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1

Molecular Structure of Acetic acid  

NSDL National Science Digital Library

Acetic Acid commonly associated with vinegar; it is the most commercially important organic acid and is used to manufacture a wide range of chemical products, such as plastics and insecticides. Acetic acid is produced naturally by Aceto bacteria but, except for making vinegar, is usually made through synthetic processes. Ethanoic acid is used as herbicide, as a micro-biocide, as a fungicide and for pH adjustment.

2003-06-02

2

Cytenamide acetic acid solvate  

PubMed Central

In the crystal structure of the title compound (systematic name: 5H-dibenzo[a,d]cyclo­hepta­triene-5-carboxamide ethanoic acid solvate), C16H13NO·C2H4O2, the cytenamide and solvent mol­ecules form a hydrogen-bonded R 2 2(8) dimer motif, which is further connected to form a centrosymmetric double ring motif arrangement. The cycloheptene ring adopts a boat conformation and the dihedral angle between the least-squares planes through the two aromatic rings is 54.7?(2)°.

Johnston, Andrea; Florence, Alastair J.; Fabianni, Francesca J. A.; Shankland, Kenneth; Bedford, Colin T.

2008-01-01

3

Cytenamide acetic acid solvate.  

PubMed

IN THE CRYSTAL STRUCTURE OF THE TITLE COMPOUND (SYSTEMATIC NAME: 5H-dibenzo[a,d]cyclo-hepta-triene-5-carboxamide ethanoic acid solvate), C(16)H(13)NO·C(2)H(4)O(2), the cytenamide and solvent mol-ecules form a hydrogen-bonded R(2) (2)(8) dimer motif, which is further connected to form a centrosymmetric double ring motif arrangement. The cycloheptene ring adopts a boat conformation and the dihedral angle between the least-squares planes through the two aromatic rings is 54.7?(2)°. PMID:21202682

Johnston, Andrea; Florence, Alastair J; Fabianni, Francesca J A; Shankland, Kenneth; Bedford, Colin T

2008-05-30

4

Investigation on isobaric vapor–liquid equilibrium for acetic acid + water + methyl ethyl ketone + isopropyl acetate  

Microsoft Academic Search

Isobaric vapor–liquid equilibrium (VLE) data for acetic acid+water, acetic acid+methyl ethyl ketone (MEK), MEK+isopropyl acetate, acetic acid+MEK+water and acetic acid+MEK+isopropyl acetate+water are measured at 101.33kPa using a modified Rose cell. The nonideal behavior in vapor phase of binary systems measured in this work is analyzed through calculating fugacity coefficients since mixture containing acetic acid deviates from ideal behavior seriously in

Qiang Xie; Hui Wan; MingJuan Han; GuoFeng Guan

2009-01-01

5

New process for producing cellulose acetate from wood in concentrated acetic acid  

Microsoft Academic Search

To explore further potential applications of acetic acid pulp, an investigation was conducted to develop a direct method for producing cellulose acetate from wood in combination with atmospheric acetic acid pulping. The process consists of delignification, totally chlorine-free bleaching, and esterification, with the concentrated acetic acid aqueous solution being used as only solvent throughout the process. The acetic acid pulp

Hironori Sato; Yasumitsu Uraki; Takao Kishimoto; Yoshihiro Sano

2003-01-01

6

REMOVAL OF ACETIC ACID IMPURITIES FROM ETHYL ACETATE BY ADSORPTION ON ION EXCHANGE RESINS  

Microsoft Academic Search

Removal of acetic acid impurities from ethyl acetate was attempted by sorption on basic ion-exchange resins. Kinetic studies showed that acid removal is controlled by intraparticle resistance from both ethyl acetate and alcohol. Breakthrough curves for uptake of the acid from ethyl acetate were obtained at different flow rates and concentrations. Desorption studies were performed using both ethyl acetate and

H. M. Anasthas; V. G. Gaikar

2001-01-01

7

Delignification of Bagasse with Acetic Acid and Ozone. Part 1. Acetic Acid Pulping  

Microsoft Academic Search

Two-stage delignification of sugarcane bagasse with acetic acid and ozone was investigated. The better pulp was obtained pulping bagasse in aqueous solution of acetic acid (80% volume) at 145°C during 60 min. The liquor\\/bagasse ratio (L\\/B) was 10:1 and the kappa number was 44; it fell to 10 in the ozone stage due to selectivity of acetic acid medium. Pulp

H. Contreras Q; Z. A. Nagieb; R. Sanjuán D

1997-01-01

8

Hybrid reactive distillation systems for n-butyl acetate production from dilute acetic acid  

Microsoft Academic Search

The recovery of dilute acetic acid, regarding as a waste stream in many chemical and petrochemical processes, becomes an important issue due to economic and environmental awareness. In this work, a simulation study on the direct utilization of dilute acetic acid to produce n-butyl acetate via esterification with butanol in a reactive distillation is presented by using Aspen Plus. The

Amornchai Arpornwichanop; Kittipong Koomsup; Suttichai Assabumrungrat

2008-01-01

9

Genera and species in acetic acid bacteria.  

PubMed

Taxonomic studies of acetic acid bacteria were historically surveyed. The genus Acetobacter was first introduced in 1898 with a single species, Acetobacter aceti. The genus Gluconobacter was proposed in 1935 for strains with intense oxidation of glucose to gluconic acid rather than oxidation of ethanol to acetic acid and no oxidation of acetate. The genus "Acetomonas" was described in 1954 for strains with polar flagellation and no oxidation of acetate. The proposals of the two generic names were due to confusion, and "Acetomonas" was a junior subjective synonym of Gluconobacter. The genus Acetobacter was in 1984 divided into two subgenera, Acetobacter and Gluconoacetobacter. The latter was elevated to the genus Gluconacetobacter in 1998. In the acetic acid bacteria, ten genera are presently recognized and accommodated to the family Acetobacteraceae, the Alphaproteobacteria: Acetobacteer, Gluconobacter, Acidomonas, Gluconacetobacter, Asaia, Kozakia, Swaminathania, Saccharibacter, Neoasaia and Granulibacter. In contrast, the genus Frateuria, strains of which were once named 'pseudacetic acid bacteria', was classified into the Gammaproteobacteria. The genus Gluconacetobacter was phylogenetically divided into two groups: the Gluconacetobacter liquefaciens group and the Gluconacetobacter xylinus group. The two groups were discussed taxonomically. PMID:18199517

Yamada, Yuzo; Yukphan, Pattaraporn

2007-12-05

10

Vinyl acetate formation in the reaction of acetylene with acetic acid catalyzed by zinc acetate supported on porous carbon spheres  

NASA Astrophysics Data System (ADS)

A kind of porous carbon spheres (PCS) was prepared by the carbonization of poly(vinylidene chloride) synthesized by suspension polymerization. Structure analyses revealed the existence of bumps and holes on the surface of PCS. The PCS, with the pore size between 0.8-1.2 nm, could be used as the support of zinc acetate because of the regular shape, high specific surface area, and good mechanical strength. Vinyl acetate was produced from acetylene and acetic acid using the PCS-supported zinc acetate (PCS-Zn) under mild conditions. In a single-pass operation performed at 220°C, the conversions of acetic acid and acetylene reached 22.6 and 5.3% respectively while the activity of vinyl acetate formation was above 1000 g mol-1 h-1.

Yan, Feng-Wen; Guo, Cun-Yue; Yan, Fang; Li, Feng-Bo; Qian, Qing-Li; Yuan, Guo-Qing

2010-05-01

11

The PVT Properties of Acetic Acid.  

National Technical Information Service (NTIS)

The PVT properties of acetic acid in the saturated and single-phase regions were measured at temperatures between 448.15 and 603.15 K, at pressures up to about 10 MPa. The experimental results were corrected for decomposition of the sample.

D. A. Lee G. B. Lewis I. J. Lawrenson

1977-01-01

12

Kinetics of Ethyl Acetate Synthesis Catalyzed by Acidic Resins  

ERIC Educational Resources Information Center

|A low-cost experiment to carry out the second-order reversible reaction of acetic acid esterification with ethanol to produce ethyl acetate is presented to illustrate concepts of kinetics and reactor modeling. The reaction is performed in a batch reactor, and the acetic acid concentration is measured by acid-base titration versus time. The…

Antunes, Bruno M.; Cardoso, Simao P.; Silva, Carlos M.; Portugal, Ines

2011-01-01

13

Acetic acid vapor levels associated with facial prosthetics  

SciTech Connect

The use of Silastic Medical Adhesive Type A in the fabrication of facial prostheses may cause health hazards to the patient and the operator because of acetic acid emissions. Caution must be exercised to remove acetic acid vapors from the air and unliberated acetic acid from material applied directly to the skin.

McElroy, T.H.; Guerra, O.N.; Lee, S.A.

1985-01-01

14

Oxidation of 3- and 4-carenes with mercuric acetate in acetic acid  

Microsoft Academic Search

1.A study was made of the oxidation of 3-carene with Hg(OAc)2 in acetic acid at 23 and 86°, and with (HgOAc)2 at 90°. The action of both of the oxidizing agents leads to the same acetylative oxidation products: the acetates of p-mentha-1,5-dien-8-ol and p-mentha-1(7),5-dien-8-ol.2.The products of the oxidation of 4-carene with Hg(OAc)2 in acetic acid at 20° contain the acetates

B. A. Arbuzov; V. V. Ratner; Z. G. Isaeva; É. Kh. Kazakova; M. G. Belyaeva

1971-01-01

15

Determination of odour detection thresholds for acetic acid and ethyl acetate in ice wine  

Microsoft Academic Search

Collectively acetic acid and ethyl acetate are responsible for ‘volatile acidity’ (VA) in wine. The detection limit or threshold for these compounds is well documented in table wine but not for ice wine. Knowledge of the ice wine thresholds is important for understanding perception limits and setting legal standards, particularly for a product with high intrinsic concentrations. Thresholds were determined

Margaret A. Cliff; Gary J. Pickering

2006-01-01

16

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

17

Recovery of very dilute acetic acid using ion exchange  

SciTech Connect

Acetic and related acids occur in many industrial wastewaters, often mixed with several other classes of organic compounds. Acetic acid can be recovered from 1% solutions using weakly basic ion exchange resins. The acid is adsorbed by the free-base form of the resin, which can then be eluted using a slurry of lime to give a solution of calcium acetate. This solution could either be evaporated to crystallize calcium acetate or reacted with sulfuric acid to form acetic acid and gypsum. Laboratory tests of the proposed process gave product solutions of 15--20% acetic acid using pure 1% acetic acid as feed. Some measurements using a typical industrial effluent gave similar recoveries and showed that there was no initial fouling of the resins.

Cloete, F.L.D.; Marais, A.P. [Univ. of Stellenbosch (South Africa). Dept. of Chemical Engineering

1995-07-01

18

[Degradation of oxytetracycline with ozonation in acetic acid solvent].  

PubMed

Use acetic acid as the media of ozone degradation of oxytetracycline (OTC), and effects of the initial dosing ratio of ozone/OTC, ozone flow, free radical scavenger, metal ions on the removal rate of OTC were investigated respectively. The results showed that acetic acid had a high ozone stability and solubility. OTC had a high removal rate and degradation rate in acetic acid solution. With the increase of OTC dosage, the removal rate of OTC decreased in acetic acid. Removal rate of OTC was increased distinctly when ozone flow increased properly. It was also observed that free radical scavenger had a significantly negative effect on OTC ozonation degradation in acetic acid. Furthermore the main reactions of OTC ozone oxidation were direct oxidation and indirect oxidation in acetic acid. When Fe3+ and Co2+ were existent in acetic acid, the degradation of OTC was inhibited significantly. PMID:23379161

Li, Shi-Yin; Li, Xiao-Rong; Zhu, Yi-Ping; Zhu, Jiang-Peng; Wang, Guo-Xiang

2012-12-01

19

Submillimeter wave spectrum of acetic acid  

NASA Astrophysics Data System (ADS)

We present a new global study of the submillimeter wave spectrum of the lowest three torsional states of acetic acid (CH3COOH). New measurements involving torsion-rotation transitions with J up to 79 and Ka up to 44 have been carried out between 230 and 845 GHz using the submillimeter wave spectrometers in University of Cologne and Jet Propulsion Laboratory. The new data were combined with previously published measurements and fitted using the rho-axis-method torsion-rotation Hamiltonian. The final fit used 93 parameters to give an overall weighted root-mean-square deviation of 0.85 for a dataset consisting of 7543, 6087, and 5171 transitions belonging, respectively, to the ground, first, and second excited torsional states and 1888 ?vt ? 0 transitions. This investigation presents more than a twofold expansion both in the J quantum number and frequency range coverage of the acetic acid spectrum. Numerous inter-torsional interactions have been observed. Furthermore, this is the highest J value ever treated with the rho-axis-method and provides a good test case for the theoretical model in use.

Ilyushin, Vadim V.; Endres, Christian P.; Lewen, Frank; Schlemmer, Stephan; Drouin, Brian J.

2013-08-01

20

Genetic organization of Acetobacter for acetic acid fermentation  

Microsoft Academic Search

Plasmid vectors for the acetic acid-producing strains ofAcetobacter andGluconobacter were constructed from their cryptic plasmids and the efficient transformation conditions were established. The systems allowed to reveal the genetic background of the strains used in the acetic acid fermentation. Genes encoding indispensable components in the acetic acid fermentation, such as alcohol dehydrogenase, aldehyde dehydrogenase and terminal oxidase, were cloned and

Teruhiko Beppu

1993-01-01

21

Comparative study of recovering acetic acid with energy integrated schemes  

Microsoft Academic Search

The heat pumping and multi-effect distillation techniques were evaluated for recovering acetic acid from aqueous solutions with low boiling solvents, methyl tert-butyl ether (MTBE) and ethyl acetate (EtOAc). The overhead vapour recompression and two types of column cascading techniques are compared to the conventional acetic acid recovery scheme. It was found that (1) by switching the solvent to MTBE, approximately

S. Kürüm; Z. Fonyo

1996-01-01

22

Oxidation of Indole-3-Acetic Acid to Oxindole-3-Acetic Acid by an Enzyme Preparation from Zea mays1  

PubMed Central

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, Dennis M.; Bandurski, Robert S.

1988-01-01

23

Acetic acid pulping of wheat straw under atmospheric pressure  

Microsoft Academic Search

Atmospheric acetic acid pulping of wheat straw was carried out. Pulping conditions and their effects on pulp properties were investigated in detail, and a comparison between acetic acid (AcOH) pulp and soda-anthraquinone (AQ) pulps of wheat straw was made of the chemical com- position, strength, and fiber morphology of the pulps. Wheat straw was successfully pulped and fractionated into pulp

Xue-Jun PanYoshihiro Sano

1999-01-01

24

Effect of ethyl acetate on carbohydrate components and crystalline structure of pulp produced in aqueous acetic acid pulping  

Microsoft Academic Search

The aim of this study was to investigate the changes in carbohydrate components and the crystalline structure in hemp bast\\u000a fibers by adding ethyl acetate to acetic acid\\/water pulping processes. It was found that ethyl acetate added to acetic acid\\/water\\u000a process had a positive effect on yield, viscosity and carbohydrate components in pulp. It was assumed that the delignification\\u000a ratio

Esat Gümü?kaya; Mustafa Usta; Mualla Balaban Uçar

2009-01-01

25

Anaerobic thermophilic fermentation for acetic acid production from milk permeate.  

PubMed

Fermentation of milk permeate to produce acetic acid under anaerobic thermophilic conditions (approximately 60 degrees C) was studied. Although none of the known thermophilic acetogenic bacteria can ferment lactose, it has been found that one strain can use galactose and two strains can use lactate. Moorella thermoautotrophica DSM 7417 and M. thermoacetica DSM 2955 were able to convert lactate to acetate at thermophilic temperatures with a yield of approximately 0.93 g g(-1). Among the strains screened for their abilities to produce acetate and lactate from lactose, Clostridium thermolacticum DSM 2910 was found precisely to produce large amounts of lactate and acetate. However, it also produced significant amounts of ethanol, CO2 and H2. The lactate yield was affected by cell growth. During the exponential phase, acetate, ethanol, CO2 and H2 were the main products of fermentation with an equimolar acetate/ethanol ratio, whereas during the stationary phase, only lactic acid was produced with a yield of 4 mol per mol lactose, thus reaching the maximal theoretical value. When this bacterium was co-cultured with M. thermoautotrophica, lactose was first converted mainly to lactic acid, then to acetic acid, with a zero residual lactic acid concentration and an overall yield of acetate around 80%. Under such conditions, only 13% of the fermented lactose was converted to ethanol by C. thermolacticum. PMID:10784299

Talabardon, M; Schwitzguébel, J P; Péringer, P

2000-01-01

26

Anaerobic thermophilic fermentation for acetic acid production from milk permeate  

Microsoft Academic Search

Fermentation of milk permeate to produce acetic acid under anaerobic thermophilic conditions (?60°C) was studied. Although none of the known thermophilic acetogenic bacteria can ferment lactose, it has been found that one strain can use galactose and two strains can use lactate. Moorella thermoautotrophica DSM 7417 and M. thermoacetica DSM 2955 were able to convert lactate to acetate at thermophilic

Mylène Talabardon; Jean-Paul Schwitzguébel; Paul Péringer

2000-01-01

27

Fast Esterification of Acetic Acid with Short Chain Alcohols in Microchannel Reactor  

Microsoft Academic Search

Microchannel reactor was used for the fast synthesis of acetic acid esters, including methyl acetate, ethyl acetate, n-propyl acetate and n-butyl acetate. Effects of the inner diameter of microchannel reactors, dosage of catalyst, residence time, reaction temperature\\u000a and molar ratio of alcohol to acetic acid on yields of esters were studied in the p-toluene sulfonic acid-catalyzed homogeneous esterification of acetic

Xingjun Yao; Jianfeng Yao; Lixiong Zhang; Nanping Xu

2009-01-01

28

Ethane to acetic acid oxidation over supported heteropoly acids  

Microsoft Academic Search

Molybdo(vanado)phosphoric heteropoly acids of Keggin structure supported on oxide supports (SiO2, TiO2, Al2O3) were used as catalysts for ethane to acetic acid oxidation in the range of reaction temperature from 250 to 400°C. Vanadium atoms introduced into Keggin structure enhanced oxidative activity of catalytic system, while vanadyl groups exchanged into cationic position diminished ethane conversion. Nature of support (acidic or

M. Sopa; A. W?c?aw-Held; M. Grossy; J. Pijanka; K. Nowi?ska

2005-01-01

29

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

Code of Federal Regulations, 2010 CFR

... 5-Hydroxyindole acetic acid/serotonin test system. 862.1390 Section... 5-Hydroxyindole acetic acid/serotonin test system. (a) Identification...A 5-hydroxyindole acetic acid/serotonin test system is a device...

