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1

Acetic Acid Catalyzed Carbon Aerogels  

Microsoft Academic Search

We prepared carbon aerogels with a wide range of structural properties and densities using the weak acetic acid as a catalyst. Two series of acetic acid catalyzed carbon aerogels with different dilution of the catalyst and the monomers were investigated accurately. Structural investigation was performed via (U)SAXS, gas sorption and SEM. The pore and particle size can be tailored according

R. Brandt; R. Petricevic; H. Pröbstle; J. Fricke

2003-01-01

2

Acetic acid bacteria in oenology  

Microsoft Academic Search

Acetic acid bacteria have always been considered the bad mi- croorganisms of oenology; responsible for wine spoiling (vine- gary taint). The taxonomy and our knowledge of the metabo- lism of acetic acid bacteria are rapidly evolving, especially as new molecular biology techniques are applied to this fastidious group of microorganisms, which are still rather difficult to work with. The dramatic

A. Mas; M. J. Torija; A. González; M. Poblet; J. M. Guillamón

3

Acidbase interaction in the acetic acid-acetic anhydride system  

Microsoft Academic Search

1.The electroconductivity and dielectric permeability of the acetic acid-acetic anhydride system have been measured. The electroconductivity of the system has a maximum close to 50% of the anhydride. The curve of the dielectric permeability is concave toward the composition axis.2.The dependence of the electroconductivity on the composition is explained by the formation of a complex between acetic acid and acetic

V. E. Bel'skii; M. I. Vinnik

1963-01-01

4

Correlation between acetic acid resistance and characteristics of PQQ-dependent ADH in acetic acid bacteria  

Microsoft Academic Search

In this study, we compared the growth properties and molecular characteristics of pyrroloquinoline quinone (PQQ)-dependent alcohol dehydrogenase (ADH) among highly acetic acid-resistant strains of acetic acid bacteria. Ga. europaeus exhibited the highest resistance to acetic acid (10%), whereas Ga. intermedius and Acetobacter pasteurianus resisted up to 6% of acetic acid. In media with different concentrations of acetic acid, the maximal

Janja Trcek; Hirohide Toyama; Jerzy Czuba; Anna Misiewicz; Kazunobu Matsushita

2006-01-01

5

Conductance of Dilute Sodium Acetate Solutions to 469 K and of Acetic Acid and Sodium Acetate\\/Acetic Acid Mixtures to 548 K and 20 MPa  

Microsoft Academic Search

In order to obtain accurate association constants for sodium acetate, a very precise flow method was used to measure the electrical conductivity of dilute aqueous solutions of sodium acetate at ambient conditions and 469 K and 20 MPa. Measurements at ambient conditions, 469 and 548 K and 20 MPa, were also made on sodium acetate\\/acetic acid mixtures and acetic acid.

G. H. Zimmerman; R. H. Wood

2002-01-01

6

Electrically generated lead(IV) acetate and manganese(III) acetate as reagents for coulometric redox titrations in acetic acid  

Microsoft Academic Search

Summary The conditions were investigated for electrochemical generation of lead(IV) acetate in acetic acid by oxidation of lead(II) acetate on a lead dioxide electrode and on a platinum electrode. Bivalent manganese ions are quantitatively oxidized on a platinum electrode to the tervalent state in the same solvent. Coulometric titration methods for the determination of small amounts of hydroquinone in acetic

Tibor J. Pastor; Vilim J. Vajgand; Zorica Kicovic

1976-01-01

7

21 CFR 582.1005 - Acetic acid.  

Code of Federal Regulations, 2012 CFR

21 Food and Drugs 6 2012-04-01...2012-04-01 false Acetic acid. 582.1005 Section 582.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION...CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED... § 582.1005 Acetic acid. (a) Product....

2012-04-01

8

21 CFR 582.1005 - Acetic acid.  

Code of Federal Regulations, 2013 CFR

21 Food and Drugs 6 2013-04-01...2013-04-01 false Acetic acid. 582.1005 Section 582.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION...CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED... § 582.1005 Acetic acid. (a) Product....

2013-04-01

9

21 CFR 582.1005 - Acetic acid.  

Code of Federal Regulations, 2011 CFR

21 Food and Drugs 6 2011-04-01...2011-04-01 false Acetic acid. 582.1005 Section 582.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION...CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED... § 582.1005 Acetic acid. (a) Product....

2011-04-01

10

21 CFR 582.1005 - Acetic acid.  

Code of Federal Regulations, 2010 CFR

21 Food and Drugs 6 2010-04-01...2010-04-01 false Acetic acid. 582.1005 Section 582.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION...CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED... § 582.1005 Acetic acid. (a) Product....

2010-04-01

11

21 CFR 582.1005 - Acetic acid.  

21 Food and Drugs 6 2014-04-01...2014-04-01 false Acetic acid. 582.1005 Section 582.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION...CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED... § 582.1005 Acetic acid. (a) Product....

2014-04-01

12

Correlation between acetic acid resistance and characteristics of PQQ-dependent ADH in acetic acid bacteria.  

PubMed

In this study, we compared the growth properties and molecular characteristics of pyrroloquinoline quinone (PQQ)-dependent alcohol dehydrogenase (ADH) among highly acetic acid-resistant strains of acetic acid bacteria. Gluconacetobacter europaeus exhibited the highest resistance to acetic acid (10%), whereas Gluconacetobacter intermedius and Acetobacter pasteurianus resisted up to 6% of acetic acid. In media with different concentrations of acetic acid, the maximal acetic acid production rate of Ga. europaeus slowly increased, but specific growth rates decreased concomitant with increased concentration of acetic acid in medium. The lag phase of A. pasteurianus was twice and four times longer in comparison to the lag phases of Ga. europaeus and Ga. intermedius, respectively. PQQ-dependent ADH activity was twice as high in Ga. europaeus and Ga. intermedius as in A. pasteurinus. The purified enzymes showed almost the same specific activity to each other, but in the presence of acetic acid, the enzyme activity decreased faster in A. pasteurianus and Ga. intermedius than in Ga. europaeus. These results suggest that high ADH activity in the Ga. europaeus cells and high acetic acid stability of the purified enzyme represent two of the unique features that enable this species to grow and stay metabolically active at extremely high concentrations of acetic acid. PMID:16133326

Trcek, Janja; Toyama, Hirohide; Czuba, Jerzy; Misiewicz, Anna; Matsushita, Kazunobu

2006-04-01

13

Oxygen17 and proton nuclear magnetic resonance studies on acetic acid exchange processes of the chloride, nitrate, and acetate of nickel(II) in acetic acid  

Microsoft Academic Search

The exchange rates of acetic acid coordinating to nickel(II) chloride, nickel(II) nitrate, and nickel(II) acetate in neat acetic acid and acetic acid\\/dichloromethane-d2 mixtures were measured by the oxygen-17 and proton NMR line-broadening methods. The activation parameters for the acetic acid exchange on these nickel(II) salts were independent of the concentration of acetic acid (HOAc) in the mixed solvents. The first-order

A. Hioki; S. Funahashi; M. Tanaka

1985-01-01

14

Acetic acid fermentation of acetobacter pasteurianus: relationship between acetic acid resistance and pellicle polysaccharide formation.  

PubMed

Acetobacter pasteurianus strains IFO3283, SKU1108, and MSU10 were grown under acetic acid fermentation conditions, and their growth behavior was examined together with their capacity for acetic acid resistance and pellicle formation. In the fermentation process, the cells became aggregated and covered by amorphous materials in the late-log and stationary phases, but dispersed again in the second growth phase (due to overoxidation). The morphological change in the cells was accompanied by changes in sugar contents, which might be related to pellicle polysaccharide formation. To determine the relationship between pellicle formation and acetic acid resistance, a pellicle-forming R strain and a non-forming S strain were isolated, and their fermentation ability and acetic acid diffusion activity were compared. The results suggest that pellicle formation is directly related to acetic acid resistance ability, and thus is important to acetic acid fermentation in these A. pasteurianus strains. PMID:20699583

Kanchanarach, Watchara; Theeragool, Gunjana; Inoue, Taketo; Yakushi, Toshiharu; Adachi, Osao; Matsushita, Kazunobu

2010-01-01

15

Anodically generated cobalt(III) acetate as reagent for coulometric titrations in acetic acid  

Microsoft Academic Search

Summary Conditions for the anodic generation of cobalt(III) acetate with high current efficiency in non-aqueous solutions of potassium acetate in acetic acid have been investigated. The presence of water or acetic anhydride in the anolyte diminishes the amount of the generated oxidant. The stability of the generated cobalt(III) acetate solution is decreased in the presence of water and at elevated

T. J. Pastor; I. ?iri?

1985-01-01

16

Acetic acid mediated interactions between alumina surfaces  

NASA Astrophysics Data System (ADS)

Low-molecular-weight organic acids have been known to modify colloidal stability of alumina-based suspensions. We investigated interaction forces between alumina surfaces mediated by acetic acid which is one of the simplest organic acids. Forces between alumina surfaces were measured using the colloid-probe method of atomic force microscope (AFM). Repulsive forces attributed to steric repulsion due to adsorbed molecules and electrostatic repulsion dominated the interaction. Results of rheological characterization of the alumina slurry containing acetic acid supported the finding.

Sato, Kimiyasu; Y?lmaz, Hüseyin; Ijuin, Atsuko; Hotta, Yuji; Watari, Koji

2012-02-01

17

DEOXYRIBONUCLEIC ACID HYBRIDS OF ACETIC ACID BACTERIA  

PubMed Central

De Ley, J. (State University, Ghent, Belgium), and S. Friedman. Deoxyribonucleic acid hybrids of acetic acid bacteria. J. Bacteriol. 88:937–945. 1964.—Deuterated N15-labeled deoxyribonucleic acid (DNA) from Acetobacter aceti (mesoxydans 4) forms hybrids with ordinary DNA from other species of this genus (A. xylinum, A. pasteurianus, A. estunensis, and possibly A. xylinoides) when the guanine plus cytosine base composition does not vary by more than 1 to 2%. Beyond this limit (A. aceti Ch31 and A. muciparus 5) no hybrids are formed. The hybrids are apparently derived from an asymmetrical part of the compositional distribution. The results lend strength to the concept of a genetic species rather than to a division of a genus into sharply separated species, based on small phenotypic differences. Taxonomic implications are discussed. PMID:14219057

De Ley, J.; Friedman, S.

1964-01-01

18

Strengths of the Chloro-acetic Acids  

Microsoft Academic Search

IT is well known that the introduction of chlorine atoms into acetic acid causes a rapid rise of dissociation constant (see ). If changes in the value of K are taken as a measure of the effect of the chlorine atoms, it would appear that the second chlorine atom has a greater effect than the first, and the third a

John Shorter; F. J. Stubbs

1949-01-01

19

Solid–liquid equilibrium in the acetic acid–acetophenone and acetic acid–formamide systems  

Microsoft Academic Search

Solid–liquid equilibrium in the binary systems acetic acid–acetophenone and acetic acid–formamide was determined from time–temperature cooling and warming curves. The first system shows a sagged curve with a eutectic point at x1?0.6 and T=267.18 K. In the second system a solid compound (2:1) was found and an equilibrium constant of the compound dissociation was calculated.

I. Malijevská; Z. Sedláková

2006-01-01

20

The behaviour of tungsten electrodes in a mixture of acetic acid and acetic anhydride  

Microsoft Academic Search

Summary Tungsten electrodes have advantageously been used for potentiometric end-point detection in perchloric acid titration of bases in a mixture of acetic acid and acetic anhydride. They have also given good results in biamperometric detection of the equivalence point in continuous coulometric titration of small quantities of bases and acids in the same solvent. Tungsten electrodes in the presence of

Tibor J. Pastor; Vilim J. Vajgand

1976-01-01

21

Polypyrrole based strong acid catalyst for acetalization  

NASA Astrophysics Data System (ADS)

Novel polypyrrole based acid catalyst has been synthesized through the neutralization reaction of polypyrrole and sulfuric acid. The polypyrrole based acid owned the acidity as high as 6.0 mmol/g, which was much higher than that of the traditional solid acids such as Nafion and Amberlyst-15 (0.8 mmol/g). The catalytic activities of the novel solid acid were investigated through the acetalization. The results showed that the novel solid acid held high activities for the reactions. Furthermore, the recycled activities of the catalyst indicated that the solid acid owned high stability during the catalytic process and little acid sites dropped from polypyrrole. The high acidity and stability made the novel polypyrrole based acid hold great potential for the green chemical processes.

Liang, Xuezheng; Cheng, Yuxiao; Qi, Chenze

2011-09-01

22

Separating acetic acid from furol (furfural) by electrodialysis method  

SciTech Connect

Furfural production by hydrolysis of fibrous plant materials is accompanied by formation of acetic acid in amounts depending on the material used. The amount of acetic formed in the hydrolysis of the fruit shell of oil-tea camellia (Camellia oleosa) (an oilseed-bearing tree) is equal to the amount of furfural. The acetic acid can be separated from the furfural and concentrated to 10% by electrodialysis. A smaller amount of furfural is separated with acetic acid.

Guan, S.F.; Li, C.S. Ye, S.T.; Shen, S.Y.; Wang, Y.T.; Yu, S.H.

1981-01-01

23

Development of an Amperometric Acetic Acid Sensor in Organic System  

Microsoft Academic Search

An amperometric method was developed by using a lead working electrode in acetonitrile organic solution for detecting acetic acid. The mechanisms of electrochemical reaction were corresponding to the reduction of acetic ions in acetonitrile organic solution. The steady state amperometric current resulted from the reduction of acetic ions to produce the aldehyde in a two-electron process. In the organic sensing

Shin Lin; Tse-Chuan Chou

24

Oxidation of indole-3-acetic acid to oxindole-3-acetic acid by an enzyme preparation from Zea mays  

NASA Technical Reports Server (NTRS)

Indole-3-acetic acid is oxidized to oxindole-3-acetic acid by Zea mays tissue extracts. Shoot, root, and endosperm tissues have enzyme activities of 1 to 10 picomoles per hour per milligram protein. The enzyme is heat labile, is soluble, and requires oxygen for activity. Cofactors of mixed function oxygenase, peroxidase, and intermolecular dioxygenase are not stimulatory to enzymic activity. A heat-stable, detergent-extractable component from corn enhances enzyme activity 6- to 10-fold. This is the first demonstration of the in vitro enzymic oxidation of indole-3-acetic acid to oxindole-3-acetic acid in higher plants.

Reinecke, D. M.; Bandurski, R. S.

1988-01-01

25

Solid–liquid equilibrium in the acetic acid–cyclohexane and acetic acid–trichloroacetic acid systems  

Microsoft Academic Search

Solid–liquid equilibrium in the binary systems acetic acid–cyclohexane and acetic acid–trichloroacetic acid was determined from time–temperature cooling and heating curves. The first system shows an eutectic point at x1?0.08 and T=271.9K. In the second system, a solid compound (1:1) was found and an equilibrium constant of the compound dissociation was calculated.

I Malijevská

2003-01-01

26

Addition of acetic acid to styrene catalyzed by ion exchanger  

Microsoft Academic Search

The possibility of preparation of 1-phenylethyl acetate by direct addition of acetic acid to styrene catalyzed by Ostion KS in the acid cycle has been investigated. The reaction is accompanied by the formation of higher molecular compounds. The effect of temperature, mole ratio of the starting compounds, stabilization of styrene, amount of the catalyst and of its repeated use on

L. ?ervený; A. Marhoul; J. Kozel

1988-01-01

27

Characterization of acetic acid bacteria in “traditional balsamic vinegar”  

Microsoft Academic Search

This study evaluated the glucose tolerance of acetic acid bacteria strains isolated from Traditional Balsamic Vinegar. The results showed that the greatest hurdle to acetic acid bacteria growth is the high sugar concentration, since the majority of the isolated strains are inhibited by 25% of glucose. Sugar tolerance is an important technological trait because Traditional Balsamic Vinegar is made with

Maria Gullo; Cinzia Caggia; Luciana De Vero; Paolo Giudici

2006-01-01

28

Cellulose production by acetic acid-resistant Acetobacter xylinum  

Microsoft Academic Search

A bacterium that could produce a gelatinous cellulosic pellicle in the presence of more than 2% acetic acid was isolated as a contaminant in a continuous surface culture for acetic acid production using Acetobacter aceti. The bacterium was identified as a strain belonging to Acetobacter xylinum and designated as strain DA. The production of cellulose in a static culture of

Kiyoshi Toda; Tomoko Asakura; Masahiro Fukaya; Etsuzo Entani; Yoshiya Kawamura

1997-01-01

29

Cathodic Hydrogen Evolution from Aqueous Solutions of Acetic Acid  

Microsoft Academic Search

In continuation of the work on establishing hydrogen donors in the hydrogen evolution reaction from different acid molecules, cathodic evolution of hydrogen on silver is investigated from solutions of monobasic acetic acid with the aim to establish the origin of reduced hydrogen. Solutions of 0.2 M acetic acid with 0.2 M perchloric acid, neutralized to different pH values by NaOH,

V. Marinovi?; A. R. Despi?

2004-01-01

30

Thermal decomposition of pyridine-substituted cobaltic acetate in acetic acid.  

PubMed

The thermal decomposition of [py(3)Co(3)O(OAc)(5)OH][PF(6)] in acetic acid solution in the absence of oxygen produced carbon dioxide, methane, carbon monoxide, picoline, and formic acid as the major products. The ratio of the products was affected by the water concentration and acidity of the mixture. Increased water concentration caused a decrease in methane and an increase in carbon monoxide. Decreased acidity resulted in an increase in methane and a decrease in carbon monoxide. Isotopic labeling experiments showed that some of the carbon monoxide originated as the carboxyl group of the acetic acid. Labeling experiments also showed that formaldehyde and formic acid could be converted to carbon monoxide under the reaction conditions. Two pathways leading to the formation of carbon monoxide were proposed; one involving the decomposition of glyoxylic acid and another involving the oxidation of the methyl radical by cobalt(III). PMID:20397646

Sumner, Charles E; Little, James; Howard, Adam S; Liang, Weimin C

2010-05-17

31

The antibacterial activity and stability of acetic acid.  

PubMed

Acetic acid has been shown to have good antibacterial activity against micro-organisms such as Pseudomonas aeruginosa. This study examined the activity against a range of bacterial pathogens and also assessed any reduction in antibacterial activity due to evaporation or inactivation by organic material in dressings. Acetic acid was active at dilutions as low as 0.166% and the activity was not reduced by evaporation nor by inactivation by cotton swabs. Burn injuries are a major problem in countries with limited resources. Acetic acid is an ideal candidate for use in patients who are treated in those parts of the world. PMID:23747099

Fraise, A P; Wilkinson, M A C; Bradley, C R; Oppenheim, B; Moiemen, N

2013-08-01

32

SOLVENT EXTRACTION OF WASTEWATERS FROM ACETIC-ACID MANUFACTURE  

EPA Science Inventory

Solvent extraction was evaluated as a potential treatment method for wastewaters generated during the manufacture of acetic acid. Possible goals for an extraction process were considered. For the wastewater samples studied, extraction appeared to be too expensive to be practical ...

33

Origin and fate of acetate in an acidic fen.  

PubMed

Acetate is a central intermediate in the anaerobic degradation of organic matter, and the resolution of its metabolism necessitates integrated strategies. This study aims to (1) estimate the contribution of acetogenesis to acetate formation in an acidic fen (pH ~ 4.9), (2) assess the genetic potential for acetogenesis targeting the fhs gene encoding formyltetrahydrofolate synthetase (FTHFS) and (3) unravel the in situ turnover of acetate using stable carbon isotope pore-water analysis. H(2)/CO(2)-supplemented peat microcosms yielded (13)C-depleted acetate (-37.2‰ vs. VPDB (Vienna Peedee belemnite standard) compared with -14.2‰ vs. VPDB in an unamended control), indicating the potential for H(2)-dependent acetogenesis. Molecular analysis revealed a high diversity and depth-dependent distribution of fhs phylotypes with the highest number of operational taxonomic units in 0-20 cm depth, but only few and distant relationships to known acetogens. In pore waters, acetate concentrations (0-170 ?M) and ?(13)C-values varied widely (-17.4‰ to -3.4‰ vs. VPDB) and did not indicate acetogenesis, but pointed to a predominance of sinks, which preferentially consumed (12)C-acetate, like acetoclastic methanogenesis. However, depth profiles of methane and ?(13)C(CH4) revealed a temporarily and spatially restricted role of this acetate sink and suggest other processes like sulfate and iron reduction played an important role in acetate turnover. PMID:22404042

Hädrich, Anke; Heuer, Verena B; Herrmann, Martina; Hinrichs, Kai-Uwe; Küsel, Kirsten

2012-08-01

34

Proteome analysis of Acetobacter pasteurianus during acetic acid fermentation.  

PubMed

Acetic acid bacteria (AAB) are Gram-negative, strictly aerobic microorganisms that show a unique resistance to ethanol (EtOH) and acetic acid (AcH). Members of the Acetobacter and Gluconacetobacter genera are capable of transforming EtOH into AcH via the alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) enzymes and are used for the industrial production of vinegar. Several mechanisms have been proposed to explain how AAB resist high concentrations of AcH, such as the assimilation of acetate through the tricarboxylic acid (TCA) cycle, the export of acetate by various transporters and modifications of the outer membrane. However, except for a few acetate-specific proteins, little is known about the global proteome responses to AcH. In this study, we used 2D-DIGE to compare the proteome of Acetobacter pasteurianus LMG 1262(T) when growing in glucose or ethanol and in the presence of acetic acid. Interesting protein spots were selected using the ANOVA p-value of 0.05 as threshold and 1.5-fold as the minimal level of differential expression, and a total of 53 proteins were successfully identified. Additionally, the size of AAB was reduced by approximately 30% in length as a consequence of the acidity. A modification in the membrane polysaccharides was also revealed by PATAg specific staining. PMID:22155126

Andrés-Barrao, Cristina; Saad, Maged M; Chappuis, Marie-Louise; Boffa, Mauro; Perret, Xavier; Ortega Pérez, Ruben; Barja, François

2012-03-16

35

Phase and reaction equilibria of acetic acid–1-pentanol–water– n-amyl acetate system at 760 mm Hg  

Microsoft Academic Search

The esterification reaction of acetic acid and alcohol is one of the processes applying reactive distillation technology. It is known that the thermodynamic properties are essential to chemical process design. In this study, the thermodynamic behaviors of vapor–liquid equilibrium (VLE) and reaction equilibrium of acetic acid, 1-pentanol, n-amyl acetate, and water mixture were determined experimentally. Since the present esterification reaction

Liang-sun Lee; Shen-jang Liang

1998-01-01

36

Tetrazole acetic acid: tautomers, conformers, and isomerization.  

PubMed

Monomers of (tetrazol-5-yl)-acetic acid (TAA) were obtained by sublimation of the crystalline compound and the resulting vapors were isolated in cryogenic nitrogen matrices at 13 K. The conformational and tautomeric composition of TAA in the matrix was characterized by infrared spectroscopy and vibrational calculations carried out at the B3LYP/6-311++G(d,p) level. TAA may adopt two tautomeric modifications, 1H- and 2H-, depending on the position of the annular hydrogen atom. Two-dimensional potential energy surfaces (PESs) of TAA were theoretically calculated at the MP2/6-311++G(d,p) level, for each tautomer. Four and six symmetry-unique minima were located on these PESs, for 1H- and 2H-TAA, respectively. The energetics of the detected minima was subsequently refined by calculations at the QCISD level. Two 1H- and three 2H-conformers fall within the 0-8 kJ mol(-1) energy range and should be appreciably populated at the sublimation temperature (?330 K). Observation of only one conformer for each tautomer (1ccc and 2pcc) is explained in terms of calculated barriers to conformational rearrangements. All conformers with the cis O=COH moiety are separated by low barriers (less than 10 kJ mol(-1)) and collapse to the most stable 1ccc (1H-) and 2pcc (2H-) forms during deposition of the matrix. On the trans O=COH surfaces, the relative energies are very high (between 12 and 27 kJ mol(-1)). The trans forms are not thermally populated at the sublimation conditions and were not detected in matrices. One high-energy form in each tautomer, 1cct (1H-) and 2pct (2H-), was found to differ from the most stable form only by rotation of the OH group and separated from other forms by high barriers. This opened a perspective for their stabilization in a matrix. 1cct and 2pct were generated in the matrices selectively by means of narrow-band near-infrared (NIR) irradiations of the samples at 6920 and 6937 cm(-1), where the first OH stretching overtone vibrations of 1ccc and 2pcc occur. The reverse transformations could be induced by irradiations at 7010 and 7030 cm(-1), transforming 1cct and 2pct back to 1ccc and 2pcc, also selectively. Besides the NIR-induced transformations, the photogenerated 1cct and 2pct forms also decay in N2 matrices back to 1ccc and 2pcc spontaneously, with characteristic decay times of hours (1H) and tens of minutes (2H). The decay mechanism is rationalized in terms of the proton tunneling. In crystals, TAA exists exclusively as 1H-tautomer. By contrast, the tautomeric composition of the matrix-isolated monomers was found to consist of both 1H- and 2H-tautomers, in comparable amounts. A mechanistic discussion of the tautomerization process occurring during sublimation, accounting also for the observed minor decomposition of TAA leading to CO2 and 5-methyl-tetrazole, is proposed. PMID:24527914

Araujo-Andrade, C; Reva, I; Fausto, R

2014-02-14

37

Tetrazole acetic acid: Tautomers, conformers, and isomerization  

NASA Astrophysics Data System (ADS)

Monomers of (tetrazol-5-yl)-acetic acid (TAA) were obtained by sublimation of the crystalline compound and the resulting vapors were isolated in cryogenic nitrogen matrices at 13 K. The conformational and tautomeric composition of TAA in the matrix was characterized by infrared spectroscopy and vibrational calculations carried out at the B3LYP/6-311++G(d,p) level. TAA may adopt two tautomeric modifications, 1H- and 2H-, depending on the position of the annular hydrogen atom. Two-dimensional potential energy surfaces (PESs) of TAA were theoretically calculated at the MP2/6-311++G(d,p) level, for each tautomer. Four and six symmetry-unique minima were located on these PESs, for 1H- and 2H-TAA, respectively. The energetics of the detected minima was subsequently refined by calculations at the QCISD level. Two 1H- and three 2H-conformers fall within the 0-8 kJ mol-1 energy range and should be appreciably populated at the sublimation temperature (˜330 K). Observation of only one conformer for each tautomer (1ccc and 2pcc) is explained in terms of calculated barriers to conformational rearrangements. All conformers with the cis O=COH moiety are separated by low barriers (less than 10 kJ mol-1) and collapse to the most stable 1ccc (1H-) and 2pcc (2H-) forms during deposition of the matrix. On the trans O=COH surfaces, the relative energies are very high (between 12 and 27 kJ mol-1). The trans forms are not thermally populated at the sublimation conditions and were not detected in matrices. One high-energy form in each tautomer, 1cct (1H-) and 2pct (2H-), was found to differ from the most stable form only by rotation of the OH group and separated from other forms by high barriers. This opened a perspective for their stabilization in a matrix. 1cct and 2pct were generated in the matrices selectively by means of narrow-band near-infrared (NIR) irradiations of the samples at 6920 and 6937 cm-1, where the first OH stretching overtone vibrations of 1ccc and 2pcc occur. The reverse transformations could be induced by irradiations at 7010 and 7030 cm-1, transforming 1cct and 2pct back to 1ccc and 2pcc, also selectively. Besides the NIR-induced transformations, the photogenerated 1cct and 2pct forms also decay in N2 matrices back to 1ccc and 2pcc spontaneously, with characteristic decay times of hours (1H) and tens of minutes (2H). The decay mechanism is rationalized in terms of the proton tunneling. In crystals, TAA exists exclusively as 1H-tautomer. By contrast, the tautomeric composition of the matrix-isolated monomers was found to consist of both 1H- and 2H-tautomers, in comparable amounts. A mechanistic discussion of the tautomerization process occurring during sublimation, accounting also for the observed minor decomposition of TAA leading to CO2 and 5-methyl-tetrazole, is proposed.

Araujo-Andrade, C.; Reva, I.; Fausto, R.

2014-02-01

38

Theoretical studies of molecular structure and vibrational spectra of melaminium acetate acetic acid solvate monohydrate.  

PubMed

The molecular geometry and vibrational frequencies of melaminium acetate acetic acid solvate monohydrate in the ground state have been calculated by using the Hartree-Fock (HF) and density functional method (B3LYP) with 6-31++G(d,p) basis set. The results of the optimized molecular structure are presented and compared with the experimental X-ray diffraction. The molecule contains the weak hydrogen bonds of N-H...O and O-H...O types, and those bonds are calculated with HF and DFT method. The computed vibrational frequencies were used to determine the types of molecular motions associated with each of the experimental bands observed. In addition, calculated results are related to the linear correlation plot of computed data versus experimental geometric parameters and IR data. PMID:20692201

Pekparlak, A; Avci, D; Cömert, H; Atalay, Y

2010-10-15

39

Asymmetric Hydrogenation of Itaconic Acid and Enol Acetate Derivatives with  

E-print Network

. A variety of chiral 2-substituted succinic acids and chiral acetates have been obtained in excellent ee efficient synthesis of chiral R-amino acids via transition metal-catalyzed asymmetric hydrogenation has become one of most efficient methods for the synthesis of chiral R-amino acids, chiral -amino

Zhang, Xumu

40

Atomic and electronic structure of acetic acid on Ge(100) Do Hwan Kim a,b  

E-print Network

Atomic and electronic structure of acetic acid on Ge(100) Do Hwan Kim a,b , Eunkyung Hwang to investigate the atomic and electronic structure of acetic acid adsorbed on Ge(100) surface. Due to its acidity, acetic acid dissociates and the resulting electron-rich acetate group reacts with the electron

Kim, Sehun

41

Bacterial utilization of formic and acetic acid in rainwater  

NASA Astrophysics Data System (ADS)

Rain samples were collected aseptically, during 1983 and 1984, in Charlottesville, Virginia to determine the ability of bacteria in precipitation to utilize formate and acetate. The total number of bacteria, as counted by Acridine Orange Direct Counts, was one to two orders of magnitude greater from April to September (10 5 cells ml -1) than during the rest of the year (10 3-10 4 cells ml -1). Formate and acetate concentrations ranged between 6-23 and 3-9 ?M, respectively and were higher from June to September. Heterotrophic uptake on the day of collection was not different from the controls, but after incubation at room temperature for a minimum of three days, the turnover rate constants were 0.14 and 0.17 h -1 for formate and acetate, respectively. Total bacterial counts increased an order of magnitude during that interval. These turnover rate constants were used to calculate losses of 44 and 24 ?moll-1day-1 of formic and acetic acid, respectively. Turnover times were 1.5 and 34 days for formate and acetate, respectively. This study demonstrated that there are viable microorganisms in the atmosphere capable of utilizing formate and acetate for growth.

Herlihy, Linda Jolley; Galloway, James N.; Mills, Aaron L.

42

Selective extraction of succinic acid from binary mixture of succinic acid and acetic acid  

Microsoft Academic Search

In production of succinic acid by fermentation, succinic acid and acetic acid are co-produced. To purify the succinic acid from binary-acid mixture of succinic acid and acetic acid, the tertiary amine-based extraction was used. In 1-octanol, the selectivity for succinic acid was proportional to the chain length of tertiary amine. But, the distribution of acids into organic phase was low

Yeon Ki Hong; Won Hi Hong; Ho Nam Chang

2000-01-01

43

Characterization of acetic acid bacteria in "traditional balsamic vinegar".  

PubMed

This study evaluated the glucose tolerance of acetic acid bacteria strains isolated from Traditional Balsamic Vinegar. The results showed that the greatest hurdle to acetic acid bacteria growth is the high sugar concentration, since the majority of the isolated strains are inhibited by 25% of glucose. Sugar tolerance is an important technological trait because Traditional Balsamic Vinegar is made with concentrated cooked must. On the contrary, ethanol concentration of the cooked and fermented must is less significant for acetic acid bacteria growth. A tentative identification of the isolated strains was done by 16S-23S-5S rDNA PCR/RFLP technique and the isolated strains were clustered: 32 strains belong to Gluconacetobacter xylinus group, two strains to Acetobacter pasteurianus group and one to Acetobacter aceti. PMID:16214251

Gullo, Maria; Caggia, Cinzia; De Vero, Luciana; Giudici, Paolo

2006-02-01

44

(Conversion of acetic acid to methane by thermophiles: Progress report)  

SciTech Connect

The objective of this project is to provide an understanding of thermophilic anaerobic microorganisms capable of breaking down acetic acid, the precursor of two-thirds of the methane produced by anaerobic bioreactors. Recent results include: (1) the isolation of Methanothrix strain CALLS-1, which grows much more rapidly than mesophilic strains; (2) the demonstration that thermophilic cultures of Methanosarcina and Methanothrix show minimum thresholds for acetate utilization of 1--2.5 mM and 10--20{mu}m respectively, in agreement with ecological data indicating that Methanothrix is favored by low acetate concentration; (3) the demonstration of high levels of thermostable acetyl-coA synthetase and carbon monoxide dehydrogenase in cell-free extracts of Methanothrix strains CALS-1; (4) the demonstration of methanogenesis from acetate and ATP in cell free extracts of strain CALS-1. (5) the demonstration that methanogenesis from acetate required 2 ATP/methane, and, in contrast to Methanosarcina, was independent of hydrogen and other electron donors; (6) the finding that entropy effects must be considered when predicting the level of hydrogen in thermophilic syntrophic cultures. (7) the isolation and characterization of the Desulfotomaculum thermoacetoxidans. Current research is centered on factors which allow thermophilic Methanothrix to compete with Methanosarcina.

Zinder, S.

1991-01-01

45

[Conversion of acetic acid to methane by thermophiles: Progress report  

SciTech Connect

The objective of this project is to provide an understanding of thermophilic anaerobic microorganisms capable of breaking down acetic acid, the precursor of two-thirds of the methane produced by anaerobic bioreactors. Recent results include: (1) the isolation of Methanothrix strain CALLS-1, which grows much more rapidly than mesophilic strains; (2) the demonstration that thermophilic cultures of Methanosarcina and Methanothrix show minimum thresholds for acetate utilization of 1--2.5 mM and 10--20{mu}m respectively, in agreement with ecological data indicating that Methanothrix is favored by low acetate concentration; (3) the demonstration of high levels of thermostable acetyl-coA synthetase and carbon monoxide dehydrogenase in cell-free extracts of Methanothrix strains CALS-1; (4) the demonstration of methanogenesis from acetate and ATP in cell free extracts of strain CALS-1. (5) the demonstration that methanogenesis from acetate required 2 ATP/methane, and, in contrast to Methanosarcina, was independent of hydrogen and other electron donors; (6) the finding that entropy effects must be considered when predicting the level of hydrogen in thermophilic syntrophic cultures. (7) the isolation and characterization of the Desulfotomaculum thermoacetoxidans. Current research is centered on factors which allow thermophilic Methanothrix to compete with Methanosarcina.

Zinder, S.

1991-12-31

46

[Conversion of acetic acid to methane by thermophiles  

SciTech Connect

The primary goal of this project is to obtain a better understanding of thermophilic microorganisms which convert acetic acid to CH[sub 4]. The previous funding period represents a departure from earlier research in this laboratory, which was more physiological and ecological. The present work is centered on the biochemistry of the thermophile Methanothrix sp. strain CALS-1. this organism presents a unique opportunity, with its purity and relatively rapid growth, to do comparative biochemical studies with the other major acetotrophic genus Methanosarcina. We previously found that Methanothrix is capable of using acetate at concentrations 100 fold lower than Methanosarcina. This finding suggests that there are significant differences in the pathways of methanogenesis from acetate in the two genera.

Zinder, S.H.

1993-01-01

47

Hydrogen bonding of hydrates of double acetic acid molecules.  

PubMed

In the chemical industry, the separation of the acetic acid from the HAc/H(2)O system is always influenced by the hydrogen bonding. In the present work, an investigation on the hydrogen bonding of various hydrates of double acetic acid (HAc) molecules is carried out with two first-principle methods including ab initio molecular dynamics (AIMD) simulation and quantum chemical calculations (QCC). From the AIMD simulation, the distribution of the head-on rings of acetic acid is revealed and shows that the favorable structures tend to be the acetic acid hydrates rather than the HAc cyclic dimer. The 6- and 10-membered head-on rings involving single and double HAc molecules, respectively, appear to be the dominant structures. According to the QCC, the most stable structure is found to be the conformer with the biggest head-on ring in each group. The energetics of the rings indicates that the stability of the ring increases with increased ring size (with the exception of the 9-membered ring), and the 10-membered ring is the most stable. The relative stability of the ring structures implied by the static QCC result is in good agreement with the statistical ring distribution of the AIMD simulation. PMID:19462952

Pu, Liang; Sun, Yueming; Zhang, Zhibing

2009-06-18

48

Original article Effect of 1-naphthalene acetic acid concentrations and  

E-print Network

) Abstract - Field experiments were performed in two successive seasons at the Experimental Station, Faculty.). Cotton plants were sprayed with the growth regulator 1-naphthalene acetic acid (NAA) once (90 days after planting (DAP)), or twice (90 and 105 DAP) or three times (90, 105 and 120 DAP), during the square

Paris-Sud XI, Université de

49

Effects of acetic acid on light scattering from cells  

PubMed Central

Abstract. Acetic acid has been used for decades as an aid for the detection of precancerous cervical lesions, and the use of acetic acid is being investigated in several other tissues. Nonetheless, the mechanism of acetowhitening is unclear. This work tests some of the hypotheses in the literature and measures changes in light scattering specific to the nucleus and the cytoplasm. Wide angle side scattering from both the nucleus and the cytoplasm increases with acetic application to tumorigenic cells, with the increase in nuclear scattering being greater. In one cell line, the changes in nuclear scattering are likely due to an increase in number or scattering efficiency of scattering centers smaller than the wavelength of excitation light. There are likely several cellular changes that cause acetowhitening and the cellular changes may differ with cell type. These results should lead to a better understanding of acetowhitening and potentially the development of adjunct techniques to improve the utility of acetic acid application. For the well-studied case of cervical tissue, acetowhitening has been shown to be sensitive, but not specific for oncogenic changes needing treatment. PMID:23224185

Marina, Oana C.; Sanders, Claire K.; Mourant, Judith R.

2012-01-01

50

Effect of Acetic Acid on the Oxidation of Ascorbic Acid in Fruits and Vegetables  

Microsoft Academic Search

IT has been established by earlier investigators that acetic acid has a destructive effect on the ascorbic acid in raw cabbage. This effect is somewhat surprising, since the lower the pH in the medium, the more stable is the ascorbic acid and, therefore, one would expect the acetic acid to have a preservative effect on the ascorbic acid in cabbage.

F. Alm

1952-01-01

51

21 CFR 184.1005 - Acetic acid.  

Code of Federal Regulations, 2012 CFR

...64-19-7) is known as ethanoic acid. It occurs naturally in plant and animal tissues. It is produced by fermentation of carbohydrates or by organic synthesis. The principal synthetic methods currently employed are oxidation of acetaldehyde derived...

2012-04-01

52

21 CFR 184.1005 - Acetic acid.  

Code of Federal Regulations, 2013 CFR

...64-19-7) is known as ethanoic acid. It occurs naturally in plant and animal tissues. It is produced by fermentation of carbohydrates or by organic synthesis. The principal synthetic methods currently employed are oxidation of acetaldehyde derived...

2013-04-01

53

21 CFR 184.1005 - Acetic acid.  

Code of Federal Regulations, 2011 CFR

...64-19-7) is known as ethanoic acid. It occurs naturally in plant and animal tissues. It is produced by fermentation of carbohydrates or by organic synthesis. The principal synthetic methods currently employed are oxidation of acetaldehyde derived...

2011-04-01

54

21 CFR 184.1005 - Acetic acid.  

...64-19-7) is known as ethanoic acid. It occurs naturally in plant and animal tissues. It is produced by fermentation of carbohydrates or by organic synthesis. The principal synthetic methods currently employed are oxidation of acetaldehyde derived...

2014-04-01

55

21 CFR 184.1005 - Acetic acid.  

Code of Federal Regulations, 2010 CFR

...64-19-7) is known as ethanoic acid. It occurs naturally in plant and animal tissues. It is produced by fermentation of carbohydrates or by organic synthesis. The principal synthetic methods currently employed are oxidation of acetaldehyde derived...

2010-04-01

56

Metabolism of Indole-3-Acetic Acid  

PubMed Central

An indoleacetic acid oxidase preparation from an acetone powder of Parthenocissus tricuspidata crown-gall tissue has been examined. An intermediate in the reaction is 3-hydroxymethyloxindole and nonenzymic conversion of it to 3-methyleneoxindole was observed. Neither reaction mixtures nor 3-methyleneoxindole have any auxin-like activity in Avena or wheat coleoptile bioassays. In vivo studies show that although 53% decarboxylation of indoleacetic acid was observed in 48 hours, only a small amount of 3-methyloxindole could be recovered from the medium. The other decarboxylated products remain to be identified but are not 3-hydroxymethyloxindole or 3-methyleneoxindole. PMID:16659625

Hamilton, Robert H.; Meyer, Harold E.; Burke, Robert E.; Feung, Chao S.; Mumma, Ralph O.

1976-01-01

57

Microwave Spectra of Molecules of Astrophysical Interest. XXVI. Acetic Acid ,,CH3COOH...  

E-print Network

Microwave Spectra of Molecules of Astrophysical Interest. XXVI. Acetic Acid ,,CH3COOH... V The microwave spectrum of acetic acid is critically reviewed and supplemented with spectral frequency; microwave spectrum; radio astronomy; rota- tional transitions. CONTENTS 1. Introduction

Magee, Joseph W.

58

The formation of acetic acid from carbon dioxide and hydrogen by anaerobic spore-forming bacteria  

Microsoft Academic Search

Summary Further experiments on an anaerobic bacillus synthesising acetic acid from CO2 and H2 are described. The organism in question was classified asClostridium aceticum n.sp. Acetic acid is also formed from sugar.

K. T. Wieringa

1939-01-01

59

Acetic Acid Synthesis by Catalytic Carbonylation of Methanol  

Microsoft Academic Search

Acetic acid synthesis via the carbonylation of methanol is one of the most important industrial applications\\u000a of catalysis using organometallic compounds. All the group 9 metals are active, with processes based on\\u000a cobalt, rhodium and iridium having been developed since the 1960s. This paper surveys some of the more\\u000a recent approaches employed for improving the performance of the rhodium- and

Anthony Haynes

60

Acetic Acid Bacteria Taxonomy from Early Descriptions to Molecular Techniques  

Microsoft Academic Search

The exploitation of acetic acid bacteria (AAB) has a long history in fermentation processes and now represents an emerging\\u000a field in biotechnological applications, especially with regard to the biosynthesis of useful chemicals with a potentially\\u000a high economic value and, in food science, through the standardization of microbiological processes for the manufacture of\\u000a both vinegar and other fermented beverages.

Maria Gullo; Paolo Giudici

61

Inhibition of C4 photosynthesis by (benzamidooxy)acetic acid.  

PubMed

(Benzamidooxy)acetic acid (common name benzadox) which has herbicidal properties was evaluated as a potential inhibitor of photosynthesis in C4 plants. Among enzymes of the C4 pathway, it was a relatively strong inhibitor of alanine aminotransferase in in vitro experiments at concentrations of 5mM. In benzadox treated leaves of Panicum miliaceum, a NAD-malic enzyme type C4 species, there was strong inhibition of both alanine and aspartate aminotransferase and of photosynthetic O2 evolution within one hour. Consistent with the inhibition of these enzymes of the C4 cycle, the pool sizes of metabolites of the cycle was altered: the aspartate level was increased two fold, while the levels of other metabolites such as pyruvate, alanine, oxalacetate and malate were decreased. Kinetic studies with partially purified alanine aminotransferase showed that benzadox is a competitive inhibitor with respect to alanine and a noncompetitive inhibitor with respect to 2-oxoglutarate. Comparisons between the structures and inhibitory actions of benzadox and (aminooxy)acetic acid, the latter a potent inhibitor of alanine and aspartate aminotransferases, suggest that in vivo, benzadox may exert its effect through metabolism to (aminooxy)acetic acid. PMID:24458342

Nakamoto, H; Ku, M S; Edwards, G E

1982-12-01

62

The enumeration and identification of acetic acid bacteria from South African red wine fermentations  

Microsoft Academic Search

Acetic acid bacteria are microorganisms that can profoundly influence the quality of wine. Surprisingly, little research has been done on these microorganisms in the winemaking field. The object of this study was to investigate the occurrence of acetic acid bacteria in South African red wine fermentations and to identify the dominant species occurring. Acetic acid bacteria were isolated and enumerated

W. J. Du Toit; M. G. Lambrechts

2002-01-01

63

21 CFR 175.350 - Vinyl acetate/crotonic acid copolymer.  

...2014-04-01 false Vinyl acetate/crotonic acid copolymer. 175.350 Section 175.350... § 175.350 Vinyl acetate/crotonic acid copolymer. A copolymer of vinyl acetate and crotonic acid may be safely used as a coating or...

2014-04-01

64

The critical temperatures and densities of acetic acid?water mixtures  

Microsoft Academic Search

The critical temperatures and densities of acetic acid?water mixtures have been measured using a sealed ampule method. The measurements for pure acetic acid were compared with data reported in the literature and were found to be in good agreement. It is shown that the critical temperatures of acetic acid?water mixtures increase with the addition of water, and that the critical

V. Vandana; Amyn S. Teja

1995-01-01

65

Cyclization of ?-terpenols and their acetates by fluorosulfonic acid  

Microsoft Academic Search

It has been shown that the superacid cyclization of ?-terpenols and their acetates takes place with structural selectivity\\u000a and chemo- and stereospecificity and leads to cyclic isoprenoids with higher yields than the cyclization of the corresponding\\u000a ?-terpenols and their acetates.

N. D. Ungur; N. P. Popa; Nguen Van Tuen; P. F. Vlad

1993-01-01

66

Acetic Acid bacteria: physiology and carbon sources oxidation.  

PubMed

Acetic acid bacteria (AAB) are obligately aerobic bacteria within the family Acetobacteraceae, widespread in sugary, acidic and alcoholic niches. They are known for their ability to partially oxidise a variety of carbohydrates and to release the corresponding metabolites (aldehydes, ketones and organic acids) into the media. Since a long time they are used to perform specific oxidation reactions through processes called "oxidative fermentations", especially in vinegar production. In the last decades physiology of AAB have been widely studied because of their role in food production, where they act as beneficial or spoiling organisms, and in biotechnological industry, where their oxidation machinery is exploited to produce a number of compounds such as l-ascorbic acid, dihydroxyacetone, gluconic acid and cellulose. The present review aims to provide an overview of AAB physiology focusing carbon sources oxidation and main products of their metabolism. PMID:24426139

Mamlouk, Dhouha; Gullo, Maria

2013-12-01

67

Kinetic Modeling of Esterification of Ethylene Glycol with Acetic Acid  

SciTech Connect

The reaction kinetics of the esterification of ethylene glycol with acetic acid in the presence of cation exchange resin has been studied and kinetic models based on empirical and Langmuir approach has been developed. The Langmuir based model involving eight kinetic parameters fits experimental data much better compared to empirical model involving four kinetic parameters. The effect of temperature and catalyst loading on the reaction system has been analyzed. Further, the activation energy and frequency factor of the rate constants for Langmuir based model has been estimated.

Yadav, Vishnu P.; Maity, Sunil K. [Department of Chemical Engineering, Indian Institute of Technology, Hyderabad, Ordnance Factory Estate, Yeddumailiram-502205, Andhra Pradesh (India); Mukherjee, Rudra Palash [Department of Chemical Engineering, National Institute of Technology, Durgapur, Mahatma Gandhi Avenue, Durgapur-713209, West Bengal (India); Bantraj, Kandi [Department of Chemical Engineering, National Institute of Technology, Rourkela-769008, Orissa (India)

2010-10-26

68

13C6-[Benzene Ring]-Indole-3-Acetic Acid  

PubMed Central

Indole-3-acetic acid (IAA) labeled with 13C in the six carbons of the benzene ring is described for use as an internal standard for quantitative mass spectral analysis of IAA by gas chromatography/selected ion monitoring. [13C6]IAA was compared to the available deuterium labeled compounds and shown to offer the advantages of nonexchangeability of the isotope label, high isotopic enrichment, and chromatographic properties identical to that of the unlabeled compound. The utility of [13C6]IAA for measurement of endogenous IAA levels was demonstrated by analysis of IAA in Lemna gibba G-3. PMID:16664570

Cohen, Jerry D.; Baldi, Bruce G.; Slovin, Janet Pernise

1986-01-01

69

Acetobacter aceti Possesses a Proton Motive Force-Dependent Efflux System for Acetic Acid  

PubMed Central

Acetic acid bacteria are obligate aerobes able to oxidize ethanol, sugar alcohols, and sugars into their corresponding acids. Among them, Acetobacter and Gluconacetobacter species have very high ethanol oxidation capacity, leading to accumulation of vast amounts of acetic acid outside the cell. Since these bacteria are able to grow in media with high concentrations of acetic acid, they must possess a specific mechanism such as an efflux pump by which they can resist the toxic effects of acetic acid. In this study, the efflux pump of Acetobacter aceti IFO 3283 was examined using intact cells and membrane vesicles. The accumulation of acetic acid/acetate in intact cells was increased by the addition of a proton uncoupler and/or cyanide, suggesting the presence of an energy-dependent efflux system. To confirm this, right-side-out and inside-out membrane vesicles were prepared from A. aceti IFO 3283, and the accumulation of acetic acid/acetate in the vesicles was examined. Upon the addition of a respiratory substrate, the accumulation of acetic acid/acetate in the right-side-out vesicles was largely decreased, while its accumulation was very much increased in the inside-out vesicles. These respiration-dependent phenomena observed in both types of membrane vesicles were all sensitive to a proton uncoupler. Acetic acid/acetate uptake in the inside-out membrane vesicles was dependent not on ATP but on the proton motive force. Furthermore, uptake was shown to be rather specific for acetic acid and to be pH dependent, because higher uptake was observed at lower pH. Thus, A. aceti IFO 3283 possesses a proton motive force-dependent efflux pump for acetic acid. PMID:15968043

Matsushita, Kazunobu; Inoue, Taketo; Adachi, Osao; Toyama, Hirohide

2005-01-01

70

A Specialized Citric Acid Cycle Requiring Succinyl-Coenzyme A (CoA):Acetate CoA-Transferase (AarC) Confers Acetic Acid Resistance on the Acidophile Acetobacter aceti  

Microsoft Academic Search

Microbes tailor macromolecules and metabolism to overcome specific environmental challenges. Acetic acid bacteria perform the aerobic oxidation of ethanol to acetic acid and are generally resistant to high levels of these two membrane-permeable poisons. The citric acid cycle (CAC) is linked to acetic acid resistance in Acetobacter aceti by several observations, among them the oxidation of acetate to CO2 by

Elwood A. Mullins; Julie A. Francois; T. Joseph Kappock

2008-01-01

71

Neutralization of acids and bases in subcritical and supercritical water: acetic acid and HCl  

Microsoft Academic Search

Acid-base titrations for the KOH-acetic acid or NH3-acetic acid systems were monitored with the optical indicator 2-naphthoic acid at 350 °C and 34 MPa, and those for the HCl?Cl? system with acridine at 380 °C and up to 34 MPa (5000 psi). KOH remains a much stronger base than NH4OH at high temperature. From 298 K to the critical temperature

Keith P. Johnston; Jerzy B. Chlistunoff

1998-01-01

72

Effect of Acetic, Lactic and other Organic Acids on the Formation of Artificial Carious Lesions  

Microsoft Academic Search

Artificial carious lesions were produced in human enamel using a diphosphonate\\/organíc acid system over periods up to 30 days, and progress assessed by depth measurement. Acids studied were lactic, acetic, propionic, isobutyric, succinic, tartaric, hydrochloric and hydrofluoric. The rate of lesion progress was found to be a function of calculated unionized acid concentration, and acid dissociation constant. Acetic acid made

J. D. B. Featherstone; B. E. Rodgers

1981-01-01

73

DESOXYCORTICOSTERONE ACETATE  

PubMed Central

1. Desoxycorticosterone acetate (DCA) and NaCl, in the dosage employed in normal rats, caused renal and cardiac hypertrophy, characteristic changes in the renal tubular epithelium, atrophic changes in the subcapsular zone of the adrenal cortex, and serum electrolyte changes characterized by a rise in sodium and fall in potassium. 2. In rats rendered nephritic with a rabbit anti-rat-kidney serum, the same regimen caused similar changes. In addition, DCA given concurrently with NaCl greatly intensified the nephritic process and gave rise to striking arterial hypertension. 3. A diet, virtually sodium-free, administered to normal and nephritic rats receiving daily injections of DCA abolished or reduced to a minimum the effects of this steroid; i.e., a liberal ingestion of NaCl was essential for the potentiation of the action of DCA. 4. The addition of KCl to the drinking water of rats receiving DCA and NaCl tended to correct the depression of the level of potassium in the serum, but had no effect upon the hypertension in nephritic animals nor upon the anatomical lesions. 5. The mechanism by which the sodium ion potentiates the activity of DCA has not been established. PMID:19871607

Knowlton, Abbie I.; Loeb, Emily N.; Stoerk, Herbert C.; Seegal, Beatrice C.

