate isomerase) and genes of Entner-Doudoroff (ED) pathway successfully redirected the carbon flux into the oxidative pentose phosphate pathway, and overexpressing the acs (encodes acetyl-CoA synthetase) reduced the acetate accumulation. These modifications increased riboflavin production to 585.2 mg/L. By further modulating the expression of ribF (encodes riboflavin kinase) for reducing the conversion of riboflavin to FMN in RF05S, the final engineering strain RF05S-M40 could produce 1036.1 mg/L riboflavin in LB medium at 37°C. After optimizing the fermentation conditions, strain RF05S-M40 produced 2702.8 mg/L riboflavin in the optimized semi-defined medium, which was a value nearly 12-fold higher than that of RF01S, with a yield of 137.5 mg riboflavin/g glucose. The engineered strain RF05S-M40 has the highest yield among all reported riboflavin production

Improving production of ?-lactam antibiotics by Penicillium chrysogenum : Metabolic engineering based on transcriptome analysis

NARCIS (Netherlands)

Veiga, T.

2012-01-01

In Chapters 2-5 of this thesis, the applicability of transcriptome analysis to guide metabolic engineering strategies in P. chrysogenum is explored by investigating four cellular processes that are of potential relevance for industrial production of ?-lactam antibiotics: - Regulation of secondary

Feeding of the water extract from Ganoderma lingzhi to rats modulates secondary bile acids, intestinal microflora, mucins, and propionate important to colon cancer.

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Yang, Yongshou; Nirmagustina, Dwi Eva; Kumrungsee, Thanutchaporn; Okazaki, Yukako; Tomotake, Hiroyuki; Kato, Norihisa

2017-09-01

Consumption of reishi mushroom has been reported to prevent colon carcinogenesis in rodents, although the underlying mechanisms remain unclear. To investigate this effect, rats were fed a high-fat diet supplemented with 5% water extract from either the reishi mushroom (Ganoderma lingzhi) (WGL) or the auto-digested reishi G. lingzhi (AWGL) for three weeks. Both extracts markedly reduced fecal secondary bile acids, such as lithocholic acid and deoxycholic acid (colon carcinogens). These extracts reduced the numbers of Clostridium coccoides and Clostridium leptum (secondary bile acids-producing bacteria) in a per g of cecal digesta. Fecal mucins and cecal propionate were significantly elevated by both extracts, and fecal IgA was significantly elevated by WGL, but not by AWGL. These results suggest that the reishi extracts have an impact on colon luminal health by modulating secondary bile acids, microflora, mucins, and propionate that related to colon cancer.

Mitochondrial biogenesis and energy production in differentiating murine stem cells: a functional metabolic study.

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Han, Sungwon; Auger, Christopher; Thomas, Sean C; Beites, Crestina L; Appanna, Vasu D

2014-02-01

The significance of metabolic networks in guiding the fate of the stem cell differentiation is only beginning to emerge. Oxidative metabolism has been suggested to play a major role during this process. Therefore, it is critical to understand the underlying mechanisms of metabolic alterations occurring in stem cells to manipulate the ultimate outcome of these pluripotent cells. Here, using P19 murine embryonal carcinoma cells as a model system, the role of mitochondrial biogenesis and the modulation of metabolic networks during dimethyl sulfoxide (DMSO)-induced differentiation are revealed. Blue native polyacrylamide gel electrophoresis (BN-PAGE) technology aided in profiling key enzymes, such as hexokinase (HK) [EC 2.7.1.1], glucose-6-phosphate isomerase (GPI) [EC 5.3.1.9], pyruvate kinase (PK) [EC 2.7.1.40], Complex I [EC 1.6.5.3], and Complex IV [EC 1.9.3.1], that are involved in the energy budget of the differentiated cells. Mitochondrial adenosine triphosphate (ATP) production was shown to be increased in DMSO-treated cells upon exposure to the tricarboxylic acid (TCA) cycle substrates, such as succinate and malate. The increased mitochondrial activity and biogenesis were further confirmed by immunofluorescence microscopy. Collectively, the results indicate that oxidative energy metabolism and mitochondrial biogenesis were sharply upregulated in DMSO-differentiated P19 cells. This functional metabolic and proteomic study provides further evidence that modulation of mitochondrial energy metabolism is a pivotal component of the cellular differentiation process and may dictate the final destiny of stem cells.

Developmental programming: exposure to testosterone excess disrupts steroidal and metabolic environment in pregnant sheep.

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Abi Salloum, B; Veiga-Lopez, A; Abbott, D H; Burant, C F; Padmanabhan, V

2015-06-01

Gestational exposure to excess T leads to intrauterine growth restriction, low birth weight, and adult metabolic/reproductive disorders in female sheep. We hypothesized that as early mediators of such disruptions, gestational T disrupts steroidal and metabolic homeostasis in both the mother and fetus by both androgenic and metabolic pathways. Maternal blood samples were measured weekly for levels of insulin, glucose, and progesterone from four groups of animals: control; gestational T (twice weekly im injections of 100 mg of T propionate from d 30 to d 90 of gestation); T plus an androgen antagonist, flutamide (15 mg/kg·d oral; T-Flutamide); and T plus the insulin sensitizer, rosiglitazone (0.11 mg/kg·d oral; T-Rosi) (n = 10-12/group). On day 90 of gestation, maternal and umbilical cord samples were collected after a 48-hour fast from a subset (n = 6/group) for the measurement of steroids, free fatty acids, amino acids, and acylcarnitines. Gestational T decreased maternal progesterone levels by 36.5% (P fetal estradiol were not prevented by either cotreatment. Gestational T disrupted associations of steroids with metabolites and progesterone with acylcarnitines, which was prevented either by androgen antagonist or insulin sensitizer cotreatment. These findings suggest a future combination of these treatments might be required to prevent alteration in maternal/fetal steroidal and metabolic milieu(s).

Multi-omic profiling of EPO producing Chinese hamster ovary cell panel reveals metabolic adaptation to heterologous protein production

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Ley, Daniel; Kazemi Seresht, Ali; Engmark, Mikael

Heterologous protein production in CHO cells imposes a burden on the host cell metabolism and impact cellular physiology on a global scale. In this work, a multi-omics approach was applied to characterize the physiological impact of erythropoietin production, and discover production bottlenecks, ...

Use of a polystyrene-divinylbenzene-based weakly acidic cation-exchange resin column and propionic acid as an eluent in ion-exclusion/adsorption chromatography of aliphatic carboxylic acids and ethanol in food samples.

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Mori, Masanobu; Hironaga, Takahiro; Kajiwara, Hiroe; Nakatani, Nobutake; Kozaki, Daisuke; Itabashi, Hideyuki; Tanaka, Kazuhiko

2011-01-01

We developed an ion-exclusion/adsorption chromatography (IEAC) method employing a polystyrene-divinylbenzene-based weakly acidic cation-exchange resin (PS-WCX) column with propionic acid as the eluent for the simultaneous determination of multivalent aliphatic carboxylic acids and ethanol in food samples. The PS-WCX column well resolved mono-, di-, and trivalent carboxylic acids in the acidic eluent. Propionic acid as the eluent gave a higher signal-to-noise ratio, and enabled sensitive conductimetric detection of analyte acids. We found the optimal separation condition to be the combination of a PS-WCX column and 20-mM propionic acid. Practical applicability of the developed method was confirmed by using a short precolumn with a strongly acidic cation-exchange resin in the H(+)-form connected before the separation column; this was to remove cations from food samples by converting them to hydrogen ions. Consequently, common carboxylic acids and ethanol in beer, wine, and soy sauce were successfully separated by the developed method.

Characterization of the marine propionate-degrading, sulfate-reducing bacterium Desulfofaba fastidiosa sp. nov. and reclassification of Desulfomusa hansenii as Desulfofaba hansenii comb. nov.