2009-04-01

30

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

Code of Federal Regulations, 2010 CFR

... 5-Hydroxyindole acetic acid/serotonin test system. 862.1390 Section... 5-Hydroxyindole acetic acid/serotonin test system. (a) Identification...A 5-hydroxyindole acetic acid/serotonin test system is a device...

2010-04-01

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

2013-06-07

32

Acetals of lactams and acid amides  

Microsoft Academic Search

A new approach to the synthesis of one-, two-, and three-ring compounds from enamides and enamino ketones was investigated. Thus the reaction of a-cyano-ß-dimethylaminoacrylamide with guanidine gave 2, 4-diamino-5-carbamidopyrimidine, the cyclization of which with dimethylformamide acetal and subsequent hydrolysis gave 2-amino-5,6-dihydro-5-oxopyrimido[4,5-d]pyrimidine. An enamino ketone — 1-benzoyl-2-dimethylamino-2-methylethylene — was subjected to condensation with guanidine, thiourea, and acetamidine, as a result of

O. Ya. Belyaeva; V. G. Granik; R. G. Glushkov; T. F. Vlasova; O. S. Anisimova

1978-01-01

33

Hydrothermal production of formic and acetic acids from syringol  

Microsoft Academic Search

The production of formic and acetic acids (or salts) by hydrothermal oxidation of syringol, a model compound for lignin, was\\u000a investigated using a batch reactor. Results show that the highest yields of formic and acetic acids were, respectively, 59.6%\\u000a and 11.3% at the reaction condition of 0.5 mol\\/L NaOH, 120% H2O2 supply and 280 °C. These results will inform studies

Lu-ting Pan; Zheng Shen; Lei Wu; Ya-lei Zhang; Xue-fei Zhou; Fang-ming Jin

2010-01-01

34

Acetic acid pulping of wheat straw under atmospheric pressure  

Microsoft Academic Search

Atmospheric acetic acid pulping of wheat straw was carried out. Pulping conditions and their effects on pulp properties were\\u000a investigated in detail, and a comparison between acetic acid (AcOH) pulp and soda-anthraquinone (AQ) pulps of wheat straw\\u000a was made of the chemical composition, strength, and fiber morphology of the pulps. Wheat straw was successfully pulped and\\u000a fractionated into pulp (cellulose),

Xue-Jun Pan; Yoshihiro Sano

1999-01-01

35

Activated carbon sheet prepared from softwood acetic acid lignin  

Microsoft Academic Search

As an example of activated carbon (AC) moldings, AC sheets were prepared from thermoplastic acetic acid lignin by lamination.\\u000a The resulting AC sheets are a new type of product that can be applied as water and air cleaners. Powdered softwood acetic\\u000a acid lignin (SAL) was molded into sheets by a thermal pressing method. When the sheet was carbonized under a

Yasumitsu Uraki; Ryo Taniwatashi; Satoshi Kubo; Yoshihiro Sano

2000-01-01

36

Conformational studies of hydantoin-5-acetic acid and orotic acid.  

PubMed

Hydantoin-5-acetic acid [2-(2,5-dioxoimidazolidin-4-yl)acetic acid] and orotic acid (2,6-dioxo-1,2,3,6-tetrahydropyrimidine-4-carboxylic acid) each contain one rigid acceptor-donor-acceptor hydrogen-bonding site and a flexible side chain, which can adopt different conformations. Since both compounds may be used as coformers for supramolecular complexes, they have been crystallized in order to examine their conformational preferences, giving solvent-free hydantoin-5-acetic acid, C(5)H(6)N(2)O(4), (I), and three crystals containing orotic acid, namely, orotic acid dimethyl sulfoxide monosolvate, C(5)H(4)N(2)O(4)·C(2)H(6)OS, (IIa), dimethylammonium orotate-orotic acid (1/1), C(2)H(8)N(+)·C(5)H(3)N(2)O(4)(-)·C(5)H(4)N(2)O(4), (IIb), and dimethylammonium orotate-orotic acid (3/1), 3C(2)H(8)N(+)·3C(5)H(3)N(2)O(4)(-)·C(5)H(4)N(2)O(4), (IIc). The crystal structure of (I) shows a three-dimensional network, with the acid function located perpendicular to the ring. Interestingly, the hydroxy O atom acts as an acceptor, even though the carbonyl O atom is not involved in any hydrogen bonds. However, in (IIa), (IIb) and (IIc), the acid functions are only slightly twisted out of the ring planes. All H atoms of the acidic functions are directed away from the rings and, with respect to the carbonyl O atoms, they show an antiperiplanar conformation in (I) and synperiplanar conformations in (IIa), (IIb) and (IIc). Furthermore, in (IIa), (IIb) and (IIc), different conformations of the acid O=C-C-N torsion angle are observed, leading to different hydrogen-bonding arrangements depending on their conformation and composition. PMID:22307261

Gerhardt, Valeska; Tutughamiarso, Maya; Bolte, Michael

2012-01-18

37

Infrared Studies of Water Adsorption on Acetic Acid thin films  

NASA Astrophysics Data System (ADS)

Infrared reflection-absorption spectroscopy is used to investigate H2O ice deposited onto non-crystalline (dimers [1]) and polycrystalline (infinite chains [1]) acetic acid films. The condensed water film grown at ˜135 K on these different substrates can be characterized as amorphous dense ice. The H2O molecules are shown to interact mainly with the carbonyl and the carboxyl oxygens, forming hydrogen bonds. Upon water adsorption on the non-crystalline acetic acid film, saturation of the change induced in the intensity of the C=O and C-O peaks occurs at an average H2O exposure of ˜ 2.52 L. The amount of H-bonding involving C=O or C-O (of acetic acid) and OH (of water) on the polycrystalline film has been reduced considerably compared to the situation on the non-annealed one, but saturation of the carbonyl oxygen even for a water exposure of 9 L has not been observed while the carboxyl oxygen saturates at ˜2.76 L. Thermal evolution studies for the ice film on non-crystalline and polycrystalline acetic acid films show that water co-evaporates with acetic acid likely as a water-acetic acid complex in the temperature range of 140-155 K, which continues until the entire ice film has been exhausted at 160 K. [1]: Q. Gao and K. T. Leung, J. Phys. Chem. B 109, (2005) 13263. .

Malick Thiam, Michel; Ebrahimi, Maryam; Tong Leung, Kam

2006-03-01

38

Fractionation of wheat straw by atmospheric acetic acid process.  

PubMed

Fractionation of wheat straw was investigated using an atmospheric acetic acid process. Under the typical conditions of 90% (v/v) aqueous AcOH, 4% H(2)SO(4) (w/w, on straw), ratio of liquor to straw (L/S) 10 (v/w), pulping temperature 105 degrees C, and pulping time 3h, wheat straw was fractionated to pulp (cellulose), lignin and monosaccharides mainly from hemicellulose with yields of approximately 50%, 15% and 35%, respectively. Acetic acid pulp from the straw had an acceptable strength for paper and could be bleached to a high brightness over 85% with a short bleaching sequence. Acetic acid pulp was also a potential feedstock for fuels and chemicals. The acetic acid process separated pentose and hexose in wheat straw to a large extent. Most of the pentose (xylan) was dissolved, whereas the hexose (glucan) remained in the pulp. Approximately 30% of carbohydrates in wheat straw were hydrolyzed to monosaccharides during acetic acid pulping, of which xylose accounted for 70% and glucose for 12%. The acetic acid lignin from wheat straw showed relatively lower molecular weight and fusibility, which made the lignin a promising raw material for many products, such as adhesive and molded products. PMID:15734313

Pan, Xuejun; Sano, Yoshihiro

2004-12-19

39

Aerobic oxidation of aqueous ethanol using heterogeneous gold catalysts: Efficient routes to acetic acid and ethyl acetate  

Microsoft Academic Search

The aerobic oxidation of aqueous ethanol to produce acetic acid and ethyl acetate was studied using heterogeneous gold catalysts. Comparing the performance of Au\\/MgAl2O4 and Au\\/TiO2 showed that these two catalysts exhibited similar performance in the reaction. By proper selection of the reaction conditions, yields of 90–95% of acetic acid could be achieved at moderate temperatures and pressures. Based on

Betina Jørgensen; Sofie Egholm Christiansen; Marie Louise Dahl Thomsen; Claus Hviid Christensen

2007-01-01

40

Formation of Amino Acids from Reactor Irradiated Ammonium Acetate  

NASA Astrophysics Data System (ADS)

Ammonium acetate in various conditions was irradiated in a reactor to examine the contributions of both the reactor radiations and recoiled14C nucleis to form the biologically interesting molecules. Present investigations demonstrated that several amino acids, glycine, alanine, ?-alanine and GABA, and may-be aspartic acid, serine and valine by prolonged irradiation, were formed in the aqueous solutions of ammonium acetate.14C-radioactivities were also found distributed in these amino acids. However, no special relationship between14C-radioactivity and these amino acids formed was observed.

Akaboshi, M.; Kawai, K.; Maki, H.; Kawamoto, K.; Honda, Y.

1982-12-01

41

Simultaneous acetic acid separation and monosaccharide concentration by reverse osmosis.  

PubMed

This study aimed to investigate the feasibility and efficiency of simultaneous acetic acid separation and sugar concentration in model lignocellulosic hydrolyzates by reverse osmosis. The effects of operation parameters such as pH, temperature, pressure and feed concentration on the solute retentions were examined with a synthetic xylose–glucose–acetic acid model solution. Results showed that the monosaccharides were almost completely rejected at above 20 bar, while the acetic acid retention increased with the increase in pH and pressure, and decreased with the temperature increase. The maximum separation factors of acetic acid over xylose and glucose reached as high as 211.5 and 228.4 at pH 2.93 (the initial pH of model lignocellulosic hydrolyzates), 40 °C and 20 bar. Furthermore, the concentration and diafiltration process were employed at optimal operation conditions. Consequently, a high sugar concentration and a beneficially lower acetic acid concentration were simultaneously achieved by reverse osmosis. PMID:23376199

Zhou, Fanglei; Wang, Cunwen; Wei, Jiang

2013-01-03

42

Photodissociation spectroscopy of the Mg{sup +}-acetic acid complex  

SciTech Connect

We have studied the structure and photodissociation of Mg{sup +}-acetic acid clusters. Ab initio calculations suggest four relatively strongly bound ground state isomers for the [MgC{sub 2}H{sub 4}O{sub 2}]{sup +} complex. These isomers include the cis and trans forms of the Mg{sup +}-acetic acid association complex with Mg{sup +} bonded to the carbonyl O atom of acetic acid, the Mg{sup +}-acetic acid association complex with Mg{sup +} bonded to the hydroxyl O atom of acetic acid, or to a Mg{sup +}-ethenediol association complex. Photodissociation through the Mg{sup +}-based 3p<-3s absorption bands in the near UV leads to direct (nonreactive) and reactive dissociation products: Mg{sup +}, MgOH{sup +}, Mg(H{sub 2}O){sup +}, CH{sub 3}CO{sup +}, and MgCH{sub 3}{sup +}. At low energies the dominant reactive quenching pathway is through dehydration to Mg(H{sub 2}O){sup +}, but additional reaction channels involving C-H and C-C bond activation are also open at higher energies.

Abate, Yohannes; Kleiber, P. D. [Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 and Optical Science and Technology Center, University of Iowa, Iowa City, Iowa 52242 (United States)

2006-11-14

43

Photoionization of small sodium-doped acetic acid clusters  

NASA Astrophysics Data System (ADS)

The uptake of sodium and the fragmentation before and after ``soft'' photoionization with ultraviolet light are investigated for small acetic acid clusters. The acetic acid clusters are generated in a supersonic expansion and ionized with ultraviolet light after doping with sodium in a pick-up chamber. The composition of the bare acetic acid clusters in the molecular beam is determined independently from complementary photoionization experiments using extreme ultraviolet light. The experimental results are analyzed with the help of density functional calculations for energetics and statistical adiabatic channel calculations for fragmentation kinetics. The study demonstrates that the detected ions originate from fragmentation in the neutral as well as in the ionic state, and in particular that the fragmentation pathway strongly depends on the cluster size.

Forysinski, Piotr W.; Zielke, Philipp; Luckhaus, David; Corbett, Jennifer; Signorell, Ruth

2011-03-01

44

Disinfection of mung bean seed with gaseous acetic acid.  

PubMed

Mung bean seed inoculated with Salmonella Typhimurium, Escherichia coli O157:H7, and Listeria monocytogenes (3 to 5 log CFU/g) was exposed to gaseous acetic acid in an aluminum fumigation chamber. Salmonella Typhimurium and E. coli O157:H7 were not detected by enrichment of seeds treated with 242 microl of acetic acid per liter of air for 12 h at 45 degrees C. L. monocytogenes was recovered by enrichment from two of 10 25-g seed samples treated in this manner. Fumigation with gaseous acetic acid was also lethal to indigenous bacteria and fungi on mung bean seed. The treatment did not significantly reduce seed germination rates, and no differences in surface microstructure were observed between treated and untreated seed viewed by scanning electron microscopy. PMID:10456753

Delaquis, P J; Sholberg, P L; Stanich, K

1999-08-01

45

Method for enzymatic determination of imidazole acetic acid.  

PubMed

A method for enzymatic assay of imidazole acetic acid (ImAA) was developed, based on the strict substrate specificity of imidazole acetate monooxygenase from Pseudomonas sp. [Maki et al. (1969) J. Biol. Chem., 244., 2942-2950], which catalyzes concomitant conversion of NADH to NAD+. Thus, ImAA was determined by measuring decrease in absorbancy at 340 nm. Tissue extracts were partially purified and/or concentrated by column chromatography on Bio-Rad AG-1 before enzymatic assay. The lowest measurable level of ImAA by this method was 2 nmol. PMID:6869819

Watanabe, T; Kambe, H; Imamura, I; Taguchi, Y; Tamura, T; Wada, H

1983-04-15

46

Condensation of acetol and acetic acid vapor with sprayed liquid  

Technology Transfer Automated Retrieval System (TEKTRAN)

A cellulose-derived fraction of biomass pyrolysis vapor was simulated by evaporating acetol and acetic acid (AA) from flasks on a hot plate. The liquid in the flasks was infused with heated nitrogen. The vapor/nitrogen stream was superheated in a tube oven and condensed by contact with a cloud of ...

47

Recovery of acetic acid from waste streams by extractive distillation  

Microsoft Academic Search

Wastes have been considered to be a serious worldwide environmental problem in recent years. Because of increasing pollution, these wastes should be treated. However, industrial wastes can contain a number of valuable organic components. Recovery of these components is important economically. Using conventional distillation techniques, the separation of acetic acid and water is both impractical and uneconomical, because it often

H. Demiral; M. Ercengiz Yildirim

48

Catalytic steam reforming of acetic acid for hydrogen production  

Microsoft Academic Search

A variety of supported metal catalysts were tested under conditions of steam reforming of acetic acid (HAc), which was selected as a model compound for pyrolysis oil. The influence of several parameters on catalytic activity and selectivity were examined, including catalyst composition, i.e. nature of the metal and the carrier, reaction temperature and time on stream. The metallic phase of

A. C. Basagiannis; X. E. Verykios

2007-01-01

49

Electrosynthesis of anisidines in aqueous sulfuric and acetic acids  

NASA Astrophysics Data System (ADS)

The influence of the concentrations of acetic and sulfuric acids on the efficiency of anisole amination by means of hydroxylamine and Ti(IV)/Ti(III) mediator was studied. Ortho- and para-anisidines were obtained with the total yields of about 79% by current and hydroxylamine.

Lisitsyn, Yu. A.; Grigor'eva, L. V.

2009-03-01

50

Intramolecular carbon isotope distribution of acetic acid in vinegar.  

PubMed

Compound-specific carbon isotope analysis of acetic acid is useful for origin discrimination and quality control of vinegar. Intramolecular carbon isotope distributions, which are each carbon isotope ratios of the methyl and carboxyl carbons in the acetic acid molecule, may be required to obtain more detailed information to discriminate such origin. In this study, improved gas chromatography-pyrolysis-gas chromatography-combustion-isotope ratio mass spectrometry (GC-Py-GC-C-IRMS) combined with headspace solid-phase microextraction (HS-SPME) was used to measure the intramolecular carbon isotope distributions of acetic acid in 14 Japanese vinegars. The results demonstrated that the methyl carbons of acetic acid molecules in vinegars produced from plants were mostly isotopically depleted in (13)C relative to the carboxyl carbon. Moreover, isotopic differences (?(13)C(carboxyl) - ?(13)C(methyl)) had a wide range from -0.3 to 18.2‰, and these values differed among botanical origins, C3, C4, and CAM plants. PMID:21830825

Hattori, Ryota; Yamada, Keita; Kikuchi, Makiko; Hirano, Satoshi; Yoshida, Naohiro

2011-08-18

51

Phenyl Acetate Preparation from Phenol and Acetic Acid: Reassessment of a Common Textbook Misconception.  