1947-01-01

74

Toxicokinetics and Oral Bioavailability of Halogenated Acetic Acids Mixtures in Naive and GSTzeta-Depleted Rats  

Microsoft Academic Search

Pharmacokinetics of halogenated acetic acid (HAA) mixtures in native and GSTzeta depleted rats was investigated. Rats were administered orally or i.v. to Mixture-1 (monobromo- dichloro-, chlorodibromo-, tribromo- acetic acids) or Mixture-2 (bromochloro-, dibromo-, trichloro- bromodichloro- acetic acids) at a dose of 25 ?mol\\/kg HAA and blood samples collected up to 36 h. GSTzeta depleted rats were also orally dosed with

Shakil A. Saghir; Irvin R. Schultz

2005-01-01

75

Effects of Acetic Acid Pretreatment and Hot Air Drying on Resistance of Salmonella on Cabbage Slices  

Microsoft Academic Search

The heat resistance of Salmonella anatum inoculated onto the surface of cabbage slices as affected by acetic acid pretreatment (0.5–1.5% v\\/v) and hot air drying at 50–60°C was investigated. Approximately 1.5 log10 of Salmonella numbers was reduced after soaking the vegetables in acetic acid solution. The inhibitory effect of acetic acid on the bacteria was more pronounced during drying. The heat

Naphaporn Chiewchan; Pornpen Morakotjinda

2009-01-01

76

Recent advances in nitrogen-fixing acetic acid bacteria.  

PubMed

Nitrogen is an essential plant nutrient, widely applied as N-fertilizer to improve yield of agriculturally important crops. An interesting alternative to avoid or reduce the use of N-fertilizers could be the exploitation of plant growth-promoting bacteria (PGPB), capable of enhancing growth and yield of many plant species, several of agronomic and ecological significance. PGPB belong to diverse genera, including Azospirillum, Azotobacter, Herbaspirillum, Bacillus, Burkholderia, Pseudomonas, Rhizobium, and Gluconacetobacter, among others. They are capable of promoting plant growth through different mechanisms including (in some cases), the biological nitrogen fixation (BNF), the enzymatic reduction of the atmospheric dinitrogen (N(2)) to ammonia, catalyzed by nitrogenase. Aerobic bacteria able to oxidize ethanol to acetic acid in neutral or acid media are candidates of belonging to the family Acetobacteraceae. At present, this family has been divided into ten genera: Acetobacter, Gluconacetobacter, Gluconobacter, Acidomonas, Asaia, Kozakia, Saccharibacter, Swaminathania, Neoasaia, and Granulibacter. Among them, only three genera include N(2)-fixing species: Gluconacetobacter, Swaminathania and Acetobacter. The first N(2)-fixing acetic acid bacterium (AAB) was described in Brazil. It was found inside tissues of the sugarcane plant, and first named as Acetobacter diazotrophicus, but then renamed as Gluconacetobacter diazotrophicus. Later, two new species within the genus Gluconacetobacter, associated to coffee plants, were described in Mexico: G. johannae and G. azotocaptans. A salt-tolerant bacterium named Swaminathania salitolerans was found associated to wild rice plants. Recently, N(2)-fixing Acetobacter peroxydans and Acetobacter nitrogenifigens, associated with rice plants and Kombucha tea, respectively, were described in India. In this paper, recent advances involving nitrogen-fixing AAB are presented. Their natural habitats, physiological and genetic aspects, as well as their association with different plants and contribution through BNF are described as an overview. PMID:18177965

Pedraza, Raúl O

2008-06-30

77

Acetate/acetyl-CoA metabolism associated with cancer fatty acid synthesis: Overview and application.  

PubMed

Understanding cancer-specific metabolism is important for identifying novel targets for cancer diagnosis and therapy. Induced acetate/acetyl CoA metabolism is a notable feature that is related to fatty acid synthesis supporting tumor growth. In this review, we focused on the recent findings related to cancer acetate/acetyl CoA metabolism. We also introduce [1-(11)C]acetate positron emission tomography (PET), which is a useful tool to visualize up-regulation of acetate/acetyl CoA metabolism in cancer, and discuss the utility of [1-(11)C]acetate PET in cancer diagnosis and its application to personalized medicine. PMID:24569091

Yoshii, Yukie; Furukawa, Takako; Saga, Tsuneo; Fujibayashi, Yasuhisa

2015-01-28

78

Simultaneous determination of uric acid and ascorbic acid using glassy carbon electrodes in acetate buffer solution  

Microsoft Academic Search

The present work reports the simultaneous determination of uric acid (UA) and ascorbic acid (AA) in 0.2M, pH 4.0, acetate buffer solution using glassy carbon (GC) electrode by square wave voltammetry. Selective detection of UA in the presence of 200-fold excess of AA is achieved at the GC electrode in acetate buffer solution. The GC electrode separates the voltammetric signal

S. Abraham John

2005-01-01

79

Inflammatory cells' role in acetic acid-induced colitis  

PubMed Central

Background: Free radicals are the known mechanisms responsible for inducing colitis with two origins: Inflammatory cells and tissues. Only the inflammatory cells can be controlled by corticosteroids. Our aim was to assess the importance of neutrophils as one of the inflammatory cells in inducing colitis and to evaluate the efficacy of corticosteroids in the treatment of inflammatory bowel disease (IBD). Materials and Methods: Thirty-six mice were divided into six groups of six mice each. Colitis was induced in three groups by exposing them to acetic acid through enema (group 1), ex vivo (group 3), and enema after immune suppression (group 5). Each group had one control group that was exposed to water injection instead of acetic acid. Tissue samples were evaluated and compared based on macroscopic damages and biochemical and pathological results. Results: Considering neutrophilic infiltration, there were significant differences between groups 1, 3, 5, and the control of group 1. Groups 3, 5, and their controls, and group 1 and the control of group 3 had significant differences in terms of goblet depletion. Based on tissue originated H2O2, we found significant differences between group 1 and its control and group 3, and also between groups 5 and the control of group 3. All the three groups were significantly different from their controls based on Ferric Reducing Ability of Plasma (FRAP) and such differences were also seen between group 1 with two other groups. Conclusion: Neutrophils may not be the only cause of oxidation process in colitis, and also makes the effectiveness of corticosteroids in the treatment of this disease doubtful. PMID:25337523

Sanei, Mohammad H.; Hadizadeh, Fatemeh; Adibi, Peyman; Alavi, Sayyed Ali

2014-01-01

80

Modification of wheat starch with succinic acid/acetic anhydride and azelaic acid/acetic anhydride mixtures I. Thermophysical and pasting properties.  

PubMed

The aim of this research was to investigate the influence of modification with succinic acid/acetic anhydride and azelaic acid/acetic anhydride mixtures on thermophysical and pasting properties of wheat starch. Starch was isolated from two wheat varieties and modified with mixtures of succinic acid and acetic anhydride, and azelaic acid and acetic anhydride in 4, 6 and 8 % (w/w). Thermophysical, pasting properties, swelling power, solubility and amylose content of modified starches were determined. The results showed that modifications with mixtures of afore mentioned dicarboxylic acids with acetic anhydride decreased gelatinisation and pasting temperatures. Gelatinisation enthalpy of Golubica starch increased, while of Srpanjka starch decreased by modifications. Retrogradation after 7 and 14 day-storage at 4 °C decreased after modifications of both starches. Maximum, hot and cold paste viscosity of both starches increased, while stability during shearing at high temperatures decreased. % setback of starches modified with azelaic acid/acetic anhydride mixture decreased. Swelling power and solubility of both starches increased by both modifications. PMID:25328203

Subari?, Drago; A?kar, Dur?ica; Babi?, Jurislav; Saka?, Nikola; Jozinovi?, Antun

2014-10-01

81

Isolation, characterization and optimization of indigenous acetic acid bacteria and evaluation of their preservation methods  

PubMed Central

Background and Objectives Acetic acid bacteria (AAB) are useful in industrial production of vinegar. The present study aims at isolation and identification of acetic acid bacteria with characterization, optimization, and evaluation of their acetic acid productivity. Materials and Methods Samples from various fruits were screened for presence of acetic acid bacteria on glucose, yeast extract, calcium carbonate (GYC) medium. Carr medium supplemented with bromocresol green was used for distinguishing Acetobacter from Gluconobacter. The isolates were cultured in basal medium to find the highest acetic acid producer. Biochemical tests followed by 16S rRNA and restriction analyses were employed for identification of the isolate and phylogenic tree was constructed. Bacterial growth and acid production conditions were optimized based on optimal inoculum size, pH, temperature, agitation, aeration and medium composition. Results Thirty-seven acetic acid bacteria from acetobacter and gluconobacter members were isolated. Acetic acid productivity yielded 4 isolates that produced higher amounts of acid. The highest producer of acid (10.03%) was selected for identification. The sequencing and restriction analyses of 16S rRNA revealed a divergent strain of Acetobacter pasteurianus (Gene bank accession number#GU059865). The optimum condition for acid production was a medium composed of 2% glucose, 2% yeast extract, 3% ethanol and 3% acid acetic at inoculum size of 4% at 3L/Min aeration level in the production medium. The isolate was best preserved in GYC medium at 12°C for more than a month. Longer preservation was possible at ?70°C. Conclusion The results are suggestive of isolation of an indigenous acetic acid bacteria. Pilot plan is suggested to study applicability of the isolated strain in acetic acid production. PMID:22347549

Sharafi, SM; Rasooli, I; Beheshti-Maal, K

2010-01-01

82

Dilute Acetic Acid Exposure Enhances Electrolyte Leakage by Hydrilla verticillata and Potamogeton pectinatus Tubers  

Microsoft Academic Search

Subterranean vegetative propagules are important life cycle stages for some species of rooted aquatic plants. Sedi- ments contain numerous compounds resulting from anaero- bic degradation of organic matter, including acetic acid. Tubers of hydrilla (Hydrilla verticillata (L.f.) Royle) and sago pondweed ( Potamogeton pectinatus L. ) were exposed to a range of acetic acid concentrations (0, 17.4, 87, 174, 348,

DAVID F. SPENCER; G. G. KSANDER

83

Acidbase equilibrium of ?-adrenoceptor blocking agents in acetic acid medium and methods for their titration  

Microsoft Academic Search

The overall dissociation constants and the formation constants of the perchlorate salts, in anhydrous acetic acid, of a series of ß-adrenoceptor blocking agents have been determined. On the basis of these values simple potentiometric and visual titration methods for the assay of ß-adrenoceptor blocking drugs in acetic acid are described.

José Barbosa; Maria Eleno Torrero

1991-01-01

84

DOI: 10.1002/chem.200700579 Selective Catalytic Oxidation of Ethanol to Acetic Acid on Dispersed  

E-print Network

, easily separated from organic reactants and products, and gas-phase process- es that avoid solid% ethanol conversion) were much higher than in previous re- ports. The presence of TiO2 during syn- thesis that are converted to acetic acid. Water increases acetic acid selec- tivity by inhibiting acetaldehyde syn- thesis

Iglesia, Enrique

85

Responses of Pisum sativum L. to exogenous indole acetic acid application under manganese toxicity.  

PubMed

Responses of pea (Pisum sativum L.) seedlings to manganese (50, 100 and 250 ?M) and indole acetic acid (10 and 100 ?M) treatments were investigated. Single and combined exposure of pea to manganese and 100 ?M indole acetic acid decreased root and shoot fresh mass, chlorophyll, carotenoids, protein and nitrogen while ammonium content increased compared to the control. Combined treatment of pea with 250 ?M manganese and 100 ?M indole acetic acid decreased root and shoot fresh mass by 54% and 51%, chlorophyll and carotenoids by 31% and 26%, root and shoot protein by 47% and 44%, and root and shoot nitrogen by 44% and 40%, respectively. Activities of glutamine synthetase and glutamate synthase were decreased by the exposure of manganese and 100 ?M indole acetic acid while glutamate dehydrogenase activity increased. Combined application of 250 ?M manganese and 100 ?M indole acetic acid decreased root and shoot glutamine synthetase activity by 44% and 39%, and glutamate synthase activity by 39% and 37% while root and shoot glutamate dehydrogenase activity increased by 47% and 42%, respectively compared to the control. In contrast, application of 10 ?M indole acetic acid together with manganese decreased the negative impacts of manganese, and promoted seedling growth compared to the manganese treatments alone. This study has shown that 10 ?M indole acetic acid protected pea seedlings appreciably from manganese toxicity by regulating ammonium content and the activities of enzymes of ammonium assimilation, while 100 ?M of indole acetic acid exhibited opposite response under manganese toxicity. PMID:21516457

Gangwar, Savita; Singh, Vijay Pratap; Maurya, Jagat Narayan

2011-06-01

86

High pressure vapour–liquid equilibria of the binary and some of the ternary and multicomponent mixtures of the carbon dioxide + acetic anhydride + ?-methylbenzyl alcohol + acetic acid + ?-methylbenzyl acetate system  

Microsoft Academic Search

Bubble-point pressures of the binary systems CO2+acetic anhydride, CO2+?-methylbenzyl alcohol, and CO2+?-methylbenzyl acetate were measured in the temperature range of 283–363K up to 15MPa in a high pressure capillary glass tube apparatus, using the synthetic method. The binary mixture CO2+acetic acid was measured for x=0.4962 and compared with previously published results. For the system CO2+?-methylbenzyl alcohol, data of the three-phase

Lourdes Calvo; Theo W. de Loos

2006-01-01

87

Putative ABC Transporter Responsible for Acetic Acid Resistance in Acetobacter aceti  

PubMed Central

Two-dimensional gel electrophoretic analysis of the membrane fraction of Acetobacter aceti revealed the presence of several proteins that were produced in response to acetic acid. A 60-kDa protein, named AatA, which was mostly induced by acetic acid, was prepared; aatA was cloned on the basis of its NH2-terminal amino acid sequence. AatA, consisting of 591 amino acids and containing ATP-binding cassette (ABC) sequences and ABC signature sequences, belonged to the ABC transporter superfamily. The aatA mutation with an insertion of the neomycin resistance gene within the aatA coding region showed reduced resistance to acetic acid, formic acid, propionic acid, and lactic acid, whereas the aatA mutation exerted no effects on resistance to various drugs, growth at low pH (adjusted with HCl), assimilation of acetic acid, or resistance to citric acid. Introduction of plasmid pABC101 containing aatA under the control of the Escherichia coli lac promoter into the aatA mutant restored the defect in acetic acid resistance. In addition, pABC101 conferred acetic acid resistance on E. coli. These findings showed that AatA was a putative ABC transporter conferring acetic acid resistance on the host cell. Southern blot analysis and subsequent nucleotide sequencing predicted the presence of aatA orthologues in a variety of acetic acid bacteria belonging to the genera Acetobacter and Gluconacetobacter. The fermentation with A. aceti containing aatA on a multicopy plasmid resulted in an increase in the final yield of acetic acid. PMID:16391084

Nakano, Shigeru; Fukaya, Masahiro; Horinouchi, Sueharu

2006-01-01

88

Evaluation of the morphological changes of gastric mucosa induced by a low concentration of acetic acid using a rat model.  

PubMed

Oral ingestion of concentrated acetic acid causes corrosive injury of the gastrointestinal tract. To assess the effects of a low concentration of acetic acid on gastric mucosa, we examined the gastric mucosal changes in rats at 1 and 3 days after the injection of 5% or 25% acetic acid into the gastric lumen. The area of the gastric ulcerative lesions in the 25% acetic acid group was significantly larger than that in the 5% acetic acid group. The lesion area was reduced significantly at 3 days after injection in the 5% acetic acid group, whereas no significant difference in lesion area was observed at 1 and 3 days in the 25% acetic acid group. Histologically, corrosive necrosis was limited to the mucosal layer in the 5% acetic acid group, whereas necrosis extended throughout the gastric wall in the 25% acetic acid group. At 3 days post-injection, the 25% acetic acid group showed widespread persistent inflammation, whereas the 5% acetic acid group showed widespread appearance of fibroblasts indicative of a healing process. These results indicate that a low concentration of acetic acid damages the gastric mucosa and that the degree of mucosal damage depends on the concentration of acetic acid. PMID:24485432

Nakao, Ken-ichiro; Ro, Ayako; Kibayashi, Kazuhiko

2014-02-01

89

Hydrogen bonding in hydrates with one acetic acid molecule.  

PubMed

Hydrogen bonding (H-bond) interaction significantly influences the separation of acetic acid (HAc) from the HAc/H(2)O mixtures, especially the dilute solution, in distillation processes. It has been examined from the HAc mono-, di-, tri-, and tetrahydrates by analyzing the structures, binding energies, and infrared vibrational frequencies from quantum chemical calculations. For the first coordinate shell the 6-membered head-on ring is surely the most favorable structure because it has (1) the most favorable H-bonding parameters, (2) almost the largest binding energy per H-bond, (3) the biggest wavenumber shifts, and (4) the highest ring distribution (the AIMD simulations). Moreover, the comparison of the calculations with the experiments (the X-ray scattering data and IR frequencies) suggests that the possible structures in dilute aqueous solution are those involving two or more coordinate shells. The H-bonding in these water-surrounded HAc hydrates are the origin of the low-efficiency problem of isolating HAc from the dilute HAc/H(2)O mixtures. It is apparently a tougher work to break the H-bonds among HAc and the surrounded H(2)O molecules with respect to the case of more concentrated solutions, where the dominant structures are HAc or H(2)O aggregates. PMID:20853886

Pu, Liang; Sun, Yueming; Zhang, Zhibing

2010-10-14

90

Scaleable production and separation of fermentation-derived acetic acid. Final CRADA report.  

SciTech Connect

Half of U.S. acetic acid production is used in manufacturing vinyl acetate monomer (VAM) and is economical only in very large production plants. Nearly 80% of the VAM is produced by methanol carbonylation, which requires high temperatures and exotic construction materials and is energy intensive. Fermentation-derived acetic acid production allows for small-scale production at low temperatures, significantly reducing the energy requirement of the process. The goal of the project is to develop a scaleable production and separation process for fermentation-derived acetic acid. Synthesis gas (syngas) will be fermented to acetic acid, and the fermentation broth will be continuously neutralized with ammonia. The acetic acid product will be recovered from the ammonium acid broth using vapor-based membrane separation technology. The process is summarized in Figure 1. The two technical challenges to success are selecting and developing (1) microbial strains that efficiently ferment syngas to acetic acid in high salt environments and (2) membranes that efficiently separate ammonia from the acetic acid/water mixture and are stable at high enough temperature to facilitate high thermal cracking of the ammonium acetate salt. Fermentation - Microbial strains were procured from a variety of public culture collections (Table 1). Strains were incubated and grown in the presence of the ammonium acetate product and the fastest growing cultures were selected and incubated at higher product concentrations. An example of the performance of a selected culture is shown in Figure 2. Separations - Several membranes were considered. Testing was performed on a new product line produced by Sulzer Chemtech (Germany). These are tubular ceramic membranes with weak acid functionality (see Figure 3). The following results were observed: (1) The membranes were relatively fragile in a laboratory setting; (2) Thermally stable {at} 130 C in hot organic acids; (3) Acetic acid rejection > 99%; and (4) Moderate ammonia flux. The advantages of producing acetic acid by fermentation include its appropriateness for small-scale production, lower cost feedstocks, low energy membrane-based purification, and lower temperature and pressure requirements. Potential energy savings of using fermentation are estimated to be approximately 14 trillion Btu by 2020 from a reduction in natural gas use. Decreased transportation needs with regional plants will eliminate approximately 200 million gallons of diesel consumption, for combined savings of 45 trillion Btu. If the fermentation process captures new acetic acid production, savings could include an additional 5 trillion Btu from production and 7 trillion Btu from transportation energy.

Snyder, S. W.; Energy Systems

2010-02-08

91

Transcript and metabolite alterations increase ganoderic acid content in Ganoderma lucidum using acetic acid as an inducer.  

PubMed

Acetic acid at 5-8 mM increased ganoderic acid (GA) accumulation in Ganoderma lucidum. After optimization by the response surface methodology, the GA content reached 5.5/100 mg dry weight, an increase of 105 % compared with the control. The intermediate metabolites of GA biosynthesis, lanosterol and squalene also increased to 47 and 15.8 ?g/g dry weight, respectively, in response to acetic acid. Acetic acid significantly induced transcription levels of sqs, lano, hmgs and cyp51 in the GA biosynthesis pathway. An acetic acid-unregulated acetyl coenzyme A synthase (acs) gene was selected from ten candidate homologous acs genes. The results indicate that acetic acid alters the expression of genes related to acetic acid assimilation and increases GA biosynthesis and the metabolic levels of lanosterol, squalene and GA-a, thereby resulting in GA accumulation. PMID:25216642

Ren, Ang; Li, Xiong-Biao; Miao, Zhi-Gang; Shi, Liang; Jaing, Ai-Liang; Zhao, Ming-Wen

2014-12-01

92

Escherichia coli and Salmonella enterica Are Protected against Acetic Acid, but Not Hydrochloric Acid, by Hypertonicity?  

PubMed Central

Chapman et al. (B. Chapman, N. Jensen, T Ross, and M. B. Cole, Appl. Environ. Microbiol. 72:5165-5172, 2006) demonstrated that an increased NaCl concentration prolongs survival of Escherichia coli O157 SERL 2 in a broth model simulating the aqueous phase of a food dressing or sauce containing acetic acid. We examined the responses of five other E. coli strains and four Salmonella enterica strains to increasing concentrations of NaCl under conditions of lethal acidity and observed that the average “lag” time prior to inactivation decreases in the presence of hydrochloric acid but not in the presence of acetic acid. For E. coli in the presence of acetic acid, the lag time increased with increasing NaCl concentrations up to 2 to 4% at pH 4.0, up to 4 to 6% at pH 3.8, and up to 4 to 7% (wt/wt of water) NaCl at pH 3.6. Salmonella was inactivated more rapidly by combined acetic acid and NaCl stresses than E. coli, but increasing NaCl concentrations still decreased the lag time prior to inactivation in the presence of acetic acid; at pH 4.0 up to 1 to 4% NaCl was protective, and at pH 3.8 up to 1 to 2% NaCl delayed the onset of inactivation. Sublethal injury kinetics suggest that this complex response is a balance between the lethal effects of acetic acid, against which NaCl is apparently protective, and the lethal effects of the NaCl itself. Compared against 3% NaCl, 10% (wt/wt of water) sucrose with 0.5% NaCl (which has similar osmotic potential) was found to be equally protective against adverse acetic acid conditions. We propose that hypertonicity may directly affect the rate of diffusion of acetic acid into cells and hence cell survival. PMID:19346344

Chapman, B.; Ross, T.

2009-01-01

93

Direct oxidation of methane to acetic acid catalyzed by Pd2+ and Cu2+ in the presence of molecular oxygen  

E-print Network

Direct oxidation of methane to acetic acid catalyzed by Pd2+ and Cu2+ in the presence of molecular to acetic acid in concentrated sulfuric acid using a combination of Pd2+ and Cu2+ in the presence of oxygen. The conversion of methane to acetic acid has attracted recent interest as a pathway for the synthesis

Bell, Alexis T.

94

Uptake kinetics of acetic acid and acetone on ice surfaces at 190 - 223 K  

Microsoft Academic Search

Heterogeneous reactions of oxygenated organics may influence the oxidation capacity of the atmosphere with a direct impact on the tropospheric ozone budget. Direct trace gas measurements in the upper troposphere have revealed a high mixing ratio acetic acid (up to 1.9 ppb) and acetone (up to 3 ppb). In the present study we have examined the heterogeneous interactions of acetic

A. Terziyski; P. Behr; U. Scharfenort; K. Demiral; R. Zellner

2003-01-01

95

Chiral phosphoric acid directed regioselective acetalization of carbohydrate-derived 1,2-diols.  

PubMed

In control: A chiral phosphoric acid catalyst significantly enhances or completely overrides the inherent regioselective acetalization profiles exhibited by monosaccharide-derived 1,2-diol substrates. This study represents the first example of chiral-catalyst-directed regio- and enantioselective intermolecular acetalizations, which are complementary to existing methods for substrate-controlled functionalization of polyols. PMID:24123751

Mensah, Enoch; Camasso, Nicole; Kaplan, Will; Nagorny, Pavel

2013-12-01

96

Acetic Acid Bacteria, Newly Emerging Symbionts of Insects?  

PubMed Central

Recent research in microbe-insect symbiosis has shown that acetic acid bacteria (AAB) establish symbiotic relationships with several insects of the orders Diptera, Hymenoptera, Hemiptera, and Homoptera, all relying on sugar-based diets, such as nectars, fruit sugars, or phloem sap. To date, the fruit flies Drosophila melanogaster and Bactrocera oleae, mosquitoes of the genera Anopheles and Aedes, the honey bee Apis mellifera, the leafhopper Scaphoideus titanus, and the mealybug Saccharicoccus sacchari have been found to be associated with the bacterial genera Acetobacter, Gluconacetobacter, Gluconobacter, Asaia, and Saccharibacter and the novel genus Commensalibacter. AAB establish symbiotic associations with the insect midgut, a niche characterized by the availability of diet-derived carbohydrates and oxygen and by an acidic pH, selective factors that support AAB growth. AAB have been shown to actively colonize different insect tissues and organs, such as the epithelia of male and female reproductive organs, the Malpighian tubules, and the salivary glands. This complex topology of the symbiosis indicates that AAB possess the keys for passing through body barriers, allowing them to migrate to different organs of the host. Recently, AAB involvement in the regulation of innate immune system homeostasis of Drosophila has been shown, indicating a functional role in host survival. All of these lines of evidence indicate that AAB can play different roles in insect biology, not being restricted to the feeding habit of the host. The close association of AAB and their insect hosts has been confirmed by the demonstration of multiple modes of transmission between individuals and to their progeny that include vertical and horizontal transmission routes, comprising a venereal one. Taken together, the data indicate that AAB represent novel secondary symbionts of insects. PMID:20851977

Crotti, Elena; Rizzi, Aurora; Chouaia, Bessem; Ricci, Irene; Favia, Guido; Alma, Alberto; Sacchi, Luciano; Bourtzis, Kostas; Mandrioli, Mauro; Cherif, Ameur; Bandi, Claudio; Daffonchio, Daniele

2010-01-01

97

Point mutation of H3/H4 histones affects acetic acid tolerance in Saccharomyces cerevisiae.  

PubMed

The molecular mechanism of acetic acid tolerance in yeast remains unclear despite of its importance for efficient cellulosic ethanol production. In this study, we examined the effects of histone H3/H4 point mutations on yeast acetic acid tolerance by comprehensively screening a histone H3/H4 mutant library. A total of 24 histone H3/H4 mutants (six acetic acid resistant and 18 sensitive) were identified. Compared to the wild-type strain, the histone acetic acid-resistant mutants exhibited improved ethanol fermentation performance under acetic acid stress. Genome-wide transcriptome analysis revealed that changes in the gene expression in the acetic acid-resistant mutants H3 K37A and H4 K16Q were mainly related to energy production, antioxidative stress. Our results provide novel insights into yeast acetic acid tolerance on the basis of histone, and suggest a novel approach to improve ethanol production by altering the histone H3/H4 sequences. PMID:25093933

Liu, Xiangyong; Zhang, Xiaohua; Zhang, Zhaojie

2014-10-10

98

Complexation of chitosan with acetic acid according to Fourier transform Raman spectroscopy data  

NASA Astrophysics Data System (ADS)

The results of the interaction between the protonated chitosan (CHI) macromolecule and the acetate ion in dilute acetic acid solutions were studied by Fourier transform Raman spectroscopy and quantum-chemical modeling. The complexation of CHI with the acetate ion showed itself as the 934 cm-1 band in the Raman spectrum, which suggests the formation of [CHI+ · CH3COO-] type ion pairs. It was concluded that a comparative analysis of the integrated intensities of the Raman bands in the range 880-940 cm-1 makes it possible to judge about the relative content of hydrated acetate ions, CHI macromolecules of the [CHI+ · CH3COO-] complex, and acetic acid molecules not involved in CHI protonation.

Mikhailov, G. P.; Tuchkov, S. V.; Lazarev, V. V.; Kulish, E. I.

2014-06-01

99

Indole-3-Acetic Acid Biosynthesis in Colletotrichum gloeosporioides f. sp. aeschynomene  

PubMed Central

We characterized the biosynthesis of indole-3-acetic acid by the mycoherbicide Colletotrichum gloeosporioides f. sp. aeschynomene. Auxin production was tryptophan dependent. Compounds from the indole-3-acetamide and indole-3-pyruvic acid pathways were detected in culture filtrates. Feeding experiments and in vitro assay confirmed the presence of both pathways. Indole-3-acetamide was the major pathway utilized by the fungus to produce indole-3-acetic acid in culture. PMID:9835603

Robinson, M.; Riov, J.; Sharon, A.

1998-01-01

100

Hydrogen-exchange reaction of alkyl halides with formic and acetic acids  

Microsoft Academic Search

1.An investigation was made of the hydrogen exchange of alkyl halides in media differing in dielectric constant, namely formic and acetic acids.2.Tertiary halides (chloride, bromides, and iodides) undergo hydrogen exchange with formic acid-d, whereas secondary alkyl halides do not undergo hydrogen exchange under the same conditions. Tertiary chlorides do not undergo hydrogen exchange with acetic acid-d, whereas under the same

D. N. Kursanov; E. V. Bykova; V. N. Setkina

1959-01-01

101

Severe renal function impairment in adult patients acutely poisoned with concentrated acetic acid.  

PubMed

Acetic acid is a widely used organic acid with corrosive properties that depend on its concentration. If acetic acid is ingested in concentrations above 30 % it may severely damage the upper gastrointestinal tract and cause intravascular haemolysis, which can result in severe kidney and liver disorders and disseminated intravascular coagulation. In this retrospective study, we analysed acetic acid ingestion data collected at the University Clinic for Toxicology of Skopje, Macedonia from 1 January 2002 to 31 December 2011. The analysis included systemic complications, kidney damage, and the outcomes in particular. Over the ten years, 84 patients were reported at the Clinic to have ingested highly concentrated acetic acid. Twenty-eight developed kidney disorders, while the remaining 56 had no complications. Fatal outcome was reported for 11 patients, seven of whom had systemic complications and four severe gastrointestinal complications. PMID:23585201

Chibishev, Andon; Sikole, Aleksandar; Pereska, Zanina; Chibisheva, Vesna; Simonovska, Natasha; Orovchanec, Nikola

2013-01-01

102

Biosynthesis of the Halogenated Auxin, 4-Chloroindole-3-Acetic Acid1[W][OA  

PubMed Central

Seeds of several agriculturally important legumes are rich sources of the only halogenated plant hormone, 4-chloroindole-3-acetic acid. However, the biosynthesis of this auxin is poorly understood. Here, we show that in pea (Pisum sativum) seeds, 4-chloroindole-3-acetic acid is synthesized via the novel intermediate 4-chloroindole-3-pyruvic acid, which is produced from 4-chlorotryptophan by two aminotransferases, TRYPTOPHAN AMINOTRANSFERASE RELATED1 and TRYPTOPHAN AMINOTRANSFERASE RELATED2. We characterize a tar2 mutant, obtained by Targeting Induced Local Lesions in Genomes, the seeds of which contain dramatically reduced 4-chloroindole-3-acetic acid levels as they mature. We also show that the widespread auxin, indole-3-acetic acid, is synthesized by a parallel pathway in pea. PMID:22573801

Tivendale, Nathan D.; Davidson, Sandra E.; Davies, Noel W.; Smith, Jason A.; Dalmais, Marion; Bendahmane, Abdelhafid I.; Quittenden, Laura J.; Sutton, Lily; Bala, Raj K.; Le Signor, Christine; Thompson, Richard; Horne, James; Reid, James B.; Ross, John J.

2012-01-01

103

Acute intestinal injury induced by acetic acid and casein: prevention by intraluminal misoprostol  

SciTech Connect

Acute injury was established in anesthetized rabbits by intraluminal administration of acetic acid with and without bovine casein, into loops of distal small intestine. Damage was quantified after 45 minutes by the blood-to-lumen movement of {sup 51}Cr-labeled ethylenediaminetetraacetic acid (EDTA) and fluorescein isothiocyanate-tagged bovine serum albumin as well as luminal fluid histamine levels. The amount of titratable acetic acid used to lower the pH of the treatment solutions to pH 4.0 was increased by the addition of calcium gluconate. Luminal acetic acid caused a 19-fold increase in {sup 51}Cr-EDTA accumulation over saline controls; casein did not modify this effect. In saline controls, loop fluid histamine levels bordered on the limits of detection (1 ng/g) but were elevated 19-fold by acetic acid exposure and markedly increased (118-fold) by the combination of acid and casein. Intraluminal misoprostol (3 or 30 micrograms/mL), administered 30 minutes before acetic acid, significantly attenuated the increase in epithelial permeability (luminal {sup 51}Cr-EDTA, fluorescein isothiocyanate-bovine serum albumin accumulation) and histamine release (P less than 0.05). Diphenhydramine, alone or in combination with cimetidine, and indomethacin (5 mg/kg IV) were not protective. It is concluded that exposure of the epithelium to acetic acid promotes the transepithelial movement of casein leading to enhanced mast cell activation and mucosal injury. Damage to the epithelial barrier can be prevented by misoprostol.

Miller, M.J.; Zhang, x.J.; Gu, x.A.; Clark, D.A. (Department of Pediatrics, Louisiana State University School of Medicine, New Orleans (USA))

1991-07-01

104

Percutaneous Sclerotherapy Using Acetic Acid After Failure of Alcohol Ablation in an Intra-abdominal Lymphangioma  

SciTech Connect

We report a case of percutaneous sclerotherapy using acetic acid in a 22-year-old woman with an intra-abdominal cystic lymphangioma who was not successfully treated with ethanol despite multiple trials.

Park, Sang Woo [Konkuk University Hospital, Konkuk University School of Medicine, Department of Diagnostic Radiology (Korea, Republic of)], E-mail: psw0224@kku.ac.kr; Cha, In Ho; Kim, Kyeong Ah; Hong, Suk Joo; Park, Cheol Min; Chung, Hwan Hoon [Department of Diagnostic Radiology, Korea University School of Medicine (Korea, Republic of)

2004-09-15

105

21 CFR 862.1390 - 5-Hydroxyindole acetic acid/serotonin test system.  

Code of Federal Regulations, 2011 CFR

...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1390 5-Hydroxyindole acetic acid/serotonin test...

2011-04-01

106

21 CFR 862.1390 - 5-Hydroxyindole acetic acid/serotonin test system.  

...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1390 5-Hydroxyindole acetic acid/serotonin test...

2014-04-01

107

Recovery of acetic acid from dilute aqueous solutions using catalytic dehydrative esterification with ethanol.  

PubMed

We have developed a direct esterification of aqueous acetic acid with ethanol (molar ratio=1:1) catalyzed by polystyrene-supported or homogeneous sulfonic acids toward the recovery of acetic acid from wastewater in chemical plants. The equilibrium yield was significantly increased by the addition of toluene, which had a high ability to extract ethyl acetate from the aqueous phase. It was shown that low-loading and alkylated polystyrene-supported sulfonic acid efficiently accelerated the reaction. These results suggest that the construction of hydrophobic reaction environments in water was critical in improving the chemical yield. Addition of inorganic salts was also effective for the reaction under not only biphasic conditions (toluene-water) but also toluene-free conditions, because the mutual solubility of ethyl acetate and water was suppressed by the salting-out effect. Among the tested salts, CaCl(2) was found to be the most suitable for this reaction system. PMID:23290939

Yagyu, Daisuke; Ohishi, Tetsuo; Igarashi, Takeshi; Okumura, Yoshikuni; Nakajo, Tetsuo; Mori, Yuichiro; Kobayashi, Sh?

2013-03-01

108

Hydrogen peroxide resistance of Acetobacter pasteurianus NBRC3283 and its relationship to acetic acid fermentation.  

PubMed

The bacterium Acetobacter pasteurianus can ferment acetic acid, a process that proceeds at the risk of oxidative stress. To understand the stress response, we investigated catalase and OxyR in A. pasteurianus NBRC3283. This strain expresses only a KatE homolog as catalase, which is monofunctional and growth dependent. Disruption of the oxyR gene increased KatE activity, but both the katE and oxyR mutant strains showed greater sensitivity to hydrogen peroxide as compared to the parental strain. These mutant strains showed growth similar to the parental strain in the ethanol oxidizing phase, but their growth was delayed when cultured in the presence of acetic acid and of glycerol and during the acetic acid peroxidation phase. The results suggest that A. pasteurianus cells show different oxidative stress responses between the metabolism via the membrane oxidizing pathway and that via the general aerobic pathway during acetic acid fermentation. PMID:18838821

Okamoto-Kainuma, Akiko; Ehata, Yasunori; Ikeda, Manami; Osono, Takemasa; Ishikawa, Morio; Kaga, Takayuki; Koizumi, Yukimichi

2008-10-01

109

Effects of Exogenously Applied Indole-3-Acetic Acid (IAA) to Cotton  

E-print Network

There is a need in the cotton industry for cultivars with enhanced lint yield potential and high-quality fiber properties. Indole-3-acetic acid (IAA) is a phytohormone that is predominantly responsible for cell elongation and required for primary...

Clement, Jenny D.

2011-08-08

110

Conductance of HCl, NaCl, Na acetate, and acetic acid in water-ethylene carbonate solvent mixtures at 25 and 40°C  

Microsoft Academic Search

The molar conductances of solutions of hydrochloric acid, sodium chloride, sodium acetate, and acetic acid were measured in water-ethylene carbonate (EC) solvent mixtures at 25 and 40°C. These solvents have dielectric constants higher than that of water. Four solvent compositions, in which the mole fraction (x2) of EC was 0.2, 0.4, 0.5, and 0.6, were studied at 25°C. For HCl

Barry R. Boerner; Roger G. Bates

1978-01-01

111

Leaching of spent lead acid battery paste components by sodium citrate and acetic acid.  

PubMed

A sustainable method, with minimal pollution and low energy cost in comparison with the conventional smelting methods, is proposed for treating components of spent lead-acid battery pastes in aqueous organic acid(s). In this study, PbO, PbO2, and PbSO4, the three major components in a spent lead paste, were individually reacted with a mixture of aqueous sodium citrate and acetic acid solution. Pure lead citrate precursor of Pb3(C6H5O7)2 · 3H2O is the only product crystallized in each leaching experiment. Conditions were optimized for individual lead compounds which were then used as the basis for leaching real industrial spent paste. In this work, efficient leaching process is achieved and raw material cost is reduced by using aqueous sodium citrate and acetic acid, instead of aqueous sodium citrate and citric acid as reported in a pioneering hydrometallurgical method earlier. Acetic acid is not only cheaper than citric acid but is also more effective in aiding dissolution of the lead compounds thus speeding up the leaching process in comparison with citric acid. Lead citrate is readily crystallized from the aqueous solution due to its low solubility and can be combusted to directly produce leady oxide as a precursor for making new battery pastes. PMID:23500418

Zhu, Xinfeng; He, Xiong; Yang, Jiakuan; Gao, Linxia; Liu, Jianwen; Yang, Danni; Sun, Xiaojuan; Zhang, Wei; Wang, Qin; Kumar, R Vasant

2013-04-15

112

The feeding value of water and acetic acid reconstituted sorghum grain for lactating dairy cows  

E-print Network

THE FEEDING VALUE OF WATER AND ACETIC ACID RECONSTITUTED SORGHUM GRAIN FOR LACTATING DAIRY COWS A Thesis by DAVID HEINIE BADE Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the degree... of MASTER OF SCIENCE May 1972 Major Subject: Animal Nutrition THE FEEDING VALUE OF WATER AND ACETIC ACID RECONSTITUTED SORGHUM GRAIN FOR LACTATING DAIRY COWS A Thesis by DAVID HEINIE BADE Approved as to style and content by: C ' man o Committee...

Bade, David Heinie

2012-06-07

113

Molecular properties of 4-substituted indole-3-acetic acids affecting pea pericarp elongation  

Microsoft Academic Search

Pea (Pisum sativum L.) fruit naturally contain the auxins, indole-3-acetic acid (IAA) and 4-chloroindole-3-acetic acid (4-Cl-IAA). However, only 4-Cl-IAA can substitute for the seeds in maintaining pea fruit growth in planta. The importance of the substituent at the 4-position of the indole ring was tested by comparing the molecular properties of 4-X-IAA (X = H, Me, Et, F, or Cl)

Dennis M. Reinecke; Jocelyn A. Ozga; Nebojša Ili?; Volker Magnus; Biserka koji?-Prodi?

1999-01-01

114

Differential effects of the microbial metabolite, acetic acid, on sprouting of aquatic plant propagules  

Microsoft Academic Search

Subterranean vegetative propagules are important life cycle stages for some species of rooted aquatic plants. Sediments contain numerous compounds resulting from anaerobic degradation of organic matter, including acetic acid. Tubers, turions, and winter buds of Hydrilla verticillata (L.f.) Royle, Potamogeton gramineus L., and Potamogeton pectinatus L. were exposed to acetic acid concentrations from 0 to 696 mmol l?1 for 1–8

David F. Spencer; Gregory G. Ksander

1995-01-01

115

Dissociation of acetic acid in 50 mass % ethylene carbonate-water from 20 to 55°C  

Microsoft Academic Search

The dissociation constant of acetic acid in 50 mass % ethylene carbonate-water solvents has been determined at eight temperatures from 20 to 55°C by emf measurements of cells without liquid-junction containing hydrogen electrodes and silver-silver chloride electrodes. Acetic acid is weaker in the mixed solvent than in pure water. At 25°C, pK is 5.645 as compared with 4.756 in water,

J-C Hallé; Roger G. Bates

1975-01-01

116

Population dynamics of acetic acid bacteria during traditional wine vinegar production  

Microsoft Academic Search

The population dynamics of acetic acid bacteria in traditional vinegar production was determined in two independent vinegar plants at both the species and strain level. The effect of barrels made of four different woods upon the population dynamics was also determined. Acetic acid bacteria were isolated on solid media and the species were identified by RFLP-PCR of 16S rRNA genes

Carlos Vegas; Estibaliz Mateo; Ángel González; Carla Jara; José Manuel Guillamón; Montse Poblet; Ma Jesús Torija; Albert Mas

2010-01-01

117

Controlling grey and blue mould diseases of apple fruits using acetic acid vapours  

Microsoft Academic Search

The effect of acetic acid vapours at three application times on grey and blue moulds on the incidence of apple fruits was studied. Acetic acid vapour at 6 µl\\/l caused complete inhibition of linear growth and spore germination of Botrytis cinerea and Penicillium sp. The most effective concentration was AA at 4 µl\\/l, which reduced spore germination and linear growth by more

Yehia Omar Fotouh

2009-01-01

118

Formic and acetic acid over the central Amazon region, Brazil 1. Dry season  

Microsoft Academic Search

We have determined the atmospheric concentrations of formic and acetic acid in the gas phase, in aerosols, and in rain during the dry season (July--August 1985) in the Amazonia region of Brazil. At ground level the average concentrations of gas phase formic and acetic acid were 1.6 +- 0.6 and 2.2 +- 1.0 ppb, respectively. The diurnal behavior of both

M. O. Andreae; R. W. Talbot; T. W. Andreae; R. C. Harriss

1988-01-01

119

Continuous Ethanol Production with a Membrane Bioreactor at High Acetic Acid Concentrations  

PubMed Central

The release of inhibitory concentrations of acetic acid from lignocellulosic raw materials during hydrolysis is one of the main concerns for 2nd generation ethanol production. The undissociated form of acetic acid can enter the cell by diffusion through the plasma membrane and trigger several toxic effects, such as uncoupling and lowered intracellular pH. The effect of acetic acid on the ethanol production was investigated in continuous cultivations by adding medium containing 2.5 to 20.0 g·L?1 acetic acid at pH 5.0, at a dilution rate of 0.5 h?1. The cultivations were performed at both high (~25 g·L?1) and very high (100–200 g·L?1) yeast concentration by retaining the yeast cells inside the reactor by a cross-flow membrane in a membrane bioreactor. The yeast was able to steadily produce ethanol from 25 g·L?1 sucrose, at volumetric rates of 5–6 g·L?1·h?1 at acetic acid concentrations up to 15.0 g·L?1. However, the yeast continued to produce ethanol also at a concentration of 20 g·L?1 acetic acid but at a declining rate. The study thereby demonstrates the great potential of the membrane bioreactor for improving the robustness of the ethanol production based on lignocellulosic raw materials. PMID:25028956

Ylitervo, Paivi; Franzen, Carl Johan; Taherzadeh, Mohammad J.

2014-01-01

120

Hydrogen-bonding interactions in acetic acid monohydrates and dihydrates by density-functional theory calculations  

NASA Astrophysics Data System (ADS)

Equilibrium structures and the respective binding energies of acetic acid monohydrates and dihydrates have been determined by density-functional theory calculations with different basis sets, including 6-31+G(3d,p), 6-311++G(d,p), and 6-311++G(3df,3pd). Given that the C ?O and OH groups in acetic acid provide the predominant hydrogen-bonding interactions with water, six stable conformer structures have been found each for the monohydrate and syn-dihydrate. Of the three syn- and three anti-conformers of acetic acid with water, the most stable monohydrate structure is found to be that of the syn-conformer bonding with water in a cyclic double H-bonded geometry. Similarly, the syn-conformer bonding with two water molecules in a cyclic double H-bonded geometry has also been determined to be the most stable among the six plausible structures for the syn-dihydrate. Frequency analysis of the stable conformers has been performed and the vibrational spectra of the most stable monohydrate and dihydrate structures are compared with the experimental gas-phase and matrix data. Furthermore, the calculated binding energies between an acetic acid and a water molecule for both monohydrate and dihydrate are larger than that between two water molecules, which supports our recent experimental observation of coevaporation of acetic acid with water upon annealing acetic acid on ice.

Gao, Q.; Leung, K. T.

2005-08-01

121

The enumeration and identification of acetic acid bacteria from South African red wine fermentations.  

PubMed

Acetic acid bacteria are microorganisms that can profoundly influence the quality of wine. Surprisingly, little research has been done on these microorganisms in the winemaking field. The object of this study was to investigate the occurrence of acetic acid bacteria in South African red wine fermentations and to identify the dominant species occurring. Acetic acid bacteria were isolated and enumerated from small-scale and commercial red must fermentations in 1998 and 1999, respectively. The initial occurrence of acetic acid bacteria in the must was shown to vary with cell numbers ranging from 10(6)-10(7) to 10(4)-10(5) cfu/ml for the 1998 and 1999 musts, respectively. The acetic acid bacteria decreased to 10(2)-10(3) cfu/ml in musts having a low pH (< or = 3.6), whereas in some musts having a high pH (> or = 3.7), the cell numbers increased during fermentation. During the process of cold soaking, the cell numbers of acetic acid bacteria also increased until inoculation with commercial wine yeast. Gluconobacter oxydans dominated in the fresh must and Acetobacter pasteurianus and A. liquefaciens during fermentation. This study showed that A. liquefaciens and A. hansenii were present in significant numbers, which has not been reported before. PMID:11930953

Du Toit, W J; Lambrechts, M G

2002-03-25

122

A Study of the Acid Properties of Structurally and Compositionally Different Heteropoly Acids in Acetic Acid  

Microsoft Academic Search

The acid properties of heteropoly acids of the following three structure types were studied by conductometry in acetic acid: Keggin (H3PW12O40, H3PMo12O40, H4SiW12O40, H3PW11ThO39; and H5PW11XO40, where X(IV) = Ti or Zr), Dawson (a-H6P2W18O62and a-H6P2Mo18O62), and H6P2W21O71(H2O)3. These compounds are electrolytes that dissociate in only the first step of this solvent. The thermodynamic dissociation constants of the heteropoly acids were

M. N. Timofeeva; M. M. Matrosova; G. M. Maksimov; V. A. Likholobov

2001-01-01

123

Quantitative relationship between indole-3-acetic acid and abscisic acid during leaf growth in Coleus blumei  

Microsoft Academic Search

Quantitative determinations by gas chromatography-mass spectrometry ofindole-3-acetic acid (IAA) and abscisic acid (ABA) in growing leaves ofColeusblumei plants show parallel declines in leaf concentrations of bothhormones,except in leaf number 3 (about three-fourths of full size) where IAA level wasthe lowest of those measured. Expansion of the most recently unfurled leaf tofull size serves, in effect, to dilute both IAA and

Clifford LaMotte; Xiaoyue Li; William Jacobs; Ephraim Epstein

2002-01-01

124

Synthesis and in vitro transdermal penetration enhancing activity of lactam N-acetic acid esters.  

PubMed

A homologous series of N-acetic acid esters of 2-pyrrolidinone and 2-piperidinone has been prepared and evaluated for its ability to enhance the skin content and flux of hydrocortisone 21-acetate in hairless mouse skin in vitro. Enhancement ratios (ER) were determined for flux (J), 24-hour diffusion cell receptor cell concentrations (Q24), and 24-h full-thickness mouse skin steroid content (SC) and compared to control values (no enhancer present). In addition, in an attempt to abrogate toxicity, these dermal penetration enhancers were designed to have the potential for biodegradation by dermal esterases. 2-Oxopyrrolidine-alpha acetic acid dodecyl ester (5) showed the highest enhancement ratios for J (ER 67.33) and Q24 (ER 180.66). 2-Oxopiperidine-alpha-acetic acid decyl ester (10) showed a high Q24 (ER 162.07) but a lower J (ER 12.67). 2-Oxopyrrolidine-alpha-acetic acid decyl ester (3) showed the highest enhancement ratio for SC (ER 8.7). The ER Q24 for 3, 5 and 10, as well as other lactam N-acetic acid esters in this work, were significantly higher than the ER found using Azone as enhancer. PMID:8683439

Michniak, B B; Player, M R; Sowell, J W

1996-02-01

125

Performance of dairy cows fed high levels of acetic acid or ethanol.  

PubMed

Ethanol and acetic acid are common end products from silages. The main objective of this study was to determine whether high concentrations of ethanol or acetic acid in total mixed ration would affect performance in dairy cows. Thirty mid-lactation Holstein cows were grouped in 10 blocks and fed one of the following diets for 7 wk: (1) control (33% Bermuda hay + 67% concentrates), (2) ethanol [control diet + 5% ethanol, dry matter (DM) basis], or (3) acetic acid (control diet + 5% acetic acid, DM basis). Ethanol and acetic acid were diluted in water (1:2) and sprayed onto total mixed rations twice daily before feeding. An equal amount of water was mixed with the control ration. To adapt animals to these treatments, cows were fed only half of the treatment dose during the first week of study. Cows fed ethanol yielded more milk (37.9 kg/d) than those fed the control (35.8 kg/d) or acetic acid (35.3 kg/d) diets, mainly due to the higher DM intake (DMI; 23.7, 22.2, and 21.6 kg/d, respectively). The significant diet × week interaction for DMI, mainly during wk 2 and 3 (when acetic acid reached the full dose), was related to the decrease in DMI observed for the acetic acid treatment. There was a diet × week interaction in excretion of milk energy per DMI during wk 2 and 3, due to cows fed acetic acid sustained milk yield despite lower DMI. Energy efficiency was similar across diets. Blood metabolites (glucose, insulin, nonesterified fatty acids, ethanol, and ?-glutamyl transferase activity) and sensory characteristics of milk were not affected by these treatments. Animal performance suggested similar energy value for the diet containing ethanol compared with other diets. Rumen conversion of ethanol to acetate and a concomitant increase in methane production might be a plausible explanation for the deviation of the predicted energy value based on the heat of combustion. Therefore, the loss of volatile compounds during the drying process in the laboratory should be considered when calculating energy content of fermented feedstuffs. PMID:23141834

Daniel, J L P; Amaral, R C; Sá Neto, A; Cabezas-Garcia, E H; Bispo, A W; Zopollatto, M; Cardoso, T L; Spoto, M H F; Santos, F A P; Nussio, L G

2013-01-01

126

IR plus vacuum ultraviolet spectroscopy of neutral and ionic organic acid molecules and clusters: Acetic acid  

NASA Astrophysics Data System (ADS)

Infrared (IR) vibrational spectroscopy of acetic acid (A) neutral and ionic monomers and clusters, employing vacuum ultraviolet (VUV), 10.5eV single photon ionization of supersonically expanded and cooled acetic acid samples, is presented and discussed. Molecular and cluster species are identified by time of flight mass spectroscopy: the major mass features observed are AnH+(n=1-9), ACOOH+ (VUV ionization) without IR radiation present, and A+ with both IR and VUV radiation present. The intense feature ACOOH+ arises from the cleavage of (A)2 at the ?-CC bond to generate ACOOH++CH3 following ionization. The vibrational spectrum of monomeric acetic acid (2500-7500cm-1) is measured by nonresonant ionization detected infrared (NRID-IR) spectroscopy. The fundamentals and overtones of the CH and OH stretches and some combination bands are identified in the spectrum. Mass selected IR spectra of neutral and cationic acetic acid clusters are measured in the 2500-3800cm-1 range employing nonresonant ionization dip-IR and IR photodissociation (IRPD) spectroscopies, respectively. Characteristic bands observed at approximately 2500-2900cm-1 for the cyclic ring dimer are identified and tentatively assigned. For large neutral acetic acid clusters An(n>2), spectra display only hydrogen bonded OH stretch features, while the CH modes (2500-2900cm-1) do not change with cluster size n. The IRPD spectra of protonated (cationic) acetic acid clusters AnH+ (n=1-7) exhibit a blueshift of the free OH stretch with increasing n. These bands finally disappear for n ?6, and one broad and weak band due to hydrogen bonded OH stretch vibrations at approximately 3350cm-1 is detected. These results indicate that at least one OH group is not involved in the hydrogen bonding network for the smaller (n?5) AnH+ species. The disappearance of the free OH stretch feature at n ?6 suggests that closed cyclic structures form for AnH+ for the larger clusters (n?6).