Science.gov (United States)

Abildgaard, Lone; Ramsing, Niels Birger; Finster, Kai

2004-03-01

A rod-shaped, slightly curved sulfate reducer, designated strain P2(T), was isolated from the sulfate-methane transition zone of a marine sediment. Cells were motile by means of a single polar flagellum. The strain reduced sulfate, thiosulfate and sulfite to sulfide and used propionate, lactate and 1-propanol as electron donors. Strain P2(T) also grew by fermentation of lactate. Propionate was oxidized incompletely to acetate and CO(2). The DNA G+C content was 48.8 mol%. Sequence analysis of the small-subunit rDNA and the dissimilatory sulfite reductase gene revealed that strain P2(T) was related to the genera Desulfonema, Desulfococcus, Desulfosarcina, 'Desulfobotulus', Desulfofaba, Desulfomusa and Desulfofrigus. These genera include incomplete as well as complete oxidizers of substrates. Strain P2(T) shared important morphological and physiological traits with Desulfofaba gelida and Desulfomusa hansenii, including the ability to oxidize propionate incompletely to acetate. The 16S rRNA gene similarities of P2(T) to Desulfofaba gelida and Desulfomusa hansenii were respectively 92.9 and 91.5 %. Combining phenotypic and genotypic traits, we propose strain P2(T) to be a member of the genus Desulfofaba. The name Desulfofaba fastidiosa sp. nov. (type strain P2(T)=DSM 15249(T)=ATCC BAA-815(T)) is proposed, reflecting the limited number of substrates consumed by the strain. In addition, the reclassification of Desulfomusa hansenii as a member of the genus Desulfofaba, Desulfofaba hansenii comb. nov., is proposed. A common line of descent and a number of shared phenotypic traits support this reclassification.

Integrating biocompatible chemistry and manipulating cofactor partitioning in metabolically engineeredLactococcus lactisfor fermentative production of (3S)-acetoin

DEFF Research Database (Denmark)

Liu, Jianming; Solem, Christian; Jensen, Peter Ruhdal

2016-01-01

Biocompatible chemistry (BC), i.e. non-enzymatic chemical reactions compatible with living organisms, is increasingly used in conjunction with metabolically engineered microorganisms for producing compounds that do not usually occur naturally. Here we report production of one such compound, (3S......)-acetoin, a valuable precursor for chiral synthesis, using a metabolically engineered Lactococcus lactis strain growing under respiratory conditions with ferric iron serving as a BC component. The strain used has all competing product pathways inactivated, and an appropriate cofactor balance is achieved by fine...

Genome-scale metabolic modeling to provide insight into the production of storage compounds during feast-famine cycles of activated sludge.

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Tajparast, Mohammad; Frigon, Dominic

2013-01-01

Studying storage metabolism during feast-famine cycles of activated sludge treatment systems provides profound insight in terms of both operational issues (e.g., foaming and bulking) and process optimization for the production of value added by-products (e.g., bioplastics). We examined the storage metabolism (including poly-β-hydroxybutyrate [PHB], glycogen, and triacylglycerols [TAGs]) during feast-famine cycles using two genome-scale metabolic models: Rhodococcus jostii RHA1 (iMT1174) and Escherichia coli K-12 (iAF1260) for growth on glucose, acetate, and succinate. The goal was to develop the proper objective function (OF) for the prediction of the main storage compound produced in activated sludge for given feast-famine cycle conditions. For the flux balance analysis, combinations of three OFs were tested. For all of them, the main OF was to maximize growth rates. Two additional sub-OFs were used: (1) minimization of biochemical fluxes, and (2) minimization of metabolic adjustments (MoMA) between the feast and famine periods. All (sub-)OFs predicted identical substrate-storage associations for the feast-famine growth of the above-mentioned metabolic models on a given substrate when glucose and acetate were set as sole carbon sources (i.e., glucose-glycogen and acetate-PHB), in agreement with experimental observations. However, in the case of succinate as substrate, the predictions depended on the network structure of the metabolic models such that the E. coli model predicted glycogen accumulation and the R. jostii model predicted PHB accumulation. While the accumulation of both PHB and glycogen was observed experimentally, PHB showed higher dynamics during an activated sludge feast-famine growth cycle with succinate as substrate. These results suggest that new modeling insights between metabolic predictions and population ecology will be necessary to properly predict metabolisms likely to emerge within the niches of activated sludge communities. Nonetheless

Urea plus nitrate pretreatment of rice and wheat straws enhances degradation and reduces methane production in in vitro ruminal culture.

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Zhang, Xiumin; Wang, Min; Wang, Rong; Ma, Zhiyuan; Long, Donglei; Mao, Hongxiang; Wen, Jiangnan; Bernard, Lukuyu A; Beauchemin, Karen A; Tan, Zhiliang

2018-04-10

Urea pretreatment of straw damages fiber structure, while nitrate supplementation of ruminal diets inhibits enteric methane production. The study examined the combined effects of these treatments on ruminal substrate biodegradation and methane production using an in vitro incubation system. Rice and wheat straws were pretreated with urea (40 g kg -1 straw dry matter, DM) and urea + ammonium nitrate (34 + 6 g kg -1 dry matter (DM), respectively), and each straw (control, urea, urea+nitrate) was used in batch culture incubations in three replications (runs). Urea pretreatment increased (P content (+17%) and in vitro DM degradation of rice straw, in comparison with control. Urea+nitrate pretreatment of rice and wheat straws had higher (P content, in vitro DM degradation and propionate molar proportion, and lower (P ruminal biodegradation, facilitate propionate production and reduce methane production from lignified straws. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

Metabolic engineering of Pseudomonas fluorescens for the production of vanillin from ferulic acid.

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Di Gioia, Diana; Luziatelli, Francesca; Negroni, Andrea; Ficca, Anna Grazia; Fava, Fabio; Ruzzi, Maurizio

2011-12-20

Vanillin is one of the most important flavors in the food industry and there is great interest in its production through biotechnological processes starting from natural substrates such as ferulic acid. Among bacteria, recombinant Escherichia coli strains are the most efficient vanillin producers, whereas Pseudomonas spp. strains, although possessing a broader metabolic versatility, rapidly metabolize various phenolic compounds including vanillin. In order to develop a robust Pseudomonas strain that can produce vanillin in high yields and at high productivity, the vanillin dehydrogenase (vdh)-encoding gene of Pseudomonas fluorescens BF13 strain was inactivated via targeted mutagenesis. The results demonstrated that engineered derivatives of strain BF13 accumulate vanillin if inactivation of vdh is associated with concurrent expression of structural genes for feruloyl-CoA synthetase (fcs) and hydratase/aldolase (ech) from a low-copy plasmid. The conversion of ferulic acid to vanillin was enhanced by optimization of growth conditions, growth phase and parameters of the bioconversion process. The developed strain produced up to 8.41 mM vanillin, which is the highest final titer of vanillin produced by a Pseudomonas strain to date and opens new perspectives in the use of bacterial biocatalysts for biotechnological production of vanillin from agro-industrial wastes which contain ferulic acid. Copyright © 2011 Elsevier B.V. All rights reserved.

Construction of a Genome-Scale Metabolic Model of Arthrospira platensis NIES-39 and Metabolic Design for Cyanobacterial Bioproduction.

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Katsunori Yoshikawa

Full Text Available Arthrospira (Spirulina platensis is a promising feedstock and host strain for bioproduction because of its high accumulation of glycogen and superior characteristics for industrial production. Metabolic simulation using a genome-scale metabolic model and flux balance analysis is a powerful method that can be used to design metabolic engineering strategies for the improvement of target molecule production. In this study, we constructed a genome-scale metabolic model of A. platensis NIES-39 including 746 metabolic reactions and 673 metabolites, and developed novel strategies to improve the production of valuable metabolites, such as glycogen and ethanol. The simulation results obtained using the metabolic model showed high consistency with experimental results for growth rates under several trophic conditions and growth capabilities on various organic substrates. The metabolic model was further applied to design a metabolic network to improve the autotrophic production of glycogen and ethanol. Decreased flux of reactions related to the TCA cycle and phosphoenolpyruvate reaction were found to improve glycogen production. Furthermore, in silico knockout simulation indicated that deletion of genes related to the respiratory chain, such as NAD(PH dehydrogenase and cytochrome-c oxidase, could enhance ethanol production by using ammonium as a nitrogen source.

Growth inhibition of S. cerevisiae, B. subtilis, and E. coli by lignocellulosic and fermentation products

NARCIS (Netherlands)

Carvalho Pereira, Joana P.C.; Verheijen, P.J.T.; Straathof, Adrie J.J.

2016-01-01

This paper describes the effect of several inhibiting components on three potential hosts for the bio-based production of methyl propionate, namely, wild-type Escherichia coli and Bacillus subtilis, and evolved Saccharomyces cerevisiae IMS0351. The inhibition by the lignocellulose-derived

Enteric bacterial metabolites propionic and butyric acid modulate gene expression, including CREB-dependent catecholaminergic neurotransmission, in PC12 cells--possible relevance to autism spectrum disorders.