ERIC Educational Resources Information Center

|Reassesses a common textbook misconception that "...phenols cannot be esterified directly." Results of experiments are discussed and data tables provided of an effective method for the direct preparation of phenyl acetate. (CS)|

Hocking, M. B.

1980-01-01

52

Organisms Associated with Acetic Acid Bacteria in Vinegar Production  

Microsoft Academic Search

Vinegars are the product of scalar fermentations carried out by several groups of microorganisms acting at different moments\\u000a in time. The initial phase is generally represented by an alcoholic fermentation commonly carried out by yeasts. Lactic acid\\u000a bacteria (LAB) can also play a role in releasing ethanol and acetic acid from heterofermentative lactic acid fermentations.\\u000a Depending on the nature of

Sandra Rainieri; Carlo Zambonelli

53

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.

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

2012-01-01

54

Effects of acetic acid on light scattering from cells.  

PubMed

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

2012-08-01

55

Occurrence and metabolism of 7-hydroxy-2-indolinone-3-acetic acid in Zea mays.  

PubMed

7-Hydroxy-2-indolinone-3-acetic acid was identified as a catabolite of indole-3-acetic acid in germinating kernels of Zea mays and found to be present in amounts of ca 3.1 nmol/kernel. 7-Hydroxy-2-indolinone-3-acetic acid was shown to be a biosynthetic intermediate between 2-indolinone-3-acetic acid and 7-hydroxy-2-indolinone-3-acetic acid-7'-O-glucoside in both kernels and roots of Zea mays. Further metabolism of 7-hydroxy-2-[5-3H]-indolinone-3-acetic acid-7'-O-glucoside occurred to yield tritiated water plus, as yet, uncharacterized products. PMID:11539052

Lewer, P; Bandurski, R S

1987-01-01

56

Determination of Formic and Acetic Acid in Chondritic Meteorites  

NASA Astrophysics Data System (ADS)

The concentrations of formic and acetic acid have been determined using ion exclusion chromatography after water extraction from several chondritic meteorite samples. Monocarboxylic acids are of great importance because of their high concentration in meteorites and for their role as precursor molecules in organic synthesis [1]. The concentration of acetic acid has been determined previously using gas chromatography [2,3]. Prior gas chromatographic analyses failed to resolve formic acid and so the results were limited to carboxylic acids having two or more carbons. Alternatively, wet chemical methods for the determination of formic acid, although precise, are lengthy and difficult to reproduce [4]. Ion exclusion chromatography (ICE) is an excellent technique for the simultaneous determination of formic and acetic acids. Using ICE the carboxylic acids can be determined in less time and with minimal sample handling. In most cases the amount of formic acid present is found to be lower than the amount of acetic acid present. This contradicts the accepted synthesis scheme of higher homologs being made from lower members, where the formic acid would be expected to have a higher concentration than acetic acid. Other monocarboxylic acids in the homologous series (C(sub)2-C(sub)7) have been shown to decrease with increasing carbon number as expected [2,3]. This data suggests that either the formic acid may have been preferentially depleted or it may have a different synthesis mechanism as compared with the other monocarboxylic acids present in meteorites. Additionally, there is a relationship between the amount of formic and acetic acid present and the oxidation state of the iron in the chondrites. As the matrix environment becomes more oxidizing, the amount of the two monocarboxylic acids increases comparatively. Furthermore, the ratio of formic to acetic acid starts to increase as the metal phase is more oxidized, suggesting that a more oxidized matrix environment in some way makes the production of higher homologs from lower members more favorable. References: [1] Cronin J. R. et al. (1988) In Meteorites and the Early Solar System (J. F. Kerridge and M. S. Matthews, eds.), 819-857. Univ. of Arizona. [2] Yuen G. U. and Kvenvolden K. A. (1974) Nature, 246, 301-303. [3] Yuen G. et al. (1984) Nature, 307, 252-254. [4] Kimball B. (1988) M.S. thesis, Arizona State Univ. [5] Urey H. C. and Craig H. (1953) GCA, 4, 36-82. [6] Sears D. W. and Dodd R. T. (1988) In Meteorites and the Early Solar System (J. F. Kerridge and M. S. Matthews, eds.), 3-31. Univ. of Arizona. Table 1, which appears here in the hard copy, shows a representative concentration of formic and acetic acid (in ppm) for select chondrites as measured by ion exclusion chromatography.

Briscoe, J. F.; Moore, C. B.

1993-07-01

57

Electrochemical behavior of graphite in electrolyte of sulfuric and acetic acid  

Microsoft Academic Search

Electrochemical formation of graphite intercalation compounds (GICs) has been studied in the electrolyte with mixed sulfuric acid and acetic acid. The results show that, with addition of acetic acid, GICs can be synthesized in the electrolyte with sulfuric acid concentration as low as 3.6M, even though no GIC is formed in pure acetic acid. The stage structure of the synthesized

F. Kang; T.-Y. Zhang; Y. Leng

1997-01-01

58

CARCINOGENICITY OF THE CHLORINATED ACETIC ACIDS  

EPA Science Inventory

Dichloroacetic Acid (DCAA) and trichloroacetic acid (TCAA) comprise a major fraction of the reaction products formed when water containing a variety of precursor humic materials is chlorinated. Both DCAA and TCAA administered in the drinking water increased the incidence of hepat...

59

High resolution acetic acid survey and water vapor radiometer  

NASA Astrophysics Data System (ADS)

Planets, comets, stars, galaxies and the interstellar medium (ISM) emit complex but distinct molecular spectra. These spectra reveal the chemical composition and physical conditions in the objects. For example, many biologically important molecules, such as acetic acid, formic acid, vinyl cyanide and ethyl cyanide, have been detected in hot molecular cores in the ISM. A diversity of molecules creates complicated and yet interesting astrochemistry in hot cores. However, the formation mechanisms of large molecules are still unclear. Hence large molecule observations are essential to understand hot core chemistry. Among these molecules, acetic acid is one of the most important large species in hot cores. It is a possible precursor of glycine, the simplest amino acid. It only has been detected in high-mass hot cores without oxygen/nitrogen chemical differentiation, which is key to hot core chemical models. Using the Combined Array for Research in Millimeter-wave Astronomy (CARMA), we have conducted an acetic acid survey in hot cores. In our survey, we have discovered a new acetic acid hot core, G19.61-0.23, which also shows no chemical differentiation. Therefore, we suggest that both large oxygen and nitrogen- bearing species play important roles in acetic acid formation. Ground-based interferometric observations are severely affected by atmospheric conditions. Phase correction is a technique to obtain high quality data and achieve great scientific goals. For our acetic acid survey, a better phase correction technique can not only detect weaker transitions of large molecules, but also increase the map resolution of hot cores. Water vapor radiometers (WVRs) are designed to improve the technique by observing tropospheric water vapor along the lines of sight of interferometers. We have numerically demonstrated the importance of phase correction for interferometric observations and examined the water vapor phase correction technique. Furthermore, we have built two WVR prototypes with new calibration, thermal regulation and backend systems. The WVR prototypes had been tested in a laboratory, on a roof and at the CARMA site to verify their performance. We conclude the WVR thermal stability and dynamic range are critical while the enormous and rapid fluctuations of the sky background emission overwhelm the WVR dynamic range and degrade the WVR sensitivity.

Shiao, Yu-Shao

2008-08-01

60

Measurement of acetic acid using a fibre Bragg grating interferometer  

Microsoft Academic Search

An optical fibre sensor for determination of acetic acid is presented. The sensing probe is based on a fibre Bragg grating (FBG) Fabry-Perot cavity, coated with a thin film of sol-gel-PVP (polyvinylpyrrolidone) composite material. The polymeric thin film renders the interferometric output sensitive to the presence of carboxylic acid species. Results show that the wavelength of the interferometric peaks changes

C. Jesus; S. F. O. Silva; M. Castanheira; G. González Aguilar; O. Frazão; P. A. S. Jorge; J. M. Baptista

2009-01-01

61

Interferometric fibre-optic sensor for acetic acid measurement  

Microsoft Academic Search

An optical fibre sensor for determination of acetic acid is presented. The sensing probe is based on a fiber Bragg grating (FBG) Fabry-Perot cavity, coated with a thin film of sol-gel-PVP (polyVynil Pirrolidone) composite material. The polymeric thin film renders interferometric output sensitive to the presence of carboxylic acid species. Results show that the wavelength of the interferometric peaks change

C. Jesus; S. F. O. Silva; M. Castanheira; G. Gonzalez Aguilar; O. Frazao; P. A. S. Jorge; J. M. Baptista

2009-01-01

62

Liquid crystalline solutions of cellulose acetate in phosphoric acid  

Microsoft Academic Search

The influence has been studied of both the acid strength of phosphoric acid and the degree of substitution of cellulose acetate on the formation of an anisotropic phase. The solvent composition is expressed as a P2O5 concentration. It was found that the clearing temperature increases strongly with decreasing amount of water in the solvent.The influence of the degree of substitution

H Boerstoel; H Maatman; S. J Picken; R Remmers; J. B Westerink

2001-01-01

63

T09PAA101 Acetic Acid Glacial  

Center for Food Safety and Applied Nutrition (CFSAN)

Text Version... 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) (hereinafter referred to as “PAA solutions”) as an antimicrobial to treat poultry carcasses, to ... More results from www.fda.gov/downloads/food/ingredientspackaginglabeling

64

Design and control of acetic acid dehydration system via heterogeneous azeotropic distillation  

Microsoft Academic Search

Acetic acid dehydration is an important operation in the production of aromatic acid, such as terephthalic acid or in the manufacture of cellulose acetate. Although acetic acid and water does not form azeotrope, but using simple distillation to separate these two components is not practical. The reason is because the system has tangent pinch on the pure water end, thus

I. Lung Chien; Kai-Luen Zeng; Huan-Yi Chao; Jun Hong Liu

2004-01-01

65

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

Microsoft Academic Search

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

Kazunobu Matsushita; Taketo Inoue; Osao Adachi; Hirohide Toyama

2005-01-01

66

Polyphasic taxonomy of acetic acid bacteria: An overview of the currently applied methodology  

Microsoft Academic Search

Acetic acid bacteria are Gram-negative, obligate aerobic bacteria that have the ability to incompletely oxidize alcohols or sugars to organic acids as end products. They are widespread in nature and most of them are capable to oxidize ethanol as substrate to acetic acid. This characteristic makes that acetic acid bacteria are often involved in foods and beverages, either in a

Ilse Cleenwerck; Paul De Vos

2008-01-01

67

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

68

Acetic acid bacteria spoilage of bottled red wine -- a review.  

PubMed

Acetic acid bacteria (AAB) are ubiquitous organisms that are well adapted to sugar and ethanol rich environments. This family of Gram-positive bacteria are well known for their ability to produce acetic acid, the main constituent in vinegar. The oxidation of ethanol through acetaldehyde to acetic acid is well understood and characterised. AAB form part of the complex natural microbial flora of grapes and wine, however their presence is less desirable than the lactic acid bacteria and yeast. Even though AAB were described by Pasteur in the 1850s, wine associated AAB are still difficult to cultivate on artificial laboratory media and until more recently, their taxonomy has not been well characterised. Wine is at most risk of spoilage during production and the presence of these strictly aerobic bacteria in grape must and during wine maturation can be controlled by eliminating, or at least limiting oxygen, an essential growth factor. However, a new risk, spoilage of wine by AAB after packaging, has only recently been reported. As wine is not always sterile filtered prior to bottling, especially red wine, it often has a small resident bacterial population (<10(3) cfu/mL), which under conducive conditions might proliferate. Bottled red wines, sealed with natural cork closures, and stored in a vertical upright position may develop spoilage by acetic acid bacteria. This spoilage is evident as a distinct deposit of bacterial biofilm in the neck of the bottle at the interface of the wine and the headspace of air, and is accompanied with vinegar, sherry, bruised apple, nutty, and solvent like off-aromas, depending on the degree of spoilage. This review focuses on the wine associated AAB species, the aroma and flavour changes in wine due to AAB metabolism, discusses the importance of oxygen ingress into the bottle and presents a hypothesis for the mechanism of spoilage of bottled red wine. PMID:18237809

Bartowsky, Eveline J; Henschke, Paul A

2007-12-23

69

Auto-catalyzed acetic acid pulping of jute  

Microsoft Academic Search

A number of acetic acid (HAc) based pulping trials were carried out to determine the best conditions to produce a jute pulp with low residual lignin content and high physical properties. The extended delignification, with increasing temperature, strongly affected the strength properties. The highest tensile strength of 24Nm\\/g was found at 150°C and 10min, 300ml CSF condition. However, increasing temperature

Halil Turgut Sahin; Raymond A. Young

2008-01-01

70

Dehydration of acetic acid by pervaporation with charged membranes  

Microsoft Academic Search

Modified Nafion membranes were prepared by charging Nafion 117 membrane with different long-chained counter ions and used for pervaporation of acetic acid–water mixture. It was observed, that the selectivity of Nafion membrane was enhanced by charging with long-chained counter ions. However, it led to a decrease in permeate flux because of decreasing solubility and diffusivity of the membranes. The results

Samuel P. Kusumocahyo; Masao Sudoh

1999-01-01

71

Potential energy surfaces for proton abstractions from acetic acid  

Microsoft Academic Search

The abstractions of hydrogen from both carbon and oxygen in acetic acid by hydride, fluoride, and hydroxide anions have been studied using ab initio electronic structure calculations. Molecular structures were optimized at the Hartree-Fock level of theory using the 6-31++G(d,p) basis set. For energetics, the 6-311++G(d,p) basis set was used, with second- and fourth-order perturbation theory corrections, for both minima

Mark S. Gordon; David R. Gano; Eugene Curtiss

1996-01-01

72

Modified alginate composite membranes for the dehydration of acetic acid  

Microsoft Academic Search

Alginate composite membranes cross-linked with 1,6-hexanediamine (HDM) or poly(vinyl alcohol) (PVA) were prepared by casting an aqueous solution of alginate and HDM or PVA on a hydrolyzed microporous polyacrylonitrile (PAN) membrane and characterized by pervaporation separation of acetic acid\\/water mixtures. The influence of hydrolysis of PAN support layer and HDM content in dense layer on separation performance of the composite

Xin-Ping Wang

2000-01-01

73

2-(3-Hy-droxy-benzyl-amino)-acetic acid  

PubMed Central

There are two independent 2-(3-hy­droxy­benzyl­amino)­acetic acid mol­ecules, C9H11NO3, in the asymmetric unit of the title compound. The dihedral angle between the benzene rings of the two independent mol­ecules is 58.12?(4)°. The crystal packing is stablized by inter­molecular O—H?O and N—H?O hydrogen bonds.

Zhi, Li-Hua; Wu, Wei-Na

2011-01-01

74

Electroacupuncture ameliorates experimental colitis induced by acetic acid in rat  

Microsoft Academic Search

The effect of electroacupuncture (EA) on experimental colitis was investigated in Sprague-Dawley rats. Colitis was induced by intracolonic instillation of 4% acetic acid. EA (2 Hz, 0.05 ms, 2 V for 20 min) was applied to bilateral Hoku (LI- 4) and Zusanli (ST-36) on 12 hrs and 36 hrs after induction of colitis. EA-treatment significantly reduced the macroscopic damage and

Jeoung-Woo Kang; Tae-Wan Kim; Jun-Ho La; Tae-Sik Sung; Hyun-Ju Kim; Young-Bae Kwon; Jeum-Yong Kim; Il-Suk Yang

2004-01-01

75

Indole3-acetic acid induces microencephaly in mouse fetuses  

Microsoft Academic Search

To determine the effect of indole-3-acetic acid (IAA), known as natural auxin, on developing fetus, pregnant mice were injected with 500 or 1000mg\\/kg on various gestation days (Days). With the repeated treatment during Days 7–15, the fetal brains exhibited a reduction in size and weight in a dose-dependent manner on Day 18. Histopathologically, hypoplasia of the cortical plate, piriform cortex,

Satoshi Furukawa; Koji Usuda; Masayoshi Abe; Seigo Hayashi; Izumi Ogawa

2007-01-01

76

Fractionation of wheat straw by atmospheric acetic acid process  

Microsoft Academic Search

Fractionation of wheat straw was investigated using an atmospheric acetic acid process. Under the typical conditions of 90% (v\\/v) aqueous AcOH, 4% H2SO4 (w\\/w, on straw), ratio of liquor to straw (L\\/S) 10 (v\\/w), pulping temperature 105°C, and pulping time 3h, wheat straw was fractionated to pulp (cellulose), lignin and monosaccharides mainly from hemicellulose with yields of approximately 50%, 15%

Xuejun Pan; Yoshihiro Sano

2005-01-01

77

75 FR 52269 - Acetic Acid Ethenyl Ester, Polymer With Oxirane; Tolerance Exemption  

Federal Register 2010, 2011, 2012, 2013

...FRL-8841-2] Acetic Acid Ethenyl Ester, Polymer With Oxirane; Tolerance Exemption AGENCY...residues of acetic acid ethenyl ester, polymer with oxirane; when used as an inert ingredient...residues of acetic acid ethenyl ester, polymer with oxirane on food or feed...