Hu, Y. J.; Fu, H. B.; Bernstein, E. R.

2006-11-01

127

Hydrogen bond mediated rotor-ring coupling in acetic acid-benzoic acid mixed dimer  

NASA Astrophysics Data System (ADS)

In this work we demonstrate that a doubly hydrogen-bonded interface of two carboxylic acid groups behaves as efficient conduit to transmit the rotor effects for IVR acceleration in a phenyl ring. The phenomenon has been demonstrated by measuring the resolved emission spectra following SVL excitations in S1 of a 1:1 mixed dimer between acetic acid and benzoic acid. The role of the methyl rotor has been ascertained by comparing the results with those obtained for an analogous dimeric system between formic acid and benzoic acid.

Nandi, Chayan K.; Hazra, Montu K.; Chakraborty, Tapas

2004-10-01

128

Electrochemical generation of manganese (III) at glassy carbon electrode in acetic acid  

Microsoft Academic Search

Conditions were established for the electrochemical generation of manganese(III) at glassy carbon in acetic acid. In the oxidation of manganese-(II) in potassium acetate supporting electrolyte high current efficiencies were achieved in a wide range of current densities at the working electrode, whereas in the presence of sodium perchlorate a successful generation of manganese(III) could be performed only at low current

Tibor J. Pastor; Vojka V. Antonijevi?

1990-01-01

129

Radiolabeled acetate kinetics and tricarboxylic acid cycle flux in the rat heart  

Microsoft Academic Search

Positron-emitting (1-¹¹C)acetate has been proposed as a tracer for noninvasive study of regional myocardial oxidative metabolism in humans with positron emission tomography (PET). To examine the relationship between tissue tracer kinetics and tricarboxylic acid (TCA) cycle flux, (1-¹⁴C)acetate was administered as a bolus to Langendorf-perfused rat hearts and effluent ¹⁴COâ and labeled metabolites measured. ¹⁴COâ cleared monoexponentially between 5 and

M. Schwaiger; H. R. Schelbert; M. E. Phelps; A. Nguyen; D. B. Buxton

1987-01-01

130

Acetate non-utilizing mutants of Arabidopsis: evidence that organic acids influence carbohydrate perception in germinating seedlings  

Microsoft Academic Search

A phenotypic screen was employed to isolate Arabidopsis plants that are deficient in their ability to utilize or sense acetate. The screening strategy, based on resistance to the toxic acetate analogue monofluoroacetic acid, was adapted from one that has been used successfully to identify important metabolic and regulatory genes involved in acetate metabolism in fungi. Following conventions established from the

M. A. Hooks; J. E. Turner; E. C. Murphy; I. A. Graham

2004-01-01

131

A case report of a chemical burn due to the misuse of glacial acetic acid.  

PubMed

As young and elastic skin is what everyone dreams of, various measures have been implemented including chemical, laser resurfacing and dermabrasion to improve the condition of ageing skin. However, the high cost of these procedures prevents the poor from having access to treatment. Glacial acetic acid is widely used as a substitute for chemical peeling because it is readily easily available and affordable. However, its use can result in a number of serious complications. A 28-year-old female patient was admitted to our hospital with deep second-degree chemical burns on her face caused by the application of a mixture of glacial acetic acid and flour for chemical peeling. During a 6-month follow-up, hypertrophic scarring developed on the both nasolabial folds despite scar management. Glacial acetic acid is a concentrated form of the organic acid, which gives vinegar its sour taste and pungent smell, and it is also an important reagent during the production of organic compounds. Unfortunately, misleading information regarding the use of glacial acetic acid for chemical peeling is causing serious chemical burns. Furthermore, there is high possibility of a poor prognosis, which includes inflammation, hypertrophic scar formation and pigmentation associated with its misuse. Therefore, we report a case of facial chemical burning, due to the misuse of glacial acetic acid, and hope that this report leads to a better understanding regarding the use of this reagent. PMID:20708991

Yoo, Jun-Ho; Roh, Si-Gyun; Lee, Nae-Ho; Yang, Kyung-Moo; Moon, Ji-Hyun

2010-12-01

132

Molecular Structure of Phenylmercuric acetate  

NSDL National Science Digital Library

Phenylmercuric acetate is white to white-yellow crystalline powder that is odorless. This phenyl mercury compound is used mainly as a fungicide, herbicide, slimicide and bacteriocide. Phenylmercuric acid serves as a preservative in canned paint, eye ointments and drops, injectable solutions, skin disinfectants and in cosmetics products such as hair shampoos, mouthwashes and toothpastes. It is also used in contraceptive gels and foams. Phenylmercuric acetate is prepared by interaction of benzene with mercuric acetate in glacial acetic acid. Phenylmercuric acetate's former production and use as a fungicide and as a mildew inhibitor in paints may have resulted in its direct release to the environment. This substance is very toxic to aquatic organisms and may be hazardous to the environment.

2004-11-10

133

The Carbon Isotopic Content and Concentration of Ambient Formic and Acetic Acid  

Microsoft Academic Search

A direct method for source determination of atmospheric formic and acetic acid, through carbon isotopic analysis of the ambient acids and their potential sources, has been successfully developed and tested. These first carbon isotopic measurements of formic acid in the atmosphere were found to be fairly constant, regardless of location. This is consistent with a single dominating source of formic

Bryan Jay Johnson

1991-01-01

134

Inactive Methyl Indole-3-Acetic Acid Ester Can Be Hydrolyzed and Activated by Several Esterases Belonging  

E-print Network

(salicylic acid binding protein 2) hydrolyzes methyl salicylate to salicylic acid. There are 20 homologsInactive Methyl Indole-3-Acetic Acid Ester Can Be Hydrolyzed and Activated by Several Esterases, and peptides. We have recently shown that IAA could be converted to its methyl ester (MeIAA) by the Arabidopsis

Pichersky, Eran

135

Acetic acid detection threshold in synthetic wine samples of a portable electronic nose.  

PubMed

Wine quality is related to its intrinsic visual, taste, or aroma characteristics and is reflected in the price paid for that wine. One of the most important wine faults is the excessive concentration of acetic acid which can cause a wine to take on vinegar aromas and reduce its varietal character. Thereby it is very important for the wine industry to have methods, like electronic noses, for real-time monitoring the excessive concentration of acetic acid in wines. However, aroma characterization of alcoholic beverages with sensor array electronic noses is a difficult challenge due to the masking effect of ethanol. In this work, in order to detect the presence of acetic acid in synthetic wine samples (aqueous ethanol solution at 10% v/v) we use a detection unit which consists of a commercial electronic nose and a HSS32 auto sampler, in combination with a neural network classifier (MLP). To find the characteristic vector representative of the sample that we want to classify, first we select the sensors, and the section of the sensors response curves, where the probability of detecting the presence of acetic acid will be higher, and then we apply Principal Component Analysis (PCA) such that each sensor response curve is represented by the coefficients of its first principal components. Results show that the PEN3 electronic nose is able to detect and discriminate wine samples doped with acetic acid in concentrations equal or greater than 2 g/L. PMID:23262483

Macías, Miguel Macías; Manso, Antonio García; Orellana, Carlos Javier García; Velasco, Horacio Manuel González; Caballero, Ramón Gallardo; Chamizo, Juan Carlos Peguero

2013-01-01

136

Candida zemplinina Can Reduce Acetic Acid Produced by Saccharomyces cerevisiae in Sweet Wine Fermentations  

PubMed Central

In this study we investigated the possibility of using Candida zemplinina, as a partner of Saccharomyces cerevisiae, in mixed fermentations of must with a high sugar content, in order to reduce its acetic acid production. Thirty-five C. zemplinina strains, which were isolated from different geographic regions, were molecularly characterized, and their fermentation performances were determined. Five genetically different strains were selected for mixed fermentations with S. cerevisiae. Two types of inoculation were carried out: coinoculation and sequential inoculation. A balance between the two species was generally observed for the first 6 days, after which the levels of C. zemplinina started to decrease. Relevant differences were observed concerning the consumption of sugars, the ethanol and glycerol content, and acetic acid production, depending on which strain was used and which type of inoculation was performed. Sequential inoculation led to the reduction of about half of the acetic acid content compared to the pure S. cerevisiae fermentation, but the ethanol and glycerol amounts were also low. A coinoculation with selected combinations of S. cerevisiae and C. zemplinina resulted in a decrease of ?0.3 g of acetic acid/liter, while maintaining high ethanol and glycerol levels. This study demonstrates that mixed S. cerevisiae and C. zemplinina fermentation could be applied in sweet wine fermentation to reduce the production of acetic acid, connected to the S. cerevisiae osmotic stress response. PMID:22247148

Rantsiou, Kalliopi; Dolci, Paola; Giacosa, Simone; Torchio, Fabrizio; Tofalo, Rosanna; Torriani, Sandra; Suzzi, Giovanna; Rolle, Luca

2012-01-01

137

Extraction and sorption of acetic acid at pH above pK{sub a} to form calcium magnesium acetate  

SciTech Connect

The use of rock salt for deicing roads has many negative effects on automobiles, highway systems, and the environment. Calcium magnesium acetate, hence-forth denoted CMA, has been identified as a more desirable, environmentally benign solid deicer for high-ways, airport runaways, and similar applications. CMA is also of interest as an additive for scavenging sulfur in combustion processes so as to reduce emissions of sulfur oxides and as a catalyst for coal gasification. Different extractants (trioctylphosphine oxide and secondary, tertiary, and quaternary amines) and solid sorbents (tertiary and quaternary amines) were investigated as agents for recovery of acetic acid as part of a process for production of CMA from fermentation acetic acid. The pH and temperature dependencies for uptake of acetic acid by these extractants and sorbents were measured, along with the degrees of regeneration by aqueous suspensions of slaked dolomitic lime. These results enable identification of agents having optimal basicity. Among the extractants, the secondary amine Amberlite LA-2 gave the best combined performance for extraction and regeneration. Among the sorbents, a tertiary amine, Amberlite IRA-35, gave the best performance. Trioctylphosphine oxide does not maintain capacity in the pH range (about 6) most attractive for acetic acid fermentation. Slurred crushed dolomite is not sufficiently basic to accomplish regeneration.

Reisinger, H.; King, C.J. [Lawrence Berkeley Lab., CA (United States)

1995-03-01

138

Influence of Medium Buffering Capacity on Inhibition of Saccharomyces cerevisiae Growth by Acetic and Lactic Acids  

PubMed Central

Acetic acid (167 mM) and lactic acid (548 mM) completely inhibited growth of Saccharomyces cerevisiae both in minimal medium and in media which contained supplements, such as yeast extract, corn steep powder, or a mixture of amino acids. However, the yeast grew when the pH of the medium containing acetic acid or lactic acid was adjusted to 4.5, even though the medium still contained the undissociated form of either acid at a concentration of 102 mM. The results indicated that the buffer pair formed when the pH was adjusted to 4.5 stabilized the pH of the medium by sequestering protons and by lessening the negative impact of the pH drop on yeast growth, and it also decreased the difference between the extracellular and intracellular pH values (?pH), the driving force for the intracellular accumulation of acid. Increasing the undissociated acetic acid concentration at pH 4.5 to 163 mM by raising the concentration of the total acid to 267 mM did not increase inhibition. It is suggested that this may be the direct result of decreased acidification of the cytosol because of the intracellular buffering by the buffer pair formed from the acid already accumulated. At a concentration of 102 mM undissociated acetic acid, the yeast grew to higher cell density at pH 3.0 than at pH 4.5, suggesting that it is the total concentration of acetic acid (104 mM at pH 3.0 and 167 mM at pH 4.5) that determines the extent of growth inhibition, not the concentration of undissociated acid alone. PMID:11916676

Thomas, K. C.; Hynes, S. H.; Ingledew, W. M.

2002-01-01

139

Bidentate Structures of Acetic Acid on Ge(100): The Role of Carboxyl Oxygen Eunkyung Hwang,, Do Hwan Kim,,, Yun Jeong Hwang, Ansoon Kim,  

E-print Network

Bidentate Structures of Acetic Acid on Ge(100): The Role of Carboxyl Oxygen Eunkyung Hwang,,§ Do structures of acetic acid on the Ge(100) surface at room temperature have been investigated by using both of acetic acid to acetate on the Ge(100) surface occurs through dissociation of the O-H bond

Kim, Sehun

140

Molecular mechanisms of Saccharomyces cerevisiae stress adaptation and programmed cell death in response to acetic acid  

PubMed Central

Beyond its classical biotechnological applications such as food and beverage production or as a cell factory, the yeast Saccharomyces cerevisiae is a valuable model organism to study fundamental mechanisms of cell response to stressful environmental changes. Acetic acid is a physiological product of yeast fermentation and it is a well-known food preservative due to its antimicrobial action. Acetic acid has recently been shown to cause yeast cell death and aging. Here we shall focus on the molecular mechanisms of S. cerevisiae stress adaptation and programmed cell death in response to acetic acid. We shall elaborate on the intracellular signaling pathways involved in the cross-talk of pro-survival and pro-death pathways underlying the importance of understanding fundamental aspects of yeast cell homeostasis to improve the performance of a given yeast strain in biotechnological applications. PMID:23430312

Giannattasio, Sergio; Guaragnella, Nicoletta; Zdralevic, Masa; Marra, Ersilia

2013-01-01

141

Effect of water-soluble vitamins on the production of indole-3-acetic acid by Azospirillum brasilense  

Microsoft Academic Search

The effects of six water-soluble vitamins on tryptophandependent synthesis of indole-3-acetic acid in Azospirillum brasilense were investigated. A multifactorial regression analysis was employed to produce models of indole-3-acetic acid synthesis versus concentrations of tryptophan and the vitamins added to the growth medium. Very low levels of the B-group vitamins added at 10 to 100?g 1?1 affected production of indole-3-acetic acid

Elena A. Zakharova; Alexander D. Iosipenko; Vladimir V. Ignatov

2000-01-01

142

An investigation of the acid properties of heteropoly acids in acetone and acetic acid by the electrical conductivity method  

Microsoft Academic Search

1.The authors have measured the electrical conductivity of heteropoly acids (HPA.) based on Mo(VI), W(VI), and V(V) with heteroatoms P and Si in acetone and acetic acid at 25°C. In acetone, H3PW12O40 and H4PW11VO40 are partially dissociated 3-1 electrolytes. In acetic acid, all the HPA investigated are 1-1 electrolytes.2.Using the Fuoss-Edelson and Fuoss-Kraus methods they have calculated the thermodynamic dissociation

S. M. Kulikov; I. V. Kozhevnikov

1981-01-01

143

Volatile acetic acid and formaldehyde emission from plywood treated with boron compound  

Microsoft Academic Search

The effects of plywood on formaldehyde and volatile acetic acid emissions treated with borax and boric acid were investigated. The treated plywood samples were manufactured by using two different methods; each veneer was first impregnated by a dipping method before the first group of plywood was manufactured. The second group of plywood panels was produced by adding preservatives (borax, boric

S. Colak; G. Colakoglu

2004-01-01

144

Structural, Biochemical, and Phylogenetic Analyses Suggest That Indole-3-Acetic Acid Methyltransferase  

E-print Network

methylate the nitrogen atom or carboxyl groups found in a variety of plant small molecules. Salicylic acid-adenosyl-L-methionine-dependent methylation of natural chemicals encompassing widely divergent structures. Indole-3- acetic acid (IAA methylation of IAA's free carboxyl group. The crystal structure of Arabidopsis (Arabidopsis thaliana) IAMT (At

Pichersky, Eran

145

Effect of acetic acid on optical coherence tomography (OCT) images of cervical epithelium.  

PubMed

Optical coherence tomography (OCT) can be used as an adjunct to colposcopy in the identification of precancerous and cancerous cervical lesions. The purpose of this study was to investigate the effect of acetic acid on OCT imaging. OCT images were taken from unsuspicious and suspicious areas of fresh conization specimens immediately after resection and 3 and 10 min after application of 6 % acetic acid. A corresponding histology was obtained from all sites. The images taken 3 and 10 min after application of acetic acid were compared to the initial images with respect to changes in brightness, contrast, and scanning depth employing a standard nonparametric test of differences of proportions. Further, mean intensity backscattering curves were calculated from all OCT images in the histological groups CIN3, inflammation, or normal epithelium. Mean difference profiles within each of these groups were determined, reflecting the mean differences between the condition before application of acetic acid and the exposure times 3 and 10 min, respectively. According to the null hypothesis, the difference profiles do not differ from profiles fluctuating around zero in a stationary way, which implies that the profiles do not differ significantly from each other. The null hypothesis was tested employing the KPSS test. The visual analysis of 137 OCT images from 46 sites of 10 conization specimens revealed a statistically significant increase in brightness for all three groups and a statistically significant decrease in contrast for normal epithelium after 10 min. Further, an increase in scanning depth was noted for normal epithelium after 10 min and for CIN3 after 3 min. The analysis of mean intensity profiles showed an increased backscattering intensity after application of acetic acid. Acetic acid significantly affects the quality of OCT images. Overall brightness and scanning depth increase with the opposite effect regarding the image contrast. Whether the observed changes facilitate the distinction between dysplastic lesions in a clinical setting needs to be shown in further studies. PMID:24828107

Gallwas, Julia; Stanchi, Anna; Dannecker, Christian; Ditsch, Nina; Mueller, Susanna; Mortensen, Uwe; Stepp, Herbert

2014-11-01

146

Evolution of Acetic Acid Bacteria During Fermentation and Storage of Wine  

PubMed Central

Acetic acid bacteria were present at all stages of wine making, from the mature grape through vinification to conservation. A succession of Gluconobacter oxydans, Acetobacter pasteurianus, and Acetobacter aceti during the course of these stages was noted. Low levels of A. aceti remained in the wine; they exhibited rapid proliferation on short exposure of the wine to air and caused significant increases in the concentration of acetic acid. Higher temperature of wine storage and higher wine pH favored the development and metabolism of these species. PMID:16346581

Joyeux, A.; Lafon-Lafourcade, S.; Ribereau-Gayon, P.

1984-01-01

147

Use of acetic and citric acids to control Salmonella Typhimurium in tahini (sesame paste).  

PubMed

Since tahini and its products have been linked to Salmonella illness outbreaks and product recalls in recent years, this study assessed the ability of Salmonella Typhimurium to survive or grow in commercial tahini and when hydrated (10% w/v in water), treated with 0.1%-0.5% acetic or citric acids, and stored at 37, 21 and 10 °C for 28 d. S. Typhimurium survived in commercial tahini up to 28 d but was reduced in numbers from 1.7 to 3.3 log10 CFU/ml. However, in the moist or hydrated tahini, significant growth of S. Typhimurium occurred at the tested temperatures. Acetic and citric acids at ?0.5% reduced S. Typhimurium by 2.7-4.8 log10 CFU/ml and 2.5-3.8 log10 CFU/ml, respectively, in commercial tahini at 28 d. In hydrated tahini the organic acids were more effective. S. Typhimurium cells were not detected in the presence of 0.5% acetic acid after 7 d or with 0.5% citric acid after 21 d at the tested temperatures. The ability of S. Typhimurium to grow or survive in commercial tahini and products containing hydrated tahini may contribute to salmonellosis outbreaks; however, use of acetic and citric acids in ready-to-eat foods prepared from tahini can significantly minimize the risk associated with this pathogen. PMID:24929724

Al-Nabulsi, Anas A; Olaimat, Amin N; Osaili, Tareq M; Shaker, Reyad R; Zein Elabedeen, Noor; Jaradat, Ziad W; Abushelaibi, Aisha; Holley, Richard A

2014-09-01

148

Comparative Indole-3-Acetic Acid Levels in the Slender Pea and Other Pea Phenotypes 1  

PubMed Central

Free indole-3-acetic acid levels were measured by gas chromatography-mass spectrometry in three ultra-tall `slender' Pisum sativum L. lines differing in gibberellin content. Measurements were made for apices and stem elongation zones of light-grown plants and values were compared with wild-type, dwarf, and nana phenotypes in which internode length is genetically regulated, purportedly via the gibberellin level. Indole-3-acetic acid levels of growing stems paralleled growth rates in all lines, and were high in all three slender genotypes. Growth was inhibited by p-chlorophenoxyisobutyric acid, demonstrating the requirement of auxin activity for stem elongation, and also by the ethylene precursor 1-aminocyclopropane-1-carboxylic acid. It is concluded that the slender phenotype may arise from constant activation of a gibberellin receptor or transduction chain event leading directly or indirectly to elevated levels of indole-3-acetic acid, and that increased indole-3-acetic acid levels are a significant factor in the promotion of stem elongation. PMID:16667653

Law, David M.; Davies, Peter J.

1990-01-01

149

Inhibition of microbial xylitol production by acetic acid and its relation with fermentative parameters.  

PubMed

Precipitated sugarcane bagasse hemicellulosic hydrolysate containing acetic acid was fermented by Candida guilliermondii FTI20037 under different operational conditions (pH 4.0 and 7.0, three aeration rates). At pH 7.0 and kLa of 10 (0.75 vvm) and 22.5/h (3.0 vvm) the acetic acid had not been consumed until the end of the fermentations, whereas at the same pH and kLa of 35/h (4.5 vvm) the acid was rapidly consumed and acetic acid inhibition was not important. On the other hand, fermentations at an initial pH of 4.0 and kLa of 22.5 and 35/h required less time for the acid uptake than fermentations at kLa of 10/h. The acetic acid assimilation by the yeast indicates the ability of this strain to ferment in partially detoxified medium, making possible the utilization of the sugarcane bagasse hydrolysate in this bio-process. The effects on xylitol yield and production are reported. PMID:10849838

Morita, T A; Silva, S S

2000-01-01

150

21 CFR 184.1721 - Sodium acetate.  

Code of Federal Regulations, 2013 CFR

...anhydrous or trihydrated form. It is produced synthetically by the neutralization of acetic acid with sodium carbonate or by treating calcium acetate with sodium sulfate and sodium bicarbonate. (b) The ingredient meets the...

2013-04-01

151

21 CFR 184.1721 - Sodium acetate.  

...anhydrous or trihydrated form. It is produced synthetically by the neutralization of acetic acid with sodium carbonate or by treating calcium acetate with sodium sulfate and sodium bicarbonate. (b) The ingredient meets the...

2014-04-01

152

21 CFR 184.1721 - Sodium acetate.  

Code of Federal Regulations, 2012 CFR

...anhydrous or trihydrated form. It is produced synthetically by the neutralization of acetic acid with sodium carbonate or by treating calcium acetate with sodium sulfate and sodium bicarbonate. (b) The ingredient meets the...

2012-04-01

153

21 CFR 184.1721 - Sodium acetate.  

Code of Federal Regulations, 2011 CFR

...anhydrous or trihydrated form. It is produced synthetically by the neutralization of acetic acid with sodium carbonate or by treating calcium acetate with sodium sulfate and sodium bicarbonate. (b) The ingredient meets the...

2011-04-01

154

21 CFR 184.1721 - Sodium acetate.  

Code of Federal Regulations, 2010 CFR

...anhydrous or trihydrated form. It is produced synthetically by the neutralization of acetic acid with sodium carbonate or by treating calcium acetate with sodium sulfate and sodium bicarbonate. (b) The ingredient meets the...

2010-04-01

155

Mechanisms leading to oligomers and SOA through aqueous photooxidation: insights from OH radical oxidation of acetic acid and methylglyoxal  

NASA Astrophysics Data System (ADS)

Previous experiments have demonstrated that the aqueous OH radical oxidation of methylglyoxal produces low volatility products including pyruvate, oxalate and oligomers. These products are found predominantly in the particle phase in the atmosphere, suggesting that methylglyoxal is a precursor of secondary organic aerosol (SOA). Acetic acid plays a central role in the aqueous oxidation of methylglyoxal and it is a ubiquitous product of gas phase photochemistry, making it a potential "aqueous" SOA precursor in its own right. However, the fate of acetic acid upon aqueous-phase oxidation is not well understood. In this research, acetic acid (20 ?M-10 mM) was oxidized by OH radicals, and pyruvic acid and methylglyoxal experimental samples were analyzed using new analytical methods, in order to better understand the formation of SOA from acetic acid and methylglyoxal. Glyoxylic, glycolic, and oxalic acids formed from acetic acid and OH radicals. In contrast to the aqueous OH radical oxidation of methylglyoxal, the aqueous OH radical oxidation of acetic acid did not produce succinic acid and oligomers. This suggests that the methylgloxal-derived oligomers do not form through the acid catalyzed esterification pathway proposed previously. Using results from these experiments, radical mechanisms responsible for oligomer formation from methylglyoxal oxidation in clouds and wet aerosols are proposed. The importance of acetic acid/acetate as an SOA precursor is also discussed. We hypothesize that this and similar chemistry is central to the daytime formation of oligomers in wet aerosols.

Tan, Y.; Lim, Y. B.; Altieri, K. E.; Seitzinger, S. P.; Turpin, B. J.

2012-01-01

156

Formic and acetic acid over the central Amazon region, Brazil 1. Dry season  

SciTech Connect

We have determined the atmospheric concentrations of formic and acetic acid in the gas phase, in aerosols, and in rain during the dry season (July--August 1985) in the Amazonia region of Brazil. At ground level the average concentrations of gas phase formic and acetic acid were 1.6 +- 0.6 and 2.2 +- 1.0 ppb, respectively. The diurnal behavior of both acids at ground level and their vertical distribution in the forest canopy point to the existence of vegetative sources as well as to production by chemical reactions in the atmosphere. Dry deposition of the gaseous acids appears to be a major sink. The concentrations of formic and acetic acid in the gas phase were about 2 orders of magnitude higher than concentrations of the corresponding species in the atmospheric aerosol. About 50--60%/sub 0/ of the aerosol (total) formate and acetate were in the size fraction below 1.0 ..mu..m diameter.

Andreae, M.O.; Talbot, R.W.; Andreae, T.W.; Harriss, R.C.

1988-02-20

157

[Conversion of acetic acid to methane by thermophiles]. Progress report, May 15, 1989--May 14, 1993  

SciTech Connect

The primary goal of this project is to obtain a better understanding of thermophilic microorganisms which convert acetic acid to CH{sub 4}. The previous funding period represents a departure from earlier research in this laboratory, which was more physiological and ecological. The present work is centered on the biochemistry of the thermophile Methanothrix sp. strain CALS-1. this organism presents a unique opportunity, with its purity and relatively rapid growth, to do comparative biochemical studies with the other major acetotrophic genus Methanosarcina. We previously found that Methanothrix is capable of using acetate at concentrations 100 fold lower than Methanosarcina. This finding suggests that there are significant differences in the pathways of methanogenesis from acetate in the two genera.

Zinder, S.H.

1993-06-01

158

GENE EXPRESSION PATTERNS OF CD-1 DAY-8 EMBRYO CULTURES EXPOSED TO BROMOCHLORO ACETIC ACID  

EPA Science Inventory

Gene expression patterns of CD-1 day-8 embryo cultures exposed to bromochloro acetic acid Edward D. Karoly?*, Judith E. Schmid* and E. Sidney Hunter III* ?Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina and *Reproductiv...

159

Detection of Acetic Acid in wine by means of an electronic nose  

NASA Astrophysics Data System (ADS)

A portable electronic nose (see Fig.1) based on metal oxide semiconductor thin-film sensors has been developed to detect acetic acid present in four types of wines. The wines analyzed are from the same cellar but are made with different varieties of grapes. Data analysis was performed by two pattern recognition methods: principal component analysis (PCA) and Artificial Neural Networks (ANN).

Lozano, Jesús; Álvarez, Fernando; Santos, José Pedro; Horrillo, Carmen

2011-09-01

160

Cervical cancer screening using visual inspection with acetic acid: operational experiences from Ghana and Thailand  

Microsoft Academic Search

Thailand in 2000 and Ghana in 2001 initiated cervical cancer prevention programmes using a single-visit approach with visual inspection with acetic acid (VIA) with cryotherapy for pre-cancerous lesions. This service was integrated into existing reproductive health services, provided by trained nurses. The providers maintained a high level of competence and performance, including after the withdrawal of external funding. In Ghana,

Harshad Sanghvi; Khunying Kobchitt Limpaphayom; Marya Plotkin; Elaine Charurat; Amy Kleine; Enriquito Lu; Wachara Eamratsameekool; Buncha Palanuwong

2008-01-01

161

Corticosteroid Pretreatment Prevents Small Intestinal Mucosal Lesion Induced by Acetic Acid-Perfusion Model in Rats  

Microsoft Academic Search

One of the important problems in experimentally induced small intestinal lesions is that there is no reproducible model of diffuse and stable mucosal lesion. In this paper, we studied in detail the effects of continuous perfusion of various concentrations of acetic acid on the rat small intestinal mucosa. In order to evaluate its applicability for screening of the preventive effect

Ivan Pacheco; Michiro Otaka; Mario Jin; Hideaki Sasahara; Akira Iwabuchi; Masaru Odashima; Noriaki Konishi; Isao Wada; Osamu Masamune; Sumio Watanabe

2000-01-01

162

Review of Croatian guidelines for use of eicosapentaenoic acid and megestrol acetate in cancer cachexia syndrome  

Microsoft Academic Search

In 2007, Croatian guidelines were developed for the use of eicosapentaenoic acid and megestrol acetate in cancer cachexia syndrome. These guidelines were first published in the Croatian medical journal Lijecnicki vjesnik (Krznaric et al. Lijec Vjesn 2007; 129: 381-6) in Croatian. After nu- merous contacts and discussions with colleagues from the international medical community, we decid- ed to present our

Z. KRZNARIC; A. JURETIC; D. ANZULOVIC

163

Diversity of acetic acid bacteria present in healthy grapes from the Canary Islands  

Microsoft Academic Search

The identification of acetic acid bacteria (AAB) from sound grapes from the Canary Islands is reported in the present study. No direct recovery of bacteria was possible in the most commonly used medium, so microvinifications were performed on grapes from Tenerife, La Palma and Lanzarote islands. Up to 396 AAB were isolated from those microvinifications and identified by 16S rRNA

Maria José Valera; Federico Laich; Sara S. González; Maria Jesús Torija; Estibaliz Mateo; Albert Mas

2011-01-01

164

Application of molecular methods for routine identification of acetic acid bacteria  

Microsoft Academic Search

Recently many new species of Acetic acid Bacteria have been described. The description and identification as new species was based on molecular techniques (sequencing of the 16S rRNA gene, DNA base ratio (% GC) determinations and DNA–DNA hybridisation) and phenotypic characterization. In the present paper, we propose a fast and reliable method for the identification most of the species currently

Ángel González; José Manuel Guillamón; Albert Mas; Montse Poblet

2006-01-01

165

Population dynamics of acetic acid bacteria during traditional wine vinegar production.  

PubMed

The population dynamics of acetic acid bacteria in traditional vinegar production was determined in two independent vinegar plants at both the species and strain level. The effect of barrels made of four different woods upon the population dynamics was also determined. Acetic acid bacteria were isolated on solid media and the species were identified by RFLP-PCR of 16S rRNA genes and confirmed by 16S rRNA gene sequencing, while strains were typed by ERIC-PCR and (GTG)(5)-rep-PCR. The most widely isolated species was Acetobacter pasteurianus, which accounted for 100% of all the isolates during most of the acetification. Gluconacetobacter europaeus only appeared at any notable level at the end of the process in oak barrels from one vinegar plant. The various A. pasteurianus strains showed a clear succession as the concentration of acetic acid increased. In both vinegar plants the relative dominance of different strains was modified as the concentrations of acetic acid increased, and strain diversity tended to reduce at the end of the process. PMID:20117853

Vegas, Carlos; Mateo, Estibaliz; González, Angel; Jara, Carla; Guillamón, José Manuel; Poblet, Montse; Torija, Ma Jesús; Mas, Albert

2010-03-31

166

A shaking bioreactor equipped with twin ceramic membranes for acetic acid production using Acetobacter pasteurianus  

Microsoft Academic Search

A shaking bioreactor system with twin internal ceramic membranes was developed for effective perfusion culture and applied to the continuous production of acetic acid using Acetobacter pasteurianus. The system makes it possible to carry out the back-washing of the membrane without stopping the continuous operation because one membrane can be washed by medium feed flow while another membrane provides filtration

J. Horiuchi; M. Narumi; K. Tada; M. Kobayashi; T. Kanno; T. Suzuki

2002-01-01

167

Uptake kinetics of acetic acid and acetone on ice surfaces at 190 - 223 K  

NASA Astrophysics Data System (ADS)

Heterogeneous reactions of oxygenated organics may influence the oxidation capacity of the atmosphere with a direct impact on the tropospheric ozone budget. Direct trace gas measurements in the upper troposphere have revealed a high mixing ratio acetic acid (up to 1.9 ppb) and acetone (up to 3 ppb). In the present study we have examined the heterogeneous interactions of acetic acid and acetone with H2O- or D2O-ice (for acetic acid) surfaces using the coated wall flow-tube technique with the detection of gaseous species and reaction products by molecular beam QMS. The experiments were carried in a temperature range between 198 K and 223 K at total pressures ranging from routinely 1 to 5 mbar. The ice surface was prepared by flowing water vapour with nitrogen as a carrier gas through the sliding injector and moving the injector slowly until a thin uniform ice surface was formed. The adsorption-desorption equilibrium of both substances on ice surfaces were measured using initial trace gas concentration between 5 x E+11 and 2 x E+14 molecules cm-3. The calculated adsorption enthalpy was 52(±10) kJ mol-1 for acetic acid and 44(±10) kJ mol-1 for acetone as derived from Langmuir isotherms measured in a temperature range between 190 and 223 K. For desorbing acetic acid molecules we observed first order kinetics with a desorption rate constant of 6?E-2 s-1 at the lowest temperature (i.e.198 K). Using this value together with the assumption of an Arrhenius like temperature dependence for desorption (kdes=Ades exp(-EA/RT)), where Ades ˜ E+13 s-1 we obtain EA,des ˜ 60 kJ mol-1. At slightly higher temperatures (203 K, 208 K) an increasing deviation from first order kinetic behavior is observed. At the same time the desorption peak is broadening and shifted to longer residence times. To estimate the residence time, the extent of dissociation and thermodynamic data of the intermediate adsorbed acetic acid molecules we performed proton exchange experiments using a D2O-ice surface. A measured proton exchange probability for acetic acid of 0.01 at 208 K leads to the assumption of a selected orientation of the molecules which dissociate on the surface. With decreasing temperature we also observe an increasing time shift (?) between the adsorption and desorption signal. At 208 K we measured ? = 3 s. The observed temperature dependence of time shifts corresponds to an activation energy for desorption of 56(±10) kJ mol-1, in good agreement with direct desorption measurements.

Terziyski, A.; Behr, P.; Scharfenort, U.; Demiral, K.; Zellner, R.

2003-04-01

168

A Possible Source of Error in the Chemical Detection of Indolyl Acetic Acid in Plants  

Microsoft Academic Search

DURING investigations on the growth substances of fruits of cacao and bananas (Musa spp.), it was of interest to find that a substance was present in seeded bananas which gave a pink colour with ferric chloride\\/perchloric acid or p-dimethyl amino-benz-aldehyde\\/hydrochloric acid, corresponding to the RF of indolyl acetic acid and to the zone of bioassay using the wheat coleoptile straight-growth

R. Nichols

1958-01-01

169

The efficiency of enhanced biological phosphorus removal from real wastewater affected by different ratios of acetic to propionic acid  

Microsoft Academic Search

The effect of different ratios of propionic to acetic acid on the efficiency of enhanced biological phosphorus removal (EBPR) from real wastewater supplemented with volatile fatty acids (VFAs) was investigated. Two sequencing batch reactors (SBRs) were used to acclimate two types (SBR1 and SBR2) of biomass. They were cultured and studied using real wastewater with an average propionic to acetic

Yinguang Chen; Andrew A. Randall; Terrence McCue

2004-01-01

170

The use of static and dynamic physical property measurements to infer structural properties of associated liquids: Acetic acid–water  

Microsoft Academic Search

The anomalies which occur in most static and dynamic physical property measurements on solutions of water in acetic acid can be used with critical analysis to infer associative molecular structures. The anomalies indicate significant structural changes. Proton magnetic resonance chemical shifts for acetic acid–water solutions show a significant structural change occurring in the region of equal molar concentration. Literature values

Robert W. Sims; M. Robert Willicott III; R. R. Inners

1979-01-01

171

The use of static and dynamic physical property measurements to infer structural properties of associated liquids: Acetic acid-water  

Microsoft Academic Search

The anomalies which occur in most static and dynamic physical property measurements on solutions of water in acetic acid can be used with critical analysis to infer associative molecular structures. The anomalies indicate significant structural changes. Proton magnetic resonance chemical shifts for acetic acid-water solutions show a significant structural change occurring in the region of equal molar concentration. Literature values

Robert W. Sims; M. Robert Willicott III; R. R. Inners

1979-01-01

172

The Acetate Switch  

PubMed Central

To succeed, many cells must alternate between life-styles that permit rapid growth in the presence of abundant nutrients and ones that enhance survival in the absence of those nutrients. One such change in life-style, the “acetate switch,” occurs as cells deplete their environment of acetate-producing carbon sources and begin to rely on their ability to scavenge for acetate. This review explains why, when, and how cells excrete or dissimilate acetate. The central components of the “switch” (phosphotransacetylase [PTA], acetate kinase [ACK], and AMP-forming acetyl coenzyme A synthetase [AMP-ACS]) and the behavior of cells that lack these components are introduced. Acetyl phosphate (acetyl?P), the high-energy intermediate of acetate dissimilation, is discussed, and conditions that influence its intracellular concentration are described. Evidence is provided that acetyl?P influences cellular processes from organelle biogenesis to cell cycle regulation and from biofilm development to pathogenesis. The merits of each mechanism proposed to explain the interaction of acetyl?P with two-component signal transduction pathways are addressed. A short list of enzymes that generate acetyl?P by PTA-ACKA-independent mechanisms is introduced and discussed briefly. Attention is then directed to the mechanisms used by cells to “flip the switch,” the induction and activation of the acetate-scavenging AMP-ACS. First, evidence is presented that nucleoid proteins orchestrate a progression of distinct nucleoprotein complexes to ensure proper transcription of its gene. Next, the way in which cells regulate AMP-ACS activity through reversible acetylation is described. Finally, the “acetate switch” as it exists in selected eubacteria, archaea, and eukaryotes, including humans, is described. PMID:15755952

Wolfe, Alan J.

2005-01-01

173

A nitrilo-tri-acetic-acid/acetic acid route for the deposition of epitaxial cerium oxide films as high temperature superconductor buffer layers  

SciTech Connect

A water based cerium oxide precursor solution using nitrilo-tri-acetic-acid (NTA) and acetic acid as complexing agents is described in detail. This precursor solution is used for the deposition of epitaxial CeO{sub 2} layers on Ni-5at%W substrates by dip-coating. The influence of the complexation behavior on the formation of transparent, homogeneous solutions and gels has been studied. It is found that ethylenediamine plays an important role in the gelification. The growth conditions for cerium oxide films were Ar-5% gas processing atmosphere, a solution concentration level of 0.25 M, a dwell time of 60 min at 900 {sup o}C and 5-30 min at 1050 {sup o}C. X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscopy (AFM), pole figures and spectroscopic ellipsometry were used to characterize the CeO{sub 2} films with different thicknesses. Attenuated total reflection-Fourier transform infrared (ATR-FTIR) was used to determine the carbon residue level in the surface of the cerium oxide film, which was found to be lower than 0.01%. Textured films with a thickness of 50 nm were obtained. - Graphical abstract: Study of the complexation and hydrolysis behavior of Ce{sup 4+} ions in the presence of nitrilo-tri-acetic acid and the subsequent development of an aqueous chemical solution deposition route suited for the processing of textured CeO{sub 2} buffer layers on Ni-W tapes.

Thuy, T.T.; Lommens, P.; Narayanan, V.; Van de Velde, N.; De Buysser, K.; Herman, G.G.; Cloet, V. [Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281 - S3, 9000 Gent (Belgium); Van Driessche, I., E-mail: Isabel.Vandriessche@UGent.b [Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281 - S3, 9000 Gent (Belgium)

2010-09-15

174

Anodic generation of cerium (IV) at glassy carbon in acetic acid and coulometric titrations with the generated reagent  

Microsoft Academic Search

Conditions for electrochemical generation of cerium(IV) at glassy carbon in acetic acid in the presence of alkali-metal acetates and sodium perchlorate, respectively, were investigated. A high current efficiency was achieved in anodic oxidation of cerium(III) in acetate supporting electrolytes. Coulometric titration methods for the determination of reducing substances with the generated oxidant were also developed. The end-points were determined by

Tibor J. Pastor; Vojka V. Antonijevi?

1993-01-01

175

Kinetic analysis on formation of poly(3-hydroxybutyrate) from acetic acid by Ralstonia eutropha under chemically defined conditions  

Microsoft Academic Search

  Batch cultures of Ralstonia eutropha in chemically defined media with acetic acid (HAc) as the sole carbon source were conducted to investigate acetate utilization,\\u000a formation of poly(3-hydroxybutyrate) (PHB) and growth of active biomass (ABM) under different carbon to nitrogen (C\\/N) weight\\u000a ratios. The specific acetate utilization rate based on ABM approached 0.16 g\\/g ABM h?1, which was not affected very

J Wang; J Yu

2001-01-01

176

PolarIndole-3-acetic AcidDiffusion inNonliving and  

Microsoft Academic Search

Polarindole-3-acetic acidmovementwasobserved inkilled plantsegments andinartificial modelsystems. Thepolar dif- fusion ofindole-3-acetic acidwasobserved intissue killed by chemical orphysical meansinan agar-plant systemandina multicelled Plexiglas dialysis chambercontaining hypocotyl tissue gradients orgradients ofanionexchange material. Itwassuggested thatpolar indole-3-acetic acidmovement in excised segments maybeareflection ofthediffusion ofindole- 3-acetic acidthrough asymmetric gradients ofmaterials with binding characteristics somewhatsimilar toionexchange. Thatpolar movementofIAA isan active process, pre- sumably dependent upon\\

W. R. KRUL

177

Acidic ionic liquid as "quasi-homogeneous" catalyst for controllable synthesis of cellulose acetate.  

PubMed

In this paper, we demonstrated that acidic ionic liquids (ILs) can be used as "quasi-homogeneous" catalysts for the efficient acetylation of cellulose. Unlike existing techniques that use large amount of ILs as solvent to dissolve and acetylate cellulose, a small amount of acidic ILs was used as catalyst in this study to overcome the low efficiency associated with relatively high viscosity and costs of ILs during homogeneous acetylation. Fully substituted cellulose acetate with a conversion of 88.8% was obtained by using only 9mol% IL 1-vinyl-3-(3-sulfopropyl) imidazolium hydrogen sulfate as catalyst, which is much higher than that of common commercialized solid acid catalysts. The degree of substitution and solubility of the obtained cellulose acetate can be facilely controlled by varying the concentration of ILs and reaction time. The dual function of swelling and catalyzing of acidic ILs for the acetylation of cellulose is responsible for the excellent catalytic performance. PMID:25256462

Tian, Dong; Han, Yangyang; Lu, Canhui; Zhang, Xinxing; Yuan, Guiping

2014-11-26

178

Regulation of Acetate Kinase Isozymes and Its Importance for Mixed-Acid Fermentation in Lactococcus lactis  

PubMed Central

Acetate kinase (ACK) converts acetyl phosphate to acetate along with the generation of ATP in the pathway for mixed-acid fermentation in Lactococcus lactis. The reverse reaction yields acetyl phosphate for assimilation purposes. Remarkably, L. lactis has two ACK isozymes, and the corresponding genes are present in an operon. We purified both enzymes (AckA1 and AckA2) from L. lactis MG1363 and determined their oligomeric state, specific activities, and allosteric regulation. Both proteins form homodimeric complexes, as shown by size exclusion chromatography and static light-scattering measurements. The turnover number of AckA1 is about an order of magnitude higher than that of AckA2 for the reaction in either direction. The Km values for acetyl phosphate, ATP, and ADP are similar for both enzymes. However, AckA2 has a higher affinity for acetate than does AckA1, suggesting an important role under acetate-limiting conditions despite the lower activity. Fructose-1,6-bisphosphate, glyceraldehyde-3-phosphate, and phospho-enol-pyruvate inhibit the activities of AckA1 and AckA2 to different extents. The allosteric regulation of AckA1 and AckA2 and the pool sizes of the glycolytic intermediates are consistent with a switch from homolactic to mixed-acid fermentation upon slowing of the growth rate. PMID:24464460

Puri, Pranav; Goel, Anisha; Bochynska, Agnieszka

2014-01-01

179

Energetics of Sheep Concerned with the Utilization of Acetic Acid1'2  

Microsoft Academic Search

The efficiency of utilization for growth-fattening, of the energy of diets resulting in high (5.4:1) and low (3.1:1) ratios of acetic acid to propionic acid in the ruminai ingesta was determined in 24 intact male and 24 female sheep by means of a slaughter-analysis experiment. To establish the chemical composition and energy value of the body at the beginning of

L. S. BULL; J. T. REID; E. JOHNSON

2010-01-01

180

Enantioselective Additions of Boronates to Chromene Acetals Catalyzed by a Chiral Brønsted acid-Lewis acid System  

PubMed Central

Chiral ?,?-dihydroxy carboxylic acids catalyze the enantioselective addition of alkenyl- and aryl boronates to chromene acetals. The optimal carboxylic acid is a tartaric acid amide, easily synthesized via a 3-step procedure. The reaction is enhanced by the addition of Lanthanide triflate salts such as cerium(IV)-and ytterbium(III) triflate. The chiral Brønsted acid and metal Lewis acid may be used in as low as 5 mol % relative to acetal substrate. Optimization of the reaction conditions can lead to yields >70% and enantiomeric ratios as high as 99:1. Spectroscopic and kinetic mechanistic studies demonstrate an exchange process leading to a reactive dioxoborolane intermediate leading to enantioselective addition to the pyrylium generated from the chromene acetal. PMID:20721997

Moquist, Philip N.; Kodama, Tomohiro; Schaus, Scott E.

2011-01-01

181

Exogenous treatment with indole-3-acetic acid and salicylic acid alleviates cadmium toxicity in wheat seedlings.  

PubMed

The seedlings of wheat were grown in the presence of CdCl2 (500 or 1000 ?M Cd), were applied with 500 ?M of indole-3-acetic acid (IAA) or 500 ?M salicylic acid (SA) as seed soaking and were sampled at 56 days after sowing. The plants exposed to Cd exhibited a substantial decline in growth, pigment content, relative water content (RWC) activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POX) and leaf structure. However, pretreatment with IAA or SA mitigated the stress generated by Cd and markedly improved the aforesaid parameters. The Cd increased proline content, electrolyte leakage and plant Cd content. However, the IAA or SA treatment attenuated the adverse effects of Cd on these attributes. The results showed that pretreatment with IAA or SA enhanced the antioxidant defense activities in Cd stressed wheat, thus alleviating Cd induced oxidative damage and enhancing Cd tolerance and leaf anatomy. PMID:23684274

Agami, Ramadan A; Mohamed, Gamal F

2013-08-01

182

Acetobacter ghanensis sp. nov., a novel acetic acid bacterium isolated from traditional heap fermentations of Ghanaian cocoa beans  

Microsoft Academic Search

Twenty-three acetic acid bacteria, isolated from traditional heap fermentations of Ghanaian cocoa beans, were subjected to a polyphasic taxonomic study. The isolates were catalase-positive, oxidase-negative, Gram-negative rods. They oxidized ethanol to acetic acid and were unable to produce 2-ketogluconic acid, 5-ketogluconic acid and 2,5-diketogluconic acid from glucose; therefore, they were tentatively identified as Acetobacter species. 16S rRNA gene sequencing and

Ilse Cleenwerck; Nicholas Camu; Katrien Engelbeen; Tom De Winter; Katrien Vandemeulebroecke; Paul De Vos; Luc De Vuyst

2007-01-01

183

Broiler chick responses to anorectic agents: dietary acetic and propionic acids and the blood metabolites.  

PubMed

The effects of dietary supplementation with acetic or propionic acid, given at a level of 3% of diets containing 2,500 or 2,750 kcal of metabolizable energy per kg, on levels of blood glucose, and on lipid, protein, and energy metabolisms were studied in female broiler chicks. Voluntary feed and energy intakes, as well as body weight gain, decreased significantly with the inclusion of the acids in either diet, in decreasing order of effect: propionate > acetate > nonsupplemented controls. The relative weight of the abdominal adipose tissue decreased significantly with the inclusion of either acid, but was unaffected by dietary energy level. In contrast, the weight of the liver was higher in birds fed the low-energy diet, but was unaffected by the anorectic agents. Inclusion of the acids increased the concentration of volatile fatty acids in the cecum and blood plasma. The rate of clearance of plasma propionate was greater than that of acetate. Anorectic agents and dietary energy density exhibited a synergistic effect on feed intake. These agents altered blood metabolites involved in lipid and energy metabolisms, but not in that of protein. Plasma metabolites and enzymes, particularly beta-hydroxybutyrate and alkaline phosphatase, reflected the degree of feed restriction, supporting the hypothesis that the hypophagic effect of these acids is due to metabolic intervention. PMID:7625770

Pinchasov, Y; Elmaliah, S

1995-01-01

184

REACTIONS OF SAMARIUM IONS WITH ETHYLENEDIAMINETETRA ACETIC ACID  

Microsoft Academic Search

Specific electric conductivity and electromotive forces of isomolar ; serles and series with constant concentrations of samarium were measured in SmCl--; NaâHâY--HâO, SmClâNaâHY--HâO, and Sm(NOâ; )â--NaY--HâO systems. It was found that in acid media the solution ; forms an H (SmY) which dissociates into H\\/sup +\\/ and STASmY!⁻. In alkali ; media a complex anion STASmY!⁻ is formed. The constant

I. V. Tananaev; G. V. Shevchenko

1961-01-01

185

Developmental Regulation of Indole-3-Acetic Acid Turnover in Scots Pine Seedlings1  

PubMed Central

Indole-3-acetic acid (IAA) homeostasis was investigated during seed germination and early seedling growth in Scots pine (Pinus sylvestris). IAA-ester conjugates were initially hydrolyzed in the seed to yield a peak of free IAA prior to initiation of root elongation. Developmental regulation of IAA synthesis was observed, with tryptophan-dependent synthesis being initiated around 4 d and tryptophan-independent synthesis occurring around 7 d after imbibition. Induction of catabolism to yield 2-oxindole-3-acetic acid and irreversible conjugation to indole-3-acetyl-N-aspartic acid was noticed at the same time as de novo synthesis was first detected. As a part of the homeostatic regulation IAA was further metabolized to two new conjugates: glucopyranosyl-1-N-indole-3-acetyl-N-aspartic acid and glucopyranosyl-1-N-indole-3-acetic acid. The initial supply of IAA thus originates from stored pools of IAA-ester conjugates, mainly localized in the embryo itself rather than in the general nutrient storage tissue, the megagametophyte. We have found that de novo synthesis is first induced when the stored pool of conjugated IAA is used up and additional hormone is needed for elongation growth. It is interesting that when de novo synthesis is induced, a distinct induction of catabolic events occurs, indicating that the seedling needs mechanisms to balance synthesis rates for the homeostatic regulation of the IAA pool. PMID:11154354

Ljung, Karin; Ostin, Anders; Lioussanne, Laetitia; Sandberg, Goran

2001-01-01

186

Firmness and cell wall characteristics of pasteurized jalapeno pepper rings affected by acetic acid, calcium chloride and preheating  

E-print Network

pasteurization and storage, especially when high acid brines are used. Development of treatments to retard softening may result in a higher quality product. This study was undertaken to investigate the effects of calcium chloride (CaCI2), acetic acid...

Burma, Prashanthi V

2012-06-07

187

STABILITY OF MFI ZEOLITE-FILLED PDMS MEMBRANES DURING PERVAPORATIVE ETHANOL RECOVERY FROM AQUEOUS MIXTURES CONTAINING ACETIC ACID  

EPA Science Inventory

Pervaporation is a potential process for recovering bioethanol produced from biomass fermentation. Fermentation broths contain ethanol, water, and a variety of other compounds, often including carboxylic acids. The effects of acetic acid on long-term pervaporation of aqueous et...

188

Clostridium stain which produces acetic acid from waste gases  

DOEpatents

A method and apparatus for converting waste gases from industrial processes such as oil refining, carbon black, coke, ammonia, and methanol production, into useful products. The method includes introducing the waste gases into a bioreactor where they are fermented to various organic acids or alcohols by anaerobic bacteria within the bioreactor. These valuable end products are then recovered, separated and purified. In an exemplary recovery process, the bioreactor raffinate is passed through an extraction chamber into which one or more non-inhibitory solvents are simultaneously introduced to extract the product. Then, the product is separated from the solvent by distillation. Gas conversion rates can be maximized by use of centrifuges, hollow fiber membranes, or other means of ultrafiltration to return entrained anaerobic bacteria from the bioreactor raffinate to the bioreactor itself, thus insuring the highest possible cell concentration.