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Bistra B Nankova

Full Text Available Alterations in gut microbiome composition have an emerging role in health and disease including brain function and behavior. Short chain fatty acids (SCFA like propionic (PPA, and butyric acid (BA, which are present in diet and are fermentation products of many gastrointestinal bacteria, are showing increasing importance in host health, but also may be environmental contributors in neurodevelopmental disorders including autism spectrum disorders (ASD. Further to this we have shown SCFA administration to rodents over a variety of routes (intracerebroventricular, subcutaneous, intraperitoneal or developmental time periods can elicit behavioral, electrophysiological, neuropathological and biochemical effects consistent with findings in ASD patients. SCFA are capable of altering host gene expression, partly due to their histone deacetylase inhibitor activity. We have previously shown BA can regulate tyrosine hydroxylase (TH mRNA levels in a PC12 cell model. Since monoamine concentration is known to be elevated in the brain and blood of ASD patients and in many ASD animal models, we hypothesized that SCFA may directly influence brain monoaminergic pathways. When PC12 cells were transiently transfected with plasmids having a luciferase reporter gene under the control of the TH promoter, PPA was found to induce reporter gene activity over a wide concentration range. CREB transcription factor(s was necessary for the transcriptional activation of TH gene by PPA. At lower concentrations PPA also caused accumulation of TH mRNA and protein, indicative of increased cell capacity to produce catecholamines. PPA and BA induced broad alterations in gene expression including neurotransmitter systems, neuronal cell adhesion molecules, inflammation, oxidative stress, lipid metabolism and mitochondrial function, all of which have been implicated in ASD. In conclusion, our data are consistent with a molecular mechanism through which gut related environmental signals

Heptadecanoylcarnitine (C17) a novel candidate biomarker for newborn screening of propionic and methylmalonic acidemias.

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Malvagia, Sabrina; Haynes, Christopher A; Grisotto, Laura; Ombrone, Daniela; Funghini, Silvia; Moretti, Elisa; McGreevy, Kathleen S; Biggeri, Annibale; Guerrini, Renzo; Yahyaoui, Raquel; Garg, Uttam; Seeterlin, Mary; Chace, Donald; De Jesus, Victor R; la Marca, Giancarlo

2015-10-23

3-Hydroxypalmitoleoyl-carnitine (C16:1-OH) has recently been reported to be elevated in acylcarnitine profiles of patients with propionic acidemia (PA) or methylmalonic acidemia (MMA) during expanded newborn screening (NBS). High levels of C16:1-OH, combined with other hydroxylated long chain acylcarnitines are related to long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD) and trifunctional protein (TFP) deficiency. The acylcarnitine profile of two LCHADD patients was evaluated using liquid chromatography-tandem mass spectrometric method. A specific retention time was determined for each hydroxylated long chain acylcarnitine. The same method was applied to some neonatal dried blood spots (DBSs) from PA and MMA patients presenting abnormal C16:1-OH concentrations. The retention time of the peak corresponding to C16:1-OH in LCHADD patients differed from those in MMA and PA patients. Heptadecanoylcarnitine (C17) has been identified as the novel biomarker specific for PA and MMA patients through high resolution mass spectrometry (Orbitrap) experiments. We found that 21 out of 23 neonates (22 MMA, and 1PA) diagnosed through the Tuscany region NBS program exhibited significantly higher levels of C17 compared to controls. Twenty-three maternal deficiency (21 vitamin B12 deficiency, 1 homocystinuria and 1 gastrin deficiency) samples and 82 false positive for elevated propionylcarnitine (C3) were also analyzed. We have characterized a novel biomarker able to detect propionate disorders during expanded newborn screening (NBS). The use of this new biomarker may improve the analytical performances of NBS programs especially in laboratories where second tier tests are not performed. Copyright © 2015 Elsevier B.V. All rights reserved.

Fluticasone propionate and increased risk of pneumonia in COPD: is it PAFR-dependent?

Directory of Open Access Journals (Sweden)

Sohal SS

2017-12-01

Full Text Available Sukhwinder Singh SohalDiscipline of Laboratory Medicine, School of Health Sciences, Faculty of Health, University of Tasmania, Launceston, AustraliaIt was with great interest that I read the recent comprehensive review by Christer Janson et al1 published in the International Journal of COPD, where authors discussed the possible mechanisms behind the increased risk of pneumonia in COPD patients using inhaled corticosteroids (ICSs, especially with fluticasone propionate (FP, where the risk was highest.1 It is an important area, and it is encouraging and reassuring that leading clinical journals are recognizing this. Understanding the fundamental mechanisms behind pneumococcal infections is critical.2 I would like to suggest that a broader discussion of new insights into the potential mechanisms contributing to the increased adherence of pneumococcus to airway wall and particularly in response to FP might has been appropriate with this opportunity.Authors’ replyChrister Janson,1 Georgios Stratelis,1,2 Anna Miller-Larsson,3 Tim W Harrison,4 Kjell Larsson51Respiratory, Allergy and Sleep Research Unit, Department of Medical Sciences, Uppsala University, Uppsala, 2Respiratory, Inflammation and Autoimmunity, AstraZeneca Nordic, Södertälje, 3Respiratory GMed, AstraZeneca Gothenburg, Mölndal, Sweden; 4Nottingham Respiratory Research Unit, City Hospital Campus, University of Nottingham, Nottingham, UK; 5Lung and Airway Research, National Institute of Environmental Medicine, Karolinska Institutet, Stockholm, SwedenWe thank Dr Sohal for his interest in our recently published manuscript discussing the scientific rationale for the possible inhaled corticosteroid (ICS intraclass difference in the risk of pneumonia in COPD. His own work on platelet-activating factor receptor (PAFR expression on airway epithelial cells in COPD patients shows a trend toward increased expression of PAFR by 6-month treatment with fluticasone propionate (FP, suggesting an

Complete Oxidation of Propionate, Valerate, Succinate, and Other Organic Compounds by Newly Isolated Types of Marine, Anaerobic, Mesophilic, Gram-Negative, Sulfur-Reducing Eubacteria

Science.gov (United States)

Finster, Kai; Bak, Friedhelm

1993-01-01

Anaerobic enrichment cultures with either propionate, succinate, lactate, or valerate and elemental sulfur and inocula from shallow marine or deep-sea sediments were dominated by rod-shaped motile bacteria after three transfers. By application of deep-agar dilutions, five eubacterial strains were obtained in pure culture and designated Kyprop, Gyprop, Kysw2, Gylac, and Kyval. All strains were gram negative and grew by complete oxidation of the electron donors and concomitant stoichiometric reduction of elemental sulfur to hydrogen sulfide. The isolates used acetate, propionate, succinate, lactate, pyruvate, oxaloacetate, maleate, glutamate, alanine, aspartate, and yeast extract. All isolates, except strain Gylac, used citrate as an electron donor but valerate was oxidized only by strain Kyval. Fumarate and malate were degraded by all strains without an additional electron donor or acceptor. Kyprop, Gyprop, and Gylac utilized elemental sulfur as the sole inorganic electron acceptor, while Kysw2 and Kyval also utilized nitrate, dimethyl sulfoxide, or Fe(III)-citrate as an electron acceptor. Images PMID:16348934

The influence of secondary processing on the structural relaxation dynamics of fluticasone propionate.

Science.gov (United States)

Depasquale, Roberto; Lee, Sau L; Saluja, Bhawana; Shur, Jagdeep; Price, Robert

2015-06-01

This study investigated the structural relaxation of micronized fluticasone propionate (FP) under different lagering conditions and its influence on aerodynamic particle size distribution (APSD) of binary and tertiary carrier-based dry powder inhaler (DPI) formulations. Micronized FP was lagered under low humidity (LH 25 C, 33% RH [relative humidity]), high humidity (HH 25°C, 75% RH) for 30, 60, and 90 days, respectively, and high temperature (HT 60°C, 44% RH) for 14 days. Physicochemical, surface interfacial properties via cohesive-adhesive balance (CAB) measurements and amorphous disorder levels of the FP samples were characterized. Particle size, surface area, and rugosity suggested minimal morphological changes of the lagered FP samples, with the exception of the 90-day HH (HH90) sample. HH90 FP samples appeared to undergo surface reconstruction with a reduction in surface rugosity. LH and HH lagering reduced the levels of amorphous content over 90-day exposure, which influenced the CAB measurements with lactose monohydrate and salmeterol xinafoate (SX). CAB analysis suggested that LH and HH lagering led to different interfacial interactions with lactose monohydrate but an increasing adhesive affinity with SX. HT lagering led to no detectable levels of the amorphous disorder, resulting in an increase in the adhesive interaction with lactose monohydrate. APSD analysis suggested that the fine particle mass of FP and SX was affected by the lagering of the FP. In conclusion, environmental conditions during the lagering of FP may have a profound effect on physicochemical and interfacial properties as well as product performance of binary and tertiary carrier-based DPI formulations.