2010-08-25

78

Effects of acetic acid treatment on plant chromosome structures analyzed by atomic force microscopy  

Microsoft Academic Search

Acetic acid treatment has been frequently used to remove cellular contaminants from plant chromosome samples for structural analyses by scanning electron microscopy and atomic force microscopy (AFM). We evaluated the effects of various concentrations of acetic acid treatments on barley chromosome structures by using AFM. The long-term 45% acetic acid treatment significantly damaged the chromosome structures, although the treatment effectively

Shigeru Sugiyama; Tomoyuki Yoshino; Hiroko Kanahara; Motoharu Shichiri; Daisuke Fukushi; Toshio Ohtani

2004-01-01

79

Separation of acetic acid-water mixtures by pervaporation through silicalite membrane  

Microsoft Academic Search

Polycrystalline silicalite membranes were prepared on two kinds of porous supports by hydrothermal synthesis. The pervaporation performance of the silicalite membrane obtained was investigated using an acetic acid-water mixture as a feed. The silicalite membrane on the sintered stainless steel support selectively permeates acetic acid in the concentration of the feed acetic acid in the region of 5 to 40

Tsuneji Sano; Shigeyuki Ejiri; Kiyoshi Yamada; Yusuke Kawakami; Hiroshi Yanagishita

1997-01-01

80

Catalysis of the Carbonylation of Alcohols to Carboxylic Acids Including Acetic Acid Synthesis from Methanol.  

ERIC Educational Resources Information Center

Monsanto's highly successful synthesis of acetic acid from methanol and carbon monoxide illustrates use of new starting materials to replace pretroleum-derived ethylene. Outlines the fundamental aspects of the acetic acid process and suggests ways of extending the synthesis to higher carboxylic acids. (JN)

Forster, Denis; DeKleva, Thomas W.

1986-01-01

81

Catalysis of the Carbonylation of Alcohols to Carboxylic Acids Including Acetic Acid Synthesis from Methanol.  

ERIC Educational Resources Information Center

|Monsanto's highly successful synthesis of acetic acid from methanol and carbon monoxide illustrates use of new starting materials to replace pretroleum-derived ethylene. Outlines the fundamental aspects of the acetic acid process and suggests ways of extending the synthesis to higher carboxylic acids. (JN)|

Forster, Denis; DeKleva, Thomas W.

1986-01-01

82

Autotrophic synthesis of activated acetic acid from two CO 2 in Methanobacterium thermoautotrophicum  

Microsoft Academic Search

An in vitro system of autotropic synthesis of activated acetic acid from14CO2 inMethanobacterium thermoautotrophicum was developed.(1)A recognized14CO2-fixation product in vitro was activated [14C] acetic acid. It could be trapped enzymatically into citrate and released again as [14C] acetate by citrate synthase and citrate lyase, respectively.(2)The synthesis of both activated acetic acid and methane from CO2 proceeded in parallel under a

Erhard Stupperich; Georg Fuchs

1984-01-01

83

Direct Determination of Citric Acid in Milk with an Improved Pyridine-Acetic Anhydride Method  

Microsoft Academic Search

SUMMARY The determination of citric acid with pyridine and acetic anhydride has been in- vestigated at reaction temperatures from 17 to 60 ° C. The optimum proportions of pyridine, acetic anhydride, water, and acetic acid for maximum color intensity and stability are given for each temperature. The procedure has been modified to eliminate the violent nature of the reaction, even

J. R. Marier; M. Boulet

1958-01-01

84

Atmospheric Acetic Acid Pulping of Rice Straw II: Behavior of Ash and Silica in Rice Straw during Atmospheric Acetic Acid Pulping and Bleaching  

Microsoft Academic Search

Summary A detailed examination was made of the behavior and distribution of ash and silica during atmospheric acetic acid pulping and subsequent bleaching of rice straw. Ash-rich pulps (in unbleached pulp, about 18 %; and in bleached pulp, 16 %) with matchable strength properties for conventional alkaline pulps were obtained from rice straw by acetic acid pulping. More than 50

Xue-Jun Pan; Yoshihiro Sano; Toshiaki Ito

1999-01-01

85

Indole 3-acetic acid production by ectomycorrhizal fungi.  

PubMed

Ability of 8 ectomycorrhizal fungi to synthesise indole 3-acetic acid from L-tryptophan and their growth rate were studied. Differences in the levels of IAA synthesis and biomass production among the 8 mycorrhizal fungi were observed. A positive correlation was recorded between IAA level and mycelial growth. The synthesis of IAA and mycelial biomass were maximum on 30th day after incubation. Pisolithus tinctorius and Laccaria laccata exhibited higher amounts of IAA production than other fungi, whereas Amanita muscaria and Rhizopogon luteolus showed least quantity of IAA. PMID:1521864

Gopinathan, S; Raman, N

1992-02-01

86

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

87

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

88

Phase and reaction equilibria of the acetic acid-isopropanol-isopropyl acetate-water system at 760 mmHg  

Microsoft Academic Search

An energy-saving process, the so-called reactive distillation process, is attracting more and more attention in the chemical industry. This process is based on the simultaneous implementation of chemical reaction and phase equilibria in a process unit. The esterification of acetic acid and isopropyl alcohol is one of the processes that use this technology. In order to understand the thermodynamic behavior

Liang-sun Lee; Ming-zhong Kuo

1996-01-01

89

Oxidation of indole-3-acetic acid to oxindole-3-acetic acid by etiolated and green corn tissues  

SciTech Connect

Etiolated corn tissues oxidase indole-3-acetic acid (IAA) to oxindole-3-acetic acid (OxIAA). This oxidation results in loss of auxin activity and may plant a role in regulating IAA-stimulated growth. The enzyme has been partially purified and characterized and shown to require O{sub 2}, and a heat-stable lipid-soluble corn factor which can be replaced by linolenic or linoleic acids in the oxidation of IAA. Corn oil was tested as a cofactor in the IAA oxidation reaction. Corn oil stimulated enzyme activity by 30% while trilinolein was inactive. The capacity of green tissue to oxidize IAA was examined by incubating leaf sections from 2 week old light-grown corn seedlings with {sup 14}C-IAA. OxIAA and IAA were separated from other IAA metabolites on a 3 ml anion exchange column. Of the IAA taken up by the sections, 13% was oxidized to OxIAA. This is the first evidence that green tissue of corn may also regulate IAA levels by oxidizing IAA to OxIAA.

Reinecke, D. (Michigan State Univ., East Lansing (USA))

1989-04-01

90

Corrosion behavior of mild steel in acetic acid solutions  

SciTech Connect

The corrosion behavior of mild steel in acetic acid (CH{sub 3}COOH) solutions was studied by weight loss and potentiostatic polarization techniques. The variation in corrosion rate of mild steel with concentrations of CH{sub 3}COOH, evaluated by weight loss and electrochemical techniques, showed marked resemblance. From both techniques, the maximum corrosion rate was observed for 20% CH{sub 3}COOH solution at all three experimental temperatures (25, 35, and 45 C). Anodic polarization curves showed active-passive behavior at each concentration, except at 80% CH{sub 3}COOH. Critical current density (i{sub c}) passive current density (I{sub n}), primary passivation potential (E{sub pp}), and potential for passivity (E{sub p}) had their highest values in 20% CH{sub 3}COOH solution. With an increase in temperature, while the anodic polarization curves shifted toward higher current density region at each concentration, the passive region became progressively less distinguishable. With the addition of sodium acetate (NaCOOCH{sub 3}) as a supporting electrolyte, the passive range was enlarged substantially. However, the transpassive region commenced at more or less the same potential. Cathodic polarization curves were almost identical irrespective of the concentration of CH{sub 3}COOH or temperature.

Singh, M.M.; Gupta, A.

2000-04-01

91

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

92

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

93

Boswellic acid acetate induces apoptosis through caspase-mediated pathways in myeloid leukemia cells.  

PubMed

The mechanism of the cytotoxic effect of boswellic acid acetate, a 1:1 mixture of alpha-boswellic acid acetate and beta-boswellic acid acetate, isolated from Boswellia carterri Birdw on myeloid leukemia cells was investigated in six human myeloid leukemia cell lines (NB4, SKNO-1, K562, U937, ML-1, and HL-60 cells). Morphologic and DNA fragmentation assays indicated that the cytotoxic effect of boswellic acid acetate was mediated by induction of apoptosis. More than 50% of the cells underwent apoptosis after treatment with 20 mug/mL boswellic acid for 24 hours. This apoptotic process was p53 independent. The levels of apoptosis-related proteins Bcl-2, Bax, and Bcl-XL were not modulated by boswellic acid acetate. Boswellic acid acetate induced Bid cleavage and decreased mitochondrial membrane potential without production of hydrogen peroxide. A general caspase inhibitor (Z-VAD-FMK) and a specific caspase-8 inhibitor II (Z-IETD-FMK) blocked boswellic acid acetate-induced apoptosis. The mRNAs of death receptors 4 and 5 (DR4 and DR5) were induced in leukemia cells undergoing apoptosis after boswellic acid acetate treatment. These data taken together suggest that boswellic acid acetate induces myeloid leukemia cell apoptosis through activation of caspase-8 by induced expression of DR4 and DR5, and that the activated caspase-8 either directly activates caspase-3 by cleavage or indirectly by cleaving Bid, which in turn decreases mitochondria membrane potential. PMID:15767547

Xia, Lijuan; Chen, Duo; Han, Rui; Fang, Qicheng; Waxman, Samuel; Jing, Yongkui

2005-03-01

94

Acetate Binding of Spinach Chloroplasts as a Facet of Fatty Acid Synthesis  

PubMed Central

A particulate fraction of spinach chloroplasts is the major site of binding when either acetate or acetyl-CoA is used as substrate. The acetate is linked covalently, and the binding is inhibited by reagents which react with sulfhydryl groups. The amount of acetate bound is lowered by both citrate and oxaloacetate; however, the binding is not reversed by oxaloacetate. Reversal of binding is also not brought about by the addition of unlabeled acetyl-CoA. If cofactors for fatty acid synthesis and cold acetyl-CoA are added, the binding of labeled acetate is reversed. Acyl carrier protein from E. coli increases the binding of labeled acetate.

Devor, K. A.; Mudd, J. B.

1968-01-01

95

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

2007-12-05

96

Oxidation of acetate through reactions of the citric acid cycle by Geobacter sulfurreducens in pure culture and in syntrophic coculture  

Microsoft Academic Search

Geobacter sulfurreducens strain PCA oxidized acetate to CO2 via citric acid cycle reactions during growth with acetate plus fumarate in pure culture, and with acetate plus nitrate in coculture with Wolinella succinogenes. Acetate was activated by succinyl-CoA:acetate CoA-transferase and also via acetate kinase plus phosphotransacetylase. Citrate was formed by citrate synthase. Soluble isocitrate and malate dehydrogenases reduced NADP+ and NAD+,

Alexander S. Galushko; Bernhard Schink

2000-01-01

97

Genome-wide identification of Saccharomyces cerevisiae genes required for tolerance to acetic acid  

Microsoft Academic Search

BACKGROUND: Acetic acid is a byproduct of Saccharomyces cerevisiae alcoholic fermentation. Together with high concentrations of ethanol and other toxic metabolites, acetic acid may contribute to fermentation arrest and reduced ethanol productivity. This weak acid is also a present in lignocellulosic hydrolysates, a highly interesting non-feedstock substrate in industrial biotechnology. Therefore, the better understanding of the molecular mechanisms underlying S.

Nuno P Mira; Margarida Palma; Joana F Guerreiro; Isabel Sá-Correia

2010-01-01

98

21 CFR 184.1185 - Calcium acetate.  

Code of Federal Regulations, 2013 CFR

...also known as acetate of lime or vinegar salts, is the calcium salt of acetic acid. It may be produced by the calcium hydroxide neutralization of acetic acid. (b) The ingredient meets the specifications of the Food Chemicals...

2013-04-01

99

Effects of Acetic Acid on the Regrowth of Heterotrophic Bacteria in the Drinking Water Distribution System  

Microsoft Academic Search

Three laboratory-scale water pipe systems were set up to study the effects of adding two levels of acetic acid (10 and 50 ?g acetate eq-C l?1) on the bacterial regrowth in water pipes. The results of the water pipe test showed that nearly all carbon in the acetic acid could be readily utilized by bacteria and resulted in an increase

Chungsying Lu; Chenghwa Chu

2005-01-01

100

Development of Acetic Acid Removal Technology for the UREX+Process  

SciTech Connect

It is imperative that acetic acid is removed from a waste stream in the UREX+process so that nitric acid can be recycled and possible interference with downstreatm steps can be avoidec. Acetic acid arises from acetohydrozamic acid (AHA), and is used to suppress plutonium in the first step of the UREX+process. Later, it is hydrolyzed into hydroxyl amine nitrate and acetic acid. Many common separation technologies were examined, and solvent extraction was determined to be the best choice under process conditions. Solvents already used in the UREX+ process were then tested to determine if they would be sufficient for the removal of acetic acid. The tributyl phosphage (TBP)-dodecane diluent, used in both UREX and NPEX, was determined to be a solvent system that gave sufficient distribution coefficients for acetic acid in addition to a high separation factor from nitric acid.

Robert M. Counce; Jack S. Watson

2009-06-30

101

Effects of cinnamic acid derivatives on indole acetic acid oxidation by peroxidase  

Microsoft Academic Search

The influence of cinnamic acid derivatives on the H2O2-independent oxidation of indole acetic acid by horseradish peroxidase was examined. Cinnamic acid derivatives show a sharp increase from a slight stimulation of the oxidative reaction to a complete inhibition in a very narrow concentration range. This threshold effect occurs not only for the diphenols caffeic and dihydrocaffeic acids but also for

Regina Volpert; Wolfgang Osswald; Erich F. Elstner

1995-01-01

102

A novel fermentation pathway in an Escherichia coli mutant producing succinic acid, acetic acid, and ethanol.  

SciTech Connect

Escherichia coli strain NZN111, which is unable to grow fermentatively because of insertional inactivation of the genes encoding pyruvate: formate lyase and the fermentative lactate dehydrogenase, gave rise spontaneously to a chromosomal mutation that restored its ability to ferment glucose. The mutant strain, named AFP111, fermented glucose more slowly than did its wild-type ancestor, strain W1485, and generated a very different spectrum of products. AFP111 produced succinic acid, acetic acid, and ethanol in proportions of approx 2:1:1. Calculations of carbon and electron balances accounted fully for the observed products; 1 mol of glucose was converted to 1 mol of succinic acid and 0.5 mol each of acetic acid and ethanol. The data support the emergence in E.coli of a novel succinic acid:acetic acid:ethanol fermentation pathway.

Donnelly, M. I.; Millard, C. S.; Clark, D. P.; Chen, M. J.; Rathke, J. W.; Southern Illinois Univ.

1998-04-01

103

Kinetics of growth of Lactobacillus plantarum with glucose, organic acids (malate, citrate, acetate) and ethanol  

Microsoft Academic Search

L. plantarum was grown on glucose and organic acids, i.e. malate, citrate, and acetate, frequently jointly encountered in wine and cider fermentation. The effect on fermentation patterns of different mixtures of acids as well as ethanol was studied. Specific growth rates and apparent biomass yields on glucose increased when adding citrate or malate. Acetate and ethanol were not consummed by

Christian Kennes; María C. Veiga; Henry Naveau; Edmond J. Nyns

1995-01-01

104

Delignification of Bagasse with Acetic Acid and Ozone. II. Ozone Stage  

Microsoft Academic Search

Ozone gas was applied as second stage in delignification of bagasse pulp obtained with acetic acid. The kappa number was reduced from 44 to 10 with 3% ozone (based on dry pulp). Because bagasse was pulped with an aqueous solution of acetic acid (80% volume), selectivity of the ozone stage was favored and does not necessary acidulate pulp, which had

H. Contreras Q; Z. A. Nagieb; R. SanjuáN D

1997-01-01

105

Effects of acetic acid on the rice gelatinization and pasting properties of rice starch during cooking  

Microsoft Academic Search

The mechanism of the textural changes such as increase in stickiness of rice cooked with acetic acid was studied focusing on the gelatinization and rheological properties of both rice starch and rice flour. The results of swelling power and solubility of rice starch indicated that acetic acid promoted water absorption of amylopectin in rice starch. It was shown by DSC

Kyoko Ohishi; Midori Kasai; Atsuko Shimada; Keiko Hatae

2007-01-01

106

Microbiological preservation of cucumbers for bulk storage by the use of acetic acid and food preservatives  

Technology Transfer Automated Retrieval System (TEKTRAN)

Microbial growth did not occur when cucumbers were preserved without a thermal process by storage in solutions containing acetic acid, sodium benzoate, and calcium chloride to maintain tissue firmness. The concentrations of acetic acid and sodium benzoate required to assure preservation were low en...

107

Energetic and economic evaluation of the production of acetic acid via ethane oxidation  

Microsoft Academic Search

Acetic acid production via the selective oxidation of ethane was studied. The feed composition and mode of dilution was taken as a major parameter in reactor and process simulation. The concentration of water (as a component improving acetic acid selectivity) in the reaction feed was varied. Heat and mass balances were predicted. Finally, the ethane direct oxidation process was compared

Q. Smejkal; D. Linke; M. Baerns

2005-01-01

108

Indole-3-acetic acid improves Escherichia coli's defences to stress.  