Gaddy, James L. (2207 Tall Oaks Dr., Fayetteville, AR 72703)

1997-01-01

189

Deciphering the origin of cooperative catalysis by dirhodium acetate and chiral spiro phosphoric acid in an asymmetric amination reaction.  

PubMed

The mechanism of asymmetric amination of diazo-acetate by tert-butyl carbamate catalyzed by dirhodium tetra(trifluoro)acetate and chiral SPINOL-phosphoric acid is examined using DFT (M06 and B3LYP) computations. A cooperative participation of both catalysts is noticed in the stereo-controlling transition state of the reaction. PMID:25313895

Kisan, Hemanta K; Sunoj, Raghavan B

2014-12-01

190

Influence of Dilute Acetic Acid Treatments on American Pondweed Winter Buds in the Nevada Irrigation District, California  

Microsoft Academic Search

American pondweed ( Potamogeton nodosus Poir.) is com- monly found in northern California irrigation canals. The purpose of this study was to test the hypothesis that exposure of American pondweed winter buds to dilute acetic acid un- der field conditions would result in reduced subsequent bio- mass. The treatment consisted of adding either 1703 or 3406 L of 2.3% acetic

D. F. SPENCER; C. L. ELMORE; G. G. KSANDER; J. A. RONCORONI

191

Chemical Behaviour of Zirconium Oxychloride Octahydrate and Acetic Acid in Precursor Solution for Zirconia Film Formation on Glass  

Microsoft Academic Search

Precursor solutions for zirconia films on soda lime silica glass substrate were prepared from zirconium oxychloride octahydrate (ZOO) and acetic acid (HOAC) maintaining the mol ratios, [HOAC]\\/[ZOO] = 2, 4, 6, 8 and 10. A characteristic UV absorption band at ~280 nm in the ~120 h aged precursor solutions was identified for acetate group of the zirconium acetato complexed species.

Sunirmal Jana; K. Biswas

1997-01-01

192

Acetic Acid Recovery from Fast Pyrolysis Oil. An Exploratory Study on Liquid-Liquid Reactive Extraction using Aliphatic Tertiary Amines  

Microsoft Academic Search

Flash pyrolysis oil or Bio-oil (BO), obtained by flash pyrolysis of lignocellulosic biomass, is very acidic in nature. The major component responsible for this acidity is acetic acid, present in levels up to 2–10 wt%. Here, we report an exploratory study on BO upgrading by reactive extraction of acetic acid using long-chain tertiary amines in a batch set-up. Factors affecting the

F. H. Mahfud; F. P. van Geel; R. H. Venderbosch; H. J. Heeres

2008-01-01

193

Decadal variations of rainwater formic and acetic acid concentrations in Wilmington, NC, USA  

NASA Astrophysics Data System (ADS)

Concentrations of formic and acetic acid from January 2008 through March 2009 were compared to two previous studies at this location (conducted in 1987-1990 and 1996-1998) in order to quantify the extent to which temporal changes in DOC and pH can be explained by changes in these organic acids. The volume weighted 2008 formic and acetic acid concentrations (5.6 and 2.6 ?M respectively) have decreased dramatically compared with those observed during the 1996-1998 study (9.9 and 7.3 ?M) and are also lower than concentrations observed in the 1987-1990 study (7.4 and 3.6 ?M). Changes in formic and acetic acids between 1996-97 and 2008 can account for approximately 50% of the DOC change and 40% of the H + change in rainwater over this same time period. These changes are most pronounced during the growing season, which is also the tourist and high traffic season at this location. Determining causation of these changes is difficult due to multiple biogenic and anthropogenic sources. However, the ratio of formic to acetic acid has also reverted back to a value consistent with reduced vehicular emissions, possibly related to the introduction of improved emission control technology including the use of reformulated gasoline in the late 1990's. Long term monitoring of seasonal, annual, and decadal trends will be of critical importance for evaluating the effects of future changes to atmospheric inputs such as the increased use of ethanol and other alternative fuels.

Willey, Joan D.; Glinski, Donna A.; Southwell, Melissa; Long, Michael S.; Avery, G. Brooks, Jr.; Kieber, Robert J.

2011-02-01

194

Influence of Acidic pH on Hydrogen and Acetate Production by an Electrosynthetic Microbiome  

PubMed Central

Production of hydrogen and organic compounds by an electrosynthetic microbiome using electrodes and carbon dioxide as sole electron donor and carbon source, respectively, was examined after exposure to acidic pH (?5). Hydrogen production by biocathodes poised at ?600 mV vs. SHE increased>100-fold and acetate production ceased at acidic pH, but ?5–15 mM (catholyte volume)/day acetate and>1,000 mM/day hydrogen were attained at pH ?6.5 following repeated exposure to acidic pH. Cyclic voltammetry revealed a 250 mV decrease in hydrogen overpotential and a maximum current density of 12.2 mA/cm2 at ?765 mV (0.065 mA/cm2 sterile control at ?800 mV) by the Acetobacterium-dominated community. Supplying ?800 mV to the microbiome after repeated exposure to acidic pH resulted in up to 2.6 kg/m3/day hydrogen (?2.6 gallons gasoline equivalent), 0.7 kg/m3/day formate, and 3.1 kg/m3/day acetate (?=?4.7 kg CO2 captured). PMID:25333313

LaBelle, Edward V.; Marshall, Christopher W.; Gilbert, Jack A.; May, Harold D.

2014-01-01

195

DFT computation and experimental analysis of vibrational and electronic spectra of phenoxy acetic acid herbicides  

NASA Astrophysics Data System (ADS)

An absolute vibrational analysis has been attempted on the basis of experimental FTIR and NIR-FT Raman spectra with calculated vibrational wavenumbers and intensities of phenoxy acetic acids. The equilibrium geometry, bonding features and harmonic vibrational wavenumbers have been calculated with the help of B3LYP method with Dunning correlation consistent basis set aug-cc-pVTZ. The electronic structures of molecular fragments were described in terms of natural bond orbital analysis, which shows intermolecular Osbnd H⋯O and intramolecular Csbnd H⋯O hydrogen bonds. The electronic absorption spectra with different solvents have been investigated in combination with time-dependent density functional theory calculation. The pKa values of phenoxy acetic acids were compared.

Arul Dhas, D.; Hubert Joe, I.; Roy, S. D. D.; Balachandran, S.

2013-05-01

196

Effect of different fertilization treatments on indole-3-acetic acid producing bacteria in soil  

Microsoft Academic Search

Purpose  Soil microorganisms directly affect the growth of plants. Especially, plant growth-promoting rhizobacteria (PGPR) play an\\u000a important role in plant growth. There are many studies about the effects of different fertilization treatments on soil microbial\\u000a community structure; however, the effects on PGPR, including indole-3-acetic acid (IAA)-producing bacteria have not been previously\\u000a reported. The objective of this study is to determine the

Chao-Lei Yuan; Cheng-Xiang Mou; Wen-Liang Wu; Yan-Bin Guo

2011-01-01

197

Solvation model for acetic acid in binary mixtures of cyclohexane–1,2-dichloroethane  

Microsoft Academic Search

The partition of acetic acid between aqueous solutions and various binary mixtures of 1,2-dichloroethane and cyclohexane were studied at 30.0°C. The observed nonlinearities of both monomer partition coefficient and dimerization constant in the organic phase with the mole fraction of 1,2-dichloroethane are interpreted in terms of the preferential solvation of various solvation sites of the involved species. Two polar sites

A. I. Abu-Shady; H. F. Al-Mudhaf; M. F. Hegazi

2004-01-01

198

Indole-3-acetic acid (IAA) production by Arthrobacter species isolated from Azolla.  

PubMed

Arthrobacter species, isolated from the leaf cavities and the microsporocarps of the aquatic fern species Azolla pinnata and Azolla filiculoides, produced indole-3-acetic acid (IAA) in culture when the precursor tryptophan was added to the medium. No IAA production was detected in the absence of tryptophan. Maximum IAA formation was obtained in the first 2 d of incubation. Part of the tryptophan was transformed to N alpha-acetyl-L-tryptophan. PMID:1564446

Forni, C; Riov, J; Grilli Caiola, M; Tel-Or, E

1992-02-01

199

(Aminooxy)acetic acid inhibits petunia growth and gibberellin- and cytokinin-stimulated growth in bioassays  

Microsoft Academic Search

(Aminooxy)acetic acid (AOA) was applied to greenhouse-grown petunias and was used in bioassays for three plant growth hormones\\u000a so that its growth regulator properties could be studied. In greenhouse studies foliar sprays of 4.8–12 mm AOA inhibited vegetative growth of petunia seedlings (Petunia xhybrida Vilm. ‘White Flash’). When gibberellin A 3 (GA3) was applied to shoot tips previously treated with

Philip E. Hammer; David S. Koranski; Richard J. Gladont

1995-01-01

200

On the unusual IR spectra of the acetic acid-trimethylamine complex in low temperature matrices  

NASA Astrophysics Data System (ADS)

Usually the stretching vibration of the A-H group in hydrogen-bonded complexes gives an intense, broad absorption in the IR spectrum. However in a few complexes it has proved difficult to detect this absorption in low temperature matrices. In this work the Ratajczak-Yaremko vibrational model of the hydrogen bond has been applied to simulate the IR spectrum obtained for one such complex: the acetic acid-trimethylamine, ACA-TMA, hydrogen bonded complex isolated in an argon matrix.

Ratajczak, Henryk; Wierzejewska, Maria; Barnes, Austin J.; Yaremko, Anatoly M.; Virko, Serdej V.

2014-06-01

201

Paper chromatography of unsaturated fatty acid esters as their mercuric acetate addition compounds  

Microsoft Academic Search

Summary  A method is described by which unsaturated fatty acid esters can be separated and identified by reversed-phase paper chromatography.\\u000a The procedure is based upon the formation of the mercuric acetate addition compounds of the esters and the detection of the\\u000a compounds on the chromatograms, using the sensitive color reaction with diphenylcarbazone. The application of this technique\\u000a to the analysis of

Yoshiyuki Inouye; Manjiro Noda; Osamu Hirayama

1955-01-01

202

Effect of yeast extract on Escherichia coli growth and acetic acid production  

Microsoft Academic Search

Fed batch cultures were performed to investigate the effect of yeast extract concentration on the kinetics of growth and acetic acid production of recombinant Escherichia coli BL21 in a synthetic medium. Three runs were performed with 40g\\/l total glucose concentration. The yeast extract\\/glucose ratio (YE\\/G; w\\/w), was 0.1, 0.05 and 0.025 in the feed. These decreasing YE\\/G values did not

D. C. Suárez; C. W. Liria; B. V. Kilikian

1998-01-01

203

Determination of Endogenous Indole-3-Acetic Acid in Plagiochila arctica (Hepaticae) 1  

PubMed Central

Endogenous indole-3-acetic acid (IAA) was found in axenically cultured gametophytes of the leafy liverwort, Plagiochila arctica Bryhn and Kaal., by high-performance liquid chromatography with electrochemical detection. Identification of the methylated auxin was confirmed by gas chromatography-mass spectrometry. Addition of 57 micromolar IAA to cultures increased relative production of ethylene. This is the first definitive (gas chromatography-mass spectrometry) demonstration of the natural occurrence of IAA in a bryophyte. PMID:16664164

Law, David M.; Basile, Dominick V.; Basile, Margaret R.

1985-01-01

204

Kinetics and Mechanism of Oxidation of Hydroquinone by Tetrabutylammonium Tribromide Ion in Aqueous Acetic Acid  

Microsoft Academic Search

The oxidation of hydroquinone by environmentally benign tetrabutyl ammonium tribromide (TBATB) was carried out in 50% V\\/V\\u000a aqueous acetic acid medium under pseudo-first-order conditions, keeping a large excess of hydroquinone over the oxidant. The\\u000a main reactive species of oxidant and substrate were found to be the ion and hydroquinone, respectively. The reaction proceeds with prior complex formation between the reactants

S. N. Zende; V. A. Kalantre; G. S. Gokavi

2010-01-01

205

The possible action mechanisms of indole-3-acetic acid methyl ester in Arabidopsis  

Microsoft Academic Search

We previously reported that Arabidopsis indole-3-acetic acid (IAA)-methyltransferase-1 (IAMT1) catalyzes the conversion of IAA, an essential phytohormone, to methyl-IAA\\u000a (MeIAA) and that IAMT1 plays an important role in leaf development. Here, we present the possible mechanisms of action of MeIAA in Arabidopsis. We showed that MeIAA was more potent than IAA in the inhibition of hypocotyl elongation and that MeIAA

Linchuan Li; Xianhui Hou; Tomohiko Tsuge; Maoyu Ding; Takashi Aoyama; Atsuhiro Oka; Hongya Gu; Yunde Zhao; Li-Jia Qu

2008-01-01

206

Biomass retention and performance of anaerobic fixed-film reactors treating acetic acid wastewater  

Microsoft Academic Search

An acetic-acid-based synthetic wastewater of different organic concentrations was successfully treated at 35 degrees C in anaerobic downflow fixed-film reactors operated at high organic loading rates and short hydraulic retention times (HRTs). Substrate removal and methane production rates close to theoretical values of complete volumetric chemical oxygen demand (COD) removal and maximum methane conversion were obtained. A high concentration of

M. F. Hamoda; K. J. Kennedy

1987-01-01

207

Effect of glyphosate on indole-3-acetic acid metabolism in tolerant and susceptible plants  

Microsoft Academic Search

A comparison study was conducted on the effect of glyphosate (N-[phosphonomethyl]glycine) on indole-3-[2-14C]acetic acid (IAA) metabolism, ethylene production, and growth of 7-day-old seedlings of different plants. The plants tested\\u000a were American germander (Teucrium canadense L.), soybean (Glycine max L. Merr.), pea (Pisum sativum L. cv. Alaska and Little marvel), mungbean (Vigna radiata L.), and buckwheat (Fagopyrum esculentum Moench). A spray

T. T. Lee; T. Dumas

1985-01-01

208

Utilization of the Plant Hormone Indole3Acetic Acid for Growth by Pseudomonas putida Strain 1290  

Microsoft Academic Search

We have isolated from plant surfaces several bacteria with the ability to catabolize indole-3-acetic acid (IAA). One of them, isolate 1290, was able to utilize IAA as a sole source of carbon, nitrogen, and energy. The strain was identified by its 16S rRNA sequence as Pseudomonas putida. Activity of the enzyme catechol 1,2-dioxygenase was induced during growth on IAA, suggesting

Johan H. J. Leveau; Steven E. Lindow

2005-01-01

209

Alkaline pre-treatment of rice hulls for hydrothermal production of acetic acid  

Microsoft Academic Search

To solve the blockage caused by silica during the hydrothermal conversion of rice hulls into acetic acid in a continuous-flow reactor, the removal of silica from rice hulls and the retainment of organics by alkaline extraction were carried out in a range of pH values from 5 to 12 and temperatures from 30 to 85°C. It was found that the

Yamin Hsieh; Yingxun Du; Fangming Jin; Zhouyu Zhou; Heiji Enomoto

2009-01-01

210

The lifespan-promoting effect of acetic acid and Reishi polysaccharide  

Microsoft Academic Search

Using Caenorhabditis elegans as a model organism, various natural substances and commercial health-food supplements were screened to evaluate their effects on longevity. Among the substances tested, acetic acid and Reishi polysaccharide fraction 3 (RF3) were shown to increase the expression of the lifespan and longevity-related transcription factor DAF-16 in C. elegans. We have shown that RF3 activates DAF-16 expression via

Ming-Hong Chuang; Shyh-Horng Chiou; Chun-Hao Huang; Wen-Bin Yang; Chi-Huey Wong

2009-01-01

211

Oxidative Decarboxylation of Indole3-acetic Acid by Mangani-Versene and by Wheat Leaf Enzyme  

Microsoft Academic Search

THERE is little agreement concerning either the pathway or the final products of the enzymic oxidation of heteroauxin1. The stoichiometry of the oxidative decarboxylation seems to be reasonably well established1, one mole of oxygen being taken up and one of carbon dioxide evolved for every mole of indole-3-acetic acid (IAA) reacting. Galston2 reported that no indole-3-aldehyde was formed when IAA

R. A. Abramovitch; K. S. Ahmed

1961-01-01

212

Antibacterial action of acetic acid soluble material isolated from Mucor rouxii and its application onto textile  

Microsoft Academic Search

Acetic acid soluble material (AcSM) is a chitosan-rich fraction isolated from the fungal cell wall materials. The final step in the traditional production of fungal chitosan is the separation of chitosan from the cell wall AcSM via raising the pH to 9–10 followed by centrifugation. This step results in further undesirable economic and environmental effects. The goal of this paper

Shaaban Moussa; Atef Ibrahim; Adel Okba; Hanafy Hamza; Klaus Opwis; Eckhard Schollmeyer

2011-01-01

213

Potentiometric investigations of (acid + base) equilibria in ( n-butylamine + acetic acid) systems in binary (acetone + cyclohexane) solvent mixtures  

Microsoft Academic Search

By using the potentiometric titration method, standard equilibrium constants have been determined of acid dissociation of molecular acid, Ka(HA), cationic acid, Ka(BH+), of anionic and cationic homoconjugation, KAHA-andKBHB+, respectively, and of molecular heteroconjugation, KAHB (KBHA), in (acid+base) systems without proton transfer consisting of n-butylamine and acetic acid in binary (acetone+cyclohexane) solvent mixtures. The results have shown that both the pKa(HA)

Ma?gorzata Czaja; Anna Kozak; Mariusz Makowski; Lech Chmurzy?ski

2005-01-01

214

Membrane lipid physiology and toxin catabolism underlie ethanol and acetic acid tolerance in Drosophila melanogaster.  

PubMed

Drosophila melanogaster has evolved the ability to tolerate and utilize high levels of ethanol and acetic acid encountered in its rotting-fruit niche. Investigation of this phenomenon has focused on ethanol catabolism, particularly by the enzyme alcohol dehydrogenase. Here we report that survival under ethanol and acetic acid stress in D. melanogaster from high- and low-latitude populations is an integrated consequence of toxin catabolism and alteration of physical properties of cellular membranes by ethanol. Metabolic detoxification contributed to differences in ethanol tolerance between populations and acclimation temperatures via changes in both alcohol dehydrogenase and acetyl-CoA synthetase mRNA expression and enzyme activity. Independent of changes in ethanol catabolism, rapid thermal shifts that change membrane fluidity had dramatic effects on ethanol tolerance. Cold temperature treatments upregulated phospholipid metabolism genes and enhanced acetic acid tolerance, consistent with the predicted effects of restoring membrane fluidity. Phospholipase D was expressed at high levels in all treatments that conferred enhanced ethanol tolerance, suggesting that this lipid-mediated signaling enzyme may enhance tolerance by sequestering ethanol in membranes as phophatidylethanol. These results reveal new candidate genes underlying toxin tolerance and membrane adaptation to temperature in Drosophila and provide insight into how interactions between these phenotypes may underlie the maintenance of latitudinal clines in ethanol tolerance. PMID:16985200

Montooth, Kristi L; Siebenthall, Kyle T; Clark, Andrew G

2006-10-01

215

Antibacterial power of sodium hypochlorite combined with surfactants and acetic Acid.  

PubMed

The aim of this ex vivo study was to compare the antibacterial power of 1% NaOCl with 1% acetic acid, 5.25% NaOCl and two commercially available NaOCl modified with surfactants in bovine root dentin. A total of 120 dentin tubes prepared from intact bovine incisors were infected for 21 days with Enterococcus faecalis and randomly divided into six groups as follows: 5.25%NaOCl; Hypoclean; Chlor-Xtra; 1% NaOCl with 1% acetic acid; infected dentin tubes (positive control); and sterile dentin tubes (negative control). At experimental times of 0, 7, 14, 21 and 28 days, dentin chips were collected using sequential round burs with increasing diameters in separate test tubes containing 3 mL of freshly prepared BHI. Statistical analysis were performed using parametric methods (one-way ANOVA, and Bonferroni's multiple comparisons test, ?=0.01). After culturing, the number of colony-forming units (CFU) was counted. All the NaOCl solutions showed small number of CFU over 28 days. ChlorXtra and Hypoclean had the smallest number of CFU at all times with greater antimicrobial efficacy than 5.25% NaOCl and 1% NaOCl solution with 1% acetic acid. PMID:25250491

Giardino, Luciano; Estrela, Carlos; Mohammadi, Zahed; Palazzi, Flavio

2014-01-01

216

Stability of MFI zeolite-filled PDMS membranes during pervaporative ethanol recovery from aqueous mixtures containing acetic acid  

Microsoft Academic Search

Pervaporation is a potential process for recovering bioethanol produced from biomass fermentation. Fermentation broths contain ethanol, water, and a variety of other compounds, often including carboxylic acids. The effects of acetic acid on long-term pervaporation of aqueous ethanol mixtures through high-silica ZSM-5 zeolite-filled polydimethylsiloxane (PDMS; silicone rubber) membranes were investigated. Acetic acid was shown to reduce the ethanol removal effectiveness

Travis C. Bowen; Richard G. Meier; Leland M. Vane

2007-01-01

217

Recognition of 2-aminothiazole-4-acetic acid derivatives by the peptide transporters PEPT1 and PEPT2  

Microsoft Academic Search

The H+\\/peptide cotransporters PEPT1 and PEPT2 have gained considerable interest in pharmaceutical sciences as routes for drug delivery. It is, therefore, of interest to develop uncommon artificial substrates for the two carriers. This study was initiated to investigate the binding affinity of 2-aminothiazole-4-acetic acid (ATAA) conjugates with amino acids to PEPT1 and PEPT2. The 2-aminothiazole-4-acetic acid derivatives have been synthesised

Annegret Biegel; Sabine Gebauer; Bianka Hartrodt; Ilka Knütter; Klaus Neubert; Matthias Brandsch; Iris Thondorf

2007-01-01

218

Acetic Acid Activates the AMP-Activated Protein Kinase Signaling Pathway to Regulate Lipid Metabolism in Bovine Hepatocytes  

PubMed Central

The effect of acetic acid on hepatic lipid metabolism in ruminants differs significantly from that in monogastric animals. Therefore, the aim of this study was to investigate the regulation mechanism of acetic acid on the hepatic lipid metabolism in dairy cows. The AMP-activated protein kinase (AMPK) signaling pathway plays a key role in regulating hepatic lipid metabolism. In vitro, bovine hepatocytes were cultured and treated with different concentrations of sodium acetate (neutralized acetic acid) and BML-275 (an AMPK? inhibitor). Acetic acid consumed a large amount of ATP, resulting in an increase in AMPK? phosphorylation. The increase in AMPK? phosphorylation increased the expression and transcriptional activity of peroxisome proliferator-activated receptor ?, which upregulated the expression of lipid oxidation genes, thereby increasing lipid oxidation in bovine hepatocytes. Furthermore, elevated AMPK? phosphorylation reduced the expression and transcriptional activity of the sterol regulatory element-binding protein 1c and the carbohydrate responsive element-binding protein, which reduced the expression of lipogenic genes, thereby decreasing lipid biosynthesis in bovine hepatocytes. In addition, activated AMPK? inhibited the activity of acetyl-CoA carboxylase. Consequently, the triglyceride content in the acetate-treated hepatocytes was significantly decreased. These results indicate that acetic acid activates the AMPK? signaling pathway to increase lipid oxidation and decrease lipid synthesis in bovine hepatocytes, thereby reducing liver fat accumulation in dairy cows. PMID:23861826

Li, Xinwei; Chen, Hui; Guan, Yuan; Li, Xiaobing; Lei, Liancheng; Liu, Juxiong; Yin, Liheng; Liu, Guowen; Wang, Zhe

2013-01-01

219

Characterization of acetic acid bacteria in traditional acetic acid fermentation of rice vinegar (komesu) and unpolished rice vinegar (kurosu) produced in Japan.  

PubMed

Bacterial strains were isolated from samples of Japanese rice vinegar (komesu) and unpolished rice vinegar (kurosu) fermented by the traditional static method. Fermentations have never been inoculated with a pure culture since they were started in 1907. A total of 178 isolates were divided into groups A and B on the basis of enterobacterial repetitive intergenic consensus-PCR and random amplified polymorphic DNA fingerprinting analyses. The 16S ribosomal DNA sequences of strains belonging to each group showed similarities of more than 99% with Acetobacter pasteurianus. Group A strains overwhelmingly dominated all stages of fermentation of both types of vinegar. Our results indicate that appropriate strains of acetic acid bacteria have spontaneously established almost pure cultures during nearly a century of komesu and kurosu fermentation. PMID:11157275

Nanda, K; Taniguchi, M; Ujike, S; Ishihara, N; Mori, H; Ono, H; Murooka, Y

2001-02-01

220

Characterization of Acetic Acid Bacteria in Traditional Acetic Acid Fermentation of Rice Vinegar (Komesu) and Unpolished Rice Vinegar (Kurosu) Produced in Japan  

PubMed Central

Bacterial strains were isolated from samples of Japanese rice vinegar (komesu) and unpolished rice vinegar (kurosu) fermented by the traditional static method. Fermentations have never been inoculated with a pure culture since they were started in 1907. A total of 178 isolates were divided into groups A and B on the basis of enterobacterial repetitive intergenic consensus-PCR and random amplified polymorphic DNA fingerprinting analyses. The 16S ribosomal DNA sequences of strains belonging to each group showed similarities of more than 99% with Acetobacter pasteurianus. Group A strains overwhelmingly dominated all stages of fermentation of both types of vinegar. Our results indicate that appropriate strains of acetic acid bacteria have spontaneously established almost pure cultures during nearly a century of komesu and kurosu fermentation. PMID:11157275

Nanda, Kumiko; Taniguchi, Mariko; Ujike, Satoshi; Ishihara, Nobuhiro; Mori, Hirotaka; Ono, Hisayo; Murooka, Yoshikatsu

2001-01-01

221

Regeneration of Cellulose Acetate Membranes.  

National Technical Information Service (NTIS)

Several simple methods for in situ one-step regeneration of both flux and salt-retention properties of service-deteriorated membranes have been developed. Membranes have been successfully regenerated using hot, 4% acetic acid, and a one-step cleaning meth...

P. A. Cantor, W. S. Higley, C. W. Saltonstall

1970-01-01

222

CTAB and acetic acid effect in the nanocrystallite growth of spray deposited CdO thin films  

NASA Astrophysics Data System (ADS)

CdO thin films were deposited on glass substrates from cadmium acetate dihydrate along with precursor additives, acetic acid and CTAB using home built splay pyrolysis unit. XRD studies imply that the CdO thin films to be preferably oriented in the (1 1 1) plane. The Williamson-Hall plot indicates the presence of microstrain, especially high with acetic acid additive. Surface morphology was found to be closely packed spherical crystallite with precursor additives. Optical studies reveal a considerable change in the transmittance and band gap. Peak position is shifted in the Raman spectra, due to precursor additives.

Pavithra, S.; Balamurugan, D.; Pandeeswari, R.; Jeyaprakash, B. G.

2014-11-01

223

Theoretical study of the hydration of atmospheric nucleation precursors with acetic Acid.  

PubMed

While atmosphere is known to contain a significant fraction of organic substance and the effect of acetic acid to stabilize hydrated sulfuric acids is found to be close that of ammonia, the details about the hydration of (CH3COOH)(H2SO4)2 are poorly understood, especially for the larger clusters with more water molecules. We have investigated structural characteristics and thermodynamics of the hydrates using density functional theory (DFT) at PW91PW91/6-311++G(3df,3pd) level. The phenomena of the structural evolution may exist during the early stage of the clusters formation, and we tentatively proposed a calculation path for the Gibbs free energies of the clusters formation via the structural evolution. The results in this study supply a picture of the first deprotonation of sulfuric acids for a system consisting of two sulfuric acid molecules, an acetic acid molecule, and up to three waters at 0 and 298.15 K, respectively. We also replace one of the sulfuric acids with a bisulfate anion in (CH3COOH)(H2SO4)2 to explore the difference of acid dissociation between two series of clusters and interaction of performance in clusters growth between ion-mediated nucleation and organics-enhanced nucleation. PMID:25143013

Zhu, Yu-Peng; Liu, Yi-Rong; Huang, Teng; Jiang, Shuai; Xu, Kang-Ming; Wen, Hui; Zhang, Wei-Jun; Huang, Wei

2014-09-11

224

Mechanisms leading to oligomers and SOA through aqueous photooxidation: insights from OH radical oxidation of acetic acid  

NASA Astrophysics Data System (ADS)

Previous experiments have demonstrated that the aqueous OH radical oxidation of methylglyoxal produces low volatility products including oxalate and oligomers. These products are found predominantly in the particle phase in the atmosphere, suggesting that methylglyoxal is a precursor of secondary organic aerosol (SOA). Acetic acid is an important intermediate in aqueous methylglyoxal oxidation and a ubiquitous product of gas phase photochemistry, making it a potential "aqueous" SOA precursor in its own right. Altieri et al. (2008) proposed that acetic acid was the precursor of oligoesters observed in methylglyoxal oxidation. However, the fate of acetic acid upon aqueous-phase oxidation is not well understood. In this research, acetic acid at concentrations relevant to atmospheric waters (20 ?M-10 mM) was oxidized by OH radical. Products were analyzed by ion chromatography (IC), electrospray ionization mass spectrometry (ESI-MS), and IC-ESI-MS. The formation of glyoxylic, glycolic, and oxalic acids were observed. In contrast to methylglyoxal oxidation, succinic acid and oligomers were not detected. Using results from these and methylglyoxal + OH radical experiments, radical mechanisms responsible for oligomer formation from methylglyoxal oxidation in clouds and wet aerosols are proposed. The importance of acetic acid/acetate as an SOA precursor is also discussed. We hypothesize that this and similar chemistry is central to the daytime formation of oligomers in wet aerosols.

Tan, Y.; Lim, Y. B.; Altieri, K. E.; Seitzinger, S. P.; Turpin, B. J.

2011-06-01

225

Effects of acetic acid and its assimilation in fed-batch cultures of recombinant Escherichia coli containing human-like collagen cDNA  

Microsoft Academic Search

The primary processing problem in recombinant Escherichia coli fermentation is the production of acetic acid, which can inhibit both cell growth and recombinant protein production. The ability of E. coli to assimilate acetate permits it to solve this problem in a rather creative manner. In this study, the effects of acetic acid assimilation through a glucose starvation period at different

Wenjiao Xue; Daidi Fan; Longan Shang; Chenhui Zhu; Xiaoxuan Ma; Xiaoli Zhu; Yuanyuan Yu

2010-01-01

226

Oxidation of ethane to ethylene and acetic acid by MoVNbO catalysts M. Roussel1  

E-print Network

1 Oxidation of ethane to ethylene and acetic acid by MoVNbO catalysts M. Roussel1 , M. Bouchard1VNbO catalysts could be made up from (VNbMo)5O14-type microdomains embedded in MoO3 matrix seems still topical. Keywords MoVNbO catalysts; acetic acid; ethylene; mild oxidation of ethane; nanosized (VNbMo)5O14

Paris-Sud XI, Université de

227

Ions in Aqueous Acetic Acid Mixtures: Solvent Reorganization around Protons and Gibbs Energies of Transfer from Water  

Microsoft Academic Search

The photo-absorbing, basic sensor, 4-nitroaniline, has been used to determine theequilibrium constant for solvent reorganization around the proton in mixtures ofvarying composition of water with acetic acid. In all the mixtures used, theself-ionization of the acetic acid was suppressed. In contrast to mixtures of waterwith the related ethanol or acetone, this equilibrium is shifted more toward thewater-solvated species as the

Cecil F. Wells

2000-01-01

228

Indole acetic acid mimics the effect of salt stress in relation to enzymes of carbohydrate metabolism in chickpea seedlings  

Microsoft Academic Search

The effect of addition of indole acetic acid (3 µM) andNaCl (75 mM) on growth and enzymes of carbohydrate metabolism inchickpea seedlings was compared. In comparison with control seedlings, theseedlings growing in the presence of indole acetic acid (IAA) had reducedamylase activity in cotyledons and enhanced sucrose synthase (SS) and sucrosephosphate synthase (SPS) activities in cotyledons and shoots at all

Satvir Kaur; Anil K. Gupta; Narinder Kaur

2003-01-01

229

Dissociation Constant of Acetic Acid in (N,N-Dimethylformamide?+?Water) Mixtures at the Temperature 298.15 K  

Microsoft Academic Search

In the present work the thermodynamic dissociation constants of acetic acid were determined in (N,N-dimethylformamide (DMF)?+?water)\\u000a mixtures over the DMF mole fraction range from 0 to 0.65 at the temperature 298.15 K by the potentiometric titration method.\\u000a The dissociation constant in pure DMF was obtained by extrapolation and comparative calculation methods. The dependence of\\u000a the acetic acid dissociation constant on

Yuliya A. Fadeeva; Lyubov P. Safonova

2011-01-01

230

Dissociation constant of acetic acid in N-methylpropionamide from 5 to 55°C and related thermodynamic quantities  

Microsoft Academic Search

The dissociation constant of acetic acid in N-methylpropionamide (NMP) has been determined at 11 temperatures from 5 to 55°C by measurement of the electromotive force of cells without liquid junction containing hydrogen gas electrodes and silver-silver chloride electrodes. The pK at 25°C was found to be 7.995 (molal scale) as compared with 4.756 in water; thus, acetic acid is much

Edgar S. Etz; R. A. Robinson; Roger G. Bates

1972-01-01

231

Involvement of Yeast HSP90 Isoforms in Response to Stress and Cell Death Induced by Acetic Acid  

PubMed Central

Acetic acid-induced apoptosis in yeast is accompanied by an impairment of the general protein synthesis machinery, yet paradoxically also by the up-regulation of the two isoforms of the heat shock protein 90 (HSP90) chaperone family, Hsc82p and Hsp82p. Herein, we show that impairment of cap-dependent translation initiation induced by acetic acid is caused by the phosphorylation and inactivation of eIF2? by Gcn2p kinase. A microarray analysis of polysome-associated mRNAs engaged in translation in acetic acid challenged cells further revealed that HSP90 mRNAs are over-represented in this polysome fraction suggesting preferential translation of HSP90 upon acetic acid treatment. The relevance of HSP90 isoform translation during programmed cell death (PCD) was unveiled using genetic and pharmacological abrogation of HSP90, which suggests opposing roles for HSP90 isoforms in cell survival and death. Hsc82p appears to promote survival and its deletion leads to necrotic cell death, while Hsp82p is a pro-death molecule involved in acetic acid-induced apoptosis. Therefore, HSP90 isoforms have distinct roles in the control of cell fate during PCD and their selective translation regulates cellular response to acetic acid stress. PMID:23967187

Silva, Alexandra; Sampaio-Marques, Belem; Fernandes, Angela; Carreto, Laura; Rodrigues, Fernando; Holcik, Martin; Santos, Manuel A. S.; Ludovico, Paula

2013-01-01

232

[Conversion of acetic acid to methane by thermophiles]. Annual progress report  

Microsoft Academic Search

Acetate is the precursor of approximately two-thirds of the methane produced by anaerobic bioreactors and many other methanogenic habitats. Besides their intrinsic interest, thermophilic acetotrophic methanogenic cultures usually grow at least twice as fast as their mesophilic counterparts, making them more amenable to study. In recent years, attention has been mainly focused on the thermophilic acetate utilizing methanogen Methanothrix strain

Zinder

1994-01-01

233

Enantioselective Synthesis of Piperidines through the Formation of Chiral Mixed Phosphoric Acid Acetals: Experimental and Theoretical Studies.  

PubMed

An enantioselective intramolecular chiral phosphoric acid-catalyzed cyclization of unsaturated acetals has been utilized for the synthesis of functionalized chiral piperidines. The chiral enol ether products of these cyclizations undergo subsequent in?situ enantioenrichment through acetalization of the minor enantiomer. A new computational reaction exploration method was utilized to elucidate the mechanism and stereoselectivity of this transformation. Rather than confirming the originally postulated cyclization proceeding directly through a vinyl oxocarbenium ion, simulations identified an alternative two-step mechanism involving the formation of a mixed chiral phosphate acetal, which undergoes a concerted, asynchronous SN 2'-like displacement to yield the product with stereoselectivity in agreement with experimental observations. PMID:25196818

Sun, Zhankui; Winschel, Grace A; Zimmerman, Paul M; Nagorny, Pavel

2014-10-13

234

Graft Loss Due to Percutaneous Sclerotherapy of a Lymphocele Using Acetic Acid After Renal Transplantation  

SciTech Connect

Development of lymphoceles after renal transplantation is a well-described complication that occurs in up to 40% of recipients. The gold standard approach for the treatment of symptomatic cases is not well defined yet. Management options include simple aspiration, marsupialization by a laparotomy or laparoscopy, and percutaneous sclerotherapy using different chemical agents. Those approaches can be associated, and they depend on type, dimension, and localization of the lymphocele. Percutaneous sclerotherapy is considered to be less invasive than the surgical approach; it can be used safely and effectively, with low morbidity, in huge, rapidly accumulating lymphoceles. Moreover, this approach is highly successful, and the complication rate is acceptable; the major drawback is a recurrence rate close to 20%. We herewith report a renal transplant case in which the patient developed a symptomatic lymphocele that was initially treated by ultrasound-guided percutaneous sclerotherapy with ethanol and thereafter using acetic acid for early recurrence. A few hours after injection of acetic acid in the lymphatic cavity, the patient started to complain of acute pain localized to the renal graft and fever. An ultrasound of the abdomen revealed thrombosis of the renal vein and artery. The patient was immediately taken to the operating room, where the diagnosis of vascular thrombosis was confirmed and the graft was urgently explanted. In conclusion, we strongly suggest avoiding the use of acetic acid as a slerosating agent for the percutaneous treatment of post-renal transplant lymphocele because, based on our experience, it could be complicated by vascular thrombosis of the kidney, ending in graft loss.

Adani, Gian Luigi, E-mail: adanigl@hotmail.com; Baccarani, Umberto; Bresadola, Vittorio; Lorenzin, Dario [University School of Medicine, Department of Surgery and Transplantation (Italy); Montanaro, Domenico [AOSMM, Sauta Maria della Misericordia Hospital, Division of Nephrology (Italy); Risaliti, Andrea; Terrosu, Giovanni [University School of Medicine, Department of Surgery and Transplantation (Italy); Sponza, Massimo [AOSMM, Sauta Maria della Misericordia Hospital, Department of Radiology (Italy); Bresadola, Fabrizio [University School of Medicine, Department of Surgery and Transplantation (Italy)

2005-12-15

235

Hydrogen peroxide measurement in seawater by (p-hydroxyphenyl)acetic acid dimerization  

SciTech Connect

The dimerization of (p-hydroxyphenyl)acetic acid by hydrogen peroxide in the presence of peroxidase has been adapted to the determination of hydrogen peroxide in seawater. The fluorometric method presented requires only one mixed reagent for sample analysis and produces a stable product that does not require immediate measurement. Changes in reaction stoichiometry resulting from naturally occurring organic material have been addressed. The detection limit, defined as 3 times the standard deviation of the blank, is 4 and 4 nM for open ocean and coastal seawater, respectively.

Miller, W.L.; Kester, D.R.

1988-12-15

236

Identification of the metabolites of Indole3-acetic acid in growing hypocotyls of Lupinus albus  

Microsoft Academic Search

The products of indole-3-acetic acid (IAA) metabolism by incubating hypocotyl sections and decapitated seedlings of Lupinus albus were investigated. Single treatments using [1-14C]-IAA, [2-14C]-IAA or [5-3H]-IAA and double treatments using [1-14C]-IAA+[5-3H]-IAA were carried out. Extracts from treated plant material were analyzed by paper chromatography (PC), Thin layer chromatography (TLC), and high performance liquid chromatography (HPLC). When hypocotyl sections were incubated

J. Sánchez-Bravo; A. Ortuño; J. M. Botía; J. A. Del Río; M. Caballero; M. Acosta; F. Sabater

1990-01-01

237

A new CO 2 disposal process via artificial weathering of calcium silicate accelerated by acetic acid  

Microsoft Academic Search

A new disposal process for anthropogenic CO2 via an artificially accelerated weathering reaction is proposed to counteract global warming. The process is essentially composed of the following two steps:(1)CaSiO3+2CH3COOH?Ca2++2CH3COO?+H2O+SiO2(2)Ca2++2CH3COO?+CO2+H2O?CaCO3?+2CH3COOHStep (1) is the extraction of calcium ions by acetic acid from calcium silicate, for example, wollastonite rocks. Step (2) is the deposition of calcium carbonate from the solution of calcium ions

M. Kakizawa; A. Yamasaki; Y. Yanagisawa

2001-01-01

238

Further modification on phenyl acetic acid based quinolines as liver X receptor modulators.  

PubMed

A series of phenyl acetic acid based quinolines was prepared as LXR modulators. An SAR study in which the C-3 and C-8 positions of the quinoline core were varied led to the identification of two potent LXR agonists 23 and 27. Both compounds displayed good binding affinity for LXRbeta and LXRalpha, and increased expression of ABCA1 in THP-1 cells. These two compounds also had desirable pharmacokinetic profiles in mice and displayed in vivo efficacy in a 12-week Apo E knockout mouse lesion model. PMID:17391964

Hu, Baihua; Jetter, James; Kaufman, David; Singhaus, Robert; Bernotas, Ronald; Unwalla, Rayomand; Quinet, Elaine; Savio, Dawn; Halpern, Anita; Basso, Michael; Keith, James; Clerin, Valerie; Chen, Liang; Liu, Qiang-Yuan; Feingold, Irene; Huselton, Christine; Azam, Farooq; Goos-Nilsson, Annika; Wilhelmsson, Anna; Nambi, Ponnal; Wrobel, Jay

2007-05-15

239

Increases in jasmonic acid caused by indole-3-acetic acid and auxin herbicides in cleavers (Galium aparine).  

PubMed

The effects of indole-3-acetic acid and auxin herbicides on endogenous jasmonic acid (JA) concentrations were studied in relation to changes in ethylene and abscisic acid (ABA) levels in cleavers (Galium aparine). When plants were root-treated with increasing concentrations of indole-3-acetic acid (IAA), ethylene biosynthesis was stimulated in response to the accumulation of endogenous IAA in the shoot tissue. Within 25h of treatment, stimulated ethylene formation was accompanied by increases in immunoreactive concentrations of JA and ABA, which reached maxima of 4.5-fold and 26-fold of the control, respectively, at 100 microM of applied IAA. Corresponding effects were obtained using synthetic auxins and when the ethylene-releasing compound ethephon was applied exogenously. This represents the first report, to our knowledge, of an auxin-mediated increase in JA levels. The increase in JA may be triggered by ethylene. PMID:15310070

Grossmann, Klaus; Rosenthal, Cindy; Kwiatkowski, Jacek

2004-07-01

240

Kinetics and energetics of hydrogen bond dissociation in isolated acetic acid- d 1 and - d 4 and trifluoroactic acid dimers  

Microsoft Academic Search

A quantitative determination of the rate constant, activation energy, entropy, and enthalpy of dissociation of hydrogen bonds in deuterated acetic acid-d1, -d4, and trifluoroacetic acid dimers in the gas phase was performed by resonant CO2 laser photoacoustic spectroscopy. Within the experimental error, the kinetics and energetics of hydrogen bond dissociation were found to be independent of deuterium substitution of the

H. Sauren; A. Winkler; P. Hess

1995-01-01

241

Rapid molecular methods for enumeration and taxonomical identification of acetic acid bacteria responsible for submerged vinegar production  

Microsoft Academic Search

The aim of the present study was to search for a rapid and reliable method to enumerate viable acetic acid bacteria (AAB)\\u000a and to identify to genera and species level AAB isolates from vinegars in full acetic fermentation elaborated by the submerged\\u000a method from cider, wine and spirit ethanol in industrial bioreactors. Results showed that the rapid epifluorescence staining\\u000a method

Rocío Fernández-Pérez; Carmen Torres; Susana Sanz; Fernanda Ruiz-Larrea

2010-01-01

242

Chemical behaviour of zirconium oxychloride octahydrate and acetic acid in precursor solution for zirconia film formation on glass  

Microsoft Academic Search

Precursor solutions for zirconia films on soda lime silica glass substrate were prepared from zirconium oxychloride octahydrate\\u000a (ZOO) and acetic acid (HOAC) maintaining the mol ratios, [HOAC]\\/[ZOO]=2, 4, 6, 8 and 10. A characteristic UV absorption band\\u000a at ?280 nm in the ?120h aged precursor solutions was identified for acetate group of the zirconium acetato complexed species.\\u000a The presence of

Sunirmal Jana; Prasanta K. Biswas

1997-01-01

243

Sources and sinks of formic, acetic, and pyruvic acids over central Amazonia. II - Wet season  

NASA Technical Reports Server (NTRS)

Potential sources and sinks of formic, acetic, and pyruvic acids over the Amazon forest were investigated using a photochemical model and data collected on gas phase concentrations of these acids in the forest canopy, boundary layer, and free troposphere over the central Amazon Basin during the 1987 wet season. It was found that the atmospheric reactions previously suggested in the literature as sources of carboxylic acids (i.e., the gas phase decomposition of isoprene, the reaction between CH3CO3 and a peroxide, and aqueous phase oxidation of CH2O) appear to be too slow to explain the observed concentrations, suggesting that other atmospheric reactions, so far unidentified, could make a major contribution to the carboxylic acid budgets.

Talbot, R. W.; Andreae, M. O.; Berresheim, H.; Jacob, D. J.; Beecher, K. M.

1990-01-01

244

Photodissociation of organic molecules in star-forming regions II: Acetic acid  

E-print Network

Fragments from organic molecule dissociation (such as reactive ions and radicals) can form interstellar complex molecules like amino acids. The goal of this work is to experimentally study photoionization and photodissociation processes of acetic acid (CH$_3$COOH), a glycine (NH$_2$CH$_2$COOH) precursor molecule, by soft X-ray photons. The measurements were taken at the Brazilian Synchrotron Light Laboratory (LNLS), employing soft X-ray photons from a toroidal grating monochromator (TGM) beamline (100 - 310 eV). Mass spectra were obtained using the photoelectron photoion coincidence (PEPICO) method. Kinetic energy distribution and abundances for each ionic fragment have been obtained from the analysis of the corresponding peak shapes in the mass spectra. Absolute photoionization and photodissociation cross sections were also determined. We have found, among the channels leading to ionization, that only 4-6% of CH$_3$COOH survive the strong ionization field. CH$_3$CO$^+$, COOH$^+$ and CH$_3^+$ ions are the main fragments, and the presence of the former may indicate that the production-destruction process of acetic acid in hot molecular cores (HMCs) could decrease the H$_2$O abundance since the net result of this process converts H$_2$O into OH + H$^+$. The COOH$^+$ ion plays an important role in ion-molecule reactions to form large biomolecules like glycine.

S. Pilling; A. C. F. Santos; H. M. Boechat-Roberty

2005-12-22

245

The impact of acetate metabolism on yeast fermentative performance and wine quality: reduction of volatile acidity of grape musts and wines  

Microsoft Academic Search

Acetic acid is the main component of the volatile acidity of grape musts and wines. It can be formed as a by-product of alcoholic\\u000a fermentation or as a product of the metabolism of acetic and lactic acid bacteria, which can metabolize residual sugars to\\u000a increase volatile acidity. Acetic acid has a negative impact on yeast fermentative performance and affects the

Alice Vilela-Moura; Dorit Schuller; Arlete Mendes-Faia; Rui D. Silva; Susana R. Chaves; Maria João Sousa; Manuela Côrte-Real

2011-01-01

246

Techno-economic Analysis for the Thermochemical Conversion of Lignocellulosic Biomass to Ethanol via Acetic Acid Synthesis  

SciTech Connect

Biomass is a renewable energy resource that can be converted into liquid fuel suitable for transportation applications. As a widely available biomass form, lignocellulosic biomass can have a major impact on domestic transportation fuel supplies and thus help meet the Energy Independence and Security Act renewable energy goals (U.S. Congress 2007). This study performs a techno-economic analysis of the thermo chemical conversion of biomass to ethanol, through methanol and acetic acid, followed by hydrogenation of acetic acid to ethanol. The conversion of syngas to methanol and methanol to acetic acid are well-proven technologies with high conversions and yields. This study was undertaken to determine if this highly selective route to ethanol could provide an already established economically attractive route to ethanol. The feedstock was assumed to be wood chips at 2000 metric ton/day (dry basis). Two types of gasification technologies were evaluated: an indirectly-heated gasifier and a directly-heated oxygen-blown gasifier. Process models were developed and a cost analysis was performed. The carbon monoxide used for acetic acid synthesis from methanol and the hydrogen used for hydrogenation were assumed to be purchased and not derived from the gasifier. Analysis results show that ethanol selling prices are estimated to be $2.79/gallon and $2.81/gallon for the indirectly-heated gasifier and the directly-heated gasifier systems, respectively (1stQ 2008$, 10% ROI). These costs are above the ethanol market price for during the same time period ($1.50 - $2.50/gal). The co-production of acetic acid greatly improves the process economics as shown in the figure below. Here, 20% of the acetic acid is diverted from ethanol production and assumed to be sold as a co-product at the prevailing market prices ($0.40 - $0.60/lb acetic acid), resulting in competitive ethanol production costs.

Zhu, Yunhua; Jones, Susanne B.

2009-04-01

247

Studies on the male antifertility agent gossypol acetic acid: in vitro studies on the effect of gossypol acetic acid on human spermatozoa.  

PubMed

The hypothesis that gossypol (an active ingredient associated with cottonseed oil) affects enzymes and other constituents of spermatozoa, resulting in alterations in motility and sperm viability after in vitro treatment, was tested using human semen samples. At a gossypol acetic acid concentration (and a 30 minute incubation) of .01 mcg, the percent motility was 71+ or -2.5 (P .01); at .1 mcg concentration, percent motility was 69+ or -4 (P .01); at 1 mcg motility was 66+ or -5 (P .005); at 10 cg, motility was 38.5+ or -3.5 (P .001). Control values for sperm motility were 77+ or -3. These investigations suggested that treatment with gossypol depletes production of adenosine triphosphate in the sperms and thus their metabolism does not proceed normally, rendering them immotile. It appears that the high vulnerability of the testis to gossypol and the uncoupling of oxidative phosphorylation in the respiratory chain of mitochondria of germ cells may be the mechanism responsible for infertility induction. PMID:12336803

Kalla, N R; Vasudev, M

1980-06-01

248

The Partitioning of Acetic, Formic, and Phosphoric Acids Between Liquid Water and Steam  

SciTech Connect

The chemical carryover of impurities and treatment chemicals from the boiler to the steam phase, and ultimately to the low-pressure turbine and condenser, can be quantified based on laboratory experiments preformed over ranges of temperature, pH, and composition. The two major assumptions are that thermodynamic equilibrium is maintained and no deposition, adsorption or decomposition occurs. The most recent results on acetic, formic and phosphoric acids are presented with consideration of the effects of hydrolysis and dimerization reactions. Complications arising from thermal decomposition of the organic acids are discussed. The partitioning constants for these acids and other solutes measured in this program have been incorporated into a simple thermodynamic computer code that calculates the effect of chemical and mechanical carryover on the composition of the condensate formed to varying extents in the water/steam cycle.

Gruszkiewicz, M.S.; Marshall, S.L.; Palmer, D.A.; Simonson, J.M.

1999-06-22

249

Protective effect of Dillenia indica L. on acetic acid induced colitis in mice.  

PubMed

The inflammatory bowel disease (IBD) is an idiopathic, immune mediated and chronic inflammation of the intestine. The study aimed to elucidate the ameliorative effect of methanolic extract of Dillenia indica (DIME), hexane fraction (HFDI) and chloroform fraction (CFDI) of Dillenia indica in acetic acid induced experimental colitis in mice. Macroscopic score, colon weight, colonic catalase (CAT), superoxide dismutase (SOD), glutathione (GSH), myeloperoxidase (MPO), malondialdehyde (MDA), tumor necrosis factor (TNF-alpha), and histological changes were recorded after the treatment regimen of 7 days. Intra-rectal instillation of acetic acid caused enhanced macroscopic score, colon weight, colonic MPO, MDA, and TNF-alpha level. It caused significant decreased level of CAT, SOD and GSH. DIME (800 mg/kg), HFDI (200 mg/kg) and CFDI (200 mg/kg) treatment exhibited significant effect in lowering macroscopic score, colon weight, MPO, MDA, TNF-alpha levels and elevation of CAT, GSH and SOD levels. The results suggest that D. indica has ameliorating effects on experimental colitis by inhibiting the proinflammatory mediators like TNF-alpha production. PMID:25241587

Somani, S J; Badgujar, L B; Sutariya, B K; Saraf, M N

2014-09-01

250

Reducing pathogens by using zinc oxide nanoparticles and acetic acid in sheep meat.  