Correlation Between Metabolic Syndrome, Periodontitis and Reactive Oxygen Species Production. A Pilot Study.

Science.gov (United States)

Patini, Romeo; Gallenzi, Patrizia; Spagnuolo, Gianrico; Cordaro, Massimo; Cantiani, Monica; Amalfitano, Adriana; Arcovito, Alessandro; Callà, Cinzia; Mingrone, Gertrude; Nocca, Giuseppina

2017-01-01

Metabolic syndrome (MetS) is associated with an increased risk of periodontitis even if the mechanism is unknown. Since both MetS and periodontitis are characterized by an alteration of inflammation status, the aim of this pilot study was to determine if differences in ROS metabolism of phagocytes isolated from (A) patients with MetS, (B) patients with both MetS and mild periodontitis, (C) healthy subjects and (D) normal weight subjects with mild periodontitis, were present. ROS metabolism was studied by a Chemiluminescence (CL) technique: the system was made up of luminol (100 nmol/L) and cells (1 × 10 5 ) in the presence or absence of stimulus constituted by opsonized zymosan (0.5 mg). The final volume (1.0 mL) was obtained using modified KRP buffer. ROS production was measured at 25°C for 2 h, using an LB 953 luminometer (Berthold, EG & G Co, Germany). All the experiments were performed in triplicate. All results are mean ± standard deviation (SD). The group of means was compared by the analysis of variance "(ANOVA)". A value of p < 0.05 was considered significant. Results showed that basal ROS production (both from PMNs and from PBMs) of groups A, B and D was increased with respect to that obtained from group C ( p <0.05). These results are congruent with literature data, although the actual clinical relevance of the phenomenon remains to be evaluated.

LC-MS Proteomics Analysis of the Insulin/IGF-1 Deficient Caenorhabditis elegans daf-2(e1370) Mutant Reveals Extensive Restructuring of Intermediary Metabolism

Energy Technology Data Exchange (ETDEWEB)

Depuydt, Geert G.; Xie, Fang; Petyuk, Vladislav A.; Smolders, Arne; Brewer, Heather M.; Camp, David G.; Smith, Richard D.; Braeckman, Bart P.

2014-02-20

The insulin/IGF-1 receptor is a major known determinant of dauer formation, stress resistance, longevity and metabolism in C. elegans. In the past, whole-genome transcript profiling was used extensively to study differential gene expression in response to reduced insulin/IGF-1 signaling, including expression levels of metabolism-associated genes. Taking advantage of the recent developments in quantitative liquid chromatography mass-spectrometry (LC-MS) based proteomics, we profiled the proteomic changes that occur in response to activation of the DAF-16 transcription factor in the germline-less glp-4(bn2); daf-2(e1370) receptor mutant. Strikingly, the daf-2 profile suggests extensive reorganization of intermediary metabolism, characterized by the up-regulation of many core intermediary metabolic pathways. These include, glycolysis/gluconeogenesis, glycogenesis, pentose phosphate cycle, citric acid cycle, glyoxylate shunt, fatty acid β-oxidation, one-carbon metabolism, propionate and tyrosine catabolism, and complex I, II, III and V of the electron transport chain. Interestingly, we found simultaneous activation of reciprocally regulated metabolic pathways, which is indicative for spatio-temporal coordination of energy metabolism and/or extensive post-translational regulation of these enzymes. This restructuring of daf-2 metabolism is reminiscent to that of hypometabolic dauers, allowing the efficient and economical utilization of internal nutrient reserves, possibly also shunting metabolites through alternative energy-generating pathways, in order to sustain longevity.

LC–MS Proteomics Analysis of the Insulin/IGF-1-Deficient Caenorhabditis elegans daf-2(e1370) Mutant Reveals Extensive Restructuring of Intermediary Metabolism

Science.gov (United States)

2015-01-01

The insulin/IGF-1 receptor is a major known determinant of dauer formation, stress resistance, longevity, and metabolism in Caenorhabditis elegans. In the past, whole-genome transcript profiling was used extensively to study differential gene expression in response to reduced insulin/IGF-1 signaling, including the expression levels of metabolism-associated genes. Taking advantage of the recent developments in quantitative liquid chromatography mass spectrometry (LC–MS)-based proteomics, we profiled the proteomic changes that occur in response to activation of the DAF-16 transcription factor in the germline-less glp-4(bn2);daf-2(e1370) receptor mutant. Strikingly, the daf-2 profile suggests extensive reorganization of intermediary metabolism, characterized by the upregulation of many core intermediary metabolic pathways. These include glycolysis/gluconeogenesis, glycogenesis, pentose phosphate cycle, citric acid cycle, glyoxylate shunt, fatty acid β-oxidation, one-carbon metabolism, propionate and tyrosine catabolism, and complexes I, II, III, and V of the electron transport chain. Interestingly, we found simultaneous activation of reciprocally regulated metabolic pathways, which is indicative of spatiotemporal coordination of energy metabolism and/or extensive post-translational regulation of these enzymes. This restructuring of daf-2 metabolism is reminiscent to that of hypometabolic dauers, allowing the efficient and economical utilization of internal nutrient reserves and possibly also shunting metabolites through alternative energy-generating pathways to sustain longevity. PMID:24555535

Improved biogas production from rice straw by co-digestion with kitchen waste and pig manure

Energy Technology Data Exchange (ETDEWEB)

Ye, Jingqing [Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640 (China); School of Environmental Sciences and Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Li, Dong; Sun, Yongming [Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640 (China); Wang, Guohui [School of Environmental Sciences and Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Yuan, Zhenhong, E-mail: yuanzh@ms.giec.ac.cn [Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640 (China); Zhen, Feng; Wang, Yao [Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640 (China)

2013-12-15

Highlights: • Biogas production was enhanced by co-digestion of rice straw with other materials. • The optimal ratio of kitchen waste, pig manure and rice straw is 0.4:1.6:1. • The maximum biogas yield of 674.4 L/kg VS was obtained. • VFA inhibition occurred when kitchen waste content was more than 26%. • The dominant VFA were propionate and acetate in successful reactors. - Abstract: In order to investigate the effect of feedstock ratios in biogas production, anaerobic co-digestions of rice straw with kitchen waste and pig manure were carried out. A series of single-stage batch mesophilic (37 ± 1 °C) anaerobic digestions were performed at a substrate concentration of 54 g/L based on volatile solids (VS). The results showed that the optimal ratio of kitchen waste, pig manure, and rice straw was 0.4:1.6:1, for which the C/N ratio was 21.7. The methane content was 45.9–70.0% and rate of VS reduction was 55.8%. The biogas yield of 674.4 L/kg VS was higher than that of the digestion of rice straw or pig manure alone by 71.67% and 10.41%, respectively. Inhibition of biogas production by volatile fatty acids (VFA) occurred when the addition of kitchen waste was greater than 26%. The VFA analysis showed that, in the reactors that successfully produced biogas, the dominant intermediate metabolites were propionate and acetate, while they were lactic acid, acetate, and propionate in the others.