PubMed

Indole-3-acetic acid (IAA) is a ubiquitous molecule playing regulatory roles in many living organisms. To elucidate the physiological changes induced by IAA treatment, we used Escherichia coli K-12 as a model system. By microarray analysis we found that 16 genes showed an altered expression level in IAA-treated cells. One-third of these genes encode cell envelope components, or proteins involved in bacterial adaptation to unfavourable environmental conditions. We thus investigated the effect of IAA treatment on some of the structural components of the envelope that may be involved in cellular response to stresses. This showed that IAA-treated cells had increased the production of trehalose, lipopolysaccharide (LPS), exopolysaccharide (EPS) and biofilm. We demonstrated further that IAA triggers an increased tolerance to several stress conditions (heat and cold shock, UV-irradiation, osmotic and acid shock and oxidative stress) and different toxic compounds (antibiotics, detergents and dyes) and this correlates with higher levels of the heat shock protein DnaK. We suggest that IAA triggers an increased level of alert and protection against external adverse conditions by coordinately enhancing different cellular defence systems. PMID:16555073

Bianco, C; Imperlini, E; Calogero, R; Senatore, B; Amoresano, A; Carpentieri, A; Pucci, P; Defez, R

2006-03-23

109

Genome-wide identification of Saccharomyces cerevisiae genes required for tolerance to acetic acid  

PubMed Central

Background Acetic acid is a byproduct of Saccharomyces cerevisiae alcoholic fermentation. Together with high concentrations of ethanol and other toxic metabolites, acetic acid may contribute to fermentation arrest and reduced ethanol productivity. This weak acid is also a present in lignocellulosic hydrolysates, a highly interesting non-feedstock substrate in industrial biotechnology. Therefore, the better understanding of the molecular mechanisms underlying S. cerevisiae tolerance to acetic acid is essential for the rational selection of optimal fermentation conditions and the engineering of more robust industrial strains to be used in processes in which yeast is explored as cell factory. Results The yeast genes conferring protection against acetic acid were identified in this study at a genome-wide scale, based on the screening of the EUROSCARF haploid mutant collection for susceptibility phenotypes to this weak acid (concentrations in the range 70-110 mM, at pH 4.5). Approximately 650 determinants of tolerance to acetic acid were identified. Clustering of these acetic acid-resistance genes based on their biological function indicated an enrichment of genes involved in transcription, internal pH homeostasis, carbohydrate metabolism, cell wall assembly, biogenesis of mitochondria, ribosome and vacuole, and in the sensing, signalling and uptake of various nutrients in particular iron, potassium, glucose and amino acids. A correlation between increased resistance to acetic acid and the level of potassium in the growth medium was found. The activation of the Snf1p signalling pathway, involved in yeast response to glucose starvation, is demonstrated to occur in response to acetic acid stress but no evidence was obtained supporting the acetic acid-induced inhibition of glucose uptake. Conclusions Approximately 490 of the 650 determinants of tolerance to acetic acid identified in this work are implicated, for the first time, in tolerance to this weak acid. These are novel candidate genes for genetic engineering to obtain more robust yeast strains against acetic acid toxicity. Among these genes there are number of transcription factors that are documented regulators of a large percentage of the genes found to exert protection against acetic acid thus being considered interesting targets for subsequent genetic engineering. The increase of potassium concentration in the growth medium was found to improve the expression of maximal tolerance to acetic acid, consistent with the idea that the adequate manipulation of nutrient concentration of industrial growth medium can be an interesting strategy to surpass the deleterious effects of this weak acid in yeast cells.

2010-01-01

110

Ozonation of trichloroethylene in acetic acid solution with soluble and solid humic acid  

Microsoft Academic Search

The combined flushing and oxidation process using acetic acid and ozone has been used successfully to remove trichloroethylene (TCE) completely from contaminated soil. In this study, the effects of humic acid, a fraction of the organic matter in soil, over the performance of TCE decomposition was evaluated. TCE decomposition by ozone was enhanced by the presence of humic acid at

Martha E. Alcántara-Garduño; Tetsuji Okuda; Wataru Nishijima; Mitsumasa Okada

2008-01-01

111

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.

Nakano, Shigeru; Fukaya, Masahiro; Horinouchi, Sueharu

2006-01-01

112

Production of Formic Acid and Acetic Acid by Hydrothermal Oxidation of Alkali Lignin  

NASA Astrophysics Data System (ADS)

The production of formic acid and acetic acid by hydrothermal oxidation of alkali lignin, a kind of biomasses, was investigated using a batch reactor with H2O2 oxidant. Experiments were performed over a wide range of conditions with temperature varying from 260 to 320° C, oxygen supply varying from 60% to 120%, and reaction time varying from 30 to 150 s. The highest yield of formic acid was 4.9% at 280° C for 120 s with the additive ratio of H2O2 100%. The highest value of acetic acid was 12.3% at 300° C for 120 s with the additive ratio of H2O2 100%. Based on the intermediate products identified by GC/MS and HPLC, reaction pathways of alkali lignin are discussed. It was found that maleic acid and fumaric acid were two primary unsaturated intermediate products. The production of formic acid and acetic acid were come from the oxidative decomposition of intermediate products in the oxidation process. Increasing the formation of saturated dicarboxylic acids and glutaconic acid would enhance the acetic acid yield.

Zeng, Xu; Jin, Fangming; Cao, Jianglin; Yin, Guodong; Zhang, Yalei; Zhao, Jianfu

2010-11-01

113

Metabolic regulation of the plant hormone indole-3-acetic acid  

SciTech Connect

The phytohormone indole-3-acetic acid (IAA, auxin) is important for many aspects of plant growth, development and responses to the environment yet the routes to is biosynthesis and mechanisms for regulation of IAA levels remain important research questions. A critical issue concerning the biosynthesis if IAA in plants is that redundant pathways for IAA biosynthesis exist in plants. We showed that these redundant pathways and their relative contribution to net IAA production are under both developmental and environmental control. We worked on three fundamental problems related to how plants get their IAA: 1) An in vitro biochemical approach was used to define the tryptophan dependent pathway to IAA using maize endosperm, where relatively large amounts of IAA are produced over a short developmental period. Both a stable isotope dilution and a protein MS approach were used to identify intermediates and enzymes in the reactions. 2) We developed an in vitro system for analysis of tryptophan-independent IAA biosynthesis in maize seedlings and we used a metabolite profiling approach to isolate intermediates in this reaction. 3) Arabidopsis contains a small family of genes that encode potential indolepyruvate decarboxylase enzymes. We cloned these genes and studied plants that are mutant in these genes and that over-express each member in the family in terms of the level and route of IAA biosynthesis. Together, these allowed further development of a comprehensive picture of the pathways and regulatory components that are involved in IAA homeostasis in higher plants.

Jerry D. Cohen

2009-11-01

114

Pervaporation of acetic acid\\/water mixtures through carbon molecular sieve-filled PDMS membranes  

Microsoft Academic Search

The pervaporation process for acetic\\/water has been investigated with carbon molecular sieve (CMS)-filled polydimethylsiloxane (PDMS) membranes. The effects of feed temperature, feed acetic acid concentration and CMS content on the performance of the membranes have been studied. It is found that the addition of CMS can improve pervaporation behavior of PDMS membranes to some extent and greatly increases the strength

Lei Li; Zeyi Xiao; Zhibing Zhang; Shujuan Tan

2004-01-01

115

Effect of Acetic Acid Supplementation on Egg Quality Characteristics of Commercial Laying Hens during Hot Season  

Microsoft Academic Search

This study was conducted to determine the effects of acetic acid supplement at four levels (control, 200, 400 and 600-ppm in drinking water) on egg production and quality in commercial Brown Leghorn reared birds during the hot season (32°C). One hundred and sixty 30 week-old laying birds were randomly divided into 4 groups and subjected to four levels of acetic

I. T. Kadim; W. Al-Marzooqi; O. Mahgoub; A. Al-Jabri; S. K. Al-Waheebi

2008-01-01

116

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

117

Kinetics and mechanism of acetic acid pulping of detannined Pinus pinaster bark  

Microsoft Academic Search

The observed kinetics of Pinus pinaster bark with acetic acid after alkali treatment, with or without intervening acid prehydrolysis, are satisfactorily explained by a model involving both solubilization and condensation reactions.

G. Vázquez; G. Antorrena; J. González

1994-01-01

118

40 CFR 721.10211 - Octadecanoic acid, reaction products with diethylenetriamine and urea, acetates.  

Code of Federal Regulations, 2013 CFR

...New Uses for Specific Chemical Substances § 721.10211 Octadecanoic acid, reaction products with diethylenetriamine...acetates. (a) Chemical substance and significant...reporting . (1) The chemical substance identified as octadecanoic acid, reaction products with...

2013-07-01

119

Isolation of cellulose from rice straw and its conversion into cellulose acetate catalyzed by phosphotungstic acid.  

PubMed

Cellulose was isolated from rice straw by pretreatment with dilute alkaline and acid solutions successively, and it was further transferred into cellulose acetate in the presence of acetic anhydride and phosphotungstic acid (H3PW12O40·6H2O). The removal of hemicellulose and lignin was affected by the concentration of KOH and the immersion time in acetic acid solution, and 83wt.% content of cellulose in the treated rice straw was obtained after pretreatment with 4% KOH and immersion in acetic acid for 5h. Phosphotungstic acid was found to be an effective catalyst for the acetylation of the cellulose derived from rice straw. The degree of substitution (DS) values revealed a significant effect for the solubility of cellulose acetate, and the acetone-soluble cellulose acetate with DS values around 2.2 can be obtained by changing the amount of phosphotungstic acid and the time of acetylation. Both the structure of cellulose separated from rice straw and cellulose acetate were confirmed by FTIR and XRD. PMID:23544511

Fan, Guozhi; Wang, Min; Liao, Chongjing; Fang, Tao; Li, Jianfen; Zhou, Ronghui

2013-02-01

120

Titanium (IV)Improved H2O2\\/O3 Process for Acetic Acid Degradation under Acid Conditions  

Microsoft Academic Search

The effect of Ti(IV) on the degradation efficiency of acetic acid by O3\\/H2O2 was investigated. The removal rate of acetic acid by O3\\/H2O2 increased from 8.0% to 62.9% after 30 min when Ti(IV) was added to acetic acid solution at pH 2.8. The optimized parameters were as follows: the pH of acetic acid solution less than 5.0; the mass concentration

Shao-Ping Tong; Wen-wen Li; Shu-qin Zhao; Chun-an Ma

2011-01-01

121

Delignification of Eucalyptus globulus saplings in two organosolv systems (formic and acetic acid)  

Microsoft Academic Search

Organosolv delignification of 2–3 years old Eucalyptus globulus with formic or acetic acid produced bleachable grade pulps with kappa number values of 20–35. Pulp yields for the acetic acid treatment (45–55%) were higher than for formic acid (32–46%) although also they showed the greater kappa number.Delignification was modelized by means of the accomplishment of respective factorial designs of experiments. Data

Pablo Ligero; Juan José Villaverde; Alberto de Vega; Manuel Bao

2008-01-01

122

RED Facts: Tridecenyl Acetates.  

National Technical Information Service (NTIS)

This fact sheet summarizes the information in the RED document for reregistration case 4116, tridecenyl acetates. Tridecenyl acetates are sex attractant pheromones used in tomato fields to disrupt the mating behavior of tomato pinworms.

1996-01-01

123

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

2013-03-01

124

Coordination of Lanthanide Acetates  

SciTech Connect

A study of the structures of hydrated and anhydrous lanthanide acetates by X-ray diffraction, infrared spectra, and absorption spectra demonstrates that there are three separate structures for hydrated lanthanide acetates and four structures for anhydrous acetates. This paper discusses the results of that study.

Karraker, D.G.

2001-08-29

125

Ozonation of trichloroethylene in acetic acid solution with soluble and solid humic acid.  

PubMed

The combined flushing and oxidation process using acetic acid and ozone has been used successfully to remove trichloroethylene (TCE) completely from contaminated soil. In this study, the effects of humic acid, a fraction of the organic matter in soil, over the performance of TCE decomposition was evaluated. TCE decomposition by ozone was enhanced by the presence of humic acid at concentrations lower than 8mgCL(-1) and then inhibited at higher concentrations. It is possible that the presence of the soluble humic acid fraction during the ozonation of TCE in acetic acid solutions produces hydroxyl radicals during the TCE ozonation which appears to be the reason for the enhanced TCE decomposition rate. Solid humic acid reduced TCE decomposition rate by acting as an ozone scavenger. Similarly, sorbed TCE reduced the amount of TCE available for decomposition by ozone in solution. PMID:18511186

Alcántara-Garduño, Martha E; Okuda, Tetsuji; Nishijima, Wataru; Okada, Mitsumasa

2008-03-30

126

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

127

Metabolic Regulation of the Plant Hormone Indole-3-Acetic Acid, (Final Report).  

National Technical Information Service (NTIS)

The phytohormone indole-3-acetic acid (IAA, auxin) is important for many aspects of plant growth, development and responses to the environment yet the routes to is biosynthesis and mechanisms for regulation of IAA levels remain important research question...

J. D. Cohen

2009-01-01

128

2-(1H-Pyrazol-4-yl)acetic acids as CRTh2 antagonists.  

PubMed

High throughput screening identified the pyrazole-4-acetic acid substructure as CRTh2 receptor antagonists. Optimisation of the compounds uncovered a tight SAR but also identified some low nanomolar inhibitors. PMID:23601708

Andrés, Miriam; Bravo, Mónica; Buil, Maria Antonia; Calbet, Marta; Castro, Jordi; Domènech, Teresa; Eichhorn, Peter; Ferrer, Manel; Gómez, Elena; Lehner, Martin D; Moreno, Imma; Roberts, Richard S; Sevilla, Sara

2013-04-02

129

Culture medium optimization for acetic acid production by a persimmon vinegar-derived bacterium.  

PubMed

A new acetic acid-producing microorganism, Acetobacter sp. RKY4, was isolated from Korean traditional persimmon vinegar, and we optimized the culture medium for acetic acid production from ethanol using the newly isolated Acetobacter sp. RKY4. The optimized culture medium for acetic acid production using this microorganism was found to be 40 g/L ethanol, 10 g/L glycerol, 10 g/L corn steep liquor, 0.5 g/L MgSO4.7H2O, and 1.0 g/L (NH4)H2PO4. Acetobacter sp. RKY4 produced 47.1 g/L of acetic acid after 48 h of fermentation in a 250 mL Erlenmeyer flask containing 50 mL of the optimized medium. PMID:15930565

Kim, Jin-Nam; Choo, Jong-Sok; Wee, Young-Jung; Yun, Jong-Sun; Ryu, Hwa-Won

2005-01-01

130

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?

2013-01-03

131

40 CFR 180.1258 - Acetic acid; exemption from the requirement of a tolerance.  

Code of Federal Regulations, 2013 CFR

...the requirement of a tolerance. (a) An exemption from the requirement of a tolerance is established for residues of the biochemical pesticide acetic acid when used as a preservative on post-harvest agricultural commodities intended for animal...

2013-07-01

132

Reaction engineering analysis of hydrogenotrophic production of acetic acid by Acetobacterium woodii.  

PubMed

Great interest has emerged in biological CO?-fixing processes in the context of current climate change discussions. One example for such a process is the hydrogenotrophic production of acetic acid by anaerobic microorganisms. Acetogenic microorganisms make use of carbon dioxide in the presence of hydrogen to produce acetic acid and biomass. In order to establish a process for the hydrogenotrophic production of acetic acid, the formation of acetate by Acetobacterium woodii was studied in a batch-operated stirred-tank bioreactor at different hydrogen partial pressures (pH?) in the gas phase. The volumetric productivity of the batch processes increased with increasing hydrogen partial pressure. A maximum of the volumetric productivity of 7.4 g(acetate)?L?¹?day?¹ was measured at a pH? of 1,700 mbar. At this pH(2) a final acetate concentration of 44 g L?¹ was measured after a process time of 11 days, if the pH was controlled at pH 7.0 (average cell density of 1.1 g L?¹ cell dry weight). The maximum cell specific actetate productivity was 6.9 g(acetate)?g(cdw)?¹?day?¹ under hydrogenotrophic conditions. PMID:20830677

Demler, Martin; Weuster-Botz, Dirk

2011-02-01

133

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

2013-02-19

134

Oxide-catalyzed conversion of acetic acid into acetone: an FTIR spectroscopic investigation  

Microsoft Academic Search

Adsorptive and catalytic interactions of gas phase acetic acid with surfaces of alumina, titania and ceria were observed by in situ Fourier-transform infrared (FTIR) spectroscopy on heating from room temperature up to 400°C. The results revealed that, on alumina the acid was irreversibly, non-dissociatively adsorbed in the form of hydrogen-bonded molecules, and dissociatively in the form of bidentate bound acetate

M. A. Hasan; M. I. Zaki; L. Pasupulety

2003-01-01

135

Investigation of acetic acid-catalyzed hydrothermal pretreatment on corn stover  

Microsoft Academic Search

Acetic acid (AA)-catalyzed liquid hot water (LHW) pretreatments on raw corn stover (RCS) were carried out at 195 °C at 15 min\\u000a with the acetic acid concentrations between 0 and 400 g\\/kg RCS. After pretreatment, the liquor fractions and water-insoluble\\u000a solids (WIS) were collected separately and tested in terms of the recoveries of glucan and xylan from both the liquor fractions\\u000a and the

Jian Xu; Mette Hedegaard Thomsen; Anne Belinda Thomsen

2010-01-01

136

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

137

Induction of endothelial cell apoptosis by the antivascular agent 5,6-dimethylxanthenone-4-acetic acid  

Microsoft Academic Search

5,6-Dimethylxanthenone-4-acetic acid, synthesised in this laboratory, reduces tumour blood flow, both in mice and in patients on Phase I trial. We used TUNEL (TdT-mediated dUTP nick end labelling) assays to investigate whether apoptosis induction was involved in its antivascular effect. 5,6-Dimethylxanthenone-4-acetic acid induced dose-dependent apoptosis in vitro in HECPP murine endothelial cells in the absence of up-regulation of mRNA for

L-M Ching; Z Cao; C Kieda; S Zwain; M B Jameson; B C Baguley

2002-01-01

138

Polycarboxylic acids containing acetal functions: calcium sequestering compounds based on oxidized carbohydrates  

Microsoft Academic Search

A number of polycarboxylic acids containing acetal functions have been prepared by a two-step oxidation of carbohydrates.\\u000a Their calcium sequestering behavior is compared with that of a series of model polycarboxylic acids. It is found that calcium\\u000a sequestration by oxidized carbohydrates is less than that by corresponding ether polycarboxylates, since (a) acetal oxygens\\u000a have a lower coordinating power than ether

M. S. Nieuwenhuizen; A. P. G. Kieboom; H. van Bekkum

1983-01-01

139

Corrosion resistance of 316L stainless steel in acetic acid by EIS and Mott-Schottky  

Microsoft Academic Search

The properties of the passivation film formed on 316L stainless steel were studied by Electrochemical Impedance Spectroscopy\\u000a (EIS), Mott-Schottky and Voltammetry measurements in high-temperature acetic acid. The results show that the passivation film\\u000a formed on 316L stainless steel is stable in 60% acetic acid solution from 25 °C to 85 °C. As temperature increased, the polarization\\u000a resistance decreased but the

Xuequn Cheng; Xiaogang Li; Lixia Yang; Cuiwei Du

2008-01-01

140

FeCl3\\/Acetic Acid-mediated Reverse Atom Transfer Radical Polymerization of Acrylonitrile  

Microsoft Academic Search

Reverse atom transfer radical polymerization (RATRP) has been successfully applied in the synthesis of polyacrylonitrile (PAN) with FeCl3\\/acetic acid as catalyst in the presence of conventional initiator azobisisobutyronitrile (AIBN) at 65°C in N,N-dimethylformamide (DMF). A FeCl3 to acetic acid ratio of 1:2 not only gave better control on polymer's molecular weight and its distribution, but also provided a rapid polymerization

Jing Ma; Hou Chen; Guangxi Zong; Chunhua Wang; Delong Liu

2010-01-01

141

Effect of acetic and tartaric acid upon the thermal decomposition of CaCO 3  

Microsoft Academic Search

In the present work the effect of acetic and tartaric acid upon the thermal decomposition of CaCO3 has been studied. Mixtures of CaC03 and 5, 10 and 20% acetic and tartaric acid have been prepared. These mixtures were heated at various temperatures in order to study the progress of calcium carbonate decomposition by loss on ignition measurements. Differential Scanning Calorimetric

V. Kasselouri; G. Dimopoulos; G. Parissakis

1995-01-01

142

Production of acetic acid by Dekkera\\/Brettanomyces yeasts under conditions of constant pH  

Microsoft Academic Search

Sixty yeast strains were previously screened for their ability to produce acetic acid, in shaken flask batch culture, from either glucose or ethanol. Seven of the strains belonging to the Brettanomyces and Dekkera genera, from the ARS Culture Collection, Peoria, IL, were further evaluated for acetic acid production in bioreactor batch culture at 28 °C, constant aeration (0.75 v\\/v\\/m) and

S. N. Freer; B. Dien; S. Matsuda

2003-01-01

143

Asaia lannaensis sp. nov., a new acetic acid bacterium in the Alphaproteobacteria.  