PubMed

Practical applications of different concentrations (0, 1, 2, 4, 6, and 8 mM) of zinc oxide (ZnO) suspensions containing 1 % acetic acid were investigated against the pathogenic bacteria Listeria monocytogenes, Escherichia coli, Staphylococcus aureus, and Bacillus cereus. ZnO suspensions (0, 1, 3, 6, and 8 mM) containing acetic acid had a significant inhibitory effect on the growth of L. monocytogenes, E. coli, and S. aureus during 12 h of incubation, and the 8 mM suspensions of ZnO were the most effective against all the strains. These data suggested that the antibacterial activity of ZnO was concentration dependent. Thus, 6 and 8 mM ZnO were selected for further studies in meat. ZnO nanoparticles reduced initial growth of all inoculated strains in meat. To our knowledge, this is the first report describing the antibacterial activity of ZnO nanoparticles in meat and indicates the potential of these nanoparticles as an antibacterial agent in the food industry. PMID:25198854

Mirhosseini, Mahboubeh; Arjmand, Vahid

2014-09-01

251

Dissociative Electron-Ion Recombination of the Protonated Interstellar Species Glycolaldehyde, Acetic Acid, and Methyl Formate  

NASA Astrophysics Data System (ADS)

Recently, the prebiotic molecule and primitive sugar glycolaldehyde and its structural isomers acetic acid and the abundant methyl formate have been detected in the interstellar medium(ISM). Understanding the processes involving these molecules is vital to understand the ISM, where stars are formed. The rate constants, ?e, for dissociative electron-ion recombination of protonated gycolaldehyde, (HOCH2CHO)H^+, and protonated methyl formate, (HCOOCH3)H^+, have been determined at 300K in a variable temperature flowing afterglow using a Langmuir probe to determine the electron density. The ?e at 300K are 3.2 x 10-7 cm^3 s-1 for protonated methyl formate and 7.5 x 10-7 cm^3 s-1 for protonated glycolaldehyde. The ?e of protonated acetic acid could not be directly measured due to difficulty in producing the ion, but it appears to have a recombination rate constant, ?e, on the ˜10-7 cm^3 s-1 scale. Additional temperature dependence information was obtained. The astrochemical implications of the ?e measurements and protonation routes are also discussed.

Lawson, Patrick; Adams, Nigel

2011-10-01

252

Acetate and hypercalciuria during total parenteral nutrition13  

Microsoft Academic Search

Hypercalciuria and negative calcium balance are complications oftotal par- enteral nutrition (TPN). Because metabolism ofthe TPN formula generates an acid load that can induce hypercalciuria, we evaluated the effect ofsupplementing the formula with acetate. In a randomized crossover study six patients on continuous and six on cyclic TPN received no added acetate or 160 mmol acetate\\/d replacing 160 mmol chloride\\/d

Charles H Berkelhammer; Richard J Wood; Michael D Sitrin

253

High temperature stimulates acetic acid accumulation and enhances the growth inhibition and ethanol production by Saccharomyces cerevisiae under fermenting conditions.  

PubMed

Cellular responses of Saccharomyces cerevisiae to high temperatures of up to 42 °C during ethanol fermentation at a high glucose concentration (i.e., 100 g/L) were investigated. Increased temperature correlated with stimulated glucose uptake to produce not only the thermal protectant glycerol but also ethanol and acetic acid. Carbon flux into the tricarboxylic acid (TCA) cycle correlated positively with cultivation temperature. These results indicate that the increased demand for energy (in the form of ATP), most likely caused by multiple stressors, including heat, acetic acid, and ethanol, was matched by both the fermentation and respiration pathways. Notably, acetic acid production was substantially stimulated compared to that of other metabolites during growth at increased temperature. The acetic acid produced in addition to ethanol seemed to subsequently result in adverse effects, leading to increased production of reactive oxygen species. This, in turn, appeared to cause the specific growth rate, and glucose uptake rate reduced leading to a decrease of the specific ethanol production rate far before glucose depletion. These results suggest that adverse effects from heat, acetic acid, ethanol, and oxidative stressors are synergistic, resulting in a decrease of the specific growth rate and ethanol production rate and, hence, are major determinants of cell stability and ethanol fermentation performance of S. cerevisiae at high temperatures. The results are discussed in the context of possible applications. PMID:24706214

Woo, Ji-Min; Yang, Kyung-Mi; Kim, Sae-Um; Blank, Lars M; Park, Jin-Byung

2014-07-01

254

Manufacturing Ethyl Acetate From Fermentation Ethanol  

NASA Technical Reports Server (NTRS)

Conceptual process uses dilute product of fermentation instead of concentrated ethanol. Low-concentration ethanol, extracted by vacuum from fermentation tank, and acetic acid constitutes feedstock for catalytic reaction. Product of reaction goes through steps that increases ethyl acetate content to 93 percent by weight. To conserve energy, heat exchangers recycle waste heat to preheat process streams at various points.

Rohatgi, Naresh K.; Ingham, John D.

1991-01-01

255

Simple differential detection of Entamoeba histolytica and Entamoeba dispar in fresh stool specimens by sodium acetate-acetic acid-formalin concentration and PCR.  

PubMed Central

Amoebiasis is caused by two distinct species, a pathogenic form (Entamoeba histolytica) and a nonpathogenic form (Entamoeba dispar), which are morphologically identical. Although the distinction between these two species is of great clinical importance, the methods developed for this purpose either are very time-consuming or involve laborious procedures for isolation of the DNA. We report here a simple PCR method starting with fresh stool specimen that allows for the sensitive and reliable distinction between E. histolytica and E. dispar. After initial concentration by the sodium acetate-acetic acid-formalin (SAF) method and digestion with proteinase K, a 0.88-kb sequence of the multicopy 16S rRNA gene served as a target for PCR amplification. The method starting with unpreserved specimens proved to be very sensitive and was not influenced by the quick exposure to SAF fixative during the initial concentration step. However, storage in SAF fixative prior to testing resulted in a decreased sensitivity within 2 days. The detection limit of the method was as low as one copy of the 16S rRNA gene. No cross-reactivity was observed with other common intestinal protozoa. Mixed infections involving both E. histolytica and E. dispar could easily be detected at a ratio of 1:10,000 by agarose gel electrophoresis or a DNA hybridization immunoassay. PMID:9196177

Troll, H; Marti, H; Weiss, N

1997-01-01

256

Production of indole-3-acetic acid and related indole derivatives from L-tryptophan by Rubrivivax benzoatilyticus JA2.  

PubMed

Rubrivivax benzoatilyticus JA2 produces indoles with simultaneous utilization of L-tryptophan. Fifteen chromatographically distinct indole derivatives were detected from the L-tryptophan-supplemented cultures of R. benzoatilyticus JA2. Nine of these were identified as, indole 3-acetamide, Methoxyindole-3-aldehyde, indole 3-aldehyde, methoxyindole-3-acetic acid, indole 3-acetic acid, indole-3-carboxylic acid, indole-3-acetonitrile, indole, and trisindoline. Tryptophan stable isotope feeding confirmed the indoles produced are from the supplemented L-tryptophan. Indole 3-acetic acid is one of the major products of L-tryptophan catabolism by R. benzoatilyticus JA2 and its production was influenced by growth conditions. Identification of indole 3-acetamide and tryptophan monooxygenase activity suggests indole 3-acetamide routed IAA biosynthesis in R. benzoatilyticus JA2. The study also indicated the possible multiple pathways of IAA biosynthesis in R. benzoatilyticus JA2. PMID:20972782

Mujahid, Md; Sasikala, Ch; Ramana, Ch V

2011-02-01

257

A novel kinetic model for polysaccharide dissolution during atmospheric acetic acid pretreatment of sugarcane bagasse.  

PubMed

Acetic acid (AcH) pretreatment of sugarcane bagasse with the catalysis of sulfuric acid (SA) could greatly enhance the enzymatic digestibility of cellulose. However, polysaccharide dissolution happened inevitably during the pretreatment. It was found that the simplest model, which assumes that the total polysaccharides were reactive to be dissolved, could not well describe the kinetic behavior of polysaccharide dissolution. A novel pseudo-homogenous kinetic model was thus developed by introducing a parameter termed as "potential dissolution degree" (?(d)) based on the multilayered structure of cell wall. It was found that solid xylan and glucan dissolutions were a first-order reaction with respect to the dissolvable fraction. Due to the delignification action of AcH, polysaccharide dissolutions were enhanced in AcH media compared with those in aqueous system. Acetylizations of cellulose and sugars were also observed, and AcH concentration showed a significant influence on the degree of acetylization. PMID:24215769

Zhao, Xuebing; Morikawa, Yuichi; Qi, Feng; Zeng, Jing; Liu, Dehua

2014-01-01

258

Euphorbia escula L. Root and Root Bud Indole-3-Acetic Acid Levels at Three Phenologic Stages.  

PubMed

Endogenous indoleacetic acid (IAA) levels of Euphorbia esula L. primary root and root buds were examined at three phenologic stages. High performance liquid chromatography coupled with fluorescence detection and gas chromatography-mass spectrometry, using (13)C(6)[benzene ring]-indole-3-acetic acid as internal standard, were used to measure root bud free and bound IAA levels in vegetative, full flower, and post-flower plants. Highest levels of free IAA (103 nanograms per gram fresh weight) were found in root buds during full flower. Esterified and amide IAA increased significantly in root buds of full flower and post-flower plants, but were not detectable in root buds of vegetative plants. Primary rootfree IAA was highest in vegetative and full flower plants (34.5 nanograms per gram fresh weight) and decreased by 50% in post-flower plants. PMID:16665432

Nissen, S J; Foley, M E

1987-06-01

259

Dynamics of three organic acids (malic, acetic and succinic acid) in sunflower exposed to cadmium and lead.  

PubMed

Sunflower (Helianthus annuus L.) has been considered as a good candidate for bioaccumulation of heavy metals. In the present study, sunflower was used to enrich the cadmium and lead in sand culture during 90 days. Biomass, Cd and Pb uptake, three organic acids and pH in cultures were investigated. Results showed that the existence of Cd and Pb showed different interactions on the organic acids exudation. In single Cd treatments, malic and acetic acids in Cd10 showed an incremental tendency with time. In the mixed treatments of Cd and Pb, malic acids increased when 10 and 40 mg x L(-1) Cd were added into Pb50, but acetic acids in Pb50 were inhibited by Cd addition. The Cd10 supplied in Pb10 stimulated the secretion of malic and succinic acids. Moreover, the Cd or Pb uptake in sunflower showed various correlations with pH and some organic acids, which might be due to the fact that the Cd and Pb interfere with the organic acids secretion in rhizosphere of sunflower, and the changes of organic acids altered the form and bioavailability of Cd and Pb in cultures conversely. PMID:23819268

Niu, Zhixin; Li, Xiaodong; Sun, Lina; Sun, Tieheng

2013-01-01

260

Metal-organic coordination architectures of azole heterocycle ligands bearing acetic acid groups: Synthesis, structure and magnetic properties  

NASA Astrophysics Data System (ADS)

Four new coordination complexes with azole heterocycle ligands bearing acetic acid groups, [Co( L1) 2] n ( 1) , [Cu L1N 3] n ( 2), [Cu( L2) 2·0.5C 2H 5OH·H 2O] n ( 3) and [Co( L2) 2] n ( 4) (here, H L1=1H-imidazole-1-yl-acetic acid, H L2=1H-benzimidazole-1-yl-acetic acid) have been synthesized and structurally characterized. Single-crystal structure analysis shows that 3 and 4 are 2D complexes with 4 4-sql topologies, while another 2D complex 1 has a (4 3) 2(4 6)-kgd topology. And 2 is a 3D complex composed dinuclear ?1,1-bridging azido Cu II entities with distorted rutile topology. The magnetic properties of 1 and 2 have been studied.

Hu, Bo-Wen; Zhao, Jiong-Peng; Yang, Qian; Hu, Tong-Liang; Du, Wen-Ping; Bu, Xian-He

2009-10-01

261

Kinetics and energetics of hydrogen bond dissociation in isolated acetic acid- d1 and - d4 and trifluoroactic acid dimers  

NASA Astrophysics Data System (ADS)

A quantitative determination of the rate constant, activation energy, entropy, and enthalpy of dissociation of hydrogen bonds in deuterated acetic acid- d1, - d4, and trifluoroacetic acid dimers in the gas phase was performed by resonant CO 2 laser photoacoustic spectroscopy. Within the experimental error, the kinetics and energetics of hydrogen bond dissociation were found to be independent of deuterium substitution of the hydroxy-hydrogen for pressures below 100 mbar. On the other hand, the dynamics, but not the energetics, of H bond dissociation are affected by the chemical nature of the rest group R (e.g., CH 3, CD 3, or CF 3) of the carboxylic acid.

Sauren, H.; Winkler, A.; Hess, P.

1995-06-01

262

Acetic-acid-catalyzed and subcritically dried carbon aerogels with a nanometer-sized structure and a wide density range  

Microsoft Academic Search

Organic acids used as catalysts allow for the preparation of resorcinol–formaldehyde (RF) and carbon aerogels without any metallic impurities. In this paper we present RF aerogels originating from an aqueous gelation and subcritical drying after the exchange of the pore water against acetone. In contrast to earlier attempts, very high catalyst concentrations of the weak acetic acid were used. The

R. Brandt; J. Fricke

2004-01-01

263

Developmental toxicity of mixtures: the water disinfection by-products dichloro-, dibromo- and bromochloro acetic acid in rat embryo culture  

EPA Science Inventory

The chlorination of drinking water results in production of numerous disinfection by-products (DBPs). One of the important classes of DBPs is the haloacetic acids. We have previously shown that the haloacetic acids (HAs), dichloro (DCA), dibromo (DBA) and bromochloro (BCA) acetic...

264

Acetal-linked branched poly(dimethyl-aminoethyl methacrylate) as an acid cleavable gene vector with reduced cytotoxicity.  

PubMed

An acid labile branched PDMAEMA/acetal copolymer with amino group was synthesized by the DE-ATRP and followed by Michael addition. The degradation of the polymer was strongly pH-dependent. High nucleic acid transfection efficiency with low cytotoxicity was observed compared to its non-degradable copolymer counterpart. PMID:25358033

Cao, H L; Dong, Y X; Aied, A; Zhao, T Y; Chen, X; Wang, W X; Pandit, A

2014-12-21

265

Autophagy and cathepsin L are involved in the antinociceptive effect of DMBC in a mouse acetic acid-writhing model  

PubMed Central

Aim: 2-(3?,5?-Dimethoxybenzylidene) cyclopentanone (DMBC) is a novel synthetic compound with antinociceptive activities. The aim of this study was to investigate the roles of the autophagic-lysosomal pathway in the antinociceptive effect of DMBC in a mouse acetic acid-writhing model. Methods: Mouse acetic acid-writhing test and hotplate test were used to assess the antinociceptive effects of DMBC, 3-MA (autophagy inhibitor) and Clik148 (cathepsin L inhibitor). The drugs were administered peripherally (ip) or centrally (icv). Results: Peripheral administration of 3-MA (7.5–30 mg/kg) or Clik148 (10–80 mg/kg) produced potent antinociceptive effect in acetic acid-writhing test. Central administration of 3-MA or Clik148 (12.5–50 nmol/L) produced comparable antinociceptive effect in acetic acid-writhing test. Peripheral administration of DMBC (25–50 mg/kg) produced potent antinociceptive effects in both acetic acid-writhing and hotplate tests. Furthermore, the antinociceptive effect produced by peripheral administration of DMBC (50 mg/kg) in acetic acid-writhing test was antagonized by low doses of 3-MA (3.75 mg/kg) or Clik148 (20 mg/kg) peripherally administered, but was not affected by 3-MA or Clik148 (25 nmol/L) centrally administered. Conclusion: Activation of central autophagy and cathepsin L is involved in nociception in mice, whereas peripheral autophagy and cathepsin L contributes, at least in part, to the antinociceptive effect of DMBC in mice. PMID:23912553

Gu, Wei-wei; Ao, Gui-zhen; Zhu, Yong-ming; Sun, Shi-chang; Zhou, Qiang; Fan, Jia-hong; Nobuhiko, Katunuma; Ishidoh, Kazumi; Zhang, Hui-ling; Gao, Xiu-mei

2013-01-01

266

Isolation and Characterization of Esters of Indole-3-Acetic Acid from the Liquid Endosperm of the Horse Chestnut (Aesculus species) 1  

PubMed Central

Esters of indole-3-acetic acid were extracted and purified from the liquid endosperm of immature fruits of various species of the horse chestnut (Aesculus parviflora, A. baumanni, A.pavia rubra, and A. pavia humulis). The liquid endosperm contained, at least 12 chromatographically distinct esters. One of these compounds was purified and characterized as an ester of indole-3-acetic acid and myo-inositol. A second compound was found to be an ester of indole-3-acetic acid and the disaccharide rutinose (glucosyl-rhamnose). A third compound was partially characterized as an ester of indole-3-acetic acid and a desoxyaminohexose. PMID:11539676

Domagalski, Wojciech; Schulze, Aga; Bandurski, Robert S.

1987-01-01

267

Preliminary analysis of monterey kerogen by mild stepwise oxidation with sodium dichromate in glacial acetic acid  

SciTech Connect

Kerogen from Monterey shale was degraded by a controlled, mild stepwise oxidation with sodium dichromate in acetic acid. The products of each step were examined by capillary gas chromatography and combined gas chromatography-mass spectrometry analyses of their methyl esters. Major oxidation products were saturated normal monocarboxylic acids (C/sub 6/-C/sub 34/), saturated normal, ..cap alpha..,omega-dicarboxylic acids (C/sub 4/-C/sub 34/), and isoprenoid acids (C/sub 14/-C/sub 21/, except C/sub 18/). Less dominant were aromatic acids, branched monocarboxylic acids (C/sub 6/-C/sub 16/), cyclic structures, heterocyclic compounds, as well as some unidentified compounds. On the basis of the evidence obtained from the qualitative and quantitative variation of the products with duration of oxidation, the following results were obtained: (a) the kerogen nucleus is mainly composed of long-chain polymethylene, cross-lined aliphatic structure from which protrude n-alkyl chains and minor amounts of isoprenoid and non-isoprenoid branched hydrocarbons; (b) the periphery, compared to the nucleus, contains a greater proportion of n-alkyl and isoprenoid moieties, particularly the C/sub 14/, C/sub 16/, and C/sub 18/ n-alkyl chains as well as the C/sub 15/ and C/sub 16/ isoprenoid chains; (c) other subordinate structures present include phenyl and tolyl groups as well as alicyclic and heterocyclic compounds.

Barakat, A.O.; Yen, T.F.

1988-02-01

268

Batch salicylic acid nitration by nitric acid/acetic acid mixture under isothermal, isoperibolic and adiabatic conditions.  

PubMed

Runaway phenomena and thermal explosions can originate during the nitration of salicylic acid by means of a nitric acid/acetic acid mixture when the thermal control is lost, mainly as a result of the formation and thermal decomposition of picric acid. The prediction of the behaviour of this system is thus of great importance in view of possible industrial applications and the need to avoid the occurrence of unwanted dangerous events. During a previous investigation a model was developed to simulate its behaviour when the starting concentration of the substrate is too low, thus, preventing the precipitation of poor soluble intermediates. In this work this model is extended to deal with more concentrated systems even in case of a solid phase separating during the process. To this purpose the previously assessed dependence of the solubility of 3-nitro and 5-nitrosalicylic acids upon temperature and nitric acid concentration is included in the model. It is assumed that when 3-nitro and 5-nitrosalicylic acids are partially suspended in the reacting medium a kinetic regime of "dissolution with reaction" is established; that is, the redissolution of these species is a fast process compared to the successive nitration to give dinitroderivatives. Good results are obtained in the comparison of the experimental data with those calculated both in isoperibolic and adiabatic conditions when the revised model is used. PMID:16842908

Andreozzi, R; Canterino, M; Caprio, V; Di Somma, I; Sanchirico, R

2006-12-01

269

Vapor phase ketonization of acetic acid on ceria based metal oxides  

SciTech Connect

The activities of CeO2, Mn2O3-CeO2 and ZrO2-CeO2 were measured for acetic acid ketonization under reaction conditions relevant to pyrolysis vapor upgrading. We show that the catalyst ranking changed depending on the reaction conditions. Mn2O3-CeO2 was the most active catalyst at 350 oC, while ZrO2 - CeO2 was the most active catalyst at 450 oC. Under high CO2 and steam concentration in the reactants, Mn2O3-CeO2 was the most active catalyst at 350 and 450 °C. The binding energies of steam and CO2 with the active phase were calculated to provide the insight into the tolerance of Mn2O3-CeO2 to steam and CO2.

Liu, Changjun; Karim, Ayman M.; Lebarbier, Vanessa MC; Mei, Donghai; Wang, Yong

2013-12-01

270

Acetic Acid Bacteria Genomes Reveal Functional Traits for Adaptation to Life in Insect Guts  

PubMed Central

Acetic acid bacteria (AAB) live in sugar rich environments, including food matrices, plant tissues, and the gut of sugar-feeding insects. By comparing the newly sequenced genomes of Asaia platycodi and Saccharibacter sp., symbionts of Anopheles stephensi and Apis mellifera, respectively, with those of 14 other AAB, we provide a genomic view of the evolutionary pattern of this bacterial group and clues on traits that explain the success of AAB as insect symbionts. A specific pre-adaptive trait, cytochrome bo3 ubiquinol oxidase, appears ancestral in AAB and shows a phylogeny that is congruent with that of the genomes. The functional properties of this terminal oxidase might have allowed AAB to adapt to the diverse oxygen levels of arthropod guts. PMID:24682158

Chouaia, Bessem; Gaiarsa, Stefano; Crotti, Elena; Comandatore, Francesco; Degli Esposti, Mauro; Ricci, Irene; Alma, Alberto; Favia, Guido; Bandi, Claudio; Daffonchio, Daniele

2014-01-01

271

A molecular molybdenum electrocatalyst for generating hydrogen from acetic acid or water  

NASA Astrophysics Data System (ADS)

The reaction of 2-pyridylamino-N,N-bis(2-methylene-4,6-difluorophenol) (H2L?) and MoCl5 affords a molybdenum(VI) complex [MoL?(O)2] 1, a new molecular electrocatalyst, which has been determined by X-ray crystallography. Electrochemical studies show that a molybdenum(IV) intermediate is responsible for the reductive proton to generate H2, and 1 can catalyze hydrogen evolution from acetic acid or aqueous buffer. Turnover frequency (TOF) reaches a maximum of 50.6 (in DMF) and 756 (in buffer, pH 6.0) moles of hydrogen per mole of catalyst per hour, respectively. Sustained proton reduction catalysis occurs at glassy carbon (GC) electrode to give H2 over a 72 h electrolysis period and no observable decomposition of the catalyst.

Cao, Jie-Ping; Zhou, Ling-Ling; Fu, Ling-Zhi; Zhan, Shuzhong

2014-12-01

272

Catalytic wet air oxidation of acetic acid on carbon-supported ruthenium catalysts  

SciTech Connect

Ruthenium catalysts prepared by ion exchange of active carbons and high-surface-area graphites are active for the wet air oxidation of aqueous solutions of acetic acid (5-20 g/liter). A total conversion into CO{sub 2} can be achieved between 448 and 473 K using air as oxidizing agent. No leaching of ruthenium can be detected which indicates that the reaction proceeds on the heterogeneous catalysts. For the same particle size (1 nm), graphite-supported ruthenium catalysts are much more active (up to 0.4 mol h{sup -1} g{sub RU}{sup -1} at 473 K in a stirred batch reactor pressurized with air at 10 MPa) than active carbon-supported catalysts. The lower activities of the latters could be due to internal diffusion limitation since the 1-nm Ru particles are located inside the micropores. However, graphite-supported catalysts might be intrinsically more active because of an electron transfer from graphite to metal particles which would increase the resistance of ruthenium to oxygen poisoning. It was also shown that the activity of ruthenium is particle size dependent: the smaller the sizes, the lower the activities. This effect could be interpreted by the higher adsorption energy of oxygen on the small particles which produces a poisoning of the metal surface. From measurements of the reaction rates on the Ru/HSAG graphite catalyst at different temperatures, pressures, and acetic acid concentrations, it was established that the reaction orders were zero and 0.65 with respect to the concentration and oxygen pressure, respectively; the activation energy of the reaction was 100.5 kJ mol{sup -1}. An equation describing the reaction kinetics was proposed. 23 refs., 4 figs., 2 tabs.

Gallezot, P.; Chaumet, S.; Perrard, A. [Institut de Recherches sur la Catalyse, Villeurbanne (France)] [and others] [Institut de Recherches sur la Catalyse, Villeurbanne (France); and others

1997-05-01

273

THE USE OF ACETIC ACID IONTOPHORESIS IN THE MANAGEMENT OF A SOFT TISSUE INJURY  

PubMed Central

Background: Contusions are common injuries that occur in athletics. If repeated, complications like myositis ossificans can occur. This case describes the examination and treatment of an athlete with an acute soft tissue injury. Objective: To describe the treatment approach used with a hockey player who sustained a soft tissue injury in his upper extremity. Case Description: A 19 year old male sustained a soft tissue injury to his upper arm while playing hockey. The athlete complained of pain rated a 2-3 out of 10. He had a well circumscribed, firm, 8 by 5 centimeter palpable mass present along the lateral arm, and was able to passively flex his elbow from 56° to 135°, demonstrating a 56° loss of elbow extension. Functionally, he was able to perform most activities of daily living, but he was unable to play hockey. Over 29 days, the athlete was treated one time with pulsed ultrasound and ice and nine times with iontophoresis using a 2% acetic acid solution. Additionally, the athlete performed pain-free active range of motion exercises for the elbow. Outcome: Following treatment, the athlete's pain resolved, the palpable mass disappeared, and his passive range of motion at the elbow was 0° to 135°. Most importantly, the athlete was able to resume playing hockey. Discussion: Acetic acid iontophoresis may be a successful intervention for soft tissue injuries of the upper extremity. In this case, it appeared helpful in decreasing the athlete's impairments and contributed to quicker resumption of all functional activities in less time than previously reported in the literature using traditional treatment interventions. PMID:21655380

Ebaugh, David

2010-01-01

274

Investigations of the pore formation in the lead selenide films using glacial acetic acid- and nitric acid-based electrolyte  

PubMed Central

We report a novel synthesis of porous PbSe layers on Si substrates by anodic electrochemical treatment of PbSe/CaF2/Si(111) epitaxial structures in an electrolyte solution based on glacial acetic acid and nitric acid. Electron microscopy, X-ray diffractometry, and local chemical microanalysis investigation results for the porous layers are presented. Average size of the synthesized mesopores with approximately 1010 cm?2 surface density was determined to be 22 nm. The observed phenomenon of the active selenium redeposition on the mesopore walls during anodic treatment is discussed. PMID:22726822

2012-01-01

275

Acetate metabolism in Methanothrix soehngenii  

Microsoft Academic Search

Acetate is quantitatively the most important intermediate in the anaerobic degradation of soluble organic matter. The conversion rate of acetate by methanogenic bacteria is proposed to be the rate limiting step in this degradation The study of acetoclastic methanogens, therefore is of relevance to our understanding of anaerobic processes and their optimal application in treatment of waste water from various

M. S. M. Jetten

1991-01-01

276

Effect of acetic acid present in bagasse hydrolysate on the activities of xylose reductase and xylitol dehydrogenase in Candida guilliermondii.  

PubMed

The first two steps in xylose metabolism are catalyzed by NAD(P)H-dependent xylose reductase (XR) (EC 1.1.1.21) and NAD(P)-dependent xylitol dehydrogenase (XDH) (EC 1.1.1.9), which lead to xylose-->xylitol-->xylulose conversion. Xylitol has high commercial value, due to its sweetening and anticariogenic properties, as well as several clinical applications. The acid hydrolysis of sugarcane bagasse allows the separation of a xylose-rich hemicellulosic fraction that can be used as a substrate for Candida guilliermondii to produce xylitol. However, the hydrolysate contains acetic acid, an inhibitor of microbial metabolism. In this study, the effect of acetic acid on the activities of XR and XDH and on xylitol formation by C. guilliermondii were studied. For this purpose, fermentations were carried out in bagasse hydrolysate and in synthetic medium. The activities of XR and XDH were higher in the medium containing acetic acid than in control medium. Moreover, none of the fermentative parameters were significantly altered during cell culture. It was concluded that acetic acid does not interfere with xylitol formation since the increase in XR activity is proportional to XDH activity, leading to a greater production of xylitol and its subsequent conversion to xylulose. PMID:15107950

Lima, Luanne Helena Augusto; das Graças de Almeida Felipe, Maria; Vitolo, Michele; Torres, Fernando Araripe Gonçalves

2004-11-01

277

Evaluation of curcumin acetates and amino acid conjugates as proteasome inhibitors.  

PubMed

Curcumin (diferuloylmethane) is the main active ingredient of turmeric, a traditional herbal medicine and food of south Asia. Curcumin has been found to have a wide range of biological activities, including antioxidant, anti-inflammatory, chemopreventive and chemotherapeutic activities. Curcumin is currently being tested in clinical trials for treatment of various types of cancers, including multiple myeloma, pancreatic cancer and colon cancer. Although no toxicity associated with curcumin (even at very high doses) has been observed, the effects of curcumin in other solid tumors have been modest, primarily due to poor water solubility and poor bioavailability in tissues remote from the gastrointestinal tract. Therefore, there is a need for the discovery of curcumin analogs with better water solubility or greater bioavailability for the treatment of solid tumors such as prostate cancer. In this study, curcumin acetates and amino acid conjugates of curcumin were studied in terms of their proteasome inhibitory and antiproliferative effects against several human cancer cell lines. It was found that the water soluble amino acid conjugates of curcumin showed a potent antiproliferative effect and are potent proteasome inhibitors. Docking studies of the curcumin amino acid conjugates for proteasome inhibition were carried out to explain their biological activities. It is suggested that they may serve as the water soluble analogs of curcumin. PMID:20818481

Wan, Sheng Biao; Yang, Huanjie; Zhou, Zhongyuan; Cui, Qiuzhi Cindy; Chen, Di; Kanwar, Jyoti; Mohammad, Imthiyaz; Dou, Q Ping; Chan, Tak Hang

2010-10-01

278

Relationship among lipoperoxides, jasmonates and indole-3-acetic acid formation in potato tuber after wounding.  

PubMed

Plant responses to biotic and abiotic stress can be mediated by oxidised products and in this study we analysed the relation among some of them and the growth factor indole-3-acetic acid (IAA). The plant material used was potato tuber sliced below bud and incubated for different lengths of time before analysis. Wounding in potato tuber leads, in a very short time (0-30?min), to the generation of lipid hydroperoxides (LOOH) from polyunsaturated fatty acids (PUFA). These reactive species could cause a subsequent increase of 9 and 13-lipoxygenase (LOX, E.C.1.13.12.12.), analysed by RT-PCR and spectrophotometric assay, LOOH, Jasmonates and IAA all quantified by GC-MS analysis. The activation of 9 and 13-LOX, using different timing, leads to the formation of LOOH with a subsequent generation of jasmonates and IAA as highlighted by the addition on the potato tuber slices of salicylhydroxamic acid (SHAM), an inhibitor of LOX activity. A correlation between jasmonates and IAA resulted by testing their reciprocal influence during wounding in potato tuber. The relationship occurring among each hormone analysed during wounding underlines the fact that the jasmonates level can be regulated in situ and this can suggest a role for these compounds in potato tuber which has been underestimated up to now. PMID:16036342

Reverberi, Massimo; Fanelli, Corrado; Zjalic, Slaven; Briganti, Stefania; Picardo, Mauro; Ricelli, Alessandra; Fabbri, Anna Adele

2005-06-01

279

The effects of citric and acetic acids on the formation of calcium-deficient hydroxyapatite at 38 °C  

Microsoft Academic Search

This study is concerned with the formation of calcium-deficient hydroxyapatite at physiological temperature. Isothermal calorimetry, solution chemistry, scanning electron microscopy, BET surface area analyses and FTIR spectroscopy were used to characterize the kinetics of HAp formation and the microstructure of the HAp formed in varying concentrations of citric and acetic acids, and in deionized water. The kinetics of HAp formation

K. S. Tenhuisen; P. W. Brown

1994-01-01

280

Metal-organic coordination architectures of azole heterocycle ligands bearing acetic acid groups: Synthesis, structure and magnetic properties  

SciTech Connect

Four new coordination complexes with azole heterocycle ligands bearing acetic acid groups, [Co(L{sup 1}){sub 2}]{sub n} (1), [CuL{sup 1}N{sub 3}]{sub n} (2), [Cu(L{sup 2}){sub 2}.0.5C{sub 2}H{sub 5}OH.H{sub 2}O]{sub n} (3) and [Co(L{sup 2}){sub 2}]{sub n} (4) (here, HL{sup 1}=1H-imidazole-1-yl-acetic acid, HL{sup 2}=1H-benzimidazole-1-yl-acetic acid) have been synthesized and structurally characterized. Single-crystal structure analysis shows that 3 and 4 are 2D complexes with 4{sup 4}-sql topologies, while another 2D complex 1 has a (4{sup 3}){sub 2}(4{sup 6})-kgd topology. And 2 is a 3D complex composed dinuclear mu{sub 1,1}-bridging azido Cu{sup II} entities with distorted rutile topology. The magnetic properties of 1 and 2 have been studied. - Graphical Abstract: The synthesis, crystal structure, and magnetic properties of the new coordination complexes with azole heterocycle ligands bearing acetic acid groups are reported.

Hu Bowen; Zhao Jiongpeng; Yang Qian; Hu Tongliang; Du Wenping [Department of Chemistry, Nankai University, Tianjin 300071 (China); Bu Xianhe, E-mail: buxh@nankai.edu.c [Department of Chemistry, Nankai University, Tianjin 300071 (China)

2009-10-15

281

Kinetics of esterification of acetic acid with n-amyl alcohol in the presence of Amberlyst-36  

Microsoft Academic Search

The kinetics of esterification of acetic acid with amyl alcohol has been studied in the presence of Amberlyst-36 in its H+ form in a batch reactor. Experimental findings showed that the reaction is controlled by chemical step rather than external and internal mass transfer steps. Experimental data well fitted the kinetic model based on homogeneous reversible reaction. Temperature dependency of

Elif Öde? Akbay; Mehmet R. Alt?okka

2011-01-01

282

Effect of Acetic Acid, pH and MEG on the CO2 Top of the Line Corrosion  

Microsoft Academic Search

This research work presents a study of Top of the Line Corrosion (TLC) on carbon steels in the presence of carbon dioxide and acetic acid. The influence of different parameters such as the presence of mono-ethylene glycol (MEG) and the use of pH control were studied in a 4\\

Concepcion Mendez; Michael Joosten; Yves Gunaltun; Alvaro Comacho; Srdjan Nesic; Yuhua Sun; Sandra Hernandez; Marc Singer

2005-01-01

283

Kinetics and Mechanism of Ethane Oxidation to Acetic Acid on Catalysts Based on Mo-V-Nb Oxides  

E-print Network

Kinetics and Mechanism of Ethane Oxidation to Acetic Acid on Catalysts Based on Mo-V-Nb Oxides and isotopic studies showed that C-H bond activation in ethane by surfaces essentially saturated with lattice oxygens is the sole kinetically relevant step in ethane oxidation on Mo-V-NbOx mixed oxides

Iglesia, Enrique

284

Application of culture culture-independent molecular biology based methods to evaluate acetic acid bacteria diversity during vinegar processing  

Microsoft Academic Search

Acetic acid bacteria (AAB) are considered fastidious microorganisms because they are difficult to isolate and cultivate. Different molecular approaches were taken to detect AAB diversity, independently of their capacity to grow in culture media. Those methods were tested in samples that originated during traditional vinegar production. Bacterial diversity was assessed by analysis of 16S rRNA gene, obtained by PCR amplifications

Carolina Ilabaca; Paola Navarrete; Pamela Mardones; Jaime Romero; Albert Mas

2008-01-01

285

Identification and characterization of thermotolerant acetic acid bacteria strains isolated from coconut water vinegar in Sri Lanka.  

PubMed

From the pellicle formed on top of brewing coconut water vinegar in Sri Lanka, three Acetobacter strains (SL13E-2, SL13E-3, and SL13E-4) that grow at 42 °C and four Gluconobacter strains (SL13-5, SL13-6, SL13-7, and SL13-8) grow at 37 °C were identified as Acetobacter pasteurianus and Gluconobacter frateurii, respectively. Acetic acid production by the isolated Acetobacter strains was examined. All three strains gave 4% acetic acid from 6% initial ethanol at 37 °C, and 2.5% acetic acid from 4% initial ethanol at 40 °C. Compared with the two other strains, SL13E-4 showed both slower growth and slower acetic acid production. As well as the thermotolerant SKU1108 strain, the activities of the alcohol dehydrogenase and the aldehyde dehydrogenase of SL13E-2 and SL13E-4 were more stable than those of the mesophilic strain. The isolated strains were used to produce coconut water vinegar at higher temperatures than typically used for vinegar production. PMID:25036846

Perumpuli, P A B N; Watanabe, Taisuke; Toyama, Hirohide

2014-01-01

286

Liquid phase esterification of acetic acid over WO3 promoted ?-SiC in a solvent free system.  

PubMed

A series of tungstate promoted ?-SiC catalysts was synthesized by a wetness impregnation method. The as synthesized catalysts were unambiguously characterized by XRD, Raman, FTIR, XPS, UV-Vis DRS, TEM, BET surface areas and FE-SEM, and simultaneously the total amount of the acidity of the catalysts was estimated by NH(3)-TPD. The catalytic activities of the synthesized materials were tested in the liquid phase esterification of acetic acid with n-butanol in a solvent free medium. The reaction parameters were optimized to a temperature of 120 °C, molar ratio of butanol and acetic acid of 1:2 and a reaction time of 6 h after performing a number of experiments. Under the optimum conditions, the catalytic esterification revealed a significant effect of 88% conversion with 100% selectivity to butyl acetate in 20 wt% WO(3)/?-SiC. This is the first report on the effective utilization of ?-SiC as a catalyst support for liquid phase esterification of acetic acid. PMID:23042240

Mishra, Gopa; Behera, Gobinda C; Singh, S K; Parida, K M

2012-12-21

287

Indole-3-acetic acid biosynthesis in isolated axes from germinating bean seeds: The effect of wounding on the biosynthetic pathway  

E-print Network

Indole-3-acetic acid biosynthesis in isolated axes from germinating bean seeds: The effect pathways were analyzed in isolated axes of germinating bean seedlings at various times after cotyledon are primarily responsible for the IAA biosynthesis occurring in isolated axes of germinating bean seedlings

Cooke, Todd J.

288

ETHANOL, ACETIC ACID, AND WATER ADSORPTION FROM BINARY AND TERNARY LIQUID MIXTURES ON HIGH-SILICA ZEOLITES  

EPA Science Inventory

Adsorption isotherms were measured for ethanol, acetic acid, and water adsorbed on high-silica ZSM-5 zeolite powder from binary and ternary liquid mixtures at room temperature. Ethanol and water adsorption on two high-silica ZSM-5 zeolites with different aluminum contents and a h...

289

Biogas Production through the Syntrophic Acetate-Oxidising Pathway  

E-print Network

retention time OLR Organic loading rate PCR Polymerase chain reaction qPCR Quantitative polymerase chain reaction RNA Ribonucleic acid SAO Syntrophic acetate oxidation SAOB Syntrophic acetate-oxidising bacteria

290

Simultaneous determination of 2-naphthoxyacetic acid and indole-3-acetic acid by first derivation synchronous fluorescence spectroscopy.  

PubMed

A simple, rapid, sensitive and selective method for simultaneously determining 2-naphthoxyacetic acid (BNOA) and Indole-3-Acetic Acid (IAA) in mixtures has been developed using derivation synchronous fluorescence spectroscopy based on their synchronous fluorescence. The synchronous fluorescence spectra were obtained with ??=100 nm in a pH 8.5 NaH2PO4-NaOH buffer solution, and the detected wavelengths of quantitative analysis were set at 239 nm for BNOA and 293 nm for IAA respectively. The over lapped fluorescence spectra were well separated by the synchronous derivative method. Under optimized conditions, the limits of detection (LOD) were 0.003 ?g/mL for BNOA and 0.012 ?g/mL for IAA. This method is simple and expeditious, and it has been successfully applied to the determination of 2-naphthoxyacetic acid and indole-3-acetic acid in fruit juice samples with satisfactory results. The samples were only filtrated through a 0.45 ?m membrane filter, which was free from the tedious separation procedures. The obtaining recoveries were in the range of 83.88-87.43% for BNOA and 80.76-86.68% for IAA, and the relative standard deviations were all less than 5.0%. Statistical comparison of the results with high performance liquid chromatography Mass Spectrometry (HPLC-MS) method revealed good agreement and proved that there were no significant difference in the accuracy and precision between these two methods. PMID:23651742

Liu, Xiangxiang; Wan, Yiqun

2013-07-01

291

Simultaneous determination of 2-naphthoxyacetic acid and indole-3-acetic acid by first derivation synchronous fluorescence spectroscopy  

NASA Astrophysics Data System (ADS)

A simple, rapid, sensitive and selective method for simultaneously determining 2-naphthoxyacetic acid (BNOA) and Indole-3-Acetic Acid (IAA) in mixtures has been developed using derivation synchronous fluorescence spectroscopy based on their synchronous fluorescence. The synchronous fluorescence spectra were obtained with ?? = 100 nm in a pH 8.5 NaH2PO4-NaOH buffer solution, and the detected wavelengths of quantitative analysis were set at 239 nm for BNOA and 293 nm for IAA respectively. The over lapped fluorescence spectra were well separated by the synchronous derivative method. Under optimized conditions, the limits of detection (LOD) were 0.003 ?g/mL for BNOA and 0.012 ?g/mL for IAA. This method is simple and expeditious, and it has been successfully applied to the determination of 2-naphthoxyacetic acid and indole-3-acetic acid in fruit juice samples with satisfactory results. The samples were only filtrated through a 0.45 ?m membrane filter, which was free from the tedious separation procedures. The obtaining recoveries were in the range of 83.88-87.43% for BNOA and 80.76-86.68% for IAA, and the relative standard deviations were all less than 5.0%. Statistical comparison of the results with high performance liquid chromatography Mass Spectrometry (HPLC-MS) method revealed good agreement and proved that there were no significant difference in the accuracy and precision between these two methods.

Liu, Xiangxiang; Wan, Yiqun

2013-07-01

292

Pb(II) and Zn(II) adsorption onto Na-and Ca-montmorillonites in acetic acid/acetate medium: Experimental approach and geochemical modelling  

E-print Network

/acetate as buffer at pH 5 in order to reproduce a biodegradable leachate of a young landfill. These experiments environmental impacts related to landfill leachate are pollution of groundwater and surface water. European landfill (5-10 years), and stabilized for an old landfill (> 10 years). The biodegradable leachate

Paris-Sud XI, Université de

293

MoVO-based catalysts for the oxidation of ethane to ethylene and acetic acid. Influence of niobium and/or palladium on physicochemical  

E-print Network

1 MoVO-based catalysts for the oxidation of ethane to ethylene and acetic acid. Influence to acetic acid and ethylene is examined. Catalysts without molybdenum (VNb031Pd3e-4Ox) are also studied for comparison. The structural properties of the precursors and of the catalysts obtained by calcination

Paris-Sud XI, Université de

294

Acetic Acid as a Sclerosing Agent for Renal Cysts: Comparison with Ethanol in Follow-Up Results  

SciTech Connect

Purpose: To compare follow-up results of sclerotherapy for renal cyst using 50% acetic acid with those using 99% ethanol as sclerosing agents.Methods: Eighty-one patients underwent sclerotherapy and 58 patients, 23 males, 35 females, aged 6-76 years, having a total of 60 cysts, were included in this study; the others were lost to follow-up. The renal cysts were diagnosed by sonography, computed tomography (CT), or magnetic resonance imaging (MRI). Sclerotherapy was performed using 50% acetic acid for 32 cysts in 31 patients and 99% ethanol for 28 cysts in 27 patients. Under fluoroscopic guidance, cystic fluid was aspirated as completely as possible. After instillation of a sclerosing agent corresponding to 11.7%-25% (4-100 ml) of the aspirated volume, the patient changed position for 20 min and then the agent was removed. Patients were followed up by sonography for a period of 1-49 months. The volume of the renal cyst after sclerotherapy was compared with that of the renal cyst calculated before sclerotherapy. Medical records were reviewed to analyze complications.Results: The mean volume after sclerotherapy of the 17 cysts followed for 3-4 months in the acetic acid group was 5.1% of the initial volume, and for the 14 cysts in the ethanol group it was 10.2%. Complete regression during follow-up was shown in 21 cysts (66%) in the acetic acid group; the mean volume of these cysts before the procedure was 245 ml. The mean volume of the nine (32%) completely regressed cysts in the ethanol group was 184 ml. Mild flank pain, which occurred in three patients in each group, was the only complication and resolved the next day.Conclusion: Acetic acid was an effective and safe sclerosing agent for renal cysts, tending to induce faster and more complete regression than ethanol.

Seo, Tae-Seok; Oh, Joo Hyeong; Yoon, Yup; Lim, Joo Won; Park, Seong Jin [Department of Diagnostic Radiology, Kyung Hee University Hospital, Hoeki-dong 1, Dongdaemun-ku, Seoul 130-702 (Korea, Republic of); Chang, Sung-Goo [Department of Urology, Kyung Hee University Hospital, Hoeki-dong 1, Dongdaemun-ku Seoul 130-702 (Korea, Republic of); Jeon, Yang Hyeon [Department of Diagnostic Radiology, Kyung Hee University Hospital, Hoeki-dong 1, Dongdaemun-ku, Seoul 130-702 (Korea, Republic of)

2000-03-15

295

Efficacy of Single-Session Percutaneous Drainage and 50% Acetic Acid Sclerotherapy for Treatment of Simple Renal Cysts  

SciTech Connect

Purpose. To evaluate the efficacy and long-term results of single-session 50% acetic acid sclerotherapy for the treatment of simple renal cysts, and to compare the therapeutic results of 5 and 20 min sclerosant dwell techniques. Methods. During the past 9 years, 50% acetic acid sclerotherapy was performed on 67 cysts in 66 patients. An acetic acid volume corresponding to a mean of 23% of the aspirated cyst volume was injected into the cysts. A 20 min dwell time with position changes was performed in 32 cysts (31 patients; group I) and 8% of volume for a 5 min dwell time in 35 cysts (35 patients; group II). Three- and 6-month sonographic or CT follow-up was performed for a minimum of 1 year. Complete regression was defined as no remaining cyst measurable on sonography with or without a scar at the renal cortex. Partial regression was defined as a decreased cyst volume compared with that before sclerotherapy. The Mann-Whitney U-test was used to compare the therapeutic results between the two groups. Results. For 67 simple renal cysts, complete regression on follow-up was observed in 21 of 32 cysts (66%; group I) and 22 of 35 cysts (63%; group II); the remaining 24 cysts all showed partial regression. The partial reduction rate of the cyst's volume was 97.4% (91.3-99.4%) in group I and 96.9% (90.8-99.5 %) in group II. There were no procedure-related major complications, and no statistically significant differences in the complete regression and partial volume reduction rates between the two groups (p > 0.05). Conclusion. Fifty percent acetic acid is an effective and safe sclerosing agent for simple renal cysts. Fifty percent acetic acid sclerotherapy with a 5 min sclerosant dwell time, using a volume of about 10% of the aspirated volume, is sufficient for satisfactory results of simple renal cyst sclerotherapy.

Kwon, Se Hwan; Oh, Joo Hyeong [Kyung Hee University Hospital, Department of Diagnostic Radiology (Korea, Republic of)], E-mail: ohjh6108@hanmail.net; Seo, Tae-Seok [Korea University Guro Hospital, Department of Radiology (Korea, Republic of); Park, Ho Chul [Kyung Hee University Hospital, Department of Surgery (Korea, Republic of)

2007-11-15

296

Kinetic and safety assessment for salicylic acid nitration by nitric acid/acetic acid system.  

PubMed

The nitration process of salicylic acid for the production of the important intermediate 5-nitrosalicylic acid is studied from thermokinetic and safety points of view. Investigations carried out by considering, as process deviations, the loss of the thermal control point out the possibility of runaway phenomena due to the occurrence of polynitration reactions. Isothermal experiments are carried out in various conditions to assess the involved reaction network and reaction kinetics. PMID:16343755

Andreozzi, R; Caprio, V; Di Somma, I; Sanchirico, R

2006-06-30

297

Fluorescence quenching of etilefrine by acetate anion  

NASA Astrophysics Data System (ADS)

Acid dissociation in the excited state of antihypotensor drug etilefrine [2-(ethylamino1-3-hydroxyphenyl)ethanol] is studied. Fluorescence of etilefrine decreases at pH<7 and is related to phenolic group dissociation. However, intensity of etilefrine fluorescence diminishes as the concentration of the acetate anion increases at pH>7. Analyses of the absorption and fluorescence spectra of aqueous solutions of etilefrine in the presence of acetate anions have been made. Considering the existence of an equilibrium in the excited state the values of 3.47×10 -9 and 0.216×10 -9 M -1 s -1 have been obtained for the rate constants for direct and inverse reactions, respectively. Moreover, the lifetime ( ?0'=0.58×10 -9 s) and quantum yield (0.01) of non-protonated etilefrine have been determined. Our results seem to support the existence of a dynamic quenching process based on a proton transfer mechanism induced by acetate anions. This process could represent a serious inconvenience in analytical fluorimetric techniques taking into account that the acetic acid/acetate pair is commonly used as a buffer. Additional fluorescence quenching by H + ions could be involved in acid aqueous mediums. At high concentrations of acetic acid, a value of 2.98×10 -9 M -1 s -1 for the bimolecular constant for the quenching by H + has been calculated.

Quintero Osso, B.; Carazo Rodríguez, F. M.; Morales Domingo, J. J.; Cabeza González, M. C.; Thomas Gómez, J.

1999-02-01

298

Phase equilibria of the ternary system water + acetic acid + 1-pentanol  

SciTech Connect

The recovery of organic acids from dilute solutions resulting from fermentation processes is becoming very important and many solvents have been tried to improve such recovery. Liquid-liquid equilibria for the ternary system water + acetic acid + 1-pentanol were measured over a temperature range of (288 to 323) K. The results were used to estimate the interaction parameters between each of the three compounds for the NRTL and UNIQUAC models and between each of the main groups of H{sub 2}O, CH{sub 2} (paraffinic CH{sub 2}), OH, and COOH for the UNIFAC model as a function of temperature. The estimated interaction parameters were successfully used to predict the equilibrium compositions by the three models. The NRTL and UNIQUAC models were almost equally good in predicting the overall equilibrium compositions of the studied system. The UNIFAC model satisfactorily predicted the equilibrium compositions. On the basis of this work, the distribution coefficients were also calculated and compared with the experimental values.

Fahim, M.A.; Al-Muhtaseb, S.A.; Al-Nashef, I.M. [U.A.E. Univ., Al-Ain (United Arab Emirates). Dept. of Chemical and Petroleum Engineering] [U.A.E. Univ., Al-Ain (United Arab Emirates). Dept. of Chemical and Petroleum Engineering

1996-05-01

299

Adaptive mutation of Acetobacter pasteurianus SKU1108 enhances acetic acid fermentation ability at high temperature.  

PubMed

In vitro adaptation is one of the most challenging subjects in biology to understand adaptive evolution. Microbial adaptation to temperature is not only interesting in terms of understanding the adaptation mechanism, but also useful for industrial applications. In this study, we attempted the in vitro adaptation of Acetobacter pasteurianus SKU1108 by repeating its cultivation under high-temperature acetic acid fermentation conditions. As a result, thermo-adapted strains having the higher fermentation ability than the wild-type strain were obtained. Mutations and/or disruptions in several proteins of the adapted strains were detected with NGS sequencing technology. In particular, two different adapted strains had mutations or disruptions in three specific genes in common, suggesting that these genes are essential for thermotolerance or fermentation at higher temperature. In order to clarify their involvement in thermotolerance, two of the three genes were disrupted and their phenotype was examined. The results showed that mutations of the two proteins, MarR and an amino acid transporter, are partly responsible for higher fermentation ability and/or thermotolerance. Thus, it was suggested that these elevated abilities of the adapted strains are acquired by assembling several single gene mutations including the above two mutations. PMID:23524057

Matsutani, Minenosuke; Nishikura, Mitsuteru; Saichana, Natsaran; Hatano, Tomoyuki; Masud-Tippayasak, Uraiwan; Theergool, Gunjana; Yakushi, Toshiharu; Matsushita, Kazunobu

2013-05-20

300

Acetic acid increases the phage-encoded enterotoxin A expression in Staphylococcus aureus  

PubMed Central

Background The effects of acetic acid, a common food preservative, on the bacteriophage-encoded enterotoxin A (SEA) expression and production in Staphylococcus aureus was investigated in pH-controlled batch cultures carried out at pH 7.0, 6.5, 6.0, 5.5, 5.0, and 4.5. Also, genomic analysis of S. aureus strains carrying sea was performed to map differences within the gene and in the temperate phage carrying sea. Results The sea expression profile was similar from pH 7.0 to 5.5, with the relative expression peaking in the transition between exponential and stationary growth phase and falling during stationary phase. The levels of sea mRNA were below the detection limit at pH 5.0 and 4.5, confirmed by very low SEA levels at these pH values. The level of relative sea expression at pH 6.0 and 5.5 were nine and four times higher, respectively, in the transitional phase than in the exponential growth phase, compared to pH 7.0 and pH 6.5, where only a slight increase in relative expression in the transitional phase was observed. Furthermore, the increase in sea expression levels at pH 6.0 and 5.5 were observed to be linked to increased intracellular sea gene copy numbers and extracellular sea-containing phage copy numbers. The extracellular SEA levels increased over time, with highest levels produced at pH 6.0 in the four growth phases investigated. Using mitomycin C, it was verified that SEA was at least partially produced as a consequence of prophage induction of the sea-phage in the three S. aureus strains tested. Finally, genetic analysis of six S. aureus strains carrying the sea gene showed specific sea phage-groups and two versions of the sea gene that may explain the different sea expression and production levels observed in this study. Conclusions Our findings suggest that the increased sea expression in S. aureus caused by acetic acid induced the sea-encoding prophage, linking SEA production to the lifecycle of the phage. PMID:20487538

2010-01-01

301

Field-scale isotopic labeling of phospholipid fatty acids from acetate-degrading sulfate-reducing bacteria.  