Improved biogas production from rice straw by co-digestion with kitchen waste and pig manure

International Nuclear Information System (INIS)

Ye, Jingqing; Li, Dong; Sun, Yongming; Wang, Guohui; Yuan, Zhenhong; Zhen, Feng; Wang, Yao

2013-01-01

Highlights: • Biogas production was enhanced by co-digestion of rice straw with other materials. • The optimal ratio of kitchen waste, pig manure and rice straw is 0.4:1.6:1. • The maximum biogas yield of 674.4 L/kg VS was obtained. • VFA inhibition occurred when kitchen waste content was more than 26%. • The dominant VFA were propionate and acetate in successful reactors. - Abstract: In order to investigate the effect of feedstock ratios in biogas production, anaerobic co-digestions of rice straw with kitchen waste and pig manure were carried out. A series of single-stage batch mesophilic (37 ± 1 °C) anaerobic digestions were performed at a substrate concentration of 54 g/L based on volatile solids (VS). The results showed that the optimal ratio of kitchen waste, pig manure, and rice straw was 0.4:1.6:1, for which the C/N ratio was 21.7. The methane content was 45.9–70.0% and rate of VS reduction was 55.8%. The biogas yield of 674.4 L/kg VS was higher than that of the digestion of rice straw or pig manure alone by 71.67% and 10.41%, respectively. Inhibition of biogas production by volatile fatty acids (VFA) occurred when the addition of kitchen waste was greater than 26%. The VFA analysis showed that, in the reactors that successfully produced biogas, the dominant intermediate metabolites were propionate and acetate, while they were lactic acid, acetate, and propionate in the others

Improved production of short-chain fatty acids from waste activated sludge driven by carbohydrate addition in continuous-flow reactors: Influence of SRT and temperature

International Nuclear Information System (INIS)

Luo, Jingyang; Feng, Leiyu; Zhang, Wei; Li, Xiang; Chen, Hong; Wang, Dongbo; Chen, Yinguang

2014-01-01

Highlights: • SRT or temperature increase benefited the hydrolysis of fermentation substrates. • SCFAs, especially propionic acid, accumulated most at SRT 8 d and 37 °C. • The activities of key enzymes were in accordance with SCFAs production. • The ratio of Bacteria to Archaea was improved at SRT 8 d and 37 °C. - Abstract: During anaerobic fermentation of waste activated sludge (WAS), the production of short-chain fatty acids (SCFAs), especially propionic acid which is considered as the most preferred carbon source for enhanced biological phosphorus removal, can be improved by controlling the suitable mass ratio of carbon to nitrogen (C/N) and pH in batch mode. In this study the influences of solids retention time (SRT) and temperature on WAS hydrolysis and acidification in the continuous-flow systems in which the C/N ratio of WAS was modified by carbohydrate addition were investigated. Experimental results showed that the increase of SRT and temperature in a pertinent range benefited the hydrolysis of fermentation substrates and the accumulation of SCFAs, and SRT 8 d and temperature 37 °C were the most preferred conditions for the production of SCFAs, especially propionic acid. As there were more consumption of protein and carbohydrate and less production of methane at SRT 8 d and temperature 37 °C, more SCFAs were accumulated. Also, both the activities of key hydrolases and acid-forming enzymes and the ratio of acidogenic bacteria to methanogens showed good agreements with SCFAs production

Process for the production of methyl methacrylate

NARCIS (Netherlands)

Eastham, G.R.; Johnson, D.W.; Straathof, A.J.J.; Fraaije, Marco; Winter, Remko

2015-01-01

A process of producing methyl methacrylate or derivatives thereof is described. The process includes the steps of; (i) converting 2-butanone to methyl propionate using a Baeyer-Villiger monooxygenase, and (ii) treating the methyl propionate produced to obtain methyl methacrylate or derivatives

Set anode potentials affect the electron fluxes and microbial community structure in propionate-fed microbial electrolysis cells

KAUST Repository

Rao, Hari Ananda

2016-12-09

Anode potential has been shown to be a critical factor in the rate of acetate removal in microbial electrolysis cells (MECs), but studies with fermentable substrates and set potentials are lacking. Here, we examined the impact of three different set anode potentials (SAPs; −0.25, 0, and 0.25 V vs. standard hydrogen electrode) on the electrochemical performance, electron flux to various sinks, and anodic microbial community structure in two-chambered MECs fed with propionate. Electrical current (49–71%) and CH4 (22.9–41%) were the largest electron sinks regardless of the potentials tested. Among the three SAPs tested, 0 V showed the highest electron flux to electrical current (71 ± 5%) and the lowest flux to CH4 (22.9 ± 1.2%). In contrast, the SAP of −0.25 V had the lowest electron flux to current (49 ± 6%) and the highest flux to CH4 (41.1 ± 2%). The most dominant genera detected on the anode of all three SAPs based on 16S rRNA gene sequencing were Geobacter, Smithella and Syntrophobacter, but their relative abundance varied among the tested SAPs. Microbial community analysis implies that complete degradation of propionate in all the tested SAPs was facilitated by syntrophic interactions between fermenters and Geobacter at the anode and ferementers and hydrogenotrophic methanogens in suspension.

Protective Effects of Lepidium meyenii (Maca) Aqueous Extract and Lycopene on Testosterone Propionate-Induced Prostatic Hyperplasia in Mice.

Science.gov (United States)

Zou, Ying; Aboshora, Waleed; Li, Jing; Xiao, Tiancun; Zhang, Lianfu

2017-08-01

The inhibitory effect of maca extractant, lycopene, and their combination was evaluated in benign prostatic hyperplasia (BPH) mice induced by testosterone propionate. Mice were divided into a saline group, solvent control group and testosterone propionate-induced BPH mice [BPH model group, solvent BPH model group, benzyl glucosinolate group (1.44 mg/kg), maca group (60 mg/kg), lycopene treated (15, 5, and 2.5 mg/kg), maca (30 mg/kg) combine lycopene treated (7.5, 2.5, and 1.25 mg/kg), and finasteride treated]. Benzyl glucosinolate was used in order to evaluate its pharmacological activity on BPH to find out whether it is the major active component of maca aqueous extract. Finasteride was used as positive control. The compounds were administered once for 30 successive days. Compared with solvent BPH model group, BPH mice fed with maca (30 mg/kg) and lycopene (7.5 mg/kg) combination exhibited significant reductions in the prostatic index, prostatic acid phospatase, estradiol, testosterone, and dihydrotestosterone levels in serum. They also had similar histological compared with those aspects observed in the mice in the solvent control group. The results indicated that combination of maca and lycopene synergistically inhibits BPH in mice. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Mathematical modeling of unicellular microalgae and cyanobacteria metabolism for biofuel production.

Science.gov (United States)

Baroukh, Caroline; Muñoz-Tamayo, Rafael; Bernard, Olivier; Steyer, Jean-Philippe

2015-06-01

The conversion of microalgae lipids and cyanobacteria carbohydrates into biofuels appears to be a promising source of renewable energy. This requires a thorough understanding of their carbon metabolism, supported by mathematical models, in order to optimize biofuel production. However, unlike heterotrophic microorganisms that utilize the same substrate as sources of energy and carbon, photoautotrophic microorganisms require light for energy and CO2 as carbon source. Furthermore, they are submitted to permanent fluctuating light environments due to outdoor cultivation or mixing inducing a flashing effect. Although, modeling these nonstandard organisms is a major challenge for which classical tools are often inadequate, this step remains a prerequisite towards efficient optimization of outdoor biofuel production at an industrial scale. Copyright © 2015 Elsevier Ltd. All rights reserved.

The prevalence of metabolic syndrome in an employed population and the impact on health and productivity.

Science.gov (United States)

Burton, Wayne N; Chen, Chin-Yu; Schultz, Alyssa B; Edington, Dee W

2008-10-01

To investigate the prevalence of metabolic syndrome in an employed population and its association with health risks, health perception, illness days, work limitation (presenteeism), and short-term disability (STD). Five thousand five hundred twelve employees of a financial services company responded to an on-site health risk appraisal which included measured waist circumference and biometric results. The metabolic syndrome criteria were based on the 2005 AHA/NHLBI scientific statement on the diagnosis and management of metabolic syndrome. Perceived health, illness days, and presenteeism were self-reported; STD days were obtained from claims data. In this employee population (61% women, average age 41 years), 22.6% met the criteria for metabolic syndrome and were more likely to report more health risks, poorer health perception, and more absent days due to illness. There was no clear association with presenteeism or STD incidence. However, as the number of metabolic risk factors increased, there was an increase in STD incidence, decrease in health perception, and increase in illness days. No association was found with number of metabolic risk factors and presenteeism. Metabolic syndrome was associated with poor perceived health, increased illness days, and an increased trend of STD incidence. Worksite health promotion programs could be useful in helping employees and employers to identify metabolic syndrome risks and take steps to reduce risk and potential productivity losses.