PubMed

Asaia lannaensis sp. nov. was described for two strains isolated from flowers of the spider lily collected in Chiang Mai, Thailand. The isolates produced acetic acid from ethanol on ethanol/calcium carbonate agar, differing from the type strains of Asaia bogorensis, Asaia siamensis, and Asaia krungthepensis, but did not grow in the presence of 0.35% acetic acid (v/v). The new species is the fourth of the genus Asaia, the family Acetobacteraceae. PMID:18323663

Malimas, Taweesak; Yukphan, Pattaraporn; Takahashi, Mai; Kaneyasu, Mika; Potacharoen, Wanchern; Tanasupawat, Somboon; Nakagawa, Yasuyoshi; Tanticharoen, Morakot; Yamada, Yuzo

2008-03-07

144

Use of titanium in the manufacture of equipment for acetic acid production  

Microsoft Academic Search

In the production of acetic acid from methanol and carbon monoxide with the use of iodine compounds as the catalyst,tantalu m, zirconium, Hastelloy type alloys, and molybdenumcontaining steels are used for the production of equipment. The production medium for the acid in the stage of synthesis and purification at I00-185~ contains up to 17% water, methyl acetate, methyl iodide, methanol,

L. M. Pischik; A. I. Tsinman; N. I. Bal'vas

1983-01-01

145

Pallidol hexa-acetate ethyl acetate monosolvate  

PubMed Central

The entire mol­ecule of pallidol hexa­acetate {systematic name: (±)-(4bR,5R,9bR,10R)-5,10-bis­[4-(acet­yloxy)phen­yl]-4b,5,9b,10-tetra­hydro­indeno­[2,1-a]indene-1,3,6,8-tetrayl tetra­acetate} is completed by the application of twofold rotational symmetry in the title ethyl acetate solvate, C40H34O12·C4H8O2. The ethyl acetate mol­ecule was highly disordered and was treated with the SQUEEZE routine [Spek (2009 ?). Acta Cryst. D65, 148–155]; the crystallographic data take into account the presence of the solvent. In pallidol hexa­acetate, the dihedral angle between the fused five-membered rings (r.m.s. deviation = 0.100?Å) is 54.73?(6)°, indicating a significant fold in the mol­ecule. Significant twists between residues are also evident as seen in the dihedral angle of 80.70?(5)° between the five-membered ring and the pendent benzene ring to which it is attached. Similarly, the acetate residues are twisted with respect to the benzene ring to which they are attached [C—O(carb­oxy)—C—C torsion angles = ?70.24?(14), ?114.43?(10) and ?72.54?(13)°]. In the crystal, a three-dimensional architecture is sustained by C—H?O inter­actions which encompass channels in which the disordered ethyl acetate mol­ecules reside.

Mao, Qinyong; Taylor, Dennis K.; Ng, Seik Weng; Tiekink, Edward R. T.

2013-01-01

146

Determination of halogenated acetic acids in chlorinated sea water and drinking water produced offshore  

Microsoft Academic Search

The formation of halogenated acetic acids in laboratory chlorinated sea water as well as chlorinated sea water and drinking water produced on an oil-installation offshore was investigated. Analyses were performed using solvent extraction and capillary gas chromatography with electron capture detection and mass spectrometry. Dichloroacetic acid, trichloroacetic acid, dibromoacetic acid and tribromoacetic acid were found in the water samples, with

Nina K. Kristiansen; Kjersti T. Aune; May Frøshaug; Georg Becher; Elsa Lundanes

1996-01-01

147

A laboratory study of the effect of acetic acid vapor on atmospheric copper corrosion  

SciTech Connect

A study was made of the copper corrosion rate and corrosion products originated by the action of acetic acid vapor at 100% relative humidity. Copper plates were exposed to an acetic acid contaminated atmosphere for a period of 21 days. Five acetic vapor concentration levels were used. The copper corrosion rate was in the range of 1 to 23 mg/dm{sup 2} day. The corrosion-product layers were characterized using electrochemical, X-ray powder diffraction, Fourier transform infrared spectrometry, and scanning electron microscopy techniques. Thermal and calorimetric studies were also performed. Some of the compounds identified were cuprite (Cu{sub 2}O), copper acetate hydrate [Cu(CH{sub 3}COO){sub 2}{center_dot}2H{sub 2}O], and copper hydroxide acetate [Cu{sub 4}(OH)(CH{sub 3}COO){sub 7}{center_dot}2H{sub 2}O]. This last compound was also characterized. The thickness of the patina layers was 4 to 8 nm for amorphous cuprite, 11 to 48 nm for cuprite, and 225 nm for copper acetate. The patina, in which the cementation process of different corrosion-product layers plays an important role, is formed by the reaction of acetic vapor with copper through porous cuprite paths.

Lopez-Delgado, A.; Cano, E.; Bastidas, J.M.; Lopez, F.A. [Centro Nacional de Investigaciones Metalurgicas, Madrid (Spain)

1998-12-01

148

Atmospheric Acetic Acid Pulping of Rice Straw IV: PhysicoChemical Characterization of Acetic Acid Lignins from Rice Straw and Woods. Part 1. Physical Characteristics  

Microsoft Academic Search

Summary Lignins obtained by atmospheric acetic acid delignification of rice straw, birch and fir were characterized by molecular weight, solubility and thermomechanical analysis, and by ultraviolet (UV), Fourier transform infra-red (FTIR) and 13 C-NMR spectroscopy. Rice straw lignins (rice lignins) were very different from birch and fir lignins. The former was difficult to dissolve in most tested solvents and infusible

Xue-Jun Pan; Yoshihiro Sano

1999-01-01

149

Atmospheric Acetic Acid Pulping of Rice Straw IV: PhysicoChemical Characterization of Acetic Acid Lignins from Rice Straw and Woods. Part 2. Chemical Structures  

Microsoft Academic Search

Summary Acetic acid lignins from rice straw (RLs), birch (BL) and fir (FL) were chemically characterized by means of elementary analysis, functional groups analysis, alkaline nitrobenzene and permanganate oxi- dation, Mannich reactivity and other techniques. The results showed that RLs had higher contents of residual polysaccharide and protein, and remarkably fewer acetyl groups than BL and FL. Results of nitrobenzene

Xue-Jun Pan; Yoshihiro Sano

1999-01-01

150

The Role of Acetate in Dialysate for Hemodialysis: Acid-Base Homeostasis and Acetate Metabolism in Patients Treated by Chronic Hemodialysis.  

National Technical Information Service (NTIS)

A sensitive and reproducible assay for acetate using gas chromatography has been used to investigate the rate of acetate metabolism in normal human subjects. Initially, it appeared that acetate metabolism could be predicted by a two compartment first orde...

M. W. Weiner

1977-01-01

151

Separation of inorganic anions and cations on titania by use of acetic acid-sodium acetate and bicine-sodium hydroxide buffers  

Microsoft Academic Search

Summary  The ion-exchange retention behavior of titania synthesized in our laboratory was investigated by ion chromatography of inorganic\\u000a anions and cations. Dilute acetic acid-sodium acetate and bicine-sodium hydroxide buffers were used as mobile phases with\\u000a no use of suppresor. We observed that the titania, although poor at separating monovalent anions expcept nitrite ion in this\\u000a experiment, was both an anion and

K. Tani; H. Kubojima

1998-01-01

152

Role of ascorbic acid in lead acetate induced lipid peroxidation and hemolysis in human RBC  

Microsoft Academic Search

Lipid peroxidation and hemolysis in humand red blood cells (RBCs) increased on their exposure to increasing concentrations\\u000a of lead acetate (0.01–1.0mM). However pretreatment of RBCs with ascorbic acid (2mM and 4mM) significantly reduced the effect\\u000a of lead acetate on lipid peroxidation and hemolysis in human RBCs.

G. L. Soni; A. K. Bansal; N. Malhotra

1992-01-01

153

Effect of Acetic Acid on Growth and Ethanol Fermentation of Xylose Fermenting Yeast and Saccharomyces cerevisiae  

Microsoft Academic Search

Growth of some xylose fermenting yeasts, Candida shehatae, Pichia stipitis CBS5773, fusant F101 and fusant F198, was completely inhibited in xylose medium added with 0.5% v\\/v acetic acid which caused the reduction of pH to 4.1. Only one xylose fermenting strain, Pachysolen tannophilus NRRL-Y2460, showed relatively low growth and ethanol fermentation. However, in the medium added with 1.0% v\\/v acetic

Savitree Limtong; Tawatchai Sumpradit; Vichien Kitpreechavanich; Manee Tuntirungkij; Tatsuji Seki; Toshiomi Yoshida

154

Radiofrequency Thermal Ablation: Increase in Lesion Diameter with Continuous Acetic Acid Infusion  

SciTech Connect

Purpose. To evaluate the influence of continuous infusion of acetic acid 50% during radiofrequency ablation (RFA) on the size of the thermal lesion produced. Methods. Radiofrequency (RF) was applied to excised bovine liver by using an expandable needle electrode with 10 retractable tines (LeVeen Needle Electrode, RadioTherapeutics, Sunnyvale, CA) connected to a commercially available RF generator (RF 2000, RadioTherapeutics, Sunnyvale, CA). Experiments were performed using three different treatment modalities: RF only (n = 15), RF with continuous saline 0.9% infusion (n = 15), and RF with continuous acetic acid 50% infusion (n = 15). RF duration, power output, tissue impedance, and time to a rapid rise in impedance were recorded. The ablated lesions were evaluated both macroscopically and histologically. Results. The ablated lesions appeared as spherical or ellipsoid, well-demarcated pale areas with a surrounding brown rim with both RF only and RF plus saline 0.9% infusion. In contrast, thermolesions generated with RF in combination with acetic acid 50% infusion were irregular in shape and the central portion was jelly-like. Mean diameter of the coagulation necrosis was 22.3 {+-} 2.1 mm (RF only), 29.2 {+-} 4.8 mm (RF + saline 0.9%) and 30.7 {+-} 5.7 mm (RF + acetic acid 50%), with a significant increase in the RF plus saline 0.9% and RF plus acetic acid 50% groups compared with RF alone. Time to a rapid rise in impedance was significantly prolonged in the RF plus saline 0.9% and RF plus acetic acid 50% groups compared with RF alone. Conclusions. A combination of RF plus acetic acid 50% infusion is able to generate larger thermolesions than RF only or RF combined with saline 0.9% infusion.

Lubienski, Andreas [Ruprecht-Karls-University Heidelberg, Department of Diagnostic Radiology (Germany)], E-mail: lubienski@radiologie.uni-luebeck.de; Duex, Markus [Hospital Northwest Frankfurt, Department of Radiology (Germany); Lubienski, Katrin; Grenacher, Lars; Kauffmann, Guenter [Ruprecht-Karls-University Heidelberg, Department of Diagnostic Radiology (Germany)

2005-12-15

155

27 CFR 21.107 - Ethyl acetate.  

Code of Federal Regulations, 2013 CFR

...107 Ethyl acetate. (a) 85 percent ester: (1) Acidity (as acetic acid). Not more than 0.015 percent by weight...and none above 80 °C. (b) 100 percent ester: (1) Acidity (as acetic acid). Not more than 0.010 percent by...

2013-04-01

156

Granulibacter bethesdensis gen. nov., sp. nov., a distinctive pathogenic acetic acid bacterium in the family Acetobacteraceae.  

PubMed

A Gram-negative, aerobic, coccobacillus to rod-shaped bacterium was isolated from three patients with chronic granulomatous disease. The organism was subjected to a polyphasic taxonomic study. A multilocus phylogenetic analysis based on the 16S rRNA gene, the internal transcribed spacer (ITS) region and the RecA protein demonstrated that the organism belongs to a new sublineage within the acetic acid bacteria in the family Acetobacteraceae. Phenotypic features are summarized as follows: the organism grew at an optimum temperature of 35-37 degrees C and optimum pH of 5.0-6.5. It produced a yellow pigment, oxidized lactate and acetate, the latter weakly, produced little acetic acid from ethanol and could use methanol as a sole carbon source. The two major fatty acids were a straight-chain unsaturated acid (C18:1omega7c) and C16:0. The DNA base composition was 59.1 mol% G+C. The very weak production of acetic acid from ethanol, the ability to use methanol, the yellow pigmentation and high optimum temperature for growth distinguished this organism from other acetic acid bacteria. The unique phylogenetic and phenotypic characteristics suggest that the bacterium should be classified within a separate genus, for which the name Granulibacter bethesdensis gen. nov., sp. nov. is proposed. The type strain is CGDNIH1T (=ATCC BAA-1260T=DSM 17861T). PMID:17082400

Greenberg, David E; Porcella, Stephen F; Stock, Frida; Wong, Alexandra; Conville, Patricia S; Murray, Patrick R; Holland, Steven M; Zelazny, Adrian M

2006-11-01

157

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

Microsoft Academic Search

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 6 -C 34 ), saturated normal , -dicarboxylic acids (C 4 -C

A. O. Barakat; T. F. Yen

1988-01-01

158

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

Microsoft Academic Search

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

Klaus Grossmann; Cindy Rosenthal; Jacek Kwiatkowski

2004-01-01

159

Diffusion and Sorption of Organic Liquids Through Polymer Membranes. VII. Elastomers Versus Acetic Acid and Dichloroacetic Acid  

Microsoft Academic Search

Diffusion coefficients of five elastomer membranes, viz., nitrile butadiene rubber, styrene–butadiene rubber, ethylene–propylene–diene terpolymer, neoprene, and natural rubber with acetic acid and dichloroacetic acids have been obtained from gravimetric sorption experiments. For acetic acid, the diffusion seems to follow the expected Fickian mechanism whereas for dichloroacetic acid, the diffusion appears to follow the non-Fickian mechanism for natural rubber and nitrile

T. M. Aminabhavi; R. S. Khinnavar; R. H. Balundgi

1994-01-01

160

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

2012-12-24

161

Acetic Acid Detection Threshold in Synthetic Wine Samples of a Portable Electronic Nose  

PubMed Central

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.

Macias, Miguel Macias; Manso, Antonio Garcia; Orellana, Carlos Javier Garcia; Velasco, Horacio Manuel Gonzalez; Caballero, Ramon Gallardo; Chamizo, Juan Carlos Peguero

2013-01-01

162

Asaia bogorensis gen. nov., sp. nov., an unusual acetic acid bacterium in the alpha-Proteobacteria.  

PubMed

Eight Gram-negative, aerobic, rod-shaped and peritrichously flagellated strains were isolated from flowers of the orchid tree (Bauhinia purpurea) and of plumbago (Plumbago auriculata), and from fermented glutinous rice, all collected in Indonesia. The enrichment culture approach for acetic acid bacteria was employed, involving use of sorbitol medium at pH 3.5. All isolates grew well at pH 3.0 and 30 degrees C. They did not oxidize ethanol to acetic acid except for one strain that oxidized ethanol weakly, and 0.35% acetic acid inhibited their growth completely. However, they oxidized acetate and lactate to carbon dioxide and water. The isolates grew well on mannitol agar and on glutamate agar, and assimilated ammonium sulfate for growth on vitamin-free glucose medium. The isolates produced acid from D-glucose, D-fructose, L-sorbose, dulcitol and glycerol. The quinone system was Q-10. DNA base composition ranged from 59.3 to 61.0 mol% G + C. Studies of DNA relatedness showed that the isolates constitute a single species. Phylogenetic analysis based on their 16S rRNA gene sequences indicated that the isolates are located in the acetic acid bacteria lineage, but distant from the genera Acetobacter, Gluconobacter, Acidomonas and Gluconacetobacter. On the basis of the above characteristics, the name Asaia bogorensis gen. nov., sp. nov. is proposed for these isolates. The type strain is isolate 71T (= NRIC 0311T = JCM 10569T). PMID:10758893

Yamada, Y; Katsura, K; Kawasaki, H; Widyastuti, Y; Saono, S; Seki, T; Uchimura, T; Komagata, K

2000-03-01

163

Brettanomyces bruxellensis: effect of oxygen on growth and acetic acid production.  