PubMed

Isotopic labeling of biomarker molecules is a technique applied to link microbial community structure with activity. Previously, we successfully labeled phospholipid fatty acids (PLFA) of suspended nitrate-reducing bacteria in an aquifer. However, the application of the method to low energy-yielding processes such as sulfate reduction, and extension of the analysis to attached communities remained to be studied. To test the feasibility of the latter application, an anoxic test solution of 500 l of groundwater with addition of 0.5 mM Br- as a conservative tracer, 1.1 mM SO4(2-), and 2.0 mM [2-13C]acetate was injected in the transition zone of a petroleum hydrocarbon-contaminated aquifer where sulfate-reducing and methanogenic conditions prevailed. Thousand liters of test solution/groundwater mixture were extracted in a stepwise fashion after 2-46 h incubation. Computed apparent first-order rate coefficients were 0.31+/-0.04 day(-1) for acetate and 0.34+/-0.05 day(-1) for SO4(2-) consumption. The delta13C increased from -71.03 per thousand to +3352.50 per thousand in CH4 and from -16.15 per thousand to +32.13 per thousand in dissolved inorganic carbon (DIC). A mass balance suggested that 43% of the acetate-derived (13)C appeared in DIC and 57% appeared in CH4. Thus, acetate oxidation coupled to sulfate reduction and acetoclastic methanogenesis occurred simultaneously. The delta13C of PLFA increased on average by 27 per thousand in groundwater samples and 4 per thousand in sediment samples. Hence, both suspended and attached communities actively degraded acetate. The PLFA labeling patterns and fluorescent in situ hybridization (FISH) analyses of sediment and groundwater samples suggested that the main sulfate-reducing bacteria degrading the acetate were Desulfotomaculum acetoxidans and Desulfobacter sp. in groundwater, and D. acetoxidans in sediment. PMID:16329868

Pombo, Silvina A; Kleikemper, Jutta; Schroth, Martin H; Zeyer, Josef

2005-01-01

302

Synthesis and evaluation of mutual azo prodrug of 5-aminosalicylic acid linked to 2-phenylbenzoxazole-2-yl-5-acetic acid in ulcerative colitis  

PubMed Central

In this study, the syntheses of 4-aminophenylbenzoxazol-2-yl-5-acetic acid, (an analogue of a known nonsteroidal anti-inflammatory drug [NSAID]) and 5-[4-(benzoxazol-2-yl-5-acetic acid)phenylazo]-2-hydroxybenzoic acid (a novel mutual azo prodrug of 5-aminosalicylic acid [5-ASA]) are reported. The structures of the synthesized compounds were confirmed using infrared (IR), hydrogen-1 nuclear magnetic resonance (1H NMR), and mass spectrometry (MS) spectroscopy. Incubation of the azo compound with rat cecal contents demonstrated the susceptibility of the prepared azo prodrug to bacterial azoreductase enzyme. The azo compound and the 4-aminophenylbenzoxazol-2-yl-5-acetic acid were evaluated for inflammatory bowel diseases, in trinitrobenzenesulfonic acid (TNB)-induced colitis in rats. The synthesized diazo compound and the 4-aminophenylbenzoxazol-2-yl-5-acetic acid were found to be as effective as 5-aminosalicylic acid for ulcerative colitis. The results of this work suggest that the 4-aminophenylbenzoxazol-2-yl-5-acetic acid may represent a new lead for treatment of ulcerative colitis. PMID:23983456

Jilani, Jamal A; Shomaf, Maha; Alzoubi, Karem H

2013-01-01

303

Standardization of DNA extraction from methanol acetic acid fixed cytogenetic cells of cattle and buffalo.  

PubMed

The aim of the study is to standardize the simple method for extracting DNA from cells fixed in fixative (3:1 ratio of methanol and acetic acid glacial) mostly used for chromosomal studies in cattle and buffaloes. These fixed cells were stored for more than 6 months at refrigerated temperature. The fixed cells were washed 2-3 times by the ice cold 1x Phosphate Buffer Saline (PBS) with pH 7.4, so that effect of fixative may be eliminated. The genomic DNA was extracted by adding cell lysis and nucleus lysis buffers. The quality and quantity of DNA were estimated. The readings of nano drop and agarose gel electrophoresis indicate good quality DNA isolated with a rapid and simple protocol routinely using in our laboratory. The method enables us to study the DNA of a cattle and buffaloes after completing cytogenetic investigation or in cases where DNA samples are otherwise not available. This protocol may be useful for molecular analysis of DNA from fixed cells palettes. PMID:24506057

Kotikalapudi, Rosaiah; Patel, Rajesh K; Katragadda, Sanghamitra

2013-12-01

304

Endohyphal bacterium enhances production of indole-3-acetic acid by a foliar fungal endophyte.  

PubMed

Numerous plant pathogens, rhizosphere symbionts, and endophytic bacteria and yeasts produce the important phytohormone indole-3-acetic acid (IAA), often with profound effects on host plants. However, to date IAA production has not been documented among foliar endophytes -- the diverse guild of primarily filamentous Ascomycota that live within healthy, above-ground tissues of all plant species studied thus far. Recently bacteria that live within hyphae of endophytes (endohyphal bacteria) have been detected, but their effects have not been studied previously. Here we show not only that IAA is produced in vitro by a foliar endophyte (here identified as Pestalotiopsis aff. neglecta, Xylariales), but that IAA production is enhanced significantly when the endophyte hosts an endohyphal bacterium (here identified as Luteibacter sp., Xanthomonadales). Both the endophyte and the endophyte/bacterium complex appear to rely on an L-tryptophan dependent pathway for IAA synthesis. The bacterium can be isolated from the fungus when the symbiotic complex is cultivated at 36°C. In pure culture the bacterium does not produce IAA. Culture filtrate from the endophyte-bacterium complex significantly enhances growth of tomato in vitro relative to controls and to filtrate from the endophyte alone. Together these results speak to a facultative symbiosis between an endophyte and endohyphal bacterium that strongly influences IAA production, providing a new framework in which to explore endophyte-plant interactions. PMID:24086270

Hoffman, Michele T; Gunatilaka, Malkanthi K; Wijeratne, Kithsiri; Gunatilaka, Leslie; Arnold, A Elizabeth

2013-01-01

305

Seed and 4-chloroindole-3-acetic acid regulation of gibberellin metabolism in pea pericarp.  

PubMed Central

In this study, we investigated seed and auxin regulation of gibberellin (GA) biosynthesis in pea (Pisum sativum L.) pericarp tissue in situ, specifically the conversion of [14C]GA19 to [14C]GA20. [14C]GA19 metabolism was monitored in pericarp with seeds, deseeded pericarp, and deseeded pericarp treated with 4-chloroindole-3-acetic acid (4-CI-IAA). Pericarp with seeds and deseeded pericarp treated with 4-CI-IAA continued to convert [14C]GA19 to [14C]GA20 throughout the incubation period (2-24 h). However, seed removal resulted in minimal or no accumulation of [14C]GA20 in pericarp tissue. [14C]GA29 was also identified as a product of [14C]GA19 metabolism in pea pericarp. The ratio of [14C]GA29 to [14C]GA20 was significantly higher in deseeded pericarp (with or without exogenous 4-CI-IAA) than in pericarp with seeds. Therefore, conversion of [14C]GA20 to [14C]GA29 may also be seed regulated in pea fruit. These data support the hypothesis that the conversion of GA19 to GA20 in pea pericarp is seed regulated and that the auxin 4-CI-IAA can substitute for the seeds in the stimulation of pericarp growth and the conversion of GA19 to GA20. PMID:8539289

van Huizen, R; Ozga, J A; Reinecke, D M; Twitchin, B; Mander, L N

1995-01-01

306

Process control, energy recovery and cost savings in acetic acid wastewater treatment.  

PubMed

An anaerobic fixed bed loop (AFBL) reactor was applied for treatment of acetic acid (HAc) wastewater. Two pH process control concepts were investigated; auxostatic and chemostatic control. In the auxostatic pH control, feed pump is interrupted when pH falls below a certain pH value in the bioreactor, which results in reactor operation at maximum load. Chemostatic control assures alkaline conditions by setting a certain pH value in the influent, preventing initial reactor acidification. The AFBL reactor treated HAc wastewater at low hydraulic residence time (HRT) (10-12 h), performed at high space time loads (40-45 kg COD/m(3) d) and high space time yield (30-35 kg COD/m(3) d) to achieve high COD (Chemical Oxygen Demand) removal (80%). Material and cost savings were accomplished by utilizing the microbial potential for wastewater neutralization during anaerobic treatment along with application of favourable pH-auxostatic control. NaOH requirement for neutralization was reduced by 75% and HRT was increased up to 20 h. Energy was recovered by applying costless CO(2) contained in the biogas for neutralization of alkaline wastewater. Biogas was enriched in methane by 4 times. This actually brings in more energy profits, since biogas extra heating for CO(2) content during biogas combustion is minimized and usage of other acidifying agents is omitted. PMID:21168957

Vaiopoulou, E; Melidis, P; Aivasidis, A

2011-02-28

307

Production of the Phytohormone Indole-3-Acetic Acid by Estuarine Species of the Genus Vibrio?  

PubMed Central

Strains of Vibrio spp. isolated from roots of the estuarine grasses Spartina alterniflora and Juncus roemerianus produce the phytohormone indole-3-acetic acid (IAA). The colorimetric Salkowski assay was used for initial screening of IAA production. Gas chromatography-mass spectroscopy (GC-MS) was then employed to confirm and quantify IAA production. The accuracy of IAA quantification by the Salkowski assay was examined by comparison to GC-MS assay values. Indole-3-acetamide, an intermediate in IAA biosynthesis by the indole-3-acetamide pathway, was also identified by GC-MS. Multilocus sequence typing of concatenated 16S rRNA, recA, and rpoA genes was used for phylogenetic analysis of environmental isolates within the genus Vibrio. Eight Vibrio type strains and five additional species-level clades containing a total of 16 environmental isolates and representing five presumptive new species were identified as IAA-producing Vibrio species. Six additional environmental isolates similar to four of the Vibrio type strains were also IAA producers. To our knowledge, this is the first report of IAA production by species of the genus Vibrio or by bacteria isolated from an estuarine environment. PMID:19218411

Gutierrez, Casandra K.; Matsui, George Y.; Lincoln, David E.; Lovell, Charles R.

2009-01-01

308

Endohyphal Bacterium Enhances Production of Indole-3-Acetic Acid by a Foliar Fungal Endophyte  

PubMed Central

Numerous plant pathogens, rhizosphere symbionts, and endophytic bacteria and yeasts produce the important phytohormone indole-3-acetic acid (IAA), often with profound effects on host plants. However, to date IAA production has not been documented among foliar endophytes -- the diverse guild of primarily filamentous Ascomycota that live within healthy, above-ground tissues of all plant species studied thus far. Recently bacteria that live within hyphae of endophytes (endohyphal bacteria) have been detected, but their effects have not been studied previously. Here we show not only that IAA is produced in vitro by a foliar endophyte (here identified as Pestalotiopsis aff. neglecta, Xylariales), but that IAA production is enhanced significantly when the endophyte hosts an endohyphal bacterium (here identified as Luteibacter sp., Xanthomonadales). Both the endophyte and the endophyte/bacterium complex appear to rely on an L-tryptophan dependent pathway for IAA synthesis. The bacterium can be isolated from the fungus when the symbiotic complex is cultivated at 36°C. In pure culture the bacterium does not produce IAA. Culture filtrate from the endophyte-bacterium complex significantly enhances growth of tomato in vitro relative to controls and to filtrate from the endophyte alone. Together these results speak to a facultative symbiosis between an endophyte and endohyphal bacterium that strongly influences IAA production, providing a new framework in which to explore endophyte-plant interactions. PMID:24086270

Hoffman, Michele T.; Gunatilaka, Malkanthi K.; Wijeratne, Kithsiri; Gunatilaka, Leslie; Arnold, A. Elizabeth

2013-01-01

309

Diversity of acetic acid bacteria present in healthy grapes from the Canary Islands.  

PubMed

The identification of acetic acid bacteria (AAB) from sound grapes from the Canary Islands is reported in the present study. No direct recovery of bacteria was possible in the most commonly used medium, so microvinifications were performed on grapes from Tenerife, La Palma and Lanzarote islands. Up to 396 AAB were isolated from those microvinifications and identified by 16S rRNA gene sequencing and phylogenetic analysis. With this method, Acetobacter pasteurianus, Acetobacter tropicalis, Gluconobacter japonicus and Gluconacetobacter saccharivorans were identified. However, no discrimination between the closely related species Acetobacter malorum and Acetobacter cerevisiae was possible. As previously described, 16S-23S rRNA gene internal transcribed spacer (ITS) region phylogenetic analysis was required to classify isolates as one of those species. These two species were the most frequently occurring, accounting for more than 60% of the isolates. For typing the AAB isolates, both the Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR and (GTG)5-PCR techniques gave similar resolution. A total of 60 profiles were identified. Thirteen of these profiles were found in more than one vineyard, and only one profile was found on two different islands (Tenerife and La Palma). PMID:21903289

Valera, Maria José; Laich, Federico; González, Sara S; Torija, Maria Jesús; Mateo, Estibaliz; Mas, Albert

2011-11-15

310

Application of molecular methods for routine identification of acetic acid bacteria.  

PubMed

Recently many new species of Acetic acid Bacteria have been described. The description and identification as new species was based on molecular techniques (sequencing of the 16S rRNA gene, DNA base ratio (% GC) determinations and DNA-DNA hybridisation) and phenotypic characterization. In the present paper, we propose a fast and reliable method for the identification most of the species currently described based on the RFLP-PCR of the 16S rRNA. According to the proposed protocol, 1 species can be identified with the use of a single enzyme, 13 with a combination of 2 enzymes, 2 species with a combination of 3 enzymes, 2 with a combination of 4 enzymes. To differentiate 5 more species RFLP-PCR of the ITS was also needed, after using 3 enzymes. Finally, a pair of species (Acetobacter pasteurianus and Acetobacter pomorum) could not be distinguished with the proposed method. However, doubts can be raised about their differentiation as separate species. Keeping these limitations in mind, the method is fast and reliable, allowing the processing of large number of samples in relatively short periods of time (less than 24 h after the isolation). PMID:16386324

González, Angel; Guillamón, José Manuel; Mas, Albert; Poblet, Montse

2006-04-15

311

Structural analysis of fructans produced by acetic acid bacteria reveals a relation to hydrocolloid function.  

PubMed

Some strains of acetic acid bacteria (Gluconobacter frateurii TMW 2.767, Gluconobacter cerinus DSM 9533T, Neoasaia chiangmaiensis NBRC 101099, Kozakia baliensis DSM 14400) produce high amounts of fructans, which can be exploited in food applications as previously demonstrated empirically for dough systems. In order to get insight into the structure and functionality of these polymers, we investigated the fructans isolated from these strains with respect to their linkage types and molecular weights/shapes using NMR spectroscopy and AF4-MALS-RI. Each fructan was identified as levan. The isolated levan fractions were highly similar according to their basic linearity and linkage types, but differed significantly in terms of their individual molecular weight distributions. In aqueous solutions the size of levan molecules present in all isolated levans continuously increased with their molecular weight and they tended to adopt a more compact molecular shape. Our data suggest that the increasing molecular weight of a levan particle enforces intramolecular interactions to reach the structural compactness of a microgel with hydrocolloid properties. PMID:23399151

Jakob, Frank; Pfaff, Andre; Novoa-Carballal, Ramon; Rübsam, Heinrich; Becker, Thomas; Vogel, Rudi F

2013-02-15

312

Temperature-Sensitive Plant Cells with Shunted Indole-3-Acetic Acid Conjugation.  

PubMed Central

Cells of henbane (Hyoscyamus muticus L.) grow indefinitely in culture without exogenous auxin. Cells of its temperature-sensitive variant XIIB2 grow like the wild type at 26[deg]C but die rapidly at 33[deg]C unless auxin is added to the medium. Despite this temperature-sensitive auxin auxotrophy, XIIB2 produces wild-type amounts of indole-3-acetic acid (IAA). IAA is the predominant auxin and is important for plant growth and development. Since the IAA production of the variant is functional, we investigated whether the synthesis or degradation of IAA metabolites, possibly active auxins themselves, is altered. The IAA metabolites were IAA-aspartate (IAAsp) and IAA-glucose. The wild type converted IAA mainly to IAAsp, whereas the variant produced mainly IAA-glucose. Exogenous auxin corrected the shunted IAA metabolism of the variant. The half-life of labeled IAAsp in the variant was reduced 21-fold, but in the presence of exogenous auxin it was not different from the wild type. The temperature sensitivity of XIIB2 was also corrected by supplying IAAsp. Pulse-chase experiments revealed that henbane rapidly metabolizes IAAsp to compounds not identical to IAA. The data show that the variant XIIB2 is a useful tool to study the function of IAA conjugates to challenge the popular hypothesis that IAA conjugates are merely slow-release storage forms of IAA. PMID:12223777

Oetiker, J. H.; Aeschbacher, G.

1997-01-01

313

Nutrient Salts Promote Light-Induced Degradation of Indole-3-Acetic Acid in Tissue Culture Media  

PubMed Central

The disappearance of indole-3-acetic acid (IAA) from cell-free liquid culture medium was followed in response to nutrient salts found in Murashige-Skoog salt base, light, and pH range of 4 to 7. The loss of IAA was accelerated by light or Murashige-Skoog salts. However, the combination of both light and Murashige-Skoog salts acted synergistically to catalyze the destruction of over 80% of the original IAA within 7 days of continuous incubation. Under these same conditions, the loss of IAA was decreased to approximately 50% by adjusting the initial pH of the medium to 7. Iron was identified as the single major contributor to light-catalyzed destruction of IAA. Removal of nitrates, which represented 87% of the molar salt composition, also reduced the light-catalyzed loss of IAA. Treatments that protected IAA from degradation, such as darkness or removal of iron from the medium, suppressed the growth of muskmelon (Cucumis melo. Naud., var. reticulatus) callus tissue cultured for 30 days. Treatments in the light that rapidly degraded IAA resulted in maximum growth. Consequently, the brief exposure to IAA prior to degradation was apparently sufficient to initiate physiological changes required for growth. Possible approaches to the preservation of IAA during incubation are discussed. PMID:16666312

Dunlap, James R.; Robacker, Karen M.

1988-01-01

314

Utilization of the Plant Hormone Indole-3-Acetic Acid for Growth by Pseudomonas putida Strain 1290†  

PubMed Central

We have isolated from plant surfaces several bacteria with the ability to catabolize indole-3-acetic acid (IAA). One of them, isolate 1290, was able to utilize IAA as a sole source of carbon, nitrogen, and energy. The strain was identified by its 16S rRNA sequence as Pseudomonas putida. Activity of the enzyme catechol 1,2-dioxygenase was induced during growth on IAA, suggesting that catechol is an intermediate of the IAA catabolic pathway. This was in agreement with the observation that the oxygen uptake by IAA-grown P. putida 1290 cells was elevated in response to the addition of catechol. The inability of a catR mutant of P. putida 1290 to grow at the expense of IAA also suggests a central role for catechol as an intermediate in IAA metabolism. Besides being able to destroy IAA, strain 1290 was also capable of producing IAA in media supplemented with tryptophan. In root elongation assays, P. putida strain 1290 completely abolished the inhibitory effect of exogenous IAA on the elongation of radish roots. In fact, coinoculation of roots with P. putida 1290 and 1 mM concentration of IAA had a positive effect on root development. In coinoculation experiments on radish roots, strain 1290 was only partially able to alleviate the inhibitory effect of bacteria that in culture overproduce IAA. Our findings imply a biological role for strain 1290 as a sink or recycler of IAA in its association with plants and plant-associated bacteria. PMID:15870323

Leveau, Johan H. J.; Lindow, Steven E.

2005-01-01

315

Improvement of sensitivity of electrolyte cathode discharge atomic emission spectrometry (ELCAD-AES) for mercury using acetic acid medium.  

PubMed

A method has been developed to improve the sensitivity of the electrolyte cathode discharge atomic emission spectrometry (ELCAD-AES) for mercury determination. Effects of various low molecular weight organic solvents at different volume percentages as well as at different acid molarities on the mercury signal were investigated using ELCAD-AES. The addition of few percent of organic solvent, acetic acid produced significant enhancement in mercury signal. Acetic acid of 5% (v/v) with the 0.2M acidity has been found to give 500% enhancement for mercury signal in flow injection mode. Under the optimized parameters the repeatability, expressed as the percentage relative standard deviation of spectral peak area for mercury with 5% acetic acid was found to be 10% for acid blank solution and 5% for 20 ng/mL mercury standard based on multiple measurements with a multiple sample loading in flow injection mode. Limit of detection of this method was determined to be 2 ng/mL for inorganic mercury. The proposed method has been validated by determining mercury in certified reference materials, Tuna fish (IAEA-350) and Aquatic plant (BCR-060). Accuracy of the method for the mercury determination in the reference materials has been found to be between 3.5% and 5.9%. This study enhances the utility of ELCAD-AES for various types of biological and environmental materials to quantify total mercury at very low levels. PMID:22483872

Shekhar, R

2012-05-15

316

Thermochemical characteristics of cellulose acetates with different degrees of acetylation  

NASA Astrophysics Data System (ADS)

The standard enthalpies of combustion and formation of cellulose acetates with different degrees of acetylation are determined. It is established that there is a proportional dependence of these thermochemical characteristics vs. the degree of acetylation, weight fraction of bonded acetic acid, and molar mass of the repeating unit of cellulose acetates.

Larina, V. N.; Ur'yash, V. F.; Kushch, D. S.

2012-12-01

317

The Acid Hydrolysis Mechanism of Acetals Catalyzed by a Supramolecular Assembly in Basic Solution  

SciTech Connect

A self-assembled supramolecular host catalyzes the hydrolysis of acetals in basic aqueous solution. The mechanism of hydrolysis is consistent with the Michaelis-Menten kinetic model. Further investigation of the rate limiting step of the reaction revealed a negative entropy of activation ({Delta}S{double_dagger} = -9 cal mol{sup -1}K{sup -1}) and an inverse solvent isotope effect (k(H{sub 2}O)/k(D{sub 2}O) = 0.62). These data suggest that the mechanism of hydrolysis that takes place inside the assembly proceeds through an A-2 mechanism, in contrast to the A-1 mechanism operating in the uncatalyzed reaction. Comparison of the rates of acetal hydrolysis in the assembly with the rate of the reaction of unencapsulated substrates reveals rate accelerations of up to 980 over the background reaction for the substrate diethoxymethane.

Pluth, Michael D.; Bergman, Robert G.; Raymond, Kenneth N.

2008-09-24

318

Densities and excess molar volumes of formic acid, acetic acid and propionic acid in pure water and in water?+?Surf Excel solutions at different temperatures  

Microsoft Academic Search

Densities, ? of the systems formic acid, acetic acid and propionic acid in water and in 0.05% and 0.1% Surf Excel (SE) solutions in water were measured at temperatures 303.15, 308.15, 313.15, 318.15 and 323.15?K respectively covering the whole composition range. Excess molar volumes, for the systems were found to be negative and their values were found to increase with

M. A. Motin; M. H. Kabir; E. M. Huque

2005-01-01

319

Electrochemical generation of manganese(III) and behaviour of the generated oxidant in acetic acid in the presence of perchlorate ions  

Microsoft Academic Search

Summary Research was carried out to determine conditions for the anodic generation of manganese(III) with high current efficiency in solutions of sodium perchlorate in acetic acid, and to examine the behaviour of the oxidant thus generated. The effects of water and acetic anhydride on current efficiency in the generation of the oxidant was also examined. The formal redox potential of

Tibor J. Pastor; Ivan ?iri?

1984-01-01

320

Biofilm formation and indole-3-acetic Acid production by two rhizospheric unicellular cyanobacteria.  

PubMed

Microorganisms that live in the rhizosphere play a pivotal role in the functioning and maintenance of soil ecosystems. The study of rhizospheric cyanobacteria has been hampered by the difficulty to culture and maintain them in the laboratory. The present work investigated the production of the plant hormone indole-3-acetic acid (IAA) and the potential of biofilm formation on the rhizoplane of pea plants by two cyanobacterial strains, isolated from rice rhizosphere. The unicellular cyanobacteria Chroococcidiopsis sp. MMG-5 and Synechocystis sp. MMG-8 that were isolated from a rice rhizosphere, were investigated. Production of IAA by Chroococcidiopsis sp. MMG-5 and Synechocystis sp. MMG-8 was measured under experimental conditions (pH and light). The bioactivity of the cyanobacterial auxin was demonstrated through the alteration of the rooting pattern of Pisum sativum seedlings. The increase in the concentration of L-tryptophan and the time that this amino acid was present in the medium resulted in a significant enhancement of the synthesis of IAA (r > 0.900 at p = 0.01). There was also a significant correlation between the concentration of IAA in the supernatant of the cyanobacteria cultures and the root length and number of the pea seedlings. Observations made by confocal laser scanning microscopy revealed the presence of cyanobacteria on the surface of the roots and also provided evidence for the penetration of the cyanobacteria in the endorhizosphere. We show that the synthesis of IAA by Chroococcidiopsis sp. MMG-5 and Synechocystis sp. MMG-8 occurs under different environmental conditions and that the auxin is important for the development of the seedling roots and for establishing an intimate symbiosis between cyanobacteria and host plants. PMID:24705871

Ahmed, Mehboob; Stal, Lucas J; Hasnain, Shahida

2014-08-28

321

Isolation and Partial Characterization of the Major Amide-Linked Conjugate of Indole-3-Acetic Acid from Phaseolus vulgaris L. 1  

PubMed Central

A major indole-3-acetic acid conjugate from Phaseolus vulgaris seed has been isolated and partially characterized. It is a 3 kilodalton peptide with apparently 2 indole-3-acetyl moieties in amide linkage per peptide. The indole-3-acetic acid component was identified by gas chromatography-mass spectrometry and the peptide characterized by polyacrylamide gel electrophoresis, by amino acid analysis using dabsyl derivatives and by its Fourier transform-infrared spectrum. This is the first higher molecular weight amide-linked indole-3-acetic acid conjugate to be characterized from higher plants. Images Fig. 4 PMID:16664615

Bialek, Krystyna; Cohen, Jerry D.

1986-01-01

322

Evaluation of nitric and acetic acid resistance of cement mortars containing high-volume black rice husk ash.  

PubMed

This paper presents the performance of cement mortar containing black rice husk ash (BRHA) under nitric and acetic acid attacks. The BRHA, collected from an electrical generating power plant that uses rice husk as fuel, was ground using a grinding machine. The compressive strength loss, weight loss, and expansion of mortars under nitric and acetic acid attack were investigated. The test results of BRHA properties in accordance with the ASTM C 618 standard found that the optimal grinding time was 4 h as this achieved a Blaine fineness of 5370 cm(2)/g. For parametric study, BRHA were used as a Portland cement Type 1 replacement at the levels of 0%, 10%, 20%, 30%, 40%, and 50% by weight of binder. The water-to-binder ratios were 0.55, 0.60, and 0.65. From test results, when the percentage replacements of BRHA in cement increased, it was observed that the strength loss and weight loss of mortars containing BRHA under acetic acid attack were higher than those of the mortars against nitric acid attack. It was found that, of the various BHRA mortars, the strength loss and weight loss due to nitric and acetic acid attacks were the lowest in the mortar with 10% BRHA replacement. For 10%, 20% and 30% BRHA replacements, the rate of expansion of the BRHA mortar decreased when compared with the control mortar. For the mortars with other percentage replacements of BRHA, the rate of expansion increased. Furthermore, the effective water-to-binder ratios of control and BRHA mortars were the primary factor for determining the durability of mortar mixed with BRHA. PMID:24412985

Chatveera, B; Lertwattanaruk, P

2014-01-15

323

Impact of trace element addition on degradation efficiency of volatile fatty acids, oleic acid and phenyl acetate and on microbial populations in a biogas digester.  

PubMed

The effect of trace element addition on anaerobic digestion of food industry- and household waste was studied using two semi-continuous lab-scale reactors, one (R30+) was supplied with Fe, Co and Ni, while the other (R30) acted as a control. Tracer analysis illustrated that methane production from acetate proceeded through syntrophic acetate oxidation (SAO) in both digesters. The effect of the trace elements was also evaluated in batch assays to determine the capacity of the microorganisms of the two digesters to degrade acetate, phenyl acetate, oleic acid or propionate, butyrate and valerate provided as a cocktail. The trace elements addition improved the performance of the process giving higher methane yields during start-up and early operation and lower levels of mainly acetate and propionate in the R30+ reactor. The batch assay showed that material from R30+ gave effects on methane production from all substrates tested. Phenyl acetate was observed to inhibit methane formation in the R30 but not in the R30+ assay. A real-time PCR analysis targeting methanogens on the order level as well as three SAO bacteria showed an increase in Methanosarcinales in the R30+ reactor over time, even though SAO continuously was the dominating pathway for methane production. Possibly, this increase explains the low VFA-levels and higher degradation rates observed in the R30+ batch incubations. These results show that the added trace elements affected the ability of the microflora to degrade VFAs as well as oleic acid and phenyl acetate in a community, where acetate utilization is dominated by SAO. PMID:22683024

Karlsson, Anna; Einarsson, Peter; Schnürer, Anna; Sundberg, Carina; Ejlertsson, Jörgen; Svensson, Bo H

2012-10-01

324

Combined application of origanum vulgare l. essential oil and acetic acid for controlling the growth of staphylococcus aureus in foods  

PubMed Central

This study evaluated the occurrence of an enhancing inhibitory effect of the combined application of Origanum vulgare L. essential oil and acetic acid against Staphylococcus aureus by the determination of Fractional Inhibitory Concentration (FIC) index and kill-time assay in nutrient broth, meat broth and in a food model (meat pieces). Acetic acid showed MIC and MFC of 0.6 and 1.25 ?L.mL-1, respectively. For O. vulgare essential oil MIC and MBC were 1.25 and 2.5 ?L.mL-1, respectively. FIC indexes of the mixture of essential oil and acetic acid at MIC x ½ were ? 1.0, showing an additive effect. No synergy was found at kill-time study. Anti-staphylococcal effect of the antimicrobials alone or in mixture (MIC x ½) was lower in meat than in nutrient and meat broths. The effective combination of essential oils and organic acids could appear as an attractive alternative for the food industry, as the doses to inhibit the microbial growth in foods can be lowered. PMID:24031377

de Souza, Evandro Leite; de Barros, Jefferson Carneiro; da Conceicao, Maria Lucia; Neto, Nelson Justino Gomes; da Costa, Ana Caroliny Vieira

2009-01-01

325

FT-IR and Raman spectra vibrational assignments and density functional calculations of 1-naphthyl acetic acid.  

PubMed

This work deals with the vibrational spectroscopy of 1-naphthyl acetic acid. The molecular vibrations of 1-naphthyl acetic acid (NAA) is investigated in polycrystalline sample, at room temperature, by Fourier transform infrared (FT-IR) and FT-Raman spectroscopy. In parallel, ab initio and various density functional (DFT) methods were used to determine the geometrical, energetic and vibrational characteristics of NAA. On the basis of B3LYP/6-311+G** method and basis set combinations, a normal mode analysis was performed to assign the various fundamental frequencies according to the total energy distribution (TED). Simulation of infrared and Raman spectra, utilizing the results of these calculations led to excellent overall agreement with observed spectral patterns by refinement of scale factors. PMID:17804282

Krishnakumar, V; Mathammal, R; Muthunatesan, S

2008-06-01

326

Myo-Inositol Esters of Indole-3-acetic Acid Are Endogenous Components of Zea mays L. Shoot Tissue 1  

PubMed Central

Indole-3-acetyl-myo-inositol esters have been demonstrated to be endogenous components of etiolated Zea mays shoots tissue. This was accomplished by comparison of the putative compounds with authentic, synthetic esters. The properties compared were liquid and gas-liquid chromatographic retention times and the 70-ev mass spectral fragmentation pattern of the pentaacetyl derivative. The amount of indole-3-acetyl-myo-inositol esters in the shoots was determined to be 74 nanomoles per kilogram fresh weight as measured by isotope dilution, accounting for 19% of the ester indole-3-acetic acid of the shoot. This work is the first characterization of an ester conjugate of indole-3-acetic acid from vegetative shoot tissue using multiple chromatographic properties and mass spectral identification. The kernel and the seedling shoot both contain indole-3-acetyl-myo-inositol esters, and these esters comprise approximately the same percentage of the total ester content of the kernel and of the shoot. PMID:11540816

Chisnell, John R.

1984-01-01

327

Decontamination of aquatic vegetable leaves by removing trace toxic metals during pickling process with acetic acid solution.  

PubMed

The heavy-metal content of aquatic plants is mainly dependent upon their ecological system. This study indicated that although the toxic heavy-metal contents could be above the recommended maximum levels depending upon their concentrations in growing water, they can be decontaminated by pickling with 5% acetic acid solution. Almost all Cd, Hg, Ba, or Sb and 99.5% Pb, 96.7% Ag, or 97.1% Al were removed from Water Spinach leaves by soaking in acetic acid solution. For Water-Shield leaves, almost all Cd, Hg, Pb, Ba, or Sb and 95.0% Ag or 96.1% Al were removed. For Watercress leaves, almost all Cd, Hg, Ba, or Sb and 99.0% Pb or 99.7% Ag were removed. For Water Hyacinth leaves, almost all Cd, Ba, or Sb and 99.0% Hg, 98.5% Pb, 95.0% Ag, or 98.7% Al were removed. PMID:21888602

Wu, Wenbiao; Yang, Yixing

2011-01-01

328

Hydrogen-bonded acetic acid dimers: Anharmonic coupling and linear infrared spectra studied with density-functional theory  

NASA Astrophysics Data System (ADS)

Anharmonic vibrational force field calculations provide a quantitative understanding of the width and substructure of the linear IR-absorption spectrum of the O-H stretching mode in acetic acid dimers (CH3-COOH)2 and (CD3-COOH)2. Anharmonic coupling of the high-frequency ?OH mode to fingerprint and low-frequency modes is included resulting in 11- and 9-dimensional vibrational Hamiltonians. A sixth-order force field covering up to three-body interactions is used. Force constants are calculated by fitting one-dimensional potential-energy surfaces and a finite difference procedure applying density-functional theory [Becke 3 Lee-Yang-Parr 6-311+G(d,p)]. It is demonstrated that both anharmonic coupling to low-frequency modes as well as Fermi resonance coupling with fingerprint modes are important mechanisms explaining the line shape of the O-H stretching IR-absorption band in acetic acid dimers.

Dreyer, Jens

2005-05-01

329

Effect of indole-acetic acid (IAA) on the development of symptoms caused by Pythium ultimum on tomato plants  

Microsoft Academic Search

The effect of indole-acetic acid (IAA) on the development of symptoms caused by Pythium ultimum on tomato plants was investigated using different bioassays. Application of IAA (5 ?g ml?1) on tomato seedlings inoculated with P. ultimum did not affect their emergence suggesting that IAA did not affect the severity of Pythium damping-off. However, IAA was shown\\u000a to influence the development of P. ultimum symptoms

Valérie Gravel; Hani Antoun; Russell J. Tweddell

2007-01-01

330

Physicochemical changes in Mazafati date fruits incubated in hot acetic acid for accelerated ripening to prevent diseases and decay  

Microsoft Academic Search

A method was developed and optimized for the accelerated ripening of date fruits of cultivar ‘Mazafati’ to prevent diseases and decay. The date fruits were incubated in hot acetic acid solution 0.5% at 40+1°C for 72h. During the process some physicochemical changes in the fruits were studied and were found to be comparable with the changes in the fruits that

Asgar Farahnaky; Hassan Afshari-Jouybari

2011-01-01

331

Inhibition of ?-amylase activity, starch degradation and sucrose formation by indole-3-acetic acid during banana ripening  

Microsoft Academic Search

.   In order to observe the effect of indole- 3-acetic acid (IAA) on carbohydrate metabolism, unripe banana (Musa acuminata AAA, cv. Nanicão) slices were infiltrated with the hormone and left to ripen under controlled conditions. The climacteric\\u000a respiration burst was reduced by the action of IAA, and starch degradation and sucrose formation were delayed. Sucrose synthase\\u000a (SuSy; EC 2.4.1.13) and

Eduardo Purgatto; Franco Maria Lajolo; João Roberto Oliveira do Nascimento; Beatriz Rosana Cordenunsi

2001-01-01

332

Friedel–Crafts acylation of anisole with acetic anhydride over silica-supported heteropolyphosphotungstic acid (HPW\\/SiO 2)  

Microsoft Academic Search

Methoxyacetophenones were synthesized through Friedel–Crafts acylation of anisole with acetic anhydride using a silica-supported heteropolyphosphotungstic acid (HPW) catalyst. High conversions and very high p-selectivity were attained in the temperature range of 61–110°C. Nevertheless, the catalyst seemed to deactivate after half an hour at 61 and 83°C, mainly due to strong but reversible adsorption of products. Cleaning the spent catalyst recovered

Luiz A. M. Cardoso; Walter Alves. Jr; Angélica R. E. Gonzaga; Leila M. G. Aguiar; Heloysa M. C. Andrade

2004-01-01

333

Stability of the Acetic Acid-Induced Bladder Irritation Model in Alpha Chloralose-Anesthetized Female Cats  

PubMed Central

Time- and vehicle-related variability of bladder and urethral rhabdosphincter (URS) activity as well as cardiorespiratory and blood chemistry values were examined in the acetic acid-induced bladder irritation model in ?-chloralose-anesthetized female cats. Additionally, bladder and urethra were evaluated histologically using Mason trichrome and toluidine blue staining. Urodynamic, cardiovascular and respiratory parameters were collected during intravesical saline infusion followed by acetic acid (0.5%) to irritate the bladder. One hour after starting acetic acid infusion, a protocol consisting of a cystometrogram, continuous infusion-induced rhythmic voiding contractions, and a 5 min “quiet period” (bladder emptied without infusion) was precisely repeated every 30 minutes. Administration of vehicle (saline i.v.) occurred 15 minutes after starting each of the first 7 cystometrograms and duloxetine (1mg/kg i.v.) after the 8th. Acetic acid infusion into the bladder increased URS-EMG activity, bladder contraction frequency, and decreased contraction amplitude and capacity, compared to saline. Bladder activity and URS activity stabilized within 1 and 2 hours, respectively. Duloxetine administration significantly decreased bladder contraction frequency and increased URS-EMG activity to levels similar to previous reports. Cardiorespiratory parameters and blood gas levels remained consistent throughout the experiment. The epithelium of the bladder and urethra were greatly damaged and edema and infiltration of neutrophils in the lamina propria of urethra were observed. These data provide an ample evaluation of the health of the animals, stability of voiding function and appropriateness of the model for testing drugs designed to evaluate lower urinary tract as well as cardiovascular and respiratory systems function. PMID:24040064

Kullmann, F. Aura; Wells, Grace I.; Langdale, Christopher L.; Zheng, Jihong; Thor, Karl B.

2013-01-01

334

Biosynthesis of Citric Acid from Glycerol by Acetate Mutants of Yarrowia lipolytica in Fed-Batch Fermentation  

Microsoft Academic Search

Summary Pure and crude glycerol from biodiesel production have been used as substrates for cit- ric acid production by acetate-negative mutants of Yarrowia lipolytica in fed-batch fermen- tation. Both the final concentration and the yield of the product were the highest when Y. lipolytica Wratislavia AWG7 strain was used in the culture with pure or crude glycerol. With a medium

Anita Rywinska; Waldemar Rymowicz; Barbara Z Larowska; Maria Wojtatowicz

335

Effect of the medium on the reaction of 4-methyl-7-azaindoline with acetic and trifluoroacetic acids  

Microsoft Academic Search

The effect of the medium on the equilibrium involved in proton transfer via a hydrogen bond and dissociation of ion pairs in systems composed of 4-methyl-7-azaindoline and acetic and trifluoroacetic acids was examined by means of PMR and IR spectroscopy. The position of the molecular H complex ? ion pair equilibrium depends on the proton-donor-acceptor properties of the solvent and

G. G. Dvoryantseva; T. N. Ul'yanova; Yu. N. Sheinker; D. M. Krasnokut-skaya; L. N. Yakhontov

1976-01-01

336

Pressure dependence of the dissociation of acetic, benzoic, mandelic and succinic acids at 298.15 K  

Microsoft Academic Search

Dissociation constants for acetic, benzoic, mandelic and succinic acids have been measured at 298.15K as a function of pressure up to 138.8MPa. The spectrophotometric technique using Bromocresol Green as the optical indicator was employed up to ionic strength of 0.03molkg?1 in aqueous solution. Thermodynamic dissociation constants were calculated with the Davies activity coefficient equation. The pressure dependences of the ionization

Anil Kumar

2005-01-01

337

Oxidation of adamantane with O 2 catalysed by VO(acac) 2 and reactivity of active species in acetic acid  

Microsoft Academic Search

The oxidation of adamantane (470mM) catalysed by VO(acac)2 (0.5mM) with 1atm O2 in acetic acid at 393K was studied. The major product was 1-adamantanol, and minor ones were 2-adamantanol and 2-adamantanone. The selectivity for 1-adamantanol (3°-selectivity) was almost constant at 75% under all oxidation conditions. The VO(acac)2 catalyst functioned efficiently in the oxidation with a turnover number (TON) of 440

Hirokazu Kobayashi; Ichiro Yamanaka

2008-01-01

338

Identification and quantification of acetic acid bacteria in wine and vinegar by TaqMan–MGB probes  

Microsoft Academic Search

A Real-Time PCR (RT-PCR) assay was developed using TaqMan minor groove binder (MGB) probes for the specific detection and quantification of five acetic acid bacteria (AAB) species (Acetobacter pasteurianus, Acetobacter aceti, Gluconacetobacter hansenii, Gluconacetobacter europaeus and Gluconobacter oxydans) in wine and vinegar. The primers and probes, designed from the 16S rRNA gene, showed good specificity with the target AAB species.

M. J. Torija; E. Mateo; J. M. Guillamón; A. Mas

2010-01-01

339

Protective effects of ascorbic acid, dl -?-tocopherol acetate, and sodium selenate on ethanol-induced liver damage of rats  

Microsoft Academic Search

In this study, the effect of a combination of vitamin C (ascorbic acid), vitamin E (dl-?-tocopherol acetate), and selenium (sodium selenate) on ethanol-induced liver damage in rats was investigated, morphologically\\u000a and biochemically. The ethanol-induced injury was produced by the administration of 1 mL of absolute ethanol to each rat.\\u000a Animals received vitamin C (250 mg\\/kg), vitamin E (250 mg\\/kg), and

Sadakat Ozdil; ?ehnaz Bolkent; Refiye Yanardag; Pelin Arda-Pirincci

2004-01-01

340

Metallic lead recovery from lead-acid battery paste by urea acetate dissolution and cementation on iron  

Microsoft Academic Search

A suitable hydrometallurgical and environmentally friendly process was studied to replace the currently used practices for recycling lead-acid batteries via smelting. Metallic lead was recovered by cementation from industrial lead sludge solutions of urea acetate (200 to 500 g\\/L) using different types of metallic iron substrates (nails, shaving or powder) as reducing agents. Under specific operating conditions, up to 99.7% of

M. Volpe; D. Oliveri; G. Ferrara; M. Salvaggio; S. Piazza; S. Italiano; C. Sunseri

2009-01-01

341

Influence of 1-aminoethoxyvinylglycine hydrochloride and ?-naphthalene acetic acid on fruit retention, quality, evolved ethylene, and respiration in apples  

Microsoft Academic Search

Effects of 1-aminoethoxyvinylglycine hydrochloride (AVG or Aviglycine HCl or ReTain) and ?- naphthalene acetic acid (NAA) on fruit retention, fruit quality, eveloved ethylene, and respiration in 'Rome Beauty' and three 'Delicious' apple cultivars (Malus domestica Borkh.) were studied. The experimental trees were treated with either AVG, applied at 120 g a.i. per 935 L. ha-1 or NAA, applied at the

E. Fallahi

342

Preparation of La-Mo-V mixed-oxide systems and their application in the direct synthesis of acetic acid  

Microsoft Academic Search

In this study, mixed metal oxides developed with a perovskite-type structure that show great potential for use in catalysis. Perovskite oxide catalysts with the composition LaMoxV1 ?xOn (x = 0.1, 0.3, 0.5, 0.7, and 0.9) have been synthesized by the sol-gel method and then used in the ethane dry reforming reaction for the direct synthesis of acetic acid. The influence

Hamid Reza Arandiyan; Matin Parvari

2008-01-01

343

Clinical aspects of a phase I trial of 5,6-dimethylxanthenone-4-acetic acid (DMXAA), a novel antivascular agent  

Microsoft Academic Search

The antitumour action of 5,6-dimethylxanthenone-4-acetic acid (DMXAA) is mediated through tumour-selective antivascular effects and cytokine induction. This clinical phase I trial was conducted to examine its toxicity, maximum tolerated dose, pharmacokinetics (PK) and pharmacodynamics (PD). A secondary objective was to assess its antitumour efficacy. DMXAA was administered every 3 weeks as a 20-min i.v. infusion. Dose escalation initially followed a

M B Jameson; P I Thompson; B C Baguley; B D Evans; V J Harvey; D J Porter; M R McCrystal; M Small; K Bellenger; L Gumbrell; G W Halbert; P Kestell

2003-01-01

344

Flavone8Acetic Acid (Flavonoid) Profoundly Reduces Platelet-Dependent Thrombosis and Vasoconstriction After Deep Arterial Injury In Vivo  

Microsoft Academic Search

Background—Flavone-8-acetic acid (FAA; (Flavonoid)), an adjuvant antitumor drug, inhibits ristocetin-induced aggre- gation of human platelets. The effect of FAA on platelet-dependent thrombosis was studied in vivo in the porcine carotid artery after deep arterial injury by balloon angioplasty. Methods and Results— 111In-labeled autologous platelet and 125I-labeled porcine fibrin(ogen) deposition, and the incidence of macroscopic mural thrombosis onto deeply injured artery

Jozef S. Mruk; Mark W. I. Webster; Magda Heras; Joel M. Reid; Diane E. Grill; James H. Chesebro

345

Oleanolic acid acetate inhibits atopic dermatitis and allergic contact dermatitis in a murine model.  

PubMed

Atopic dermatitis (AD) and allergic contact dermatitis (ACD) are common allergic and inflammatory skin diseases caused by a combination of eczema, scratching, pruritus, and cutaneous sensitization with allergens. This paper examines whether oleanolic acid acetate (OAA) modulates AD and ACD symptoms by using an existing AD model based on the repeated local exposure of mite extract (Dermatophagoides farinae extract, DFE) and 2,4-dinitrochlorobenzene to the ears of BALB/c mice. In addition, the paper uses a 2,4-dinitrofluorobenzene-sensitized local lymph node assay (LLNA) for the ACD model. The oral administration of OAA over a four-week period attenuated AD symptoms in terms of decreased skin lesions, epidermal thickness, the infiltration of immune cells (CD4? cells, eosinophils, and mast cells), and serum IgE, IgG2a, and histamine levels. The gene expression of Th1, Th2, Th17, and Th22 cytokines was reduced by OAA in the lymph node and ear tissue, and the LLNA verified that OAA suppressed ACD. The oral administration of OAA over a three-day period attenuated ACD symptoms in terms of ear thickness, lymphocyte proliferation, and serum IgG2a levels. The gene expression of Th1, Th2, and Th17 cytokines was reduced by OAA in the thymus and ear tissue. Finally, to define the underlying mechanism, this paper uses a TNF-?/IFN-?-activated human keratinocyte (HaCaT) model. OAA inhibited the expression of cytokines and chemokines through the downregulation of NF-?B and MAPKs in HaCaT cells. Taken together, the results indicate that OAA inhibited AD and ACD symptoms, suggesting that OAA may be effective in treating allergic skin disorders. PMID:23499868

Choi, Jin Kyeong; Oh, Hyun-Mee; Lee, Soyoung; Park, Jin-Woo; Khang, Dongwoo; Lee, Seung Woong; Lee, Woo Song; Rho, Mun-Chual; Kim, Sang-Hyun

2013-05-15

346

Global effect of indole-3-acetic acid biosynthesis on multiple virulence factors of Erwinia chrysanthemi 3937.  

PubMed

Production of the plant hormone indole-3-acetic acid (IAA) is widespread among plant-associated microorganisms. The non-gall-forming phytopathogen Erwinia chrysanthemi 3937 (strain Ech3937) possesses iaaM (ASAP16562) and iaaH (ASAP16563) gene homologues. In this work, the null knockout iaaM mutant strain Ech138 was constructed. The IAA production by Ech138 was reduced in M9 minimal medium supplemented with l-tryptophan. Compared with wild-type Ech3937, Ech138 exhibited reduced ability to produce local maceration, but its multiplication in Saintpaulia ionantha was unaffected. The pectate lyase production of Ech138 was diminished. Compared with wild-type Ech3937, the expression levels of an oligogalacturonate lyase gene, ogl, and three endopectate lyase genes, pelD, pelI, and pelL, were reduced in Ech138 as determined by a green fluorescent protein-based fluorescence-activated cell sorting promoter activity assay. In addition, the transcription of type III secretion system (T3SS) genes, dspE (a putative T3SS effector) and hrpN (T3SS harpin), was found to be diminished in the iaaM mutant Ech138. Compared with Ech3937, reduced expression of hrpL (a T3SS alternative sigma factor) and gacA but increased expression of rsmA in Ech138 was also observed, suggesting that the regulation of T3SS and pectate lyase genes by IAA biosynthesis might be partially due to the posttranscriptional regulation of the Gac-Rsm regulatory pathway. PMID:17189441

Yang, Shihui; Zhang, Qiu; Guo, Jianhua; Charkowski, Amy O; Glick, Bernard R; Ibekwe, A Mark; Cooksey, Donald A; Yang, Ching-Hong

2007-02-01

347

Global Effect of Indole-3-Acetic Acid Biosynthesis on Multiple Virulence Factors of Erwinia chrysanthemi 3937?  

PubMed Central

Production of the plant hormone indole-3-acetic acid (IAA) is widespread among plant-associated microorganisms. The non-gall-forming phytopathogen Erwinia chrysanthemi 3937 (strain Ech3937) possesses iaaM (ASAP16562) and iaaH (ASAP16563) gene homologues. In this work, the null knockout iaaM mutant strain Ech138 was constructed. The IAA production by Ech138 was reduced in M9 minimal medium supplemented with l-tryptophan. Compared with wild-type Ech3937, Ech138 exhibited reduced ability to produce local maceration, but its multiplication in Saintpaulia ionantha was unaffected. The pectate lyase production of Ech138 was diminished. Compared with wild-type Ech3937, the expression levels of an oligogalacturonate lyase gene, ogl, and three endopectate lyase genes, pelD, pelI, and pelL, were reduced in Ech138 as determined by a green fluorescent protein-based fluorescence-activated cell sorting promoter activity assay. In addition, the transcription of type III secretion system (T3SS) genes, dspE (a putative T3SS effector) and hrpN (T3SS harpin), was found to be diminished in the iaaM mutant Ech138. Compared with Ech3937, reduced expression of hrpL (a T3SS alternative sigma factor) and gacA but increased expression of rsmA in Ech138 was also observed, suggesting that the regulation of T3SS and pectate lyase genes by IAA biosynthesis might be partially due to the posttranscriptional regulation of the Gac-Rsm regulatory pathway. PMID:17189441

Yang, Shihui; Zhang, Qiu; Guo, Jianhua; Charkowski, Amy O.; Glick, Bernard R.; Ibekwe, A. Mark; Cooksey, Donald A.; Yang, Ching-Hong

2007-01-01

348

Dietary supplementation with tributyrin alleviates intestinal injury in piglets challenged with intrarectal administration of acetic acid.  