Advances in metabolic engineering of yeast Saccharomyces cerevisiae for production of chemicals

DEFF Research Database (Denmark)

Borodina, Irina; Nielsen, Jens

2014-01-01

Yeast Saccharomyces cerevisiae is an important industrial host for production of enzymes, pharmaceutical and nutraceutical ingredients and recently also commodity chemicals and biofuels. Here, we review the advances in modeling and synthetic biology tools and how these tools can speed up the deve......Yeast Saccharomyces cerevisiae is an important industrial host for production of enzymes, pharmaceutical and nutraceutical ingredients and recently also commodity chemicals and biofuels. Here, we review the advances in modeling and synthetic biology tools and how these tools can speed up...... the development of yeast cell factories. We also present an overview of metabolic engineering strategies for developing yeast strains for production of polymer monomers: lactic, succinic, and cis,cis-muconic acids. S. cerevisiae has already firmly established itself as a cell factory in industrial biotechnology...

Contribution to the study of calcium metabolism in the deficiency of testosterone

International Nuclear Information System (INIS)

Correa, S.M.J.C.

1980-01-01

Kinetic parameters of calcium mobilization in rats were determined to estimate the role of testosterone in the metabolism of this ion. Calcium multicompartimental theory was combined to and used in measurements of metabolic balance (for 45 CaCl 2 or 40 CaCl 2 ). Three groups of 60 day old rats were used: G I-control; G II-castrated; G III-castrated and treated with testosterone propionate. Data were obtained from measurements of Ca ++ in samples of plasma, feces and urine. Balance studies suggest that calcium level in blood plasma remained constant in all groups, the increase of bone reabsorption in groups II and III being counterbalanced by the elevation of the urinary excrection. This result implies the equilibrium occurring at renal level. Intestinal calcium absorption remained the same in the three groups of animals, indicating that testosterone has no consistent effect at intestinal level. The increase of total calcium in feces of groups II and III arises from a great endogenous secretion. A significant negative balance of calcium was also observed in these groups. This fact permits the conclusion that in the absence of testosterone the organism doesn't retain calcium efficiently. (M.A.) [pt

Changes in Blood Values of Glucose, Insulin and Inorganic Phosphorus in Healthy and Ketotic Dairy Cows after Intravenous Infusion of Propionate Solution

Directory of Open Access Journals (Sweden)

R. Djoković

2007-01-01

Full Text Available The aim of the present study was to determine the degree of blood glucose utilization by peripheral tissue on the basis of changes in blood concentrations of glucose, insulin and inorganic phosphorus in healthy (n = 10 and ketotic cows (n = 10 after intravenous infusion of propionate solution. Blood samples were taken in both groups of examined cows at the following time intervals: just before (time 0 and 8, 30, 60, 120, 180, 240 and 480 min after the intravenous infusion of 1.84 mol l-1 solution of propionate in the amount of 1 ml kg-1 of body weight. Glucose and insulin blood serum values in both groups of cows increased significantly within 120 min of the experiment (p p p p < 0.05 in blood value of inorganic phosphorus in ketotic cows in comparison with healthy ones. This is linked with the active entry of glucose into glucolytic pathway of peripheral tissues. It can thus be concluded that there is a higher degree of blood glucose utilization by peripheral tissues in ketotic cows.

Influence of chosen microbes and some chemical substances on the production of aflatoxins

Directory of Open Access Journals (Sweden)

Iveta Brožková

2015-03-01

Full Text Available Aflatoxins are produced as secondary metabolites by A. flavus, A. parasiticus, A. nomius and A. tamarii. The aflatoxin biosynthetic pathway involves several enzymatic steps and genes (apa-2, ver-1 that appear to be regulated by the aflR gene in these fungi. The aim of this work was the detection of aflatoxins by the HPLC method and the ascertainment of factors influencing their production. A. parasiticus CCM F-108, A. parasiticus CCF 141, A. parasiticus CCF 3137 and two isolates A. flavus were used. These toxigenic isolates were recovered from spice (strain 1 and wraps (strain 2. The gene for the production of aflatoxin B1 for each species of fungi was detected using an optimized PCR method. Rhodotorula spp.*, Lactococcus lactis subsp. lactis CCM 1881, Flavobacterium spp. and fungal strain Pythium oligandrum* were tested for inhibition of aflatoxins production and fungal growth. Having used the HPLC detection, various preservatives (propionic acid, citric acid, potassium sorbate were tested from the viewpoint of their influence on the growth of aflatoxigenic fungi followed by the production of aflatoxins. The growth of A. flavus and A. parasiticus and aflatoxin production in Potato Dextrose Agar supplemented with propionic acid (1000-2000-3000 mg/kg, citric acid (2000-3000-4000 mg/kg and potassium sorbate (500-800-1000 mg/kg was tested by Agar Dilution Method. After 72 h of incubation was evaluated growth of fungi, all samples were frozen for later extraction and aflatoxins quantification by HPLC. Effect of peptone and sucrose additions were studied in yeast extract (2% supplemented with peptone (5-10-15% or sucrose (15%. Growth inhibition of Aspergillus by Pythium oligandrum was tested on wood surface. As shown, the highest inhibition effect on the aflatoxins production was obtained when propionic acid was applied in concentrations since 1000 mg/kg. A total inhibition of the fungi growth and aflatoxins production was observed in all samples

Modeling of Zymomonas mobilis central metabolism for novel metabolic engineering strategies.

Science.gov (United States)

Kalnenieks, Uldis; Pentjuss, Agris; Rutkis, Reinis; Stalidzans, Egils; Fell, David A

2014-01-01

Mathematical modeling of metabolism is essential for rational metabolic engineering. The present work focuses on several types of modeling approach to quantitative understanding of central metabolic network and energetics in the bioethanol-producing bacterium Zymomonas mobilis. Combined use of Flux Balance, Elementary Flux Mode, and thermodynamic analysis of its central metabolism, together with dynamic modeling of the core catabolic pathways, can help to design novel substrate and product pathways by systematically analyzing the solution space for metabolic engineering, and yields insights into the function of metabolic network, hardly achievable without applying modeling tools.

Water deprivation induces appetite and alters metabolic strategy in Notomys alexis: unique mechanisms for water production in the desert.

Science.gov (United States)

Takei, Yoshio; Bartolo, Ray C; Fujihara, Hiroaki; Ueta, Yoichi; Donald, John A

2012-07-07

Like many desert animals, the spinifex hopping mouse, Notomys alexis, can maintain water balance without drinking water. The role of the kidney in producing a small volume of highly concentrated urine has been well-documented, but little is known about the physiological mechanisms underpinning the metabolic production of water to offset obligatory water loss. In Notomys, we found that water deprivation (WD) induced a sustained high food intake that exceeded the pre-deprivation level, which was driven by parallel changes in plasma leptin and ghrelin and the expression of orexigenic and anorectic neuropeptide genes in the hypothalamus; these changed in a direction that would stimulate appetite. As the period of WD was prolonged, body fat disappeared but body mass increased gradually, which was attributed to hepatic glycogen storage. Switching metabolic strategy from lipids to carbohydrates would enhance metabolic water production per oxygen molecule, thus providing a mechanism to minimize respiratory water loss. The changes observed in appetite control and metabolic strategy in Notomys were absent or less prominent in laboratory mice. This study reveals novel mechanisms for appetite regulation and energy metabolism that could be essential for desert rodents to survive in xeric environments.

Improved Production of a Heterologous Amylase in Saccharomyces cerevisiae by Inverse Metabolic Engineering

DEFF Research Database (Denmark)

Liu, Zihe; Liu, Lifang; Osterlund, Tobias

2014-01-01

this modification alone, the amylase secretion could be improved by 35%. As a complement to the identification of genomic variants, transcriptome analysis was also performed in order to understand on a global level the transcriptional changes associated with the improved amylase production caused by UV mutagenesis.......The increasing demand for industrial enzymes and biopharmaceutical proteins relies on robust production hosts with high protein yield and productivity. Being one of the best-studied model organisms and capable of performing posttranslational modifications, the yeast Saccharomyces cerevisiae...... is widely used as a cell factory for recombinant protein production. However, many recombinant proteins are produced at only 1% (or less) of the theoretical capacity due to the complexity of the secretory pathway, which has not been fully exploited. In this study, we applied the concept of inverse metabolic...

Effects of a propionic acid-based preservative on storage characteristics, nutritive value, and energy content for alfalfa hays packaged in large, round bales

Science.gov (United States)

During 2009 and 2010, alfalfa (Medicago sativa L.) hays from two cuttings that were harvested from the same field site were used to evaluate the effects of a propionic acid-based preservative on the storage characteristics and nutritive value of hays stored as large, round bales. A total of 87 large...