PubMed

The influence of the oxygen supply on the growth, acetic acid and ethanol production by Brettanomyces bruxellensis in a glucose medium was investigated with different air flow rates in the range 0-300 l h(-1 ) x (0-0.5 vvm). This study shows that growth of this yeast is stimulated by moderate aeration. The optimal oxygen supply for cellular synthesis was an oxygen transfer rate (OTR) of 43 mg O(2) l(-1) x h(-1). In this case, there was an air flow rate of 60 l h(-1) (0.1 vvm). Above this value, the maximum biomass concentration decreased. Ethanol and acetic acid production was also dependent on the level of aeration: the higher the oxygen supply, the greater the acetic acid production and the lower the ethanol production. At the highest aeration rates, we observed a strong inhibition of the ethanol yield. Over 180 l h(-1) x (0.3 vvm, OTR =105 mg O(2) l(-1) x h(-1)), glucose consumption was inhibited and a high concentration of acetic acid (6.0 g x l(-1)) was produced. The ratio of "ethanol + acetic acid" produced per mole of consumed glucose using carbon balance calculations was analyzed. It was shown that this ratio remained constant in all cases. This makes it possible to establish a stoichiometric equation between oxygen supply and metabolite production. PMID:12655458

Aguilar Uscanga, M G; Délia, M-L; Strehaiano, P

2003-01-14

164

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

165

Ethenzamide-gentisic acid-acetic acid (2/1/1)  

PubMed Central

In the title co-crystal solvate, 2-ethoxy­benzamide–2,5-dihydroxy­benzoic acid–ethanoic acid (2/1/1), 2C9H11NO2·C7H6O4·C2H4O2, two nonsteroidal anti-inflammatory drugs, ethenzamide (systematic name: 2-ethoxy­benzamide) and gentisic acid (systematic name: 2,5-dihydroxy­benzoic acid), together with acetic acid (systematic name: ethanoic acid) form a four-component mol­ecular assembly held together by N—H?O and O—H?O hydrogen bonds. This assembly features two symmetry-independent mol­ecules of ethenzamide, forming supra­molecular acid–amide heterosynthons with gentisic acid and acetic acid. These heterosynthons involve quite strong O—H?O [O?O = 2.5446?(15) and 2.5327?(15)?Å] and less strong N—H?O [N?O = 2.9550?(17) and 2.9542?(17)?Å] hydrogen bonds. The overall crystal packing features several C—H?O and ?–? stacking inter­actions [centroid–centroid distance = 3.7792?(11)?Å].

Aitipamula, Srinivasulu; Chow, Pui Shan; Tan, Reginald B.H.

2010-01-01

166

Ethenzamide-gentisic acid-acetic acid (2/1/1).  

PubMed

In the title co-crystal solvate, 2-ethoxy-benzamide-2,5-dihydroxy-benzoic acid-ethanoic acid (2/1/1), 2C(9)H(11)NO(2)·C(7)H(6)O(4)·C(2)H(4)O(2), two nonsteroidal anti-inflammatory drugs, ethenzamide (systematic name: 2-ethoxy-benzamide) and gentisic acid (systematic name: 2,5-dihydroxy-benzoic acid), together with acetic acid (systematic name: ethanoic acid) form a four-component mol-ecular assembly held together by N-H?O and O-H?O hydrogen bonds. This assembly features two symmetry-independent mol-ecules of ethenzamide, forming supra-molecular acid-amide heterosynthons with gentisic acid and acetic acid. These heterosynthons involve quite strong O-H?O [O?O = 2.5446?(15) and 2.5327?(15)?Å] and less strong N-H?O [N?O = 2.9550?(17) and 2.9542?(17)?Å] hydrogen bonds. The overall crystal packing features several C-H?O and ?-? stacking inter-actions [centroid-centroid distance = 3.7792?(11)?Å]. PMID:21579106

Aitipamula, Srinivasulu; Chow, Pui Shan; Tan, Reginald B H

2010-04-10

167

Modeling of yeast Brettanomyces bruxellensis growth at different acetic acid concentrations under aerobic and anaerobic conditions.  

PubMed

Glucose utilization by Brettanomyces bruxellensis at different acetic acid concentrations under aerobic and anaerobic conditions was investigated. The presence of the organic acid disturbs the growth and fermentative activity of the yeast when its concentration exceeds 2 g l(-1). A mathematical model is proposed for the kinetic behavior analysis of yeast growing in batch culture. A Matlab algorithm was used for estimation of model parameters, whose confidence intervals were also calculated at a 0.95 probability level using a t-Student distribution for f degrees of freedom. The model successfully simulated the batch kinetics observed at different concentrations of acetic acid under both oxygen conditions. PMID:17622565

Yahara, Garcia Alvarado; Javier, Mendez Ancona; Tulio, Mata Jimenez Marco; Javier, Gómez Rodriguez; Guadalupe, Aguilar Uscanga Maria

2007-07-11

168

Acetic acid production from fructose by clostridium formicoaceticum immobilized in a fibrous-Bed bioreactor  

PubMed

The fermentation kinetics of acetic acid production from fructose by Clostridium formicoaceticum was studied at pH 7.6 and 37 degreesC. Recycle batch, fed-batch, and continuous fermentations using immobilized cells in a fibrous-bed bioreactor were studied for their potential application in producing acetic acid from fructose, a fermentable sugar commonly found in corn steep liquor and many other food processing wastes. For the immobilized cell fermentation, acetic acid yield from fructose was approximately 1.0 g/g, with a final acetate concentration of approximately 78 g/L and the overall reactor productivity (based on the fibrous bed bioreactor volume) of approximately 0.95 g/(L.h) in the fed-batch fermentation. For a similar fed-batch fermentation with free cells, acetic acid yield was approximately 0.9 g/g, the highest final acetate concentration was approximately 46 g/L, and the overall productivity was approximately 0.12 g/(L.h). In the continuous fermentation with immobilized cells, the reactor productivity decreased from 3.2 to 1. 3 g/(L.h) as retention time increased from 16 to 72 h to reach 100% conversion. Compared to free-cell fermentations, the superior performance of the fibrous-bed bioreactor can be attributed to the high density (>30 g/L) of viable cells immobilized in the fibrous bed. The fermentation product, acetic acid, was found to be a noncompetitive inhibitor to the cells. However, the immobilized cells had a higher maximum production rate (pmax) and a higher value for the inhibition rate constant (Kp) than those for the free cells, suggesting that the immobilized cells in the fibrous-bed bioreactor were less sensitive to acetic acid inhibition than the free cells. This improvement in kinetic behaviors for immobilized cells confirms that the fibrous-bed bioreactor can be used as an effective tool for adapting and screening for acetate-tolerant strains. PMID:9758672

Huang; Mann; Novak; Yang

1998-09-01

169

Effect of acetic acid fumigation on soil-borne fungi and cucumber root rot disease under greenhouse conditions  

Microsoft Academic Search

The effect of acetic acid vapour on soil-borne fungi and root rot disease of cucumber plants under greenhouse conditions was studied. Acetic acid vapour at four concentrations was tested against linear growth and spore germination of some soil-borne fungi, in vitro. The most sensitive fungus to acetic acid vapours was Rhizoctonia solani which inhibited at 4 µl l, while Fusarium solani,

Farid Abd-El-Kareem

2009-01-01

170

[Continuous irrigation of the bladder with acetic acid solution and its therapeutic effect on candida-infection].  

PubMed

Our clinical experience with acetic acid solution in the treatment of candida infection of the bladder was confirmed by in vitro experiments. We apply continuous bladder irrigation with increasing concentrations of acetic acid solution up to pH 5.0. The majority of patients had received antibiotics or cytostatic drugs and suffered from chronic and malignant diseases. A case report is given with endoscopic documentation of the influence of acetic acid solution on the bladder. PMID:234644

Böcker, R; Fröhlich, G

1975-01-01

171

Changes in indole-3-acetic acid, indole-3-acetic acid oxidase, and peroxidase isoenzymes in the seeds of developing peach fruits  

Microsoft Academic Search

Changes in indole-3-acetic acid (IAA) content of peach (Prunus persica L. Batsch cv. Merry) seeds were followed during fruit development. The highest concentration of IAA, 2.7 ?g\\/g fresh weight,\\u000a was found at the beginning of Stage III of fruit development, approximately 50–60 days after anthesis. The IAA-decarboxylating\\u000a capacity of crude extracts of seeds was also greatest at 55–60 days after

Victoriano Valpuesta; Miguel A. Quesada; Cristina Sánchez-Roldán; Horacio A. Tigier; Antonio Heredia; Martin J. Bukovac

1989-01-01

172

In vivo characterization of horseradish peroxidase with indole-3-acetic acid and 5-bromoindole-3-acetic acid for gene therapy of cancer  

Microsoft Academic Search

Gene-directed enzyme prodrug therapy is a form of targeted cancer therapy, in which an enzyme is used to convert a non-toxic prodrug to a cytotoxin within the tumor. Horseradish peroxidase (HRP) is able to convert the indole prodrugs indole-3-acetic acid (IAA) and the halogenated derivative 5-bromo-IAA (5Br-IAA) to toxic agents able to induce cell kill in vitro. This study characterized

J Tupper; M R Stratford; S Hill; G M Tozer; G U Dachs

2010-01-01

173

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.

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

2002-01-01

174

Main and interaction effects of acetic acid, furfural, and p-hydroxybenzoic acid on growth and ethanol productivity of yeasts  

Microsoft Academic Search

The influence of the factors acetic acid, furfural, and p-hydroxybenzoic acid on the ethanol yield (Y{sub EtOH}) of Saccharomyces cerevisiae, bakers` yeast, S. cerevisiae ATCC 96581, and Candida shehatae NJ 23 was investigated using a 2³-full factorial design with 3 centerpoints. The results indicated that acetic acid inhibited the fermentation by C. shehatae NJ 23 markedly more than by bakers`

Eva Palmqvist; Halfdan Grage; Nina Q. Meinander; B. Hahn-Haegerdal

1999-01-01

175

Improving cyclodextrin complexation of a new antihepatitis drug with glacial acetic acid.  

PubMed

The purpose of this study was to develop and evaluate a solid nonaqueous oral dosage form for a new hepatitis C drug, PG301029, which is insoluble and unstable in water. Hydroxypropyl-beta-cyclodextrin (HPbetaCD) and PG301029 were dissolved in glacial acetic acid. The acetic acid was removed by rotoevaporation such that the drug exists primarily in the complexed form. The stability of formulated PG301029 was determined upon dry storage and after reconstitution in simulated intestinal fluid (SIF), simulated gastric fluid (SGF), and water. Formulated PG301029 was found to be stable upon storage and can be reconstituted with water to a concentration 200 times that of the intrinsic solubility. Once reconstituted, the powder dissolves rapidly and PG301029 remains stable for 21 hours in SGF, SIF, and water. The unique use of acetic acid and HPbetaCD results in a solid dosage form of PG301029 that is both soluble and stable in water. PMID:16584148

Johnson, Jennifer L H; He, Yan; Jain, Akash; Yalkowsky, Samuel H

2006-02-24

176

Acetic acid opens large-conductance Ca2+-activated K+ channels in guinea pig detrusor smooth muscle cells.  

PubMed

Acetic acid was found to have actions on urinary bladder smooth muscle in our routine ion channel screening assays. Numerous studies have examined the mechanisms of bladder irritation by acetic acid; however, the direct effect of acetic acid on ion channels in detrusor smooth muscle cells has not been evaluated. We used whole-cell patch-clamp techniques to examine the effect of acetic acid on large-conductance Ca2+-activated K+ channels (BKCa) from guinea pig detrusor smooth muscle cells and CHO cells expressing recombinant human BKCaalphabeta1 (CHO BKCaalphabeta1) and human BKCaalpha (CHO BKCaalpha). Acetic acid activated BKCa currents in a concentration-dependent (0.01% to 0.05% v/v) manner in all the cell systems studied. Acetic acid (0.05%) increased BKCa current at +30 mV by 2764+/-918% (n=8) in guinea pig detrusor smooth muscle cells. Acetic acid (0.03%) shifted the V1/2 of conductance-voltage curve by 64+/-14 (n=5), 128+/-14 (n=5), and 126+/-12 mV (n=4) in CHO BKCaalpha, CHO BKCaalphabeta1 and detrusor smooth muscle cells, respectively. This effect of acetic acid was found to be independent of pH and was also not produced by its salt form, sodium acetate. Automated patch-clamp experiments also showed similar activation of CHO BKCaalphabeta1 by acetic acid. In conclusion, acetic acid directly activates BKCa channels in detrusor smooth muscle cells. This novel study necessitates caution while interpreting the results from acetic acid bladder irritation model. PMID:17382925

Ghatta, Srinivas; Lozinskaya, Irina; Lin, Zuojun; Gordon, Earl; Willette, Robert N; Brooks, David P; Xu, Xiaoping

2007-02-27

177

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

178

Hydrogen production by catalytic steam reforming of acetic acid, a model compound of biomass pyrolysis liquids  

Microsoft Academic Search

An environmentally friendly and cost-competitive way of producing hydrogen is the catalytic steam reforming of biomass pyrolysis liquids, known as bio-oil, which can be separated into two fractions: ligninic and aqueous. Acetic acid has been identified as one of the major organic acids present in the latter, and catalytic steam reforming has been studied for this model compound. Three different

F. Bimbela; M. Oliva; J. Ruiz; L. García; J. Arauzo

2007-01-01

179

Induction of endothelial cell apoptosis by the antivascular agent 5,6-dimethylxanthenone-4-acetic acid  

PubMed Central

5,6-Dimethylxanthenone-4-acetic acid, synthesised in this laboratory, reduces tumour blood flow, both in mice and in patients on Phase I trial. We used TUNEL (TdT-mediated dUTP nick end labelling) assays to investigate whether apoptosis induction was involved in its antivascular effect. 5,6-Dimethylxanthenone-4-acetic acid induced dose-dependent apoptosis in vitro in HECPP murine endothelial cells in the absence of up-regulation of mRNA for tumour necrosis factor. Selective apoptosis of endothelial cells was detected in vivo in sections of Colon 38 tumours in mice within 30?min of administration of 5,6-Dimethylxanthenone-4-acetic acid (25?mg?kg?1). TUNEL staining intensified with time and after 3?h, necrosis of adjacent tumour tissue was observed. Apoptosis of central vessels in splenic white pulp was also detected in tumour-bearing mice but not in mice without tumours. Apoptosis was not observed in liver tissue. No apoptosis was observed with the inactive analogue 8-methylxanthenone-4-acetic acid. Positive TUNEL staining of tumour vascular endothelium was evident in one patient in a Phase I clinical trial, from a breast tumour biopsy taken 3 and 24?h after infusion of 5,6-Dimethylxanthenone-4-acetic acid (3.1?mg?m?2). Tumour necrosis and the production of tumour tumour necrosis factor were not observed. No apoptotic staining was seen in tumour biopsies taken from two other patients (doses of 3.7 and 4.9?mg?m?2). We conclude that 5,6-Dimethylxanthenone-4-acetic acid can induce vascular endothelial cell apoptosis in some murine and human tumours. The action is rapid and appears to be independent of tumour necrosis factor induction. British Journal of Cancer (2002) 86, 1937–1942. doi:10.1038/sj.bjc.6600368 www.bjcancer.com © 2002 Cancer Research UK

Ching, L-M; Cao, Z; Kieda, C; Zwain, S; Jameson, M B; Baguley, B C

2002-01-01

180

Alcohol dehydrogenase of acetic acid bacteria: structure, mode of action, and applications in biotechnology  

Microsoft Academic Search

Pyrroquinoline quinone-dependent alcohol dehydrogenase (PQQ-ADH) of acetic acid bacteria is a membrane-bound enzyme involved\\u000a in the acetic acid fermentation by oxidizing ethanol to acetaldehyde coupling with reduction of membranous ubiquinone (Q),\\u000a which is, in turn, re-oxidized by ubiquinol oxidase, reducing oxygen to water. PQQ-ADHs seem to have co-evolved with the organisms\\u000a fitting to their own habitats. The enzyme consists of

Toshiharu Yakushi; Kazunobu Matsushita

2010-01-01

181

Solubility of sulfur dioxide in aqueous solutions of acetic acid, sodium acetate, and ammonium acetate in the temperature range from 313 to 393 K at pressures up to 3.3 MPa: Experimental results and comparison with correlations/predictions  

SciTech Connect

In many chemical plants, for example in coal gasification processes or desulfurization equipment, sour gas absorption columns and sour water strippers are used to remove weak electrolyte gases like sulfur dioxide, hydrogen cyanide, hydrogen sulfide or carbon dioxide from aqueous solutions. The basic design of such equipment requires physico-chemical models to describe the phase equilibrium as well as the caloric properties of such mixtures. New experimental results for the solubility of sulfur dioxide in aqueous solutions of single solutes acetic acid, sodium acetate and ammonium acetate at temperatures from 313 to 393 K and total pressures up to 3.3 MPa are reported. Similar to the system sulfur dioxide-water, also in such systems with acetic acid and sodium or ammonium acetate a second (sulfur dioxide rich) liquid phase is observed at high sulfur dioxide concentrations. A model to describe the phase equilibrium is presented and calculated (i.e., predicted as well as correlated) phase equilibria are compared to the new experimental data.