PubMed

Tributyrin (TBU) is a good dietary source of butyrate and has beneficial effects on the maintenance of normal intestinal morphology. The present study tested the hypothesis that dietary TBU supplementation could alleviate intestinal injury in the acetic acid (ACA)-induced porcine model of colitis. A total of eighteen piglets (25 d old) were randomly allocated to one of three treatment groups (control, ACA and TBU). The control and ACA groups were fed a basal diet and the TBU group was fed the basal diet supplemented with 0·1 % TBU. On day 15 of the trial, under anaesthesia, a soft catheter was inserted into the rectum of piglets (20-25 cm from the anus), followed by administration of either saline (control group) or ACA (10 ml of 10 % ACA solution for ACA and TBU groups). On day 22 of the trial, after venous blood samples were collected, piglets were killed to obtain mid-ileum and mid-colon mucosae. Compared with the control group, the ACA group exhibited an increase (P< 0·05) in lymphocyte counts, creatinine, PGE2, and malondialdehyde concentrations and diamine oxidase and inducible NO synthase activities in the plasma and lymphocyte density in the colon and a decrease in insulin concentrations and glutathione peroxidase activity, ileal villus height:crypt depth ratios and goblet cell numbers in the colon. These adverse effects of ACA were attenuated by TBU supplementation. Moreover, TBU prevented the ACA-induced increase in caspase-3 levels while enhancing claudin-1 protein and epidermal growth factor receptor (EGFR) mRNA expression in the colonic mucosa. Collectively, these results indicate that dietary supplementation with 0·1 % TBU alleviates ACA-induced intestinal injury possibly by inhibiting apoptosis, promoting tight-junction formation and activating EGFR signalling. PMID:24506942

Hou, Yongqing; Wang, Lei; Yi, Dan; Ding, Binying; Chen, Xing; Wang, Qingjing; Zhu, Huiling; Liu, Yulan; Yin, Yulong; Gong, Joshua; Wu, Guoyao

2014-05-28

349

Correlation between urinary 2-methoxy acetic acid and exposure of 2- methoxy ethanol  

PubMed Central

OBJECTIVES: To examine the correlation between airborne 2-methoxy ethanol (ME) exposures and the urinary 2-methoxy acetic acid (MAA) and to recommend a biological exposure index (BEI) for ME. METHODS: 8 Hour time weighted average (TWA) personal breathing zone samples and urine samples before and after the shift were collected from Monday to Saturday for 27 workers exposed to ME and on Friday for 30 control workers. RESULTS: No correlation was found between airborne exposure to ME and urinary MAA for nine special operation workers due to the use of personal protective equipment. For 18 regular operation workers, a significant correlation (r = 0.702, p = 0.001) was found between urinary MAA (mg/g creatinine) on Friday at the end of the shift and the weekly mean exposures of ME in a 5 day working week. The proposed BEI, which corresponds to exposure for 5 days and 8 hours a day to 5 ppm, extrapolated from the regression equation is 40 mg MAA/g creatinine. A significant correlation was also found between the weekly increase of urinary MAA (Friday after the shift minus Monday before the shift) and the weekly mean exposures of ME (r = 0.741). The recommended value of the weekly increase of urinary MAA for 5 days repeated exposures of 5 ppm ME is 20 mg/g creatinine. No urinary MAA was detected in workers in the non-exposed control group. CONCLUSIONS: The Friday urinary MAA after the shift or the weekly increase of urinary MAA is a specific and a good biomarker of weekly exposure to ME.   PMID:10658546

Shih, T. S.; Liou, S. H.; Chen, C. Y.; Chou, J. S.

1999-01-01

350

Healing Effect of Pistacia Atlantica Fruit Oil Extract in Acetic Acid-Induced Colitis in Rats  

PubMed Central

Background: Considering the anti-oxidant properties of Pistacia atlantica and lack of data regarding its efficacy in the treatment of ulcerative colitis, this study aims at investigating the effect of the Pistacia atlantica fruit extract in treating experimentally induced colitis in a rat model. Methods: Seventy male Sprague-Dawley rats (weighing 220±20 g) were used. All rats fasted 24 hours before the experimental procedure. The rats were randomly divided into 7 groups, each containing 10 induced colitis with 2ml acetic acid (3%). Group 1 (Asacol), group 2 (base gel) and group 7 (without treatment) were assigned as control groups. Group 3 (300 mg/ml) and group 4 (600 mg/ml) received Pistacia atlantica fruit orally. Group 5 (10% gel) and group 6 (20% gel) received Pistacia atlantica in the form of gel as enema. Macroscopic, histopathological examination and MDA measurement were carried out. Results: All groups revealed significant macroscopic healing in comparison with group 7 (P<0.001). Regarding microscopic findings in the treatment groups compared with group 7, the latter group differed significantly with groups 1, 2, 4 and 6 (P<0.001). There was a significant statistical difference in MDA scores of the seven treatment groups (F(5,54)=76.61, P<0.001). Post-hoc comparisons indicated that the mean±SD score of Asacol treated group (1.57±0.045) was not significantly different from groups 4 (1.62±0.024) and 6 (1.58±0.028). Conclusion: Our study showed that a high dose of Pistacia atlantica fruit oil extract, administered orally and rectally can improve colitis physiologically and pathologically in a rat model, and may be efficient for ulcerative colitis.

Tanideh, Nader; Masoumi, Samira; Hosseinzadeh, Massood; Safarpour, Ali Reza; Erjaee, Hoda; Koohi-Hosseinabadi, Omid; Rahimikazerooni, Salar

2014-01-01

351

Photoinduced amino-imino tautomerization reaction in 2-aminopyrimidine and its methyl derivatives with acetic acid  

NASA Astrophysics Data System (ADS)

The electronic absorption and fluorescence spectra of 2-aminopyrimidine (2APM), 2-amino-4-methylpyrimidine (2A4MPM), and 2-amino-4,6-dimethylpyrimidine (2ADMPM) with acetic acid (AcOH) were measured in isooctane (2,2,4-trimethylpentane) at room temperature. From the absorption spectra, a hydrogen-bonded complex formation of the 2APM/AcOH, 2A4MPM/AcOH, and 2ADMPM/AcOH systems was recognized in isooctane. The enthalpy changes (-? H) for the complex formation were estimated to be ca. 41.2-45.1 kJ mol -1 and increased in proportion to the numbers of the methyl group introduced into the 2APM. The -? H values refer to the formation of the hydrogen-bonded 1:1 complex between the ring nitrogen atom and NH 2 group of the aminopyrimidine and the OH and C dbnd O groups of AcOH, respectively. In the 2A4MPM/AcOH double hydrogen-bonded complex the OH group of AcOH is thought to be linked to the ring nitrogen at the 1-postion of 2A4MPM. The fluorescence spectral results indicate that the double proton transfer reaction takes place during the excited state, and gives rise to an imino-tautomer vibration emission, from analogy with the fluorescences of 1-methyl-2(1H)-pyrimidinimine (MPMI), 1,4-dimethyl-2(1H)-pyrimidinimine (DMPMI), and 1,4,6-trimethyl-2(1H)-pyrimidinimine (TMPMI). The fluorescence quantum yields of the imino-tautomers also increased in proportion to the numbers of the methyl group introduced into the 2APM.

Kitamura, Teruyoshi; Hikita, Atushi; Ishikawa, Hironori; Fujimoto, Akira

2005-12-01

352

Estrogen treatment of acetic acid burns to the vagina, cervix, and perineum: a case report and review of the literature.  

PubMed

In colposcopic evaluation of the cervix, acetic acid of 3 to 5% is commonly used for identification of preneoplastic and neoplastic cells. Acetic acid is a known caustic substance and has the potential to cause irritation and chemical burns when there is sufficient concentration or duration of contact. The authors present a unique case of a woman who inadvertently received undiluted acetic acid during a routine colposcopy, resulting in significant chemical burns of the vagina, cervix, and perineum. Her burns were treated with topical estrogen cream of 1 g twice daily applied directly to the wounds. The burn wounds were fully healed within 8 weeks without complication or additional treatment. At 6 months after the injury, the patient was allowed to engage in sexual activity, and vaginal dilation and pelvic floor therapy were initiated. At 12 months postinjury, her only symptomatic scarring at the left vaginal wall continues to improve. Thus, topical estrogen treatment of 1 g applied twice daily should be continued until burn scar maturation is complete and treatment improvement plateaus in cases of burns to the vagina, cervix, and perineum. This case is further clinical evidence of estrogen's positive effect on wound healing and its potential role in burn treatment. PMID:25144814

Ching, Jessica A; Kuykendall, Lauren V; Troy, Jared S; Smith, David J

2014-01-01

353

Selective liquid chromatographic separation of yttrium from heavier rare earth elements using acetic acid as a novel eluent.  

PubMed

One of the major difficulties in the rare earth elements separation is purification of yttrium from heavy rare earth elements. Thus, an HPLC method using acetic acid as novel eluent was explored for selective separation of yttrium form the heavy rare earth elements. When acetic acid is used as a mobile phase yttrium eluted with the lighter lanthanides. This is contrary to its relative position amongst heavier lanthanides when eluents commonly used for separation of rare earth elements were employed. The shift in elution position of yttrium with acetic acid as eluent may reflect a relatively lower stability constant of the yttrium-AcOH complex (in the same order as for the lighter lanthanides) compared to the corresponding AcOH complexes with heavy lanthanides, enabling selective separation of yttrium from the latter. The method was successfully used for selective separation of yttrium in mixed rare earth sample containing about 80% of yttrium and about 20% of heavy rare earth oxides. Thus, the use of AcOH as eluent is an effective approach for separating and determining the trace amounts of heavy rare earth elements in large amounts of yttrium matrix. Separation was performed on C18 column by running appropriate elution programs. The effluent from the column was monitored with diode array detector at absorbance wavelength of 658nm after post column derivatization with Arsenazo III. PMID:23932372

Kifle, Dejene; Wibetoe, Grethe

2013-09-13

354

Density Functional Investigation of the Adsorption of Isooctane, Ethanol, and Acetic Acid on a Water-Covered Fe(100) Surface  

PubMed Central

The presence of water in biofuels poses the question of how it affects the frictional performance of additives in fuels containing organic substances. To investigate the effect of water on the adsorption of molecules present in fuel and its additives we simulated within the framework of density functional theory the adsorption of ethanol, isooctane (2,2,4-trimethylpentane), and acetic acid on a bare and a water-covered Fe(100) surface. Van der Waals interactions are taken into account in our computations. In those molecules, where dispersion forces contribute significantly to the binding mechanism, the water layer has a stronger screening effect. Additionally, this effect can be enhanced by the presence of polar functional groups in the molecule. Thus, with the introduction of a water layer, the adsorption energy of isooctane and ethanol is reduced but it is increased in the case of the acetic acid. The adsorption configuration of ethanol is changed, while the one of acetic acid is moderately, and for isooctane only very slightly altered. Therefore, the effect of a water layer in the adsorption of organic molecules on an Fe(100) surface strongly depends on the type of bond and consequently, so do the tribological properties.

2014-01-01

355

Changes in the structure of water in aqueous solutions of acetic acid, depending on concentration and temperature according to densitometry, viscosimetry, and IR spectroscopy data  

NASA Astrophysics Data System (ADS)

The structural features of aqueous solutions of acetic acid are studied by means of viscosimetry, densimetry, and IR spectroscopy within the temperature range of 283.15-333.15 K and a concentration range of 0-80%. The results from our experiments are used to calculate the parameters of viscous flow activation, the structural temperature, the partial molar volume of acetic acid in the solution, the thermal expansion coefficient, and the energies and lengths of the hydrogen bonds between water molecules. The concentration dependences of these parameters are analyzed. Based on the obtained results, we conclude that acetic acid disrupts the structure of water.

Masimov, E. A.; Khasanov, G. Sh.; Pashaev, B. G.

2013-06-01

356

Effects of indole-3-acetic acid on Botrytis cinerea isolates obtained from potted plants.  

PubMed

We study the growth of different isolates of Botrytis cinerea collected from potted plants which were affected by Botrytis blight in southern Spain during recent years. These isolates, which show widely phenotypic differences when grown in vitro, are differentially affected by growth temperature, gibberellic acid applications and paclobutrazol, an efficient plant growth retardant and fungicide at the same time. In this work, we have evaluated the effect of the auxin indole-3-acetic acid (IAA) dose (0, 1, 10, and 100 mg/plate) on the growth of the collection of B. cinerea isolates obtained from the following potted plants: Cyclamen persicum, Hydrangea macrophylla, Lantona camara, and Lonicera japonica. B. cinerea produces indolacetic acid, but so far the precise biosynthetic pathway and some effects on this fungal species are still unclear, although recent studies have revealed an antifungal activity of IAA on several fungi, including B. cinerea isolated from harvested fruits. Mycelial growth curves and growth rates assessed from difference in colony areas during the both linear and deceleration phase, conidiation (measured as time of appearance), conidia length (microm), and sclerotia production (number/plate) were evaluated in the isolates, which were grown at 26 degrees C on Petri dishes containing potato dextrose agar for up to 35 days. Mycelial growth curves fitted a typical kinetic equation of fungi grown on solid media. B. cinerea isolates showed a high degree of variability in their growth kinetics, depending on the isolate and auxin dose. This plant growth substance delayed mycelial growth during the linear phase in an isolate-dependent manner, thus isolates from C. persicum, H. macrophylla and L. camara were more affected by IAA than L. japonica. On the other hand, 100 mg of IAA was the critical dose to significantly reduce the growth rate in all isolates and to promote brown-striped hyphae development, especially in isolate from C. persicum. 10 and 100 mg IAA delayed conidiation in isolates from H. macrophylla but scarcely effects were found in the conidia length. The sclerotia production process was blocked at IAA doses of 100 mg in isolates from L. camara and L. japonica, and was reduced in isolate from H. macrophylla. However, dose of 100 mg IAA had no effect on sclerotia production in isolate from C. persicum. It was concluded that the effect of IAA on B. cinerea growth depends on the isolate, thus isolates from H. macrophylla and L. camara were the most affected by IAA. B. cinerea reduced its development under IAA applications, depending on the isolate and dose. These results confirm those recently published on the inhibitory effect of IAA on Botrytris species growth. PMID:22702183

Martínez, J A; Valdés, R; Gómez-Bellot, M J; Bañón, S

2011-01-01

357

Pretreatment of Gymnema sylvestre revealed the protection against acetic acid-induced ulcerative colitis in rats  

PubMed Central

Background Overproduction of free radicals and decreased antioxidant capacity are well-known risk factors for inflammatory bowel diseases. Gymnema sylvestre (GS) leaves extract is distinguished for its anti-diabetic, antioxidant and anti-inflammatory properties. Present study is designed to evaluate the preventative activities of GS against acetic acid (AA)-induced ulcerative colitis in Wistar rats. Methods Experimentally ulcerative colitis (UC) was induced by AA in animals pretreated with three different doses of GS leaves extract (50, 100, 200 mg/kg/day) and a single dose of mesalazine (MES, 300 mg/kg/day) for seven days. Twenty four hours later, animals were sacrificed and the colonic tissues were collected. Colonic mucus content was determined using Alcian blue dye binding technique. Levels of thiobarbituric acid reactive substances (TBARS), total glutathione sulfhydryl group (T-GSH) and non-protein sulfhydryl group (NPSH) as well as the activity of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) were estimated in colon tissues. Colonic nucleic acids (DNA and RNA) and total protein (TP) concentrations were also determined. Levels of pro-inflammatory cytokines including interleukin-1 beta (IL-1?), tumor necrosis factor-alpha (TNF-?) and interleukin-6 (IL-6) as well as prostaglandin E2 (PGE2) and nitric oxide (NO) were estimated in colonic tissues. The histopathological changes of the colonic tissues were also observed. Results In AA administered group TBARS levels were increased, while colonic mucus content, T-GSH and NP-SH, SOD and CAT were reduced in colon. Pretreatment with GS inhibited TBARS elevation as well as mucus content, T-GSH and NP-SH reduction. Enzymatic activities of SOD and CAT were brought back to their normal levels in GS pretreated group. A significant reduction in DNA, RNA and TP levels was seen following AA administration and this inhibition was significantly eliminated by GS treatment. GS pretreatment also inhibited AA-induced elevation of pro-inflammatory cytokines, PGE2 and NO levels in colon. The apparent UC protection was further confirmed by the histopathological screening. Conclusion The GS leaves extract showed significant amelioration of experimentally induced colitis, which may be attributed to its anti-inflammatory and antioxidant property. PMID:24507431

2014-01-01

358

Exchange of atmospheric formic and acetic acids with trees and crop plants under controlled chamber and purified air conditions  

NASA Astrophysics Data System (ADS)

We investigated the exchange of formic and acetic acids between the atmosphere and various tree species such as beech ( Fagus sylvatica L.), ash ( Fraxinus excelsior L.), spruce ( Picea abies L.) Karst, holm oak ( Quercus ilex L.), and birch ( Betula pendula L.). and some crop-plant species such as corn ( Zea mays, var. Banjo), pea ( Pisum sativum, var. Solara), barley ( Hordeum vulgare, var. Igri) and oat (Avena sativa, var. Wiesel). All experiments were done with dynamic enclosures flushed with purified oxidant-free air, containing only low or controlled amounts of the two acids. Significant and light-triggered emission of both acids from all tree species was observed. For one tree species (ash) a seasonal large increase in fall due to early leaf decomposition was found. The standard emission factors (30°C and PAR=1000 ?mol m 2 s -1) given as (nmol m -2 min -1) for acetic and formic acids, respectively, were 8.1 and 29.7 (ash, autumn), 1.0 and 3.3 (ash, summer), 0.9 and 1.4 (beech), 0.7 and 1.45 (spruce), 1.9 and 2.4 (Holm oak) and 1.7 and 6.7 (birch). Rough estimation of global annual emissions range between 20 and 130 Gmol formic acid and 10 and 33 Gmol acetic acid. These numbers reflect a 15-30% contribution by forest emissions to the continental organic acid budget. As compared to the global total NMHC emissions low molecular weight organic acids are of minor importance. In contrast to the trees, none of the crop-plant species investigated showed an emission, but always a clear deposition of both acids. Both emission from trees as well as uptake by the agricultural plants could be related to transpiration rates and leaf conductances.

Kesselmeier, J.; Bode, K.; Gerlach, C.; Jork, E.-M.

359

The Conjugated Auxin Indole-3-Acetic Acid-Aspartic Acid Promotes Plant Disease Development[C][W  

PubMed Central

Auxin is a pivotal plant hormone that regulates many aspects of plant growth and development. Auxin signaling is also known to promote plant disease caused by plant pathogens. However, the mechanism by which this hormone confers susceptibility to pathogens is not well understood. Here, we present evidence that fungal and bacterial plant pathogens hijack the host auxin metabolism in Arabidopsis thaliana, leading to the accumulation of a conjugated form of the hormone, indole-3-acetic acid (IAA)-Asp, to promote disease development. We also show that IAA-Asp increases pathogen progression in the plant by regulating the transcription of virulence genes. These data highlight a novel mechanism to promote plant susceptibility to pathogens through auxin conjugation. PMID:22374398

Gonzalez-Lamothe, Rocio; El Oirdi, Mohamed; Brisson, Normand; Bouarab, Kamal

2012-01-01

360

Sol-gel process for preparation of YBa{sub 2}Cu{sub 4}O{sub 8} from acidic acetates/ammonia/ascorbic acid systems  

SciTech Connect

YBa{sub 2}Cu{sub 4}O{sub x} sols were prepared by addition of ammonia to acidic acetate solutions of Y{sup 3+}, Ba{sup 2+}, and Cu{sup 2+}. Ascorbic acid was added to part of the sol. The resultant sols were gelled to a shard or a coating by evaporation at 60 C. Addition of ethanol to the sols facilitated formation of gel coatings, fabricated by a dipping technique, on Ag or glass or substrates. At 100 C, gels formed in the presence of ascorbic acid were perfectly amorphous, in contrast to crystalline acetate gels. The quality of coatings prepared from ascorbate gels was superior to that of acetate gel coatings.

Deptula, A.; Lada, W.; Olczak, T. [Inst. of Nuclear Chemistry and Technology, Warsaw (Poland)] [Inst. of Nuclear Chemistry and Technology, Warsaw (Poland); Goretta, K.C. [Argonne National Lab., IL (United States). Energy Technology Div.] [Argonne National Lab., IL (United States). Energy Technology Div.; Bartolomeo, A.; Casadio, S. [C.R.E. Casaccia, Rome (Italy)] [C.R.E. Casaccia, Rome (Italy)

1997-03-01

361

Metabolizable Energy Values and Amino Acid Availability of Vetch (Vicia sativa) and Ervil (Vicia ervilia) Seeds Soaked in Water and Acetic Acid  

Microsoft Academic Search

In two experiments we evaluated the effect of water and acetic acid soaking on ME, apparent amino acid (AA) availability, and true AA availability of vetch (V) and ervil (E) seeds. In Experiment 1, the feedstuffs were untreated (U) V or coarsely ground V soaked in water (1:10, wt\\/vol) at 40 C for 72 h with a water change every

M. T. Farran; G. W. Barbour; M. G. Uwayjan; V. M. Ashkarian

362

Spontaneous organic cocoa bean box fermentations in Brazil are characterized by a restricted species diversity of lactic acid bacteria and acetic acid bacteria  

Microsoft Academic Search

Spontaneous organic cocoa bean box fermentations were carried out on two different farms in Brazil. Physical parameters, microbial growth, bacterial species diversity [mainly lactic acid bacteria (LAB) and acetic acid bacteria (AAB)], and metabolite kinetics were monitored, and chocolates were produced from the fermented dry cocoa beans. The main end-products of the catabolism of the pulp substrates (glucose, fructose, and

Zoi Papalexandratou; Gino Vrancken; Katrien De Bruyne; Peter Vandamme; Luc De Vuyst

2011-01-01

363

Biodiversity of yeasts, lactic acid bacteria and acetic acid bacteria in the fermentation of “Shanxi aged vinegar”, a traditional Chinese vinegar  

Microsoft Academic Search

Shanxi aged vinegar is a famous traditional Chinese vinegar made from several kinds of cereal by spontaneous solid-state fermentation techniques. In order to get a comprehensive understanding of culturable microorganism’s diversity present in its fermentation, the indigenous microorganisms including 47 yeast isolates, 28 lactic acid bacteria isolates and 58 acetic acid bacteria isolates were recovered in different fermenting time and

Jia Jia Wu; Ying Kun Ma; Fen Fen Zhang; Fu Sheng Chen

364

Ecosystem-Scale Compensation Point Analysis of Formic and Acetic Acid in the Central Amazon  

NASA Astrophysics Data System (ADS)

Organic acids, central to terrestrial carbon metabolism and atmospheric photochemistry, are ubiquitous in the troposphere in the gas, particle, and aqueous phases. As the dominant organic acids in the atmosphere, formic acid (FA, HCOOH) and acetic acid (AA, CH3COOH) control precipitation acidity in remote regions and may represent a critical link between the terrestrial carbon and water cycles by acting as key intermediates in plant carbon and energy metabolism and aerosol-cloud-precipitation interactions. However, our understanding of the exchange of these acids between terrestrial ecosystems and the atmosphere is limited by a lack of field observations, the existence of biogenic and anthropogenic primary and secondary sources whose relative importance is unclear, and the fact that vegetation can act as both a source and a sink. Here, we present results from the tropical rainforest mescosom at Biosphere 2 which isolates primary vegetation sources. Strong light and temperature dependent emissions of FA and AA were simultaneously observed from individual branches and mesocosm ambient air with a strong enrichment in FA (FA/AA = 1.4 +/- 0.3, R2 of 0.89 +/- 0.10). We also present long-term observations of vertical concentration gradients of FA and AA within and above a primary rainforest canopy in central Amazonia during the 2010 dry and 2011 wet seasons. We observed a seasonal switch from net ecosystem-scale deposition during the dry season to net emissions during the wet season. This switch was associated with reduced ambient concentrations in the wet season (FA < 1.3 ppbv, AA < 2.0 ppbv) relative to the dry season (FA up to 3.3 ppbv, AA up to 6.0 ppbv), and a simultaneous increase in the FA/AA ambient concentration ratios from 0.3-0.8 in the dry season to 1.0-2.1 in the wet season. These observations are consistent with a switch between a biomass burning dominated source in the dry season (FA/AA < 1.0) to a vegetation dominated source in the wet season and call into question the view that secondary production of FA and AA from biogenic precursors like isoprene are the largest atmospheric source. Our observations provide the first ecosystem-scale evidence of bidirectional FA and AA exchange between a forest canopy and the atmosphere controlled by ambient concentrations and ecosystem scale compensation points (estimated to be 1.3 ppbv: FA, and 2.1 ppbv: AA). These results suggest the need for a fundamental change in how future biosphere-atmosphere exchange models should treat FA and AA with a focus on factors that influence net exchange rates (ambient concentrations and ecosystem compensation points) rather than treating emissions and deposition separately.

Yanez-Serrano, A. M.; Jardine, K. J.; Arneth, A.; Abrell, L.; Jardine, A. B.; Artaxo, P.; Gomes, E.; Kesselmeier, J.; Saleska, S. R.; Huxman, T. E.

2011-12-01

365

Ecosystem-scale compensation points of formic and acetic acid in the central Amazon  

NASA Astrophysics Data System (ADS)

Organic acids, central to terrestrial carbon metabolism and atmospheric photochemistry, are ubiquitous in the troposphere in the gas, particle, and aqueous phases. As the dominant organic acids in the atmosphere, formic acid (FA, HCOOH) and acetic acid (AA, CH3COOH) control precipitation acidity in remote regions and may represent a critical link between the terrestrial carbon and water cycles by acting as key intermediates in plant carbon and energy metabolism and aerosol-cloud-precipitation interactions. However, our understanding of the exchange of these acids between terrestrial ecosystems and the atmosphere is limited by a lack of field observations, the existence of biogenic and anthropogenic primary and secondary sources whose relative importance is unclear, and the fact that vegetation can act as both a source and a sink. Here, we first present data obtained from the tropical rainforest mesocosm at Biosphere 2 which isolates primary vegetation sources. Strong light and temperature dependent emissions enriched in FA relative to AA were simultaneously observed from individual branches (FA/AA = 3.0 ± 0.7) and mesocosm ambient air (FA/AA = 1.4 ± 0.3). We also present long-term observations of vertical concentration gradients of FA and AA within and above a primary rainforest canopy in the central Amazon during the 2010 dry and 2011 wet seasons. We observed a seasonal switch from net ecosystem-scale deposition during the dry season to net emissions during the wet season. This switch was associated with reduced ambient concentrations in the wet season (FA < 1.3 nmol mol-1, AA < 2.0 nmol mol-1) relative to the dry season (FA up to 3.3 nmol mol-1, AA up to 6.0 nmol mol-1), and a simultaneous increase in the FA/AA ambient concentration ratios from 0.3-0.8 in the dry season to 1.0-2.1 in the wet season. These observations are consistent with a switch between a biomass burning dominated source in the dry season (FA/AA < 1.0) to a vegetation dominated source in the wet season (FA/AA > 1.0). Our observations provide the first ecosystem-scale evidence of bidirectional FA and AA exchange between a forest canopy and the atmosphere controlled by ambient concentrations and ecosystem scale compensation points (estimated to be 1.3 ± 0.3 nmol mol-1: FA, and 2.1 ± 0.4 nmol mol-1: AA). These results suggest the need for a fundamental change in how future biosphere-atmosphere exchange models should treat FA and AA with a focus on factors that influence net exchange rates (ambient concentrations and ecosystem compensation points) rather than treating emissions and deposition separately.

Jardine, K.; Yañez Serrano, A.; Arneth, A.; Abrell, L.; Jardine, A.; Artaxo, P.; Alves, E.; Kesselmeier, J.; Taylor, T.; Saleska, S.; Huxman, T.

2011-12-01

366

Ecosystem-scale compensation points of formic and acetic acid in the central Amazon  

NASA Astrophysics Data System (ADS)

Organic acids, central to terrestrial carbon metabolism and atmospheric photochemistry, are ubiquitous in the troposphere in the gas, particle, and aqueous phases. As the dominant organic acids in the atmosphere, formic acid (FA, HCOOH) and acetic acid (AA, CH3COOH) control precipitation acidity in remote regions and may represent a critical link between the terrestrial carbon and water cycles by acting as key intermediates in plant carbon and energy metabolism and aerosol-cloud-precipitation interactions. However, our understanding of the exchange of these acids between terrestrial ecosystems and the atmosphere is limited by a lack of field observations, the existence of biogenic and anthropogenic primary and secondary sources whose relative importance is unclear, and the fact that vegetation can act as both a source and a sink. Here, we first present data obtained from the tropical rainforest mesocosm at Biosphere 2 which isolates primary vegetation sources. Strong light and temperature dependent emissions enriched in FA relative to AA were simultaneously observed from individual branches (FA/AA = 2.1 ± 0.6) and mesocosm ambient air (FA/AA = 1.4 ± 0.3). We also present long-term observations of vertical concentration gradients of FA and AA within and above a primary rainforest canopy in the central Amazon during the 2010 dry and 2011 wet seasons. We observed a seasonal switch from net ecosystem-scale deposition during the dry season to net emissions during the wet season. This switch was associated with reduced ambient concentrations in the wet season (FA < 1.3 nmol mol-1, AA < 2.0 nmol mol-1) relative to the dry season (FA up to 3.3 nmol mol-1, AA up to 6.0 nmol mol-1), and a simultaneous increase in the FA/AA ambient concentration ratios from 0.3-0.8 in the dry season to 1.0-2.1 in the wet season. These observations are consistent with a switch between a biomass burning dominated source in the dry season (FA/AA < 1.0) to a vegetation dominated source in the wet season (FA/AA > 1.0). Our observations provide the first ecosystem-scale evidence of bidirectional FA and AA exchange between a forest canopy and the atmosphere controlled by ambient concentrations and ecosystem scale compensation points (estimated to be 1.3 nmol mol-1: FA, and 2.1 nmol mol-1: AA). These results suggest the need for a fundamental change in how future biosphere-atmosphere exchange models should treat FA and AA with a focus on factors that influence net exchange rates (ambient concentrations and ecosystem compensation points) rather than treating emissions and deposition separately.

Jardine, K.; Yañez Serrano, A.; Arneth, A.; Abrell, L.; Jardine, A.; Artaxo, P.; Alves, E.; Kesselmeier, J.; Taylor, T.; Saleska, S.; Huxman, T.

2011-09-01

367

Bacterial indole-3-acetic acid production: a key mediator of plant-microbe interactions between Phaseolus vulgaris and the foliar epiphyte Pantoea agglomerans 299R  

E-print Network

the architecture of plant galls (Lee et al. , 2009; Gafni etplant hormone indole-3-acetic acid (IAA), including symbiotes, both gall-plant disease in a variety of bacterial and fungal pathogens. In gall-

Powell, Tracy Kathleen

2011-01-01

368

Recovering/concentrating of hemicellulosic sugars and acetic acid by nanofiltration and reverse osmosis from prehydrolysis liquor of kraft based hardwood dissolving pulp process.  

PubMed

This work investigated the feasibility of recovering and concentrating sugars and acetic acid (HAc) from prehydrolysis liquor (PHL) of the kraft-based dissolving pulp process prior to fermentation of hemicellulosic sugars, by the combination of activated carbon adsorption, nanofiltration (NF) and reverse osmosis (RO) processes. To reduce the fouling PHL was subjected to adsorption on activated carbon, then the treated PHL (TPHL) passed through a nanofiltration (NF DK) membrane to retain the sugars, and the permeate of acetic acid rich solution was passed through a reverse osmosis membrane (RO SG). It was found that for NF process sugars were concentrated from 48 to 227g/L at a volume reduction factor (VRF) of 5 while 80 to 90% of acetic acid was permeated. For the reverse osmosis process, 68% of acetic acid retention was achieved at pH 4.3 and 500 psi pressure and the HAc concentration increased from 10 to 50g/L. PMID:24434701

Ahsan, Laboni; Jahan, M Sarwar; Ni, Yonghao

2014-03-01

369

Protective effects of N-acetylcysteine on acetic acid-induced colitis in a porcine model  

PubMed Central

Background Ulcerative colitis is a chronic inflammatory disease and involves multiple etiological factors. Acetic acid (AA)-induced colitis is a reproducible and simple model, sharing many characteristics with human colitis. N-acetylcysteine (NAC) has been widely used as an antioxidant in vivo and in vitro. NAC can affect several signaling pathways involving in apoptosis, angiogenesis, cell growth and arrest, redox-regulated gene expression, and inflammatory response. Therefore, NAC may not only protect against the direct injurious effects of oxidants, but also beneficially alter inflammatory events in colitis. This study was conducted to investigate whether NAC could alleviate the AA-induced colitis in a porcine model. Methods Weaned piglets were used to investigate the effects of NAC on AA-induced colitis. Severity of colitis was evaluated by colon histomorphology measurements, histopathology scores, tissue myeloperoxidase activity, as well as concentrations of malondialdehyde and pro-inflammatory mediators in the plasma and colon. The protective role of NAC was assessed by measurements of antioxidant status, growth modulator, cell apoptosis, and tight junction proteins. Abundances of caspase-3 and claudin-1 proteins in colonic mucosae were determined by the Western blot method. Epidermal growth factor receptor, amphiregulin, tumor necrosis factor-alpha (TNF-?), and toll-like receptor 4 (TLR4) mRNA levels in colonic mucosae were quantified using the real-time fluorescent quantitative PCR. Results Compared with the control group, AA treatment increased (P?

2013-01-01

370

Treatments with acetic acid followed by curing reduce postharvest decay on Citrus fruit.  

PubMed

Citrus fruit are susceptible to many postharvest diseases and disorders, but Penicillium digitatum and Penicillium italicum are the most common and serious pathogens during storage and marketing. The continuous employ in packing houses of synthetic fungicides such as imazalil (IMZ) or thiabendazote for the control of these pathogens is promoting the selection of resistant biotypes. These considerations together with an increased attention for human health and the environment have multiplied the studies on new ecological technologies. In recent years researchers studies focused on alternatives to the chemical control of post-harvest decay, such as the utilization of GRAS compounds as well as physical methods. In the present study is reported the sequential use of acetic acid (AAC) followed by curing. The lemon variety "Verna" and the orange variety "Jaffa", naturally inoculated, were treated with vapours of AAC performed at three different concentration (15, 25 and 50 microL/L) for 15 minutes, after an incubation period of 24 hours at 27 degrees C and 90% relative humidity (RH). After treatments fruits were cured at 36 degrees C for 36 hours with 90% RH and subsequently stored at 8 degrees C and 90% of RH for eight weeks. Both citrus varieties were also treated with IMZ at a concentration of 200 mL/HL. At the end of the experiment decay and weight loss were evaluated. After 8 weeks of storage, in the lemon variety, the lowest percentage of infected wounds was 1.5% for both the fruit treated with IMZ or with AAC at 25 microL/L. Fruit treated with 15 mciroL/L or untreated (control) showed similar results with 13.6% and 16.6% of rotted fruit respectively. Different results were obtained with the orange variety, in this case the synthetic fungicide was the most effective at the end of the storage period, with 18.0% of decay. AAC treatments were not a successful as on lemons, the best result was achieved even in this case with AAC performed at 25 pL/L, but with 39.9% of decay. In both species the weight loss was not affected by the treatments. These results show that a good control of postharvest decay could be achieved, on lemon fruit, by combining the effect of a GRAS compound such as AAC with curing. Conversely the results obtained, by applying this control method to the orange variety were not so promising. Further researches are needed to shed light on the different behaviour between the two species. PMID:20222556

Venditti, T; Angiolino, C; Dore, A; Molinu, M G; Petretto, A; D'Hallewin, G

2009-01-01

371

Catalytic partial oxidation of ethane to acetic acid over Mo 1V 0.25Nb 0.12Pd 0.0005O x : reactor operation  

Microsoft Academic Search

The operation of a fixed-bed and fluidized-bed reactor for the partial oxidation of ethane to acetic acid was simulated. For the fixed-bed reactor a two-dimensional homogenous model and for fluidized-bed reactor the bubble assemblage model was applied. A kinetic model was used for reactor simulation, which describes the primary oxidative dehydrogenation of ethane to ethylene, the formation of acetic acid

David Linke; Dorit Wolf; Manfred Baerns; Sabine Zeyß; Uwe Dingerdissen; Leslaw Mleczko

2002-01-01

372

Determination of the Glass Electrode Parameters by Means of Potentiometric Titration of Acetic Acid in Aqueous Sodium or Potassium Chloride Solutions at 25°C  

Microsoft Academic Search

Single-ion activity coefficient equations are presented for the calculation of stoichiometric (molality scale) dissociation constants Km for acetic acid in aqueous NaCl or KCl solutions at 25°C. These equations are of the Pitzer or Hückel type and apply to the case where the inert electrolyte alone determines the ionic strength of the acetic acid solution considered. Km for a certain

Jaakko I. Partanen; Pekka M. Juusola; Pentti O. Minkkinen

1999-01-01

373

Effects of acetic acid injection and operating conditions on NO emission in a vortexing fluidized bed combustor using response surface methodology  

SciTech Connect

The effects of acetic acid injection and operating conditions on NO emission were investigated in a pilot scale vortexing fluidized bed combustor (VFBC), an integration of circular freeboard and a rectangular combustion chamber. Operating conditions, such as the stoichiometric oxygen in the combustion chamber, the bed temperature and the injecting location of acetic acid, were determined by means of response surface methodology (RSM), which enables the examination of parameters with a moderate number of experiments. In RSM, NO emission concentration after acetic acid injection and NO removal percentage at the exit of the VFBC are used as the objective function. The results show that the bed temperature has a more important effect on the NO emission than the injecting location of acetic acid and the stoichiometric oxygen in the combustion chamber. Meanwhile, the injecting location of acetic acid and the stoichiometric oxygen in the combustion chamber have a more important effect on the NO removal percentage than the bed temperature. NO emission can be decreased by injecting the acetic acid into the combustion chamber, and NO emission decreases with the height of the acetic acid injecting location above the distributor. On the other hand, NO removal percentage increases with the height of the acetic acid injecting location, and NO emission increases with the stoichiometric oxygen in the combustion chamber and the bed temperature. NO removal percentage increases with the stoichiometric oxygen, and increases first, then decreases with the bed temperature. Also, a higher NO removal percentage could be obtained at 850{sup o}C. 26 refs., 12 figs., 8 tabs.

Fuping Qian; Chiensong Chyang; Weishen Yen [Anhui University of Technology, Ma'anshan (China). School of Civil Engineering and Architecture

2009-07-15

374

Process for the preparation of vinyl acetate  

DOEpatents

This invention pertains to the preparation of vinyl acetate by contacting within a contact zone a mixture of ketene and acetaldehyde with an acid catalyst at about one bar pressure and between about 85 and 200 C and removing the reaction products from the contact zone.

Tustin, G.C.; Zoeller, J.R.; Depew, L.S.

1998-02-17

375

Process for the preparation of vinyl acetate  

DOEpatents

This invention pertains to the preparation of vinyl acetate by contacting within a contact zone a mixture of ketene and acetaldehyde with an acid catalyst at about one bar pressure and between about 85.degree. and 200.degree. C. and removing the reaction products from the contact zone.

Tustin, Gerald Charles (Kingsport, TN); Zoeller, Joseph Robert (Kingsport, TN); Depew, Leslie Sharon (Kingsport, TN)

1998-01-01

376

Isolation of a high malic and low acetic acid-producing sake yeast Saccharomyces cerevisiae strain screened from respiratory inhibitor 2,4-dinitrophenol (DNP)-resistant strains.  

PubMed

We isolated 2,4-dinitrophenol (DNP)-resistant sake yeast strains by UV mutagenesis. Among the DNP-resistant mutants, we focused on strains exhibiting high malic acid and low acetic acid production. The improved organic acid composition is unlikely to be under the control of enzyme activities related to malic and acetic acid synthesis pathways. Instead, low mitochondrial activity was observed in DNP-resistant mutants, indicating that the excess pyruvic acid generated during glycolysis is not metabolized in the mitochondria but converted to malic acid in the cytosol. In addition, the NADH/NAD(+) ratio of the DNP-resistant strains was higher than that of the parental strain K901. These results suggest that the increased NADH/NAD(+) ratio together with the low mitochondrial activity alter the organic acid composition because malic acid synthesis requires NADH, while acetic acid uses NAD(+). PMID:23867095

Kosugi, Shingo; Kiyoshi, Keiji; Oba, Takahiro; Kusumoto, Kenichi; Kadokura, Toshimori; Nakazato, Atsumi; Nakayama, Shunichi

2014-01-01

377

Effect of royal jelly on experimental colitis Induced by acetic acid and alteration of mast cell distribution in the colon of rats.  

PubMed

This study investigated the effects of royal jelly (RJ) on acetic acid-induced colitis in rats. Twenty adult female Wistar albino rats were divided into four treatment groups of 5 animals each, including a control group (Group I); Group II was treated orally with RJ (150 mg kg(-1) body weight); Group III had acetic acid-induced colitis; and Group IV had acetic acid-induced colitis treated orally with RJ (150 mg kg(-1) body weight) for 4 weeks. Colitis was induced by intracolonic instillation of 4% acetic acid; the control group received physiological saline (10 mL kg(-1)). Colon samples were obtained under deep anaesthesia from animals in all groups. Tissues were fixed in 10% formalin neutral buffer solution for 24 h and embedded in paraffin. Six-micrometre-thick sections were stained with Mallory’s triple stain and toluidine blue in 1% aqueous solution at pH 1.0 for 5 min (for Mast Cells). RJ was shown to protect the colonic mucosa against the injurious effect of acetic acid. Colitis (colonic damage) was confirmed histomorphometrically as significant increases in the number of mast cells (MC) and colonic erosions in rats with acetic acid-induced colitis. The RJ treatment significantly decreased the number of MC and reduced the area of colonic erosion in the colon of RJ-treated rats compared with rats with untreated colitis. The results suggest that oral treatment with RJ could be used to treat colitis. PMID:21263740

Karaca, T; Bayiroglu, F; Yoruk, M; Kaya, M S; Uslu, S; Comba, B; Mis, L

2010-01-01

378

Biodiversity of yeasts, lactic acid bacteria and acetic acid bacteria in the fermentation of "Shanxi aged vinegar", a traditional Chinese vinegar.  

PubMed

Shanxi aged vinegar is a famous traditional Chinese vinegar made from several kinds of cereal by spontaneous solid-state fermentation techniques. In order to get a comprehensive understanding of culturable microorganism's diversity present in its fermentation, the indigenous microorganisms including 47 yeast isolates, 28 lactic acid bacteria isolates and 58 acetic acid bacteria isolates were recovered in different fermenting time and characterized based on a combination of phenotypic and genotypic approaches including inter-delta/PCR, PCR-RFLP, ERIC/PCR analysis, as well as 16S rRNA and 26S rRNA partial gene sequencing. In the alcoholic fermentation, the dominant yeast species Saccharomyces (S.) cerevisiae (96%) exhibited low phenotypic and genotypic diversity among the isolates, while Lactobacillus (Lb.) fermentum together with Lb. plantarum, Lb. buchneri, Lb. casei, Pediococcus (P.) acidilactici, P. pentosaceus and Weissella confusa were predominated in the bacterial population at the same stage. Acetobacter (A.) pasteurianus showing great variety both in genotypic and phenotypic tests was the dominant species (76%) in the acetic acid fermentation stage, while the other acetic acid bacteria species including A. senegalensis, A. indonesiensis, A. malorum and A. orientalis, as well as Gluconobacter (G.) oxydans were detected at initial point of alcoholic and acetic acid fermentation stage respectively. PMID:22265314

Wu, Jia Jia; Ma, Ying Kun; Zhang, Fen Fen; Chen, Fu Sheng

2012-05-01

379

Corrosion of Stainless Steel During Acetate Production  

Microsoft Academic Search

Corrosion of types 304, 304L, 316, and 316L stainless steel (SS) during the esterification of acetic acid and alcohol or glycol ether was investigated. The catalyst for this reaction, sulfuric acid or para-toluene sulfonic acid (PTSA), was shown to cause more corrosion on reactor equipment than CHâCOOH under the process conditions commonly practiced in industry. The corrosive action of the

J. S. Qi; G. C. Lester

1996-01-01

380

Accelerated Ulcer Healing and Resistance to Ulcer Recurrence with Gastroprotectants in Rat Model of Acetic Acid-induced Gastric Ulcer  

PubMed Central

Quality of ulcer healing (QOUH) is defined as ideal ulcer healing featuring with the fine granular ulcer scar, high functional restoration and the resistance to recurrence. This study was designed to compare the rates of QOUH achievement in rat gastric ulcer model between acid suppressant treated group and gastroprotectant treated group accompanied with elucidations of molecular mechanisms. Serosal injection of acetic acids for generating gastric ulcer and intraperitoneal (ip) injection of recombinant interleukin 1-beta (IL-1?) for recurring healed ulcer was done in SD rats. The 72 rats were divided into three groups according to treatment as follows; Group I, no further treatment, Group II, 8 weeks treatment of omeprazole, and Group III, 8 weeks of gastroprotectant treatment. IL-1? was administered for ulcer recurrence after 28 weeks of acetic acid injection. At four weeks after gastric ulcerogenesis, 58.3% (7/12) of active gastric ulcer were converted to healing stage in Group III, but 16.7% (2/12) in Group II and none in Group I, for which significant levels of epidermal growth factor, mucin, and pS2/trefoil peptide1 were contributive to these accelerated healings of Group III. ip injections of rIL-1? (200 µg/kg) at 28 weeks after acetic acid injection led to 100% of ulcer recurrence in Group I and 75.0% in Group II, but only 16.7% of Group III rats showed ulcer recurrence. Significantly attenuated levels of inflammatory cytokines including IL-2, transforming growth factor-alpha (TNF-?), cyclooxygenase-2 (COX-2), nitrotyrosine were responsible for the resistance to ulcer recurrence in Group III. Conclusively, gastroprotectant might be prerequisite in order to achieve ideal QOUH through significant inductions of remodeling. PMID:18545642

Young Oh, Tae; Ok Ahn, Byung; Jung Jang, Eun; Sang Park, Joo; Jong Park, Sang; Wook Baik, Hyun; Hahm, Ki-Baik

2008-01-01

381

Protective Role of Omega-3 Polyunsaturated Fatty Acid against Lead Acetate-Induced Toxicity in Liver and Kidney of Female Rats  

PubMed Central

The present study was conducted to investigate the protective role of Omega-3 polyunsaturated fatty acids against lead acetate-induced toxicity in liver and kidney of female rats. Animals were divided into four equal groups; group 1 served as control while groups 2 and 3 were treated orally with Omega-3 fatty acids at doses of 125 and 260?mg/kg body weight, respectively, for 10 days. These groups were also injected with lead acetate (25?mg/kg body weight) during the last 5 days. Group 4 was treated only with lead acetate for 5 days and served as positive control group. Lead acetate increased oxidative stress through an elevation in MDA associated with depletion in antioxidant enzymes activities in the tissues. Moreover, the elevation of serum enzymes activities (ALT, AST, ALP, and LDH) and the levels of urea and creatinine were estimated but total proteins were decreased. Also, lead acetate-treatment induced hyperlipidemia via increasing of lipid profiles associated with decline in HDL-c level. Significant changes of Hb, PCV, RBCs, PLT, and WBCs in group 4 were recorded. The biochemical alterations of lead acetate were confirmed by histopathological changes and DNA damage. The administration of Omega-3 provided significant protection against lead acetate toxicity. PMID:25045676

Abdou, Heba M.; Hassan, Mohamed A.

2014-01-01

382

Rate of electrophilic addition of acetic acid to 1-hexene when catalyzed by heteropoly acids  

Microsoft Academic Search

1.The catalytic activity of heteropoly acids (HPA) in the reaction for the electrophilic addition of AcOH to 1-hexene is slightly dependent on the composition of the HPA and substantially exceeds the activity of H2SO4. The catalytic activity correlates with the dissociation constants of the acids.2.The activity of the W HPA is higher than that of the Mo HPA due to

S. M. Kulikov; I. V. Kozhevnikov

1982-01-01

383

Milk Synthetic Response of the Bovine Mammary Gland to an Increase in the Local Concentration of Amino Acids and Acetate  

Microsoft Academic Search

Rates of secretion of components into milk are a func- tion of precursor concentrations and parameters that describe expression of the milk synthetic enzymes and their sensitivity to precursor concentrations. To estab- lish the enzymatic sensitivities of milk fat yield and mammary acetate utilization to circulating acetate con- centration, lactating cows were infused for 10 h with 0 or 40

N. G. Purdie; D. R. Trout; D. P. Poppi; J. P. Cant

2008-01-01

384

Studies on the growth and indole-3-acetic acid and abscisic acid content of Zea mays seedlings grown in microgravity  

NASA Technical Reports Server (NTRS)

Measurements were made of the fresh weight, dry weight, dry weight-fresh weight ratio, free and conjugated indole-3-acetic acid, and free and conjugated abscisic acid in seedlings of Zea mays grown in darkness in microgravity and on earth. Imbibition of the dry kernels was 17 h prior to launch. Growth was for 5 d at ambient orbiter temperature and at a chronic accelerational force of the order of 3 x 10(-5) times earth gravity. Weights and hormone content of the microgravity seedlings were, with minor exceptions, not statistically different from seedlings grown in normal gravity. The tissues of the shuttle-grown plants appeared normal and the seedlings differed only in the lack of orientation of roots and shoots. These findings, based upon 5 d of growth in microgravity, cannot be extrapolated to growth in microgravity for weeks, months, and years, as might occur on a space station. Nonetheless, it is encouraging, for prospects of bioregeneration of the atmosphere and food production in a space station, that no pronounced differences in the parameters measured were apparent during the 5 d of plant seedling growth in microgravity.

Schulze, A.; Jensen, P. J.; Desrosiers, M.; Buta, J. G.; Bandurski, R. S.

1992-01-01

385

Interaction of Gibberellic Acid and Indole-3-acetic Acid in the Growth of Excised Cuscuta Shoot Tips in Vitro1  

PubMed Central

Gibberellic acid (GA3) induced a marked elongation of 2.5-centimeter shoot tips of Cuscuta chinensis Lamk. cultured in vitro. In terms of the absolute amount of elongation, this growth may be the largest reported for an isolated plant system. The response to hormone was dependent on an exogenous carbohydrate supply. The hormone-stimulated growth was due to both cell division and cell elongation. The growth response progressively decreased if GA3 was given at increasingly later times after culturing, but the decreased growth response could be restored by the application of indole-3-acetic acid (IAA) to the apex. Explants deprived of GA3 gradually lost their ability to transport IAA basipetally, but this ability was also restored by auxin application. The observations are explained on the basis that: (a) the growth of Cuscuta shoot tip in vitro requires, at least, both an auxin and a gibberellin; and (b) in the absence of gibberellin the cultured shoot tip explants lose the ability to produce and/or transport auxin. PMID:16661158

Maheshwari, Ramesh; Shailini, C.; Veluthambi, K.; Mahadevan, S.

1980-01-01

386

Corrosion of stainless steel during acetate production  

SciTech Connect

Corrosion of types 304, 304L, 316, and 316L stainless steel (SS) during the esterification of acetic acid and alcohol or glycol ether was investigated. The catalyst for this reaction, sulfuric acid or para-toluene sulfonic acid (PTSA), was shown to cause more corrosion on reactor equipment than CH{sub 3}COOH under the process conditions commonly practiced in industry. The corrosive action of the catalyst occurred only in the presence of water. Thus, for the batch processes, corrosion occurred mostly during the initial stage of esterification, where water produced by the reaction created an aqueous environment. After water was distilled off, the corrosion rate declined to a negligible value. The corrosion inhibitor copper sulfate, often used in industrial acetate processes, was found to work well for a low-temperature process (< 95 C) such as in production of butyl acetate, but it accelerated corrosion in the glycol ether acetate processes where temperatures were > 108 C. Process conditions that imparted low corrosion rates were determined.

Qi, J.S.; Lester, G.C. [Occidental Chemical Corp. Technology Center, Grand Island, NY (United States)

1996-07-01

387

Effects of sodium nitrate and sodium acetate concentrations on the growth and fatty acid composition of Brachiomonas submarina  

NASA Astrophysics Data System (ADS)

One isolate of Brachiomonas submarina was tested for its ability to grow heterotrophicly on 5 different organic compounds. Sodium acetate and glucose were found to be effective in supporting the growth. Sodium acetate was chosen as the organic nutrient to test the combined effects of organic and inorganic solutions on the growth and fatty acid composition of Brachiomonas submarina. The best growth rates were achieved at 3 mmol L-1 CH3COONa and 0.88 mmol L-1 NaNO3 in heterotrophic condition, and 4 mmol L-1 CH3COONa and 3.52 mmol L-1 NaNO3 in mixotrophic condition. The differences between fatty acid contents were significant. The total polyunsaturated fatty acids (T. P. U. F. As) varied from 55.79% to 67.72% in heteritrophic growth and from 52.39% to 65.55% in mixotrophic growth. It is concluded that CH3COONa and NaNO3 at 3 mmol L-1 and 3.52 mmol L-1 should respectively be used in order to achieve the highest growth rate and fatty acid content.

Xiuxia, Yang; Xiaoqi, Zeng; Yupeng, Ji; Qun, Liu

2003-04-01

388

Concentrating aqueous acetate solutions with tertiary amines  

E-print Network

Water may be extracted from aqueous calcium acetate or sodium acetate solutions using low miscibility, low molecular weight tertiary amines, e.g. triethylamine (TEA) and N,N- dietliylmethylaniine (DEMA). This novel extraction technology...