Unraveling and engineering the production of 23,24-bisnorcholenic steroids in sterol metabolism.

Science.gov (United States)

Xu, Li-Qin; Liu, Yong-Jun; Yao, Kang; Liu, Hao-Hao; Tao, Xin-Yi; Wang, Feng-Qing; Wei, Dong-Zhi

2016-02-22

The catabolism of sterols in mycobacteria is highly important due to its close relevance in the pathogenesis of pathogenic strains and the biotechnological applications of nonpathogenic strains for steroid synthesis. However, some key metabolic steps remain unknown. In this study, the hsd4A gene from Mycobacterium neoaurum ATCC 25795 was investigated. The encoded protein, Hsd4A, was characterized as a dual-function enzyme, with both 17β-hydroxysteroid dehydrogenase and β-hydroxyacyl-CoA dehydrogenase activities in vitro. Using a kshAs-null strain of M. neoaurum ATCC 25795 (NwIB-XII) as a model, Hsd4A was further confirmed to exert dual-function in sterol catabolism in vivo. The deletion of hsd4A in NwIB-XII resulted in the production of 23,24-bisnorcholenic steroids (HBCs), indicating that hsd4A plays a key role in sterol side-chain degradation. Therefore, two competing pathways, the AD and HBC pathways, were proposed for the side-chain degradation. The proposed HBC pathway has great value in illustrating the production mechanism of HBCs in sterol catabolism and in developing HBCs producing strains for industrial application via metabolic engineering. Through the combined modification of hsd4A and other genes, three HBCs producing strains were constructed that resulted in promising productivities of 0.127, 0.109 and 0.074 g/l/h, respectively.

Selective Hydrodeoxygenation of Alkyl Lactates to Alkyl Propionates with Fe-based Bimetallic Supported Catalysts

DEFF Research Database (Denmark)

Khokarale, Santosh Govind; He, Jian; Schill, Leonhard

2018-01-01

Hydrodeoxygenation (HDO) of methyl lactate (ML) to methyl propionate (MP) was performed with various base-metal supported catalysts. A high yield of 77 % MP was obtained with bimetallic Fe-Ni/ZrO2 in methanol at 220 °C and 50 bar H2 . A synergistic effect of Ni increased the yield of MP...... of the material. Interestingly, it was observed that Fe-Ni/ZrO2 also effectively catalyzed methanol reforming to produce H2 in situ, followed by HDO of ML, yielding 60 % MP at 220 °C with 50 bar N2 instead of H2. Fe-Ni/ZrO2 also catalyzed HDO of other short-chain alkyl lactates to the corresponding alkyl...

Reconstruction and in silico analysis of an Actinoplanes sp. SE50/110 genome-scale metabolic model for acarbose production

Directory of Open Access Journals (Sweden)

Yali eWang

2015-06-01

Full Text Available Actinoplanes sp. SE50/110 produces the -glucosidase inhibitor acarbose, which is used to treat type 2 diabetes mellitus. To obtain a comprehensive understanding of its cellular metabolism, a genome-scale metabolic model of strain SE50/110, iYLW1028, was reconstructed on the bases of the genome annotation, biochemical databases, and extensive literature mining. Model iYLW1028 comprises 1028 genes, 1128 metabolites and 1219 reactions. 122 and 81 genes were essential for cell growth on acarbose synthesis and sucrose media, respectively, and the acarbose biosynthetic pathway in SE50/110 was expounded completely. Based on model predictions, the addition of arginine and histidine to the media increased acarbose production by 78% and 59%, respectively. Additionally, dissolved oxygen has a great effect on acarbose production based on model predictions. Furthermore, genes to be overexpressed for the overproduction of acarbose were identified, and the deletion of treY eliminated the formation of by-product component C. Model iYLW1028 is a useful platform for optimizing and systems metabolic engineering for acarbose production in Actinoplanes sp. SE50/110.

Genetic and metabolic engineering for microbial production of poly-γ-glutamic acid.

Science.gov (United States)

Cao, Mingfeng; Feng, Jun; Sirisansaneeyakul, Sarote; Song, Cunjiang; Chisti, Yusuf

2018-05-28

Poly-γ-glutamic acid (γ-PGA) is a natural biopolymer of glutamic acid. The repeating units of γ-PGA may be derived exclusively from d-glutamic acid, or l-glutamic acid, or both. The monomer units are linked by amide bonds between the α-amino group and the γ-carboxylic acid group. γ-PGA is biodegradable, edible and water-soluble. It has numerous existing and emerging applications in processing of foods, medicines and cosmetics. This review focuses on microbial production of γ-PGA via genetically and metabolically engineered recombinant bacteria. Strategies for improving production of γ-PGA include modification of its biosynthesis pathway, enhancing the production of its precursor (glutamic acid), and preventing loss of the precursor to competing byproducts. These and other strategies are discussed. Heterologous synthesis of γ-PGA in industrial bacterial hosts that do not naturally produce γ-PGA is discussed. Emerging trends and the challenges affecting the production of γ-PGA are reviewed. Copyright © 2018. Published by Elsevier Inc.

Metabolic Engineering and Modeling of Metabolic Pathways to Improve Hydrogen Production by Photosynthetic Bacteria

Energy Technology Data Exchange (ETDEWEB)

Jiao, Y. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Navid, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2014-12-19

traits act as the biocatalysts of the process designed to both enhance the system efficiency of CO₂ fixation and the net hydrogen production rate. Additionally we applied metabolic engineering approaches guided by computational modeling for the chosen model microorganisms to enable efficient hydrogen production.

Metabolic Engineering of the Actinomycete Amycolatopsis sp. Strain ATCC 39116 towards Enhanced Production of Natural Vanillin

OpenAIRE

Fleige, Christian; Meyer, Florian; Steinbüchel, Alexander

2016-01-01

The Gram-positive bacterium Amycolatopsis sp. ATCC 39116 is used for the fermentative production of natural vanillin from ferulic acid on an industrial scale. The strain is known for its outstanding tolerance to this toxic product. In order to improve the productivity of the fermentation process, the strain's metabolism was engineered for higher final concentrations and molar yields. Degradation of vanillin could be decreased by more than 90% through deletion of the vdh gene, which codes for ...

LC–MS Proteomics Analysis of the Insulin/IGF-1-Deficient Caenorhabditis elegans daf-2(e1370) Mutant Reveals Extensive Restructuring of Intermediary Metabolism

Energy Technology Data Exchange (ETDEWEB)

Depuydt, Geert; Xie, Fang; Petyuk, Vladislav A.; Smolders, Arne; Brewer, Heather M.; Camp, David G.; Smith, Richard D.; Braeckman, Bart P.

2014-04-04

The insulin/IGF-1 receptor is a major known determinant of dauer formation, stress resistance, longevity, and metabolism in Caenorhabditis elegans. In the past, whole-genome transcript profiling was used extensively to study differential gene expression in response to reduced insulin/IGF-1 signaling, including the expression levels of metabolism-associated genes. Taking advantage of the recent developments in quantitative liquid chromatography mass spectrometry (LC–MS)-based proteomics, we profiled the proteomic changes that occur in response to activation of the DAF-16 transcription factor in the germline-less glp-4(bn2);daf-2(e1370) receptor mutant. Strikingly, the daf-2 profile suggests extensive reorganization of intermediary metabolism, characterized by the upregulation of many core intermediary metabolic pathways. These include glycolysis/gluconeogenesis, glycogenesis, pentose phosphate cycle, citric acid cycle, glyoxylate shunt, fatty acid β-oxidation, one-carbon metabolism, propionate and tyrosine catabolism, and complexes I, II, III, and V of the electron transport chain. Interestingly, we found simultaneous activation of reciprocally regulated metabolic pathways, which is indicative of spatiotemporal coordination of energy metabolism and/or extensive post-translational regulation of these enzymes. Finally, this restructuring of daf-2 metabolism is reminiscent to that of hypometabolic dauers, allowing the efficient and economical utilization of internal nutrient reserves and possibly also shunting metabolites through alternative energy-generating pathways to sustain longevity.

Studies on acetate, propionate and glucose utilization for milk fat and other milk components in buffalo and cows

International Nuclear Information System (INIS)

Wahal, C.K.; Varma, A.; Singh, U.B.; Ranjhan, S.K.