Lee, Champion

2012-06-07

389

The Healing Effect of Teucrium polium in Acetic Acid-Induced Ulcerative Colitis in the Dog as an Animal Model  

PubMed Central

BACKGROUND Inflammatory bowel diseases (IBD), which include ulcerative colitis (UC) and Crohn’s disease (CD), are debilitating and chronic disorders with unpredictable courses and complicated treatment measures. Therefore, an efficient treatment protocol seems necessary as therapeutic prophylaxis for these disorders. This study aims to determine the healing effect of Teucrium polium (T. polium) in acetic acid-induced UC in an experimental dog model. METHODS From September to December 2010, eight male (20-25 kg) crossbred dogs were used for induction of UC by 6% acetic acid, transrectally. After one week, three biopsies (10, 20 and 30 cm proximal to the anal verge) were taken from the colon of each animal for histological studies. In the presence of UC, 400 mg/kg/day of T. polium extract was administered orally and transrectally (via enema) for 30 days in six of the dogs. The remaining two dogs were used as controls and did not receive T. polium. Multiple biopsies were taken 7, 14, and 30 days after discontinuation of T. polium in the same manner as before treatment. RESULTS After administration of acetic acid, we noted the presence of multiple ulcers, diffuse inflammation, PMN infiltration in the lamina propria, glandular destruction and goblet cell depletion. Treatment with T. polium restored the colonic architecture with an increased number of healthy cells and a reduction in inflammatory cells. Damage of the surface epithelial cells and mucosal layer of the lumen were reversed, which lead to faster ulcer healing. CONCLUSION T. polium may be a treatment choice for UC and can broaden the current therapy options for UC. PMID:24829634

Mehrabani, Davood; Bahrami, Faranak; Hosseini, Seyed Vahid; Ashraf, Mohammad Javad; Tanideh, Nader; Rezaianzadeh, Abbas; Amini, Masoud; Amini, Afshin

2012-01-01

390

As, Cd, Cr, Ni and Pb pressurized liquid extraction with acetic acid from marine sediment and soil samples  

NASA Astrophysics Data System (ADS)

Rapid leaching procedures by Pressurized Liquid Extraction (PLE) have been developed for As, Cd, Cr, Ni and Pb leaching from environmental matrices (marine sediment and soil samples). The Pressurized Liquid Extraction is completed after 16 min. The released elements by acetic acid Pressurized Liquid Extraction have been evaluated by inductively coupled plasma-optical emission spectrometry. The optimum multi-element leaching conditions when using 5.0 ml stainless steel extraction cells, were: acetic acid concentration 8.0 M, extraction temperature 100 °C, pressure 1500 psi, static time 5 min, flush solvent 60%, two extraction steps and 0.50 g of diatomaceous earth as dispersing agent (diatomaceous earth mass/sample mass ratio of 2). Results have showed that high acetic acid concentrations and high extraction temperatures increase the metal leaching efficiency. Limits of detection (between 0.12 and 0.5 ?g g - 1 ) and repeatability of the over-all procedure (around 6.0%) were assessed. Finally, accuracy was studied by analyzing PACS-2 (marine sediment), GBW-07409 (soil), IRANT-12-1-07 (cambisol soil) and IRANT-12-1-08 (luvisol soil) certified reference materials (CRMs). These certified reference materials offer certified concentrations ranges between 2.9 and 26.2 ?g g - 1 for As, from 0.068 to 2.85 ?g g - 1 for Cd, between 26.4 and 90.7 ?g g - 1 for Cr, from 9.3 to 40.0 ?g g - 1 for Ni and between 16.3 and 183.0 ?g g - 1 for Pb. Recoveries after analysis were between 95.7 and 105.1% for As, 96.2% for Cd, 95.2 and 100.6% for Cr, 95.7 and 103% for Ni and 94.2 and 105.5% for Pb.

Moreda-Piñeiro, Jorge; Alonso-Rodríguez, Elia; López-Mahía, Purificación; Muniategui-Lorenzo, Soledad; Prada-Rodríguez, Darío; Moreda-Piñeiro, Antonio; Bermejo-Barrera, Adela; Bermejo-Barrera, Pilar

2006-12-01

391

Crystal growth, structure analysis and characterisation of 2 - (1, 3 - dioxoisoindolin - 2 - yl) acetic acid single crystal  

NASA Astrophysics Data System (ADS)

Single crystal of dielectric material 2 - (1, 3 - dioxoisoindolin - 2 - yl) acetic acid has been grown by slow evaporation solution growth method. The grown crystal was harvested in 25 days. The crystal structure was analyzed by Single crystal X - ray diffraction. UV-vis-NIR analysis was performed to examine the optical property of the grown crystal. The thermal property of the grown crystal was studied by thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The dielectric measurements were carried out and the dielectric constant was calculated and plotted at all frequencies.

Sankari, R. Siva; Perumal, Rajesh Narayana

2014-04-01

392

Unusual kinetic properties of anionic tobacco peroxidase related to the mechanism of oxidation of indole-3-acetic acid  

Microsoft Academic Search

Anionic tobacco peroxidase (TOP) (mol wt 36 kDa, pI 3.5) was purified from transgenic tobacco plants with the yield of 60\\u000a mg\\/1 kg leaves. The enzyme exhibits unusual properties, i.e., Compound I is less reactive than Compound II. The enzyme was\\u000a investigated in oxidation of indole-3-acetic acid (IAA) oxidation by oxygen in the air. The aerobic steady-state spectral\\u000a studies reveal

I. G. Gazarian; G. A. Ashby; R. N. F. Thorneley; L. M. Lagrimini

1996-01-01

393

Vapor-phase esterification of acetic acid with ethanol catalyzed by a macroporous sulfonated styrene-divinylbenzene (20%) resin  

SciTech Connect

The kinetics of the vapor-phase (85-120/sup 0/C) esterification of acetic acid with ethyl alcohol, at atmospheric pressure, catalyzed by a macroporous sulfonated styrene-divinylbenzene (DVB;20%) resin, has been studied. A simple first-order model (r = kp/sub 1/) fits experimental kinetic data properly for a constant reactants ratio. Discussion by means of L-H-H-W models shows that the rate-controlling step is the surface reaction with a single-site mechanism. The apparent activation energy is 4000 cal/mol.

Gimenez, J.; Costa, J.; Cervera, S.

1987-02-01

394

Effect of ethanolic extract of leaves of Paederia foetida Linn. on acetic acid induced colitis in albino rats  

PubMed Central

Objectives: To evaluate the effect of ethanolic extract of leaves of Paederia foetida on acetic acid induced colitis in albino rats. Materials and Methods: Ethanolic extract of Paederia foetida (EEPF) was prepared by percolation method. Acute toxicity test was done by using Organization for Economic Cooperation and Development guidelines. Albino rats were divided into four groups of five animals each. Groups A and B received 3% gum acacia. Groups C and D received EEPF 500 mg/kg body weight (BW) and 5-aminosalisylic acid 100 mg/kg BW respectively. Colitis was induced by transrectal administration of 4% acetic acid on 5th day. All animals were sacrificed after 48 h of colitis induction and distal 10 cm of the colon was dissected. Colon was weighed for disease activity index (DAI) and scored macroscopically and microscopically. Biochemical assessment of tissue myeloperoxidase (MPO), catalase (CAT) and superoxide dismutase (SOD) was done in colonic tissue homogenate and malondialdehyde (MDA) was estimated in serum. Results: P. foetida showed significant (P < 0.05) reduction in DAI, macroscopic and microscopic lesion score as well as significant (P < 0.05) improvement in MPO, MDA, CAT, and SOD level as compared to Group B. Conclusions: The ethanolic extract of leaves of P. foetida showed significant amelioration of experimentally induced colitis, which may be attributed to its anti-inflammatory and antioxidant property. PMID:24130378

Das, Swarnamoni; Kanodia, Lalit; Mukherjee, Apurba; Hakim, Abdul

2013-01-01

395

Acetate absorption and metabolism in the rabbit hindgut.  

PubMed Central

Acetate disappearance from the loops of the hindgut in the rabbit was evaluated by measuring variations in the concentration of acetate in caecocolonic loops and differences in the arterial and venous plasma. In vivo metabolism in gut and liver tissues was studied after introduction of (1-14C) acetate into caecocolonic loops. The rate of disappearance from the loops was quantitatively significant and showed little variation irrespective of the location in the hindgut. Hindgut tissue metabolised acetate and the intensity of the metabolism varied with the segment studied. The distal position of the gut showed by far the highest acetate uptake. Radioactivity was found in a certain number of free amino acids, organic acids, and sugars. Acetate was mainly converted into aspartate and glutamate. These can be considered as 'stock forms' which can be diverted either towards oxidative metabolism or towards protein synthesis. Images Fig. 1 PMID:4007603

Marty, J F; Vernay, M Y; Abravanel, G M

1985-01-01

396

Endogenous Abscisic Acid and Indole-3-Acetic Acid and Somatic Embryogenesis in Cultured Leaf Explants of Pennisetum purpureum Schum. 1  

PubMed Central

Effects of application in vivo of glyphosate, fluridone, and paclobutrazol to glasshouse-grown donor plants of Pennisetum purpureum Schum. on endogenous levels of abscisic acid (ABA) and indole-3-acetic acid (IAA) in young leaves and on somatic embryogenesis in cultured leaf explants were studied. Treatment of plants with glyphosate (100 milligrams per liter) resulted in elevated levels of endogenous ABA and IAA in young leaves. In contrast, paclobutrazol (50% active ingredient; 200 milligrams per liter) did not alter the endogenous levels of ABA and IAA. Fluridone (100 milligrams per liter) markedly inhibited synthesis of ABA and leaf explants from fluridone-treated plants lost the capacity for somatic embryogenesis. Explants from glyphosate- or paclobutrazol-treated plants did not show any reduction in embryogenic capacity when compared with untreated control plants. Glyphosate and fluridone were also incorporated into the culture media at various concentrations (0 to 20 milligrams per liter) to study their effects in vitro on somatic embryogenesis in leaf explants from untreated, field-grown plants. Glyphosate was inhibitory to somatic embryogenesis but only at concentrations above 5 milligrams per liter. Fluridone inhibited somatic embryogenesis at all concentrations tested. Inhibition of somatic embryogenesis by fluridone, by either in vivo or in vitro application, could be overcome partially by (±)-ABA added to the culture medium. Exogenous application of (±)-ABA enhanced somatic embryogenesis and reduced the formation of nonembryogenic callus. Application of IAA or gibberellic acid (GA3; >5 milligrams per liter) was inhibitory to somatic embryogenesis. These results indicate that endogenous ABA is one of the important factors controlling the embryogenic capacity of leaf explants in Napier grass. PMID:16665403

Rajasekaran, Kanniah; Hein, Mich B.; Vasil, Indra K.

1987-01-01

397

Modeling the Effects of Sodium Chloride, Acetic Acid, and Intracellular pH on Survival of Escherichia coli O157:H7 ? †  

PubMed Central

Microbiological safety has been a critical issue for acid and acidified foods since it became clear that acid-tolerant pathogens such as Escherichia coli O157:H7 can survive (even though they are unable to grow) in a pH range of 3 to 4, which is typical for these classes of food products. The primary antimicrobial compounds in these products are acetic acid and NaCl, which can alter the intracellular physiology of E. coli O157:H7, leading to cell death. For combinations of acetic acid and NaCl at pH 3.2 (a pH value typical for non-heat-processed acidified vegetables), survival curves were described by using a Weibull model. The data revealed a protective effect of NaCl concentration on cell survival for selected acetic acid concentrations. The intracellular pH of an E. coli O157:H7 strain exposed to acetic acid concentrations of up to 40 mM and NaCl concentrations between 2 and 4% was determined. A reduction in the intracellular pH was observed for increasing acetic acid concentrations with an external pH of 3.2. Comparing intracellular pH with Weibull model predictions showed that decreases in intracellular pH were significantly correlated with the corresponding times required to achieve a 5-log reduction in the number of bacteria. PMID:21115706

Hosein, Althea M.; Breidt, Frederick; Smith, Charles E.

2011-01-01

398

Mesophilic syntrophic acetate oxidation during methane formation in biogas reactors  

Microsoft Academic Search

The reaction pathway for the formation of methane from acetate was investigated in sludge from 13 different biogas reactors. By following the conversion of [2-14C]acetate and [14C]bicarbonate it was shown that methane formation by syntrophic acetate oxidation was the dominating mechanism for acetotrophic methanogenesis in sludge containing high levels of salts, mainly ammonium, and volatile fatty acids. In one biogas

Anna Schnürer; Gerhard Zellner; Bo H. Svensson

1999-01-01

399

Wet deposition and related atmospheric chemistry in the São Paulo metropolis, Brazil: Part 2—contribution of formic and acetic acids  

NASA Astrophysics Data System (ADS)

Wet-only deposition samples were collected at a site in the urban area of the São Paulo metropolis between February (end of the rainy summer) and October (beginning of spring) 2000, an atypical period due to rainfall 40% below the 30-year average. The majority ions in rainwater were measured by capillary zone electrophoresis with contactless conductivity detection, CZE-CCD, applied for the first time to the organic anions acetate and formate. The volume weight mean (VWM) concentrations of the majority anions NO 3-, SO 42- and Cl - were, respectively, 15.6, 9.5 and 4.7 ?mol l -1. The VWM concentration of HCOO -t, (HCOO -+HCOOH) was 17.0 ?mol l -1, about twice the 8.9 ?mol l -1 of CH 3COO -t. The VWM concentration of free H + was low ( 16.9 ?mol l -1), corresponding to pH 4.77. This denotes the relevance of species like ammonia, analyzed as NH4+ ( VWM=27.9 ?mol l -1), and calcium carbonate ( VWM=5.3 ?mol l -1 Ca2+) as partial neutralizers of the acidity. By hypothetically assuming that H + is the only counterion of the non-sea-salt fraction of the dissociated anions, their contribution to the total potential acidity would decrease in the following order: sulfate (29%), formate (29%), nitrate (26%), acetate (15%) and chloride (1%). The 44% potential participation of the carboxylic acids reveals their importance to the acidity of São Paulo's rainwater during the study period. Direct vehicular emission of lower carboxylic acids and aldehydes (in particular, acetic acid and acetaldehyde) is singularly high in the metropolis due to the extensive use of ethanol and gasohol (containing ˜20% of ethanol) as fuels of the light fleet of 5.5 million cars; in addition, regional atmospheric conditions favor the photochemical formation of the acids, since concentrations of ozone and aldehydes are high and solar irradiation is intense at the 23°34'S latitude. The presence of higher concentrations of HCOOH than CH 3COOH indicates a prevalence of its photochemical production by H 2CO oxidation in the atmosphere.

Fornaro, Adalgiza; Gutz, Ivano G. R.

400

Inhibitory effects of ursolic and oleanolic acid on skin tumor promotion by 12-O-tetradecanoylphorbol-13-acetate.  

PubMed

Ursolic acid (UA) and oleanolic acid (OA), which had been isolated from Glechoma hederacea as inhibitors of Epstein-Barr virus (EBV) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA), were tested against inhibitory effect on tumor promotion by TPA in vivo. They inhibited effectively the tumor promotion in mouse skin and the activities were comparable to that of a known inhibitor of tumor promotion, retinoic acid (RA). Interestingly, UA was more effective on a single application before initial TPA-treatment than on a continuous application before each TPA-treatment, while OA and RA were ineffective in the same treatment. These data suggest that the role of UA for inhibitory action on tumor promotion differs slightly from those of RA and OA. PMID:3802058

Tokuda, H; Ohigashi, H; Koshimizu, K; Ito, Y

1986-12-01

401

Rabbit gastric ulcer models: comparison and evaluation of acetic acid-induced ulcer and mucosectomy-induced ulcer  

PubMed Central

In this study, we examined rabbit gastric ulcer models that can serve as more clinically relevant models. Two types of ulcer model were studied: acetic acid-induced ulcers (AAU) and mucosal resection-induced ulcers (MRU). For AAU, rabbit gastric mucosa was exposed by median laparotomy and treated with bottled acetic acid. MRU was examined as a model for endoscopic mucosal resection (EMR). Normal saline was injected into the submucosal layer and the swollen mucosa was resected with scissors. Endoscopic mucosal resection (EMR) is frequently performed for treatment of early gastric cancers. This procedure inevitably leads to ulcers and bleeding. Bleeding control is the major concern in endoscopic mucosectomy, and some endoscopic hemostatic agents are currently under clinical and preclinical studies. MRU was developed as a model for these induced ulcers and the evaluation of the healing process. The clinical relevancy of those models was compared with that of rat models. Progressive healing was observed for 7 days based on histology. Rabbit models demonstrate round, deep ulcers with clear margins and well-defined healing stages that were difficult to define in rat models. PMID:23825482

Maeng, Jin Hee; Lee, Eunhye

2013-01-01

402

Sulphydryl groups and iodo-(/sup 3/H)acetic acid labeling in proteolipids from Torpedo electroplax  

SciTech Connect

Several fractions of proteolipids from Torpedo electroplax were separated by DEAE-cellulose chromatography in organic solvents, and the sulphydryl groups were determined by a spectrophotometric method. On the same fractions the covalent labeling with iodo-(/sup 3/H)acetic acid to sulphydryl groups was studied. In total proteolipids there were 30.3 nmol/mg protein of sulphydryl groups of which 20.6 nmoles were in the form of disulfide bonds and 10.9 nmol as free--SH groups. The highest content of sulphydryl groups (36.7 nmol/mg protein) was found in fraction II; while fraction I, that binds the cholinergic ligands, has a lower content (23.7 nmol/mg protein). The 42 Kdaltons polypeptide, which is the major band in Fraction II, has the strongest labeling with iodo-(/sup 3/H)acetic acid, while the 39 Kdaltons cholinergic polypeptide shows a lower labeling. The importance of proteolipids as channel-forming macromolecules is discussed in connection with the possible significance of the 42 Kdaltons polypeptide.

Criado, M.; Aguilar, J.S.; De Robertis, E.

1983-05-01

403

Application of culture culture-independent molecular biology based methods to evaluate acetic acid bacteria diversity during vinegar processing.  

PubMed

Acetic acid bacteria (AAB) are considered fastidious microorganisms because they are difficult to isolate and cultivate. Different molecular approaches were taken to detect AAB diversity, independently of their capacity to grow in culture media. Those methods were tested in samples that originated during traditional vinegar production. Bacterial diversity was assessed by analysis of 16S rRNA gene, obtained by PCR amplifications of DNA extracted directly from the acetification container. Bacterial composition was analyzed by RFLP-PCR of 16S rRNA gene, Temporal Temperature Gradient Gel Electrophoresis (TTGE) separation of amplicons containing region V3-V5 of 16S rRNA gene and cloning of those amplicons. TTGE bands and clones were grouped based on their electrophoretic pattern similarity and sequenced to be compared with reference strains. The main microorganism identified in vinegar was Acetobacter pasteurianus, which at the end of the acetification process was considered to be the only microorganism present. The diversity was the highest at 2% acetic acid, where indefinite species of Gluconacetobacter xylinus/europaeus/intermedius were also present. PMID:18571262

Ilabaca, Carolina; Navarrete, Paola; Mardones, Pamela; Romero, Jaime; Mas, Albert

2008-08-15

404

Epibrassinolide ameliorates Cr (VI) stress via influencing the levels of indole-3-acetic acid, abscisic acid, polyamines and antioxidant system of radish seedlings  

Microsoft Academic Search

The present investigation determined the effects of epibrassinolide (EBL) on the levels of indole-3-acetic acid (IAA), abscisic acid (ABA), and polyamine (PA) and antioxidant potential of 7-d old Raphanus sativus L. cv. ‘Pusa chetki’ seedlings grown under Cr (VI) metal stress. Reduced titers of free (0.767?gg?1 FW) and bound (0.545?gg?1 FW) IAA in Cr (VI) stressed seedlings were observed over

Sikander Pal Choudhary; Mukesh Kanwar; Renu Bhardwaj; B. D. Gupta; R. K. Gupta

2011-01-01

405

Effects of propionate and methylmalonate on conversions of acetate, butyrate, and D(-)-3-hydroxybutyrate to fatty acids and carbon dioxide by mammary tissue slices of goats  

SciTech Connect

Incorporations of (1-carbon-14) acetate, (1-carbon-14) propionate, n-(1-carbon-14) butyrate, and D(-)-3-hydroxy(3-carbon-14) butyrate into individual milk fatty acids and their conversion to carbon dioxide were studied in vitro with caprine mammary tissue slices in the presence and absence of propionate and methylmalonate. Neither propionate nor methylmalonate affected incorporation of these substances into fatty acids. In a decreasing order butyrate, acetate, propionate, and D(-)-3-hydroxybutyrate were converted to carbon dioxide. Acetate had the highest incorporation rate into fatty acids followed by D(-)-3-hydroxybutyrate, butyrate, and propionate. Labeled propionate was incorporated mainly into odd-numbered fatty acids. Results do not support the theory that either propionate or its metabolite, methylmalonate, inhibit de novo synthesis of fatty acids in the mammary gland in relation to the etiology of low milk fat syndrome.

Emmanuel, B.; Kennelly, J.J.

1985-03-01

406

Molecular Structure of Ethyl acetate  

NSDL National Science Digital Library

Ethyl acetate is a colorless, volatile liquid with a mild and fragrant odor. It is used as solvent in chemistry laboratories but can also be found in many household products such as paints, coatings, and adhesives. The compound is also used in some extraction processes such as decaffeination or purification of antibiotics. It is present in both nail polish and removers. Some synthetic fruit essences may contain this and other esters. Etymologists like to use this solvent for insect collecting as the vapor kill the insect quickly and keep it soft for mounting.

2006-03-08

407

Indole-3-acetic Acid (IAA) and IAA Conjugates Applied to Bean Stem Sections: IAA Content and the Growth Response.  

PubMed

High resolution growth recording techniques and reverse isotope dilution analysis were used to study the relationship between indole-3-acetic acid (IAA) concentration and curvature of excised bean (Phaseolus vulgaris L. cv Bush Burpee Stringless) first internode sections unilaterally treated with hormone. The maximum rate of curvature occurred rapidly (within 25 minutes) and was proportional to the log of the amount of applied IAA recovered in the tissue. The rate of curvature decreased after 30 minutes although little or no lateral migration of applied IAA occurred and tissue levels of IAA increased. The biologic activity of IAA-amino acid conjugates was found to be directly related to the amount of free IAA, resulting from their hydrolysis, which could be recovered from the tissue. PMID:16663161

Bialek, K; Meudt, W J; Cohen, J D

1983-09-01

408

Functional Properties of Extruded Starch Acetate Blends  

Microsoft Academic Search

Starch acetate, with degree of substitution of 2, was blended with 0, 7.5 and 15% polylactic acid (PLA), Eastar Bio Copolyester 14766 (EBC) or Mater-Bi ZF03U (MBI) and 10%, 13%, or 16% (d.b.) ethanol and twin-screw extruded at 160°C barrel temperature. Physical characteristics of the extrudates, such as radial expansion ratio, unit and bulk densities, and of the mechanical properties,

J. Guan; Q. Fang; M. A. Hanna

2004-01-01

409

Metabolic pathway engineering based on metabolomics confers acetic and formic acid tolerance to a recombinant xylose-fermenting strain of Saccharomyces cerevisiae  

PubMed Central

Background The development of novel yeast strains with increased tolerance toward inhibitors in lignocellulosic hydrolysates is highly desirable for the production of bio-ethanol. Weak organic acids such as acetic and formic acids are necessarily released during the pretreatment (i.e. solubilization and hydrolysis) of lignocelluloses, which negatively affect microbial growth and ethanol production. However, since the mode of toxicity is complicated, genetic engineering strategies addressing yeast tolerance to weak organic acids have been rare. Thus, enhanced basic research is expected to identify target genes for improved weak acid tolerance. Results In this study, the effect of acetic acid on xylose fermentation was analyzed by examining metabolite profiles in a recombinant xylose-fermenting strain of Saccharomyces cerevisiae. Metabolome analysis revealed that metabolites involved in the non-oxidative pentose phosphate pathway (PPP) [e.g. sedoheptulose-7-phosphate, ribulose-5-phosphate, ribose-5-phosphate and erythrose-4-phosphate] were significantly accumulated by the addition of acetate, indicating the possibility that acetic acid slows down the flux of the pathway. Accordingly, a gene encoding a PPP-related enzyme, transaldolase or transketolase, was overexpressed in the xylose-fermenting yeast, which successfully conferred increased ethanol productivity in the presence of acetic and formic acid. Conclusions Our metabolomic approach revealed one of the molecular events underlying the response to acetic acid and focuses attention on the non-oxidative PPP as a target for metabolic engineering. An important challenge for metabolic engineering is identification of gene targets that have material importance. This study has demonstrated that metabolomics is a powerful tool to develop rational strategies to confer tolerance to stress through genetic engineering. PMID:21219616

2011-01-01

410

Adsorption of acetic acid on ice studied by ambient-pressure XPS and partial-electron-yield NEXAFS spectroscopy at 230-240 K.  

PubMed

Ice plays a key role in the environment, and the ice-air interface influences heterogeneous chemical reactions between snowpack or cirrus clouds and the surrounding air. Soluble gases have been suspected to affect the topmost, disordered layer on ice (often referred to as a quasiliquid layer, QLL). Changes are especially expected in the hydrogen-bonding structure of water in the presence of solutes at the ice surface. Here, we used ambient-pressure X-ray photoelectron spectroscopy (XPS) to detect acetic acid at the ice surface at 230-240 K under atmospheric conditions for the first time. Electron-kinetic-energy-dependent C 1s spectra indicate that acetic acid remains confined to the topmost ice surface layers. Spectral analysis provides information about the protonation state of acetate at the ice surface. Surface-sensitive Auger-electron-yield C-edge near-edge X-ray absorption fine structure (NEXAFS) spectra were recorded to probe the molecular state of the adsorbed species. The O-edge NEXAFS spectra show only minor differences between clean ice and ice with adsorbed acetic acid and thus indicate that acetic acid does not lead to an extended disordered layer on the ice surface between 230 and 240 K. PMID:23252403

K?epelová, Adéla; Bartels-Rausch, Thorsten; Brown, Matthew A; Bluhm, Hendrik; Ammann, Markus

2013-01-17

411

Effects of metal and acidic sites on the reaction by-products of butyl acetate oxidation over palladium-based catalysts.  

PubMed

Catalytic oxidation is widely used in pollution control technology to remove volatile organic compounds. In this study, Pd/ZSM-5 catalysts with different Pd contents and acidic sites were prepared via the impregnation method. All the catalysts were characterized by means of N2 adsorption-desorption, X-ray fluorescence (XRF), H2 temperature programmed reduction (H2-TPR), and NH3 temperature programmed desorption (NH3-TPD). Their catalytic performance was investigated in the oxidation of butyl acetate experiments. The by-products of the reaction were collected in thermal desorption tubes and identified by gas chromatography/mass spectrometry. It was found that the increase of Pd content slightly changed the catalytic activity of butyl acetate oxidation according to the yield of CO2 achieved at 90%, but decreased the cracking by-products, whereas the enhancement of strong acidity over Pd-based catalysts enriched the by-product species. The butyl acetate oxidation process involves a series of reaction steps including protolysis, dehydrogenation, dehydration, cracking, and isomerization. Generally, butyl acetate was cracked to acetic acid and 2-methylpropene and the latter was an intermediate of the other by-products, and the oxidation routes of typical by-products were proposed. Trace amounts of 3-methylpentane, hexane, 2-methylpentane, pentane, and 2-methylbutane originated from isomerization and protolysis reactions. PMID:25079284

Yue, Lin; He, Chi; Hao, Zhengping; Wang, Shunbing; Wang, Hailin

2014-03-01

412

A comparison of the electrophilic reactivities of Zn2+ and acetic acid as catalysts of enolization: imperatives for enzymatic catalysis of proton transfer at carbon.  

PubMed

The deprotonation of the alpha-CH3 and alpha-CH2OD groups of hydroxyacetone and the alpha-CH3 groups of acetone in the presence of acetate buffer and zinc chloride in D2O at 25 degrees C was followed by monitoring the incorporation of deuterium by 1H NMR spectroscopy, and the rate laws for catalysis of these reactions by acetate anion and zinc dication were evaluated. Relative to solvent water at a common standard state of 1 M, Zn2+ provides 6.3 and 4.4 kcal/mol stabilizations, respectively, of the transition states for deprotonation of the alpha-CH2OD and alpha-CH3 groups of hydroxyacetone by acetate anion, and a smaller 3.3 kcal/mol stabilization of the transition state for deprotonation of the alpha-CH3 group of acetone. There is only a 1.4 kcal/mol smaller stabilization of the transition state for the acetate-ion-promoted deprotonation of acetone by the Brønsted acid acetic acid than by Zn2+, which shows that, in the absence of a chelate effect, there is no large advantage to the use of a metal dication rather than a Brønsted acid to stabilize the transition state for deprotonation of alpha-carbonyl carbon. PMID:15099099

Crugeiras, Juan; Richard, John P

2004-04-28

413

Syntheses, Characterization and Antitumour Activities of Rare Earth Metal Complexes with 2-(((4,6-dimethyl)-2-Pyrimidinyl)thio)Acetic Acid  

Microsoft Academic Search

Eight rare earth metal (III) complexes with 2-(((4,6-dimethyl)-2-pyrimidinyl)thio)-acetic acid, LnL3-nH2O [HL = 2-(((4,6-dimethyl)-2-pyrimidinyl)thio)-acetic acid; Ln = La, Ce, Pr, Nd, Sm Eu, Gd, Tb; n = 4 or 5], were prepared and characterized by elemental analysis, complexometric titration, thermal analysis, conductivity, IR and 1H-NMR. The results reveal that carboxyl group of the ligand coordinates with rare earth ions in bidentate

Jianqiang Qu; Liufang Wang; Yingqi Liu; Yumin Song; Yinyue Wang; Xiaofei Jia

2006-01-01

414

Direct observation of the cyclic dimer in liquid acetic acid by probing the C=O vibration with ultrafast coherent Raman spectroscopy.  

PubMed

We present a comparison of spontaneous Raman and ultrafast coherent anti-Stokes Raman scattering (CARS) spectra of the C=O vibration of liquid acetic acid. The former technique cannot clearly reveal the number of contributions in the spectrum. However, the additional time and spectrally resolved CARS experiment supports strictly the existence of four modes, which proves the coexistence of more than one H-bonded configuration in liquid acetic acid. A comparably slowly dephasing mode which is obscured by a broad band in the linear Raman spectrum is assigned to the cyclic dimer and can be observed freed from all other contributions by ultrafast CARS. PMID:25051009

Lütgens, Matthias; Friedriszik, Frank; Lochbrunner, Stefan

2014-09-01

415

Syntheses, crystal structure and properties of two novel coordination polymers with the flexible tetrazole-1-acetic acid (Htza)  

NASA Astrophysics Data System (ADS)

Two new coordination polymers, [Ag(tza)] ? ( 1) (Htza=tetrazole-1-acetic acid) and [Cu(tza) 2] ? ( 2) have been prepared at room temperature and characterized by X-ray crystallography, IR, UV-vis, fluorescence spectra and magnetism analysis. Compound 1 exhibits extended helical chains through bridging ligand tza. The Ag rad rad rad Ag interactions between the adjacent chains form a 3-D framework featuring the extended tza-connected Ag chains that obviously affect the photoluminescent property. Compound 2 features undulated layered structure with hourglass-shaped [Cu 4(tza) 4] as subunits with the weak ferromagnetic interactions between Cu(II) ions, which are further stabilized by inter-lamellar C sbnd H rad rad rad O hydrogen bonds in the resulting 3-D supramolecular framework.

Dong, Wen-Wen; Zhao, Jun; Xu, Li

2008-05-01

416

Spontaneous cell-mediated cytotoxicity (SCMC) associated with lymphocytes negative for acid alpha-naphthyl acetate esterase (ANAE) activity.  

PubMed

A modified histochemical procedure for nonspecific acid alpha-naphthyl acetate esterase (ANAE) activity in human lymphocytes was used to identify a subpopulation of E-rosette forming cells. Performing a one hour reaction at pH 6.5 the distinct dot-like staining pattern was almost exclusively observed on high affinity E-rosettes which sedimented readily in a regular Ficoll-Metrizoate gradient. By combining latex phagocytosis with staining for ANAE activity, a clear-cut distinction between mononuclear phagocytes and lymphocytes could be made. An attempt was undertaken to relate the ANAE marker on human lymphocytes to their functional capacity in spontaneous cell-mediated cytotoxicity (SCMC) reactions. Using as targets two allogeneic (K562,IGR3) and a xenogeneic cell line (L1210) it could be clearly demonstrated that high SCMC activity is mediated by ANAE negative mononuclear cells, whereas enrichment for ANAE positive lymphocytes resulted in a loss of SCMC. PMID:88829

Rajvanshi, V; Peter, H H; Avenarius, H J

1979-03-01

417

An in Vitro System from Maize Seedlings for Tryptophan-Independent Indole-3-Acetic Acid Biosynthesis1  

PubMed Central

The enzymatic synthesis of indole-3-acetic acid (IAA) from indole by an in vitro preparation from maize (Zea mays L.) that does not use tryptophan (Trp) as an intermediate is described. Light-grown seedlings of normal maize and the maize mutant orange pericarp were shown to contain the necessary enzymes to convert [14C]indole to IAA. The reaction was not inhibited by unlabeled Trp and neither [14C]Trp nor [14C]serine substituted for [14C]indole in this in vitro system. The reaction had a pH optimum greater than 8.0, required a reducing environment, and had an oxidation potential near that of ascorbate. The results obtained with this in vitro enzyme preparation provide strong, additional evidence for the presence of a Trp-independent IAA biosynthesis pathway in plants. PMID:9880358

Ostin, Anders; Ilic, Nebojsa; Cohen, Jerry D.

1999-01-01

418

[Kinetic model of enhanced biological phosphorus removal with mixed acetic and propionic acids as carbon sources. (II): Process simulation].  

PubMed

Two groups of sequencing batch reactors were used to study the metabolism substrate transformation of phosphorus-accumulating organisms (PAO) and glycogen-accumulating organisms (GAO) fed with mixed acetic and propionic acids. Seven stoichiometry parameters and 24 kinetic parameters were contained in the PAO and GAO kinetic model, and stoichiometry parameters were deduced from the stoichiometry models, while kinetic parameters were determined by experimental results. The kinetic model parameters of stoichiometry and kinetics were determined according the experiments and the literature. Subsequently, the substrate transformations of PAO and GAO were calculated by the Matlab software. The model curves matched the SBR experimental data well, indicating that the kinetic model based on SCFAs metabolism could be used to simulate PAO and GAO in anaerobic-aerobic conditions. PMID:23745407

Zhang, Chao; Chen, Yin-Guang

2013-03-01

419

Role of Water in Chromosome Spreading and Swelling Induced by Acetic Acid Treatment: A Ftir Spectroscopy Study  

PubMed Central

The so called chromosome preparation is a procedure consisting of three strictly connected stages that enables to obtain chromosomes of quality suitable for cytogenetic analysis. Interestingly, experimental evidence strongly suggested that chromosome spreading and swelling (key processes that allow their counting and detailed structural analysis) are induced in the last fixative-evaporation stage by the interaction, mediated by acetic acid, between water from the environmental humidity, and the cytoplasmic matrix and the chromatin. However, since a considerable variation in the quality of chromosome preparations is observed, strongly depending on the environmental conditions in which the procedure takes place, a better comprehension of the mechanisms underlying chromosome preparation is required. To this aim, here we analysed intact lymphocytes before and at each stage of the chromosome preparation protocol by Fourier transform infrared (FTIR) spectroscopy, a technique widely used for the study not only of isolated biomolecules, but also of complex biological systems, such as whole cells. Interestingly, we found that the chromosome preparation protocol induces significant structural changes of cell proteins and DNA, in particular due to the interaction with acetic acid. Moreover, noteworthy, through the monitoring of changes in the water combination band between 2300 and 1800 cm–1, we provided evidence at molecular level of the crucial role of the bound water to the cytoplasmic matrix and to the chromatin in determining the chromosome spreading and swelling. Our FTIR results, therefore, underline the need to perform the last fixative-evaporation stage in standardized and optimized temperature and relative humidity conditions, thus providing chromosomes of high quality for the cytogenetic analysis that would lead in this way to more reliable results. PMID:24705001

Ami, D.; Di Segni, M.; Forcella, M.; Meraviglia, V.; Baccarin, M.; Doglia, S.M.; Terzoli, G.

2014-01-01

420

Metabolism of steroid acetates by Streptomyces albus.  

PubMed

Fermentation of 16-dehydropregnenolone acetate (1a) with Streptomyces albus yielded 16-dehydropregnenolone (1b) and 16-dehydroprogesterone (IIa). Similar incubation of pregnenolone acetate (Ic) with the strain afforded pregnenolone (Id), progesterone (IIb) and 20 alpha-hydroxy progesterone (IIc) while dehydroepiandrosterone acetate (IIIa) under the conditions was converted to dehydroepiandrosterone (IIIb), androstenedione (IVa) and testosterone (IVc). The strain was also capable of converting testosterone acetate (IVb) having the 17-acetoxy function in the 5-membered D-ring to testosterone (IVc) and androstenedione (IVa). All the products were identified by the application of various chemical and spectrometric techniques. PMID:6708550

Mukherjee, A; Mahato, S B

1984-03-01

421

Probing reaction pathways on model catalyst surfaces: Vinyl acetate synthesis and olefin metathesis  

Microsoft Academic Search

The reaction pathway for the palladium-catalyzed synthesis of vinyl acetate from acetic acid, ethylene and oxygen is investigated using reflection–absorption infrared spectroscopy by monitoring the rate of acetate titration by gas-phase ethylene. This reveals that acetate species are removed by reaction with gas-phase ethylene resulting in vinyl acetate formation. Reaction with C2D4 reveals a large (?6) isotope effect indicating that

Feng Gao; Yilin Wang; Florencia Calaza; Dario Stacchiola; Wilfred T. Tysoe

2008-01-01

422

Mechanism of 12-O-tetradecanoylphorbol-13-acetate enhanced metabolism of arachidonic acid in dog urothelial cells.  

PubMed

The mechanism of 12-O-tetradecanoylphorbol-13-acetate (TPA) enhanced arachidonic acid metabolism was investigated in dog urothelial cells. Primary cultures of dog urothelial cells were grown to confluency and evaluated in the presence or absence of overnight prelabeling with [3H]arachidonic acid. High-performance liquid chromatography analysis of media from TPA stimulated cells indicated that prostaglandin E2 (PGE2) was the major eicosanoid produced. Lipoxygenase products were not detected. Control cell media contained only arachidonic acid. Effects of selected inhibitors on TPA and exogenous arachidonic acid mediated increases in radioimmunoassayable PGE2 were assessed. Prostaglandin H synthase inhibitors (indomethacin and aspirin) prevented both TPA and arachidonic acid increases in PGE2. By contrast, inhibitors of phospholipases (quinacrine, W-7, and trifluoropromazine), protein synthesis (cycloheximide), and protein kinase C (staurosporine) prevented TPA but not arachidonic acid increases in PGE2. The latter agents also reduced TPA mediated increases in the release of total radioactivity from cells labeled with [3H]arachidonic acid. However, aspirin reduced the amount of 3H-prostaglandins formed with TPA. A calcium requirement was demonstrated when increases in radioimmunoassayable PGE2 elicited by TPA and the calcium ionophore A23187 were reduced with calcium depleted media. When epidermal growth factor in combination with either TPA or bradykinin was used, at least additive effects were observed with respect to release of [3H]arachidonic acid, 3H-prostaglandins, and radioimmunoassayable PGE2. These experiments suggest that separate pathways may be involved in enhanced arachidonic acid metabolism demonstrated with different agonists. For TPA, increased arachidonic acid release occurs by a calcium dependent process involving phospholipase(s), protein synthesis, and protein kinase C. PMID:2114944

Zenser, T V; Eling, T E; Duniec, Z M; Wong, Y H; Davis, B B

1990-08-01

423

Positron scattering from vinyl acetate  

NASA Astrophysics Data System (ADS)

Using a Beer-Lambert attenuation approach, we report measured total cross sections (TCSs) for positron scattering from vinyl acetate (C4H6O2) in the incident positron energy range 0.15-50 eV. In addition, we also report an independent atom model with screening corrected additivity rule computation results for the TCSs, differential and integral elastic cross sections, the positronium formation cross section and inelastic integral cross sections. The energy range of these calculations is 1-1000 eV. While there is a reasonable qualitative correspondence between measurement and calculation for the TCSs, in terms of the energy dependence of those cross sections, the theory was found to be a factor of ˜2 larger in magnitude at the lower energies, even after the measured data were corrected for the forward angle scattering effect.

Chiari, L.; Zecca, A.; Blanco, F.; García, G.; Brunger, M. J.

2014-09-01

424

Cloning and characterization of a locus encoding an indolepyruvate decarboxylase involved in indole-3-acetic acid synthesis in Erwinia herbicola.  

PubMed Central

Erwinia herbicola 299R synthesizes indole-3-acetic acid (IAA) primarily by the indole-3-pyruvic acid pathway. A gene involved in the biosynthesis of IAA was cloned from strain 299R. This gene (ipdC) conferred the synthesis of indole-3-acetaldehyde and tryptophol upon Escherichia coli DH5 alpha in cultures supplemented with L-tryptophan. The deduced amino acid sequence of the gene product has high similarity to that of the indolepyruvate decarboxylase of Enterobacter cloacae. Regions within pyruvate decarboxylases of various fungal and plant species also exhibited considerable homology to portions of this gene. This gene therefore presumably encodes an indolepyruvate decarboxylase (IpdC) which catalyzes the conversion of indole-3-pyruvic acid to indole-3-acetaldehyde. Insertions of Tn3-spice within ipdC abolished the ability of strain 299R to synthesize indole-3-acetaldehyde and tryptophol and reduced its IAA production in tryptophan-supplemented minimal medium by approximately 10-fold, thus providing genetic evidence for the role of the indolepyruvate pathway in IAA synthesis in this strain. An ipdC probe hybridized strongly with the genomic DNA of all E. herbicola strains tested in Southern hybridization studies, suggesting that the indolepyruvate pathway is common in this species. Maximum parsimony analysis revealed that the ipdC gene is highly conserved within this group and that strains of diverse geographic origin were very similar with respect to ipdC. PMID:8900003

Brandl, M T; Lindow, S E

1996-01-01

425

The Effects of Exogenous Auxins on Endogenous Indole-3-Acetic Acid Metabolism (The Implications for Carrot Somatic Embryogenesis).  

PubMed Central

The effect of auxin application on auxin metabolism was investigated in excised hypocotyl cultures of carrot (Daucus carota). Concentrations of both free and conjugated indole-3-acetic acid (IAA), [2H4]IAA, 2,4-dichlorophenoxyacetic acid, and naphthaleneacetic acid (NAA) were measured by mass spectroscopy using stable-isotope-labeled internal standards. [13C1]NAA was synthesized for this purpose, thus extending the range of auxins that can be assayed by stable-isotope techniques. 2,4-Dichlorophenoxyacetic acid promoted callus proliferation of the excised hypocotyls, accumulated as the free form in large quantities, and had minor effects on endogenous IAA concentrations. NAA promoted callus proliferation and the resulting callus became organogenic, producing both roots and shoots. NAA was found mostly in the conjugated form and had minor effects on endogenous IAA concentrations. [2H4]IAA had no visible effect on the growth pattern of cultured hypocotyls, possibly because it was rapidly metabolized to form inactive conjugates or possibly because it mediated a decrease in endogenous IAA concentrations by an apparent feedback mechanism. The presence of exogenous auxins did not affect tryptophan labeling of either the endogenous tryptophan or IAA pools. This suggested that exogenous auxins did not alter the IAA biosynthetic pathway, but that synthetic auxins did appear to be necessary to induce callus proliferation, which was essential for excised hypocotyls to gain the competence to form somatic embryos. PMID:12226408

Ribnicky, D. M.; Ilic, N.; Cohen, J. D.; Cooke, T. J.

1996-01-01

426

Glycerol acetals as anti-freezing additives for biodiesel.  

PubMed

Glycerol acetals from butanal, pentanal, hexanal, octanal and decanal were prepared with the use of Amberlyst-15 acid resin as catalyst. The glycerol conversion decreases with the size of the hydrocarbon chain. This fact has been associated with formation of micelles and aggregates of the aldehyde to minimize the interaction between the polar glycerol molecule with the hydrocarbon chain. The Z+E mixture of the acetals with five and six-member rings were produced in all cases. The distribution of the acetal isomers varied with the reaction time, especially for the long chain aldehydes. Addition of 5 vol.% of the butanal-glycerol acetal reduced the pour point of animal fat biodiesel (methyl ester) from 18 to 13 degrees C. The decrease in the pour point of the glycerol acetals-biodiesel mixtures were dependent on the size of the hydrocarbon chain and the percent blended. PMID:20304633

Silva, Paulo H R; Gonçalves, Valter L C; Mota, Claudio J A

2010-08-01

427

Value-added lipid production from brown seaweed biomass by two-stage fermentation using acetic acid bacterium and thraustochytrid.  

PubMed

Thraustochytrid production of polyunsaturated fatty acids and xanthophylls have been generally sourced from crop-derived substrates, making the exploration of alternative feedstocks attractive since they promise increased sustainability and lower production costs. In this study, a distinct two-stage fermentation system was conceptualized for the first time, using the brown seaweed sugar mannitol as substrate for the intermediary biocatalyst Gluconobacter oxydans, an acetic acid bacterium, along with the marine thraustochytrid Aurantiochytrium sp. to produce the value-added lipids and xanthophylls. Jar fermenter culture resulted in seaweed mannitol conversion to fructose with an efficiency of 83 % by G. oxydans and, after bacteriostasis with sea salts, production of astaxanthin and docosahexaenoic acid by Aurantiochytrium sp. KH105. Astaxanthin productivity was high at 3.60 mg/L/day. This new system, therefore, widens possibilities of obtaining more varieties of industrially valuable products including foods, cosmetics, pharmaceuticals, and biofuel precursor lipids from seaweed fermentation upon the use of suitable thraustochytrid strains. PMID:25086614

Arafiles, Kim Hazel V; Iwasaka, Hiroaki; Eramoto, Yuri; Okamura, Yoshiko; Tajima, Takahisa; Matsumura, Yukihiko; Nakashimada, Yutaka; Aki, Tsunehiro

2014-11-01

428

A PHYSIOLOGICALLY-BASED PHARMACOKINETIC MODEL FOR INTRAVENOUS AND INHALATION-ROUTE PHARMACOKINETICS OF BUTYL ACETATE AND METABOLITES N-BUTANOL AND N-BUTYRIC ACID  

EPA Science Inventory

Risk assessment for n-butyl acetate and metabolites n-butanol and n-butyric acid (the butyl series) can be accomplished with limited toxicity data and pharmacokinetic data for each compound through application of the "family approach" (Barton et al., 2000). The necessary quantita...

429

Anti-inflammatory effects of leptin and cholecystokinin on acetic acid-induced colitis in rats: role of capsaicin-sensitive vagal afferent fibers  

Microsoft Academic Search

Leptin and cholecystokinin (CCK) have a synergistic interaction in the suppression of food intake, and afford similar gastroprotective activity. The present study was designed to investigate the putative protective effects of CCK and leptin on acute colonic inflammation. Leptin or CCK-8s was injected to rats intraperitoneally immediately before and 6 h after the induction of colitis with acetic acid. CCK-A

Ayhan Bozkurt; Bar?? Çak?r; Feriha Ercan; Berrak Ç. Ye?en

2003-01-01

430

Electrolytic deposition of calcium phosphate\\/chitosan coating on titanium alloy: Growth kinetics and influence of current density, acetic acid, and chitosan  

Microsoft Academic Search

Electrolytically deposited calcium phosphate\\/chitosan coating demonstrated good bone marrow stromal cell attachment. The aim of this study was to understand the coating's growth kinetics as well as the effects of current density, acetic acid, and chitosan on the coating's formation. The scanning electron micrographs found that calcium phosphate crystals homogeneously distributed into chitosan aggregates as early as 30 min. X-ray

Jiawei Wang; Apeldoorn van Aart; Groot de Klaas

2006-01-01

431

Preliminary evaluation of effects of invasive tunicate management with acetic acid and calcium hydroxide on non-target marine organisms in Prince Edward Island, Canada  

Microsoft Academic Search

The proliferation of invasive tunicates in Prince Edward Island (PEI) estuaries has necessitated the development of approaches for managing tunicates that foul aquaculture structures, especially Styela clava and Ciona intestinalis. Spraying or immersion with a saturated solution of hydrated lime (calcium hydroxide) or 5% acetic acid are effective against these tunicates, but are also biocidal to a variety of non-target

Andrea Locke; Kenneth G. Doe; Wayne L. Fairchild; Paula M. Jackman; Erica J. Reese

2009-01-01

432

Analysis of several methods for the extraction of high quality DNA from acetic acid bacteria in wine and vinegar for characterization by PCR-based methods  

Microsoft Academic Search

Acetic acid bacteria (AAB) are fastidious microorganisms with poor recovery in culture. Culture-independent methods are currently under examination. Good DNA extraction is a strict requirement of these methods. We compared five methods for extracting the DNA of AAB directly from wine and vinegar samples. Four matrices (white wine, red wine, superficial vinegar and submerged vinegar) contaminated with two AAB strains

C. Jara; E. Mateo; J. M. Guillamón; M. J. Torija; A. Mas

2008-01-01

433

Gaussian analysis of Raman spectroscopy of acetic acid reveals a significant amount of monomers that effectively cooperate with hydrogen bonded linear chains.  

PubMed

Gaussian analysis of Raman spectroscopy reveals three significant structures in the liquid acetic acid (AA): linear chains involving C-H···O=C and O-H···O=C hydrogen bonding, cyclic dimers and dissociated monomers that can effectively cooperate with hydrogen bonded stacks of linear AA or polymer chains. PMID:25231359

Wu, Jianping

2014-11-01

434

Application of N,N-dimethylformamide dineopentyl acetal for efficient anchoring of N alpha-9-fluorenylmethyloxycarbonylamino acids as p-alkoxybenzyl esters in solid-phase peptide synthesis.  

PubMed

The attachment of Fmoc-amino acids onto p- alkoxybenzyl alcohol resins via DCC-DMAP coupling suffers from two different problems: formation of dimers and racemization. The use of N,N-dimethylformamide dineopentyl acetal for the preparation of Fmoc- aminoacyloxybenzyl handles is the basis of a safe and efficient anchoring method that avoids both problems. PMID:6547115

Albericio, F; Barany, G

1984-04-01

435

Biodegradable Plastics Based on Cellulose Acetate  

Microsoft Academic Search

It is generally known that secondary cellulose acetate (with 53 to 56% acetyl groups) is suitable for thermoplastic processing. With appropriate plasticizers a plastic material is obtained which excels in transparency and pleasant texture, and it is therefore often used for tool handles, combs, spectacle frames, and the like. In principle, cellulose acetate with such a degree of substitution is

Alexander Ach

1993-01-01

436

Dynamics and biodiversity of populations of lactic acid bacteria and acetic acid bacteria involved in spontaneous heap fermentation of cocoa beans in Ghana.  

PubMed

The Ghanaian cocoa bean heap fermentation process was studied through a multiphasic approach, encompassing both microbiological and metabolite target analyses. A culture-dependent (plating and incubation, followed by repetitive-sequence-based PCR analyses of picked-up colonies) and culture-independent (denaturing gradient gel electrophoresis [DGGE] of 16S rRNA gene amplicons, PCR-DGGE) approach revealed a limited biodiversity and targeted population dynamics of both lactic acid bacteria (LAB) and acetic acid bacteria (AAB) during fermentation. Four main clusters were identified among the LAB isolated: Lactobacillus plantarum, Lactobacillus fermentum, Leuconostoc pseudomesenteroides, and Enterococcus casseliflavus. Other taxa encompassed, for instance, Weissella. Only four clusters were found among the AAB identified: Acetobacter pasteurianus, Acetobacter syzygii-like bacteria, and two small clusters of Acetobacter tropicalis-like bacteria. Particular strains of L. plantarum, L. fermentum, and A. pasteurianus, originating from the environment, were well adapted to the environmental conditions prevailing during Ghanaian cocoa bean heap fermentation and apparently played a significant role in the cocoa bean fermentation process. Yeasts produced ethanol from sugars, and LAB produced lactic acid, acetic acid, ethanol, and mannitol from sugars and/or citrate. Whereas L. plantarum strains were abundant in the beginning of the fermentation, L. fermentum strains converted fructose into mannitol upon prolonged fermentation. A. pasteurianus grew on ethanol, mannitol, and lactate and converted ethanol into acetic acid. A newly proposed Weissella sp., referred to as "Weissella ghanaensis," was detected through PCR-DGGE analysis in some of the fermentations and was only occasionally picked up through culture-based isolation. Two new species of Acetobacter were found as well, namely, the species tentatively named "Acetobacter senegalensis" (A. tropicalis-like) and "Acetobacter ghanaensis" (A. syzygii-like). PMID:17277227

Camu, Nicholas; De Winter, Tom; Verbrugghe, Kristof; Cleenwerck, Ilse; Vandamme, Peter; Takrama, Jemmy S; Vancanneyt, Marc; De Vuyst, Luc

2007-03-01

437

Studies on seasonal variation of plant hormones, nitrogen flixation and indole acetic acid metabolism in root nodulus of Butea monosperma (Lam.) Taub  

Microsoft Academic Search

Summary Mature nodules ofButea monosperma (Lam.) Taub. (B. monosperma) contained higher amounts of indole acetic acid-like (IAA), cytokinin-like (CK), gibberellic acid-like (GA) and abscisic acid-like (ABA) substances, and were more active in IAA metabolism and nitrogen fixation. Roots contained lower amount of all the hormones. The higher level of IAA in the nodules than the roots was due to more

T. K. Dangar; P. S. Basu

1985-01-01