1974-01-01

Experiments were conducted on two lactating buffaloes and two lactating cows, to study the differences in the utilization of 14 C-acetate, 14 C-propionate and 3 H-glucose for the synthesis of milk fat, milk casein and milk lactalbumin. The animals were maintained on identical condition of feed. Single infusion technique was used throughout the course of investigation. Samples of milk were collected at different time intervals between 0 to 48 h and the radioactivity was determined in different milk fractions after separation. (author)

Studies on acetate, propionate and glucose utilization for milk fat and other milk components in buffalo and cows

Energy Technology Data Exchange (ETDEWEB)

Wahal, C K; Varma, A; Singh, U B; Ranjhan, S K [Indian Veterinary Research Inst., Izatnagar. Div. of Animal Nutrition

1974-12-01

Experiments were conducted on two lactating buffaloes and two lactating cows, to study the differences in the utilization of /sup 14/C-acetate, /sup 14/C-propionate and /sup 3/H-glucose for the synthesis of milk fat, milk casein and milk lactalbumin. The animals were maintained on identical condition of feed. Single infusion technique was used throughout the course of investigation. Samples of milk were collected at different time intervals between 0 to 48 h and the radioactivity was determined in different milk fractions after separation.

Heptadecanoylcarnitine (C17) a novel candidate biomarker for propionic and methylmalonic acidemias during expanded newborn screening

Science.gov (United States)

Malvagia, Sabrina; Haynes, Christopher A.; Grisotto, Laura; Ombrone, Daniela; Funghini, Silvia; Moretti, Elisa; McGreevy, Kathleen; Buggeri, Annibale; Guerrini, Renzo; Yahyaoui, Raquel; Garg, Uttam; Seeterlin, Mary; Chace, Donald; De Jesus, Victor; la Marca, Giancarlo

2017-01-01

Background 3-hydroxypalmitoleoyl-carnitine (C16:1-OH) was recently reported to be elevated in acylcarnitine profile of propionic acidemia (PA) or methylmalonic acidemia (MMA) patients during expanded newborn screening (NBS). High levels of C16:1-OH, combined with other hydroxylated long chain acylcarnitines are related to long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD). Methods The acylcarnitine profile of two LCHADD patients was evaluated using liquid chromatography-tandem mass spectrometric method. A specific retention time was reported for each hydroxylated long chain acylcarnitine. The same method was applied to some neonatal dried blood spots (DBS) from PA and MMA patients presenting abnormal C16:1-OH concentrations. Results The final retention time of the peak corresponding to C16:1-OH in LCHADD patients differed from those in MMA and PA patients. Heptadecanoylcarnitine (C17) has been identified as the novel biomarker specific for PA and MMA patients through high resolution mass spectrometry (Orbitrap) experiments. We found that 21 out of 23 neonates (22 MMA, and 1PA) diagnosed through the Tuscany region NBS program had significantly higher levels of C17 compared to levels detected in controls. Twenty-three maternal deficiencies (21 vitamin B12 deficiency, 1 homocystinuria and 1 gastrin deficiency) and 82 false positive for propionylcarnitine (C3) results were also analyzed. Conclusions This paper reports on the characterization of a novel biomarker able to detect propionate disorders during expanded newborn screening (NBS). The use of this new biomarker may improve the analytical performances of NBS programs especially in laboratories where second tier tests are not performed. PMID:26368264

Selected biomarkers as predictive tools in testing efficacy of melatonin and coenzyme Q on propionic acid - induced neurotoxicity in rodent model of autism.

Science.gov (United States)

Al-Ghamdi, Mashael; Al-Ayadhi, Laila; El-Ansary, Afaf

2014-02-25

Exposures to environmental toxins are now thought to contribute to the development of autism spectrum disorder. Propionic acid (PA) found as a metabolic product of gut bacteria has been reported to mimic/mediate the neurotoxic effects of autism. Results from animal studies may guide investigations on human populations toward identifying environmental contaminants that produce or drugs that protect from neurotoxicity. Forty-eight young male Western Albino rats were used in the present study. They were grouped into six equal groups 8 rats each. The first group received a neurotoxic dose of buffered PA (250 mg/Kg body weight/day for 3 consecutive days). The second group received only phosphate buffered saline (control group). The third and fourth groups were intoxicated with PA as described above followed by treatment with either coenzyme Q (4.5 mg/kg body weight) or melatonin (10 mg/kg body weight) for one week (therapeutically treated groups). The fifth and sixth groups were administered both compounds for one week prior to PA (protected groups). Heat shock protein70 (Hsp70), Gamma amino-butyric acid (GABA), serotonin, dopamine, oxytocin and interferon γ-inducible protein 16 together with Comet DNA assay were measured in brain tissues of the six studied groups. The obtained data showed that PA caused multiple signs of brain toxicity revealed in depletion of GABA, serotonin, and dopamine, are which important neurotransmitters that reflect brain function, interferon γ-inducible protein 16 and oxytocin. A high significant increase in tail length, tail DNA% damage and tail moment was reported indicating the genotoxic effect of PA. Administration of melatonin or coenzyme Q showed both protective and therapeutic effects on PA-treated rats demonstrated in a remarkable amelioration of most of the measured parameters. In conclusion, melatonin and coenzyme Q have potential protective and restorative effects against PA-induced brain injury, confirmed by improvement in

Development and scintigraphic evaluation of submicron sized dry powder inhalation formulation of fluticasone propionate in healthy human volunteers

International Nuclear Information System (INIS)

Ali, Sultana S.; Ahmad, F.J.; Khar, R.K.; Rathore, V.P.; Ali, Rashid; Rawat, H.S.; Chopra, M.K.; Mittal, G.; Bhatnagar, A.

2010-01-01

Full text: Objective of the present study concerns formulation and evaluation of submicron sized dry powder inhalation formulation of Fluticasone propionate for the treatment of bronchial asthma, COPD and a new life saving treatment option in restrictive lung diseases such as Interstitial Lung Disease (ILD), toxic and non-cardiogenic pulmonary inflammations or pulmonary edema, which have no effective treatment presently. Materials and Methods: The submicron sized particles were prepared by precipitation method using acetone as solvent and water as antisolvent. Poloxamer F127 was used as stabilizer. Both submicronized and micronized particles were characterized using FTIR, XRD, DSC, SEM and TEM. The mass median aerodynamic diameter (MMAD) of the submicronized and micronized API was calculated using Andersen cascade impactor. The prepared particles and micronized Active Pharmaceutical Ingredient (API) were radiolabeled with 99m Tc. Size3 HPMC capsules were filled with the 12.5 mg radiolabeled blend (100μg Fluticasone propionate and 12.4mg inhalable lactose) and given to healthy volunteers to assess the comparative pulmonary deposition. Results: The prepared formulation has shown better lung deposition as compared to micronized API. The MMAD of submicronized particles was in the range of 1 - 5 μm while the MMAD of micronized API was in the range of 5 - 15μm. Conclusion: The developed submicron sized dry powder inhalation formulation has better lung deposition as compared to micron sized API and it will become a better treatment option for the bronchial asthma, COPD and ILDs

Long-term stability of thermophilic co-digestion submerged anaerobic membrane reactor encountering high organic loading rate, persistent propionate and detectable hydrogen in biogas.

Science.gov (United States)

Qiao, Wei; Takayanagi, Kazuyuki; Niu, Qigui; Shofie, Mohammad; Li, Yu You

2013-12-01

The performance of thermophilic anaerobic co-digestion of coffee grounds and sludge using membrane reactor was investigated for 148 days, out of a total research duration of 263 days. The OLR was increased from 2.2 to 33.7 kg-COD/m(3)d and HRT was shortened from 70 to 7 days. A significant irreversible drop in pH confirmed the overload of reactor. Under a moderately high OLR of 23.6 kg-COD/m(3)d, and with HRT and influent total solids of 10 days and 150 g/L, respectively, the COD removal efficiency was 44.5%. Hydrogen in biogas was around 100-200 ppm, which resulted in the persistent propionate of 1.0-3.2g/L. The VFA consumed approximately 60% of the total alkalinity. NH4HCO3 was supplemented to maintain alkalinity. The stability of system relied on pH management under steady state. The 16SrDNA results showed that hydrogen-utilizing methanogens dominates the archaeal community. The propionate-oxidizing bacteria in bacterial community was insufficient. Copyright © 2013 Elsevier Ltd. All rights reserved.

Multi-omic profiling of EPO-producing Chinese hamster ovary cell panel reveals metabolic adaptation to heterologous protein production