Xia, J.; Rumpf, B.; Maurer, G. [Univ. Kaiserslautern (Germany). Lehrstuhl fuer Technische Thermodynamik

1999-03-01

182

Application of molecular methods to demonstrate species and strain evolution of acetic acid bacteria population during wine production  

Microsoft Academic Search

The growth of acetic acid bacteria on grapes or throughout the winemaking process influences the quality of wine, mainly because it increases the volatile acidity. The objective of this study was to analyse how the acetic acid bacteria population evolves in the changing environment of the grape surface and during wine fermentation. We have analysed the influence of yeast inoculation

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

2005-01-01

183

Formation of formic acid, acetic acid and lactic acid from decomposition of citric acid by coal ash particles at room temperature  

Microsoft Academic Search

It was found for the first time that citric acid was decomposed to formic acid, acetic acid and lactic acid in the presence of coal ash particles at pH 3 at 20°C, while it was not decomposed at more than pH 5. The yield of organic acid at stirring time of 60min is in the order of formic acid>acetic acid>lactic

Hiroyuki Nakui; Kenji Okitsu; Yasuaki Maeda; Rokuro Nishimura

2009-01-01

184

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

Microsoft Academic Search

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 (Câ-Cââ), saturated normal, ..cap alpha..,omega-dicarboxylic acids (Câ-Cââ), and isoprenoid acids (Cââ-Cââ, except Cââ).

A. O. Barakat; T. F. Yen

1988-01-01

185

The use of DRIFTS-MS and kinetic studies to determine the role of acetic acid in the palladium-catalyzed vapor-phase synthesis of vinyl acetate  

SciTech Connect

Supported palladium catalyzes the synthesis of vinyl acetate (VA) by oxyacetylation of ethylene. Alkali promoters increase activity and selectivity. The role of acetic acid (HOAc) in these processes is not well understood. Activation energy studies show that HOAc alters the catalyst site and lowers the reaction barrier to VA formation. After correction for this effect, the kinetics reveal that as a reagent HOAc is zero order. This is probably due to a strong adsorption of HOAc and Pd which forms the catalyst active phase. Detailed spectroscopic studies support this conclusion. The surface processes on a supported vinyl acetate catalyst were studied using a method which couples diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) with mass spectrometry (MS). The DRIFTS-MS technique combines the capability of selectively analyzing IR-active surface species with sensitive detection of transient reaction products. By comparing the catalyst with mixtures of palladium acetate powder physically dispersed in potassium chloride, it is determined that the active phase on the catalyst is a form of palladium acetate. Compound formation is consistent with the strong chemisorption of HOAc on Pd. Kinetic analysis of temperature-programmed reaction(TPRxn) data suggests that Pd metal or metal oxide adjacent to the active site is important in the reaction mechanism. 25 refs., 10 figs., 2 tabs.

Augustine, S.M.; Blitz, J.P. (Quantum Chemical Corp., Cincinnati, OH (United States))

1993-07-01

186

Acetate Induced Enhancement of Photocatalytic Hydrogen Peroxide Production from Oxalic Acid and Dioxygen.  

PubMed

The addition of acetate ion to an O2-saturated mixed solution of acetonitrile and water containing oxalic acid as a reductant and 2-phenyl-4-(1-naphthyl)quinolinium ion (QuPh(+)-NA) as a photocatalyst dramatically enhanced the turnover number of hydrogen peroxide (H2O2) production. In this photocatalytic H2O2 production, a base is required to facilitate deprotonation of oxalic acid forming oxalate dianion, which acts as an actual electron donor, whereas a Brønsted acid is also necessary to protonate O2(•-) for production of H2O2 by disproportionation. The addition of acetate ion to a reaction solution facilitates both the deprotonation of oxalic acid and the protonation of O2(•-) owing to a pH buffer effect. The quantum yield of the photocatalytic H2O2 production under photoirradiation (? = 334 nm) of an O2-saturated acetonitrile-water mixed solution containing acetate ion, oxalic acid and QuPh(+)-NA was determined to be as high as 0.34, which is more than double the quantum yield obtained by using oxalate salt as an electron donor without acetate ion (0.14). In addition, the turnover number of QuPh(+)-NA reached more than 340. The reaction mechanism and the effect of solvent composition on the photocatalytic H2O2 production were scrutinized by using nanosecond laser flash photolysis. PMID:23631436

Yamada, Yusuke; Nomura, Akifumi; Miyahigashi, Takamitsu; Ohkubo, Kei; Fukuzumi, Shunichi

2013-04-30

187

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

188

Lipidomic Profiling of Saccharomyces cerevisiae and Zygosaccharomyces bailii Reveals Critical Changes in Lipid Composition in Response to Acetic Acid Stress  

PubMed Central

When using microorganisms as cell factories in the production of bio-based fuels or chemicals from lignocellulosic hydrolysate, inhibitory concentrations of acetic acid, released from the biomass, reduce the production rate. The undissociated form of acetic acid enters the cell by passive diffusion across the lipid bilayer, mediating toxic effects inside the cell. In order to elucidate a possible link between lipid composition and acetic acid stress, the present study presents detailed lipidomic profiling of the major lipid species found in the plasma membrane, including glycerophospholipids, sphingolipids and sterols, in Saccharomyces cerevisiae (CEN.PK 113_7D) and Zygosaccharomyces bailii (CBS7555) cultured with acetic acid. Detailed physiological characterization of the response of the two yeasts to acetic acid has also been performed in aerobic batch cultivations using bioreactors. Physiological characterization revealed, as expected, that Z. bailii is more tolerant to acetic acid than S. cerevisiae. Z. bailii grew at acetic acid concentrations above 24 g L?1, while limited growth of S. cerevisiae was observed after 11 h when cultured with only 12 g L?1 acetic acid. Detailed lipidomic profiling using electrospray ionization, multiple-reaction-monitoring mass spectrometry (ESI-MRM-MS) showed remarkable changes in the glycerophospholipid composition of Z. bailii, including an increase in saturated glycerophospholipids and considerable increases in complex sphingolipids in both S. cerevisiae (IPC 6.2×, MIPC 9.1×, M(IP)2C 2.2×) and Z. bailii (IPC 4.9×, MIPC 2.7×, M(IP)2C 2.7×), when cultured with acetic acid. In addition, the basal level of complex sphingolipids was significantly higher in Z. bailii than in S. cerevisiae, further emphasizing the proposed link between lipid saturation, high sphingolipid levels and acetic acid tolerance. The results also suggest that acetic acid tolerance is associated with the ability of a given strain to generate large rearrangements in its lipid profile.

Riezman, Howard; Olsson, Lisbeth; Bettiga, Maurizio

2013-01-01

189

Lipidomic Profiling of Saccharomyces cerevisiae and Zygosaccharomyces bailii Reveals Critical Changes in Lipid Composition in Response to Acetic Acid Stress.  

PubMed

When using microorganisms as cell factories in the production of bio-based fuels or chemicals from lignocellulosic hydrolysate, inhibitory concentrations of acetic acid, released from the biomass, reduce the production rate. The undissociated form of acetic acid enters the cell by passive diffusion across the lipid bilayer, mediating toxic effects inside the cell. In order to elucidate a possible link between lipid composition and acetic acid stress, the present study presents detailed lipidomic profiling of the major lipid species found in the plasma membrane, including glycerophospholipids, sphingolipids and sterols, in Saccharomyces cerevisiae (CEN.PK 113_7D) and Zygosaccharomyces bailii (CBS7555) cultured with acetic acid. Detailed physiological characterization of the response of the two yeasts to acetic acid has also been performed in aerobic batch cultivations using bioreactors. Physiological characterization revealed, as expected, that Z. bailii is more tolerant to acetic acid than S. cerevisiae. Z. bailii grew at acetic acid concentrations above 24 g L(-1), while limited growth of S. cerevisiae was observed after 11 h when cultured with only 12 g L(-1) acetic acid. Detailed lipidomic profiling using electrospray ionization, multiple-reaction-monitoring mass spectrometry (ESI-MRM-MS) showed remarkable changes in the glycerophospholipid composition of Z. bailii, including an increase in saturated glycerophospholipids and considerable increases in complex sphingolipids in both S. cerevisiae (IPC 6.2×, MIPC 9.1×, M(IP)2C 2.2×) and Z. bailii (IPC 4.9×, MIPC 2.7×, M(IP)2C 2.7×), when cultured with acetic acid. In addition, the basal level of complex sphingolipids was significantly higher in Z. bailii than in S. cerevisiae, further emphasizing the proposed link between lipid saturation, high sphingolipid levels and acetic acid tolerance. The results also suggest that acetic acid tolerance is associated with the ability of a given strain to generate large rearrangements in its lipid profile. PMID:24023914

Lindberg, Lina; Santos, Aline Xs; Riezman, Howard; Olsson, Lisbeth; Bettiga, Maurizio

2013-09-04

190

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

Microsoft Academic Search

Smectites are usually used as a clay barrier at the bottom of subsurface waste landfills due to their low permeability and their capacity to retain pollutants. The Na- and Ca-saturated SWy2 montmorillonites were interacted with initial Zn(NO3)2 or Pb(NO3)2 concentrations ranging from 10?6 to 10?2M with a solid\\/liquid ratio of 10gL?1 and using acetic acid\\/acetate as buffer at pH 5

Mariem Ghayaza; Lydie Le Forestier; Fabrice Muller; Christophe Tournassat; Jean-Michel Beny

2011-01-01

191

Cellulose esterification with fatty acids and acetic anhydride in lithium chloride\\/ N,N -dimethylacetamide medium  

Microsoft Academic Search

Homogeneous esterification of cellulose with saturated fatty acids (n-octanoic to n-octadecanoic) was accomplished with acetic anhydride co-reactant in lithium chloride\\/N,N-dimethylacetamide (LiCl\\/DMAc) medium. Cellulose mixed triesters (CMT) were obtained after 5 h at 130°C with an average of\\u000a 2.2 acetyl groups and 0.8 fatty substituents per anhydroglucose unit. A mixed acetic-fatty anhydride, formed in situ, accounts for the grafting of the

C. Vaca-Garcia; S. Thiebaud; M. E. Borredon; G. Gozzelino

1998-01-01

192

Kinetics of the catalytic destruction of acetic acid in p-XYLENE undergoing oxidation  

SciTech Connect

The oxidation of p-xylene in acetic acid medium was studied in the presence of a cobalt-manganese bromide catalyst at 145/sup 0/C and 1.82 /SUP ./ 10/sup 6/ Pa. It was established that the introduction of 5-10% manganese into a cobalt bromide catalyst leads to an acceleration of the oxidation of p-xylene and simultaneously to a decrease in the proportion of decarboxylation and burnout of the solvent. The observed kinetic principles are explained by peculiarities of the thermolysis of cobalt (III) and manganese (III) acetates, as well as by the formation of cobalt-manganese bromide complexes possessing increased activity.

Kenigsberg, T.P.; Ariko, N.G.; Mitskevich, N.I.; Nazimok, V.F.

1986-06-01

193

A temperature-sensitive auxin auxotroph not deficient in indole-3-acetic acid  

Microsoft Academic Search

A temperature-sensitive variant of Hyoscyamus muticus L. expressing a lethal phenotype in both cultured cells and regenerated plants has been shown to be a conditional auxin auxotroph with an absolute requirement for an exogenous auxin at temperatures above 30° C but not at lower temperatures. The requirement was satisfied by indole-3-acetic acid (IAA) and all active auxin analogous tested. Despite

Jiirg Oetiker; Christiane Gebhardt; Patrick J. King

1990-01-01

194

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...

195

Strain typing of acetic acid bacteria responsible for vinegar production by the submerged elaboration method  

Microsoft Academic Search

Strain typing of 103 acetic acid bacteria isolates from vinegars elaborated by the submerged method from ciders, wines and spirit ethanol, was carried on in this study. Two different molecular methods were utilised: pulsed field gel electrophoresis (PFGE) of total DNA digests with a number of restriction enzymes, and enterobacterial repetitive intergenic consensus (ERIC) – PCR analysis. The comparative study

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

2010-01-01

196

The thermal conductivity and viscosity of acetic acid-water mixtures  

Microsoft Academic Search

The viscosity and thermal conductivity of acetic acid water mixtures were measured over the entire composition range and at temperatures ranging from 293 to 453 K. Viscosity measurements were performed with a high-pressure viscometer and thermal conductivity was measured using a modified transient hot-wire technique. A mercury filled. glass capillary was used as the insulated hot wire in the measurements.

J. G. Bleazard; T. F. Sun; A. S. Teja

1996-01-01

197

Pervaporation of acetic acid\\/water mixtures through silicalite filled polydimethylsiloxane membranes  

Microsoft Academic Search

The preferential pervaporation of acetic acid over water is achieved with silicalite filled polydimethylsiloxane (PDMS) membranes. The effect of silicalite addition is not positive at the feed temperature of 25°C, but improves with increasing feed temperature. At a feed temperature of 45°C, silicalite addition enhances not only the separation factor but also the permeation flux of the pervaporation. This improvement

Shih-Yuan Lu; Chung-Ping Chiu; Hsiang-Yuan Huang

2000-01-01

198

Interactions of indole acetic acid with EGF and FSH in the culture of ovine preantral follicles  

Microsoft Academic Search

The mechanisms that regulate the gradual exit of ovarian follicles from the non-growing, primordial pool are very poorly understood. The objective of this study was to evaluate the effects of adding indole acetic acid (IAA), epidermal growth factor (EGF) and follicle stimulating hormone (FSH) to the media for in vitro culture of ovine ovarian fragments and determine their effects on

Evelyn Rabelo Andrade; Marcelo Marcondes Seneda; Amauri Alcindo Alfieri; João Ademir de Oliveira; Ana Paula Frederico Rodrigues Loureiro Bracarense; José Ricardo Figueiredo; Ricardo Toniolli

2005-01-01

199

Properties of acetic-acid alcohol-containing solutions of chitosan  

Microsoft Academic Search

It was shown that incorporation of ethyl alcohol in acetic-acid solutions of chitosan reduces their turbidity and intrinsic\\u000a viscosity and increases the dynamic viscosity more the higher the concentration of chitosan and the amount of alcohol added.

S. A. Uspenskii; G. A. Vikhoreva; A. N. Sonina; L. S. Gal’braikh

2010-01-01

200

Preparation of carbon fibers from softwood lignin by atmospheric acetic acid pulping  

Microsoft Academic Search

Infusible softwood acetic acid lignin (SAL) was converted to a fusible one as a raw material for carbon fibers by removing the infusible high molecular mass fraction. The resulting low molecular mass fraction (SAL-L) was spun by fusion spinning after thermal treatment to remove volatile materials. Carbon fibers (CFs) were prepared from these fibers by direct carbonization without thermostabilization, leading

S. Kubo; Y. Uraki; Y. Sano

1998-01-01

201

Recovery of lignin and furfural from acetic acid–water–HCl pulping liquors  

Microsoft Academic Search

The feasibility of the HCl–water–acetic acid pulping technology (Acetosolv process) depends on the efficiency of solvent and byproduct recovery. Experimental data and computer simulation calculations are presented to assess these points. The recovery of precipitable, dissolved solids derived from lignin by mixing pulping liquors and water in various proportions was studied. Computer simulation of selected operational strategies enabling the recovery

C Vila; V Santos; J. C Parajó

2003-01-01

202

Effects of Benzyladenine and Naphthalene Acetic Acid on Growth and Camptothecin Accumulation in Camptotheca acuminata Seedlings  

Microsoft Academic Search

The effects of the cytokinin benzyladenine (BA) and the auxin naphthalene acetic acid (NAA) on Camptotheca acuminata Decaisne growth and camptothecin (CPT) accumulation (leaf CPT concentration and total leaf CPT yield) were studied in a hydroponic culture system for three weeks. Increasing BA concentrations from 0 to 3 mg l -1 in growth medium decreased plant height, stem weight, and

Zhanhai Li; Zhijun Liu

2003-01-01

203

Visualization of Early Events in Acetic Acid Denaturation of HIV-1 Protease: A Molecular Dynamics Study  

PubMed Central

Protein denaturation plays a crucial role in cellular processes. In this study, denaturation of HIV-1 Protease (PR) was investigated by all-atom MD simulations in explicit solvent. The PR dimer and monomer were simulated separately in 9 M acetic acid (9 M AcOH) solution and water to study the denaturation process of PR in acetic acid environment. Direct visualization of the denaturation dynamics that is readily available from such simulations has been presented. Our simulations in 9 M AcOH reveal that the PR denaturation begins by separation of dimer into intact monomers and it is only after this separation that the monomer units start denaturing. The denaturation of the monomers is flagged off by the loss of crucial interactions between the ?-helix at C-terminal and surrounding ?-strands. This causes the structure to transit from the equilibrium dynamics to random non-equilibrating dynamics. Residence time calculations indicate that denaturation occurs via direct interaction of the acetic acid molecules with certain regions of the protein in 9 M AcOH. All these observations have helped to decipher a picture of the early events in acetic acid denaturation of PR and have illustrated that the ?-helix and the ?-sheet at the C-terminus of a native and functional PR dimer should maintain both the stability and the function of the enzyme and thus present newer targets for blocking PR function.

Borkar, Aditi Narendra; Rout, Manoj Kumar; Hosur, Ramakrishna V.

2011-01-01

204

Kinetics of hydroxyapatite dissolution in acetic, lactic, and phosphoric acid solutions  

Microsoft Academic Search

Summary The present study was undertaken in an attempt to relate the kinetics of hydroxyapatite dissolution to solution parameters, under experimental conditions relevant to the dental caries process. Thus, the dissolution of hydroxyapatite was studied in acetic, lactic, and dilute phosphoric acid solutions having initial pH values from 4 to 6. Rates of dissolution and the corresponding degree of saturation

H. C. Margolis; E. C. Moreno

1992-01-01

205

Vinegar (20% acetic acid) broadcast application for broadleaf weed control in spring-transplanted onions  

Technology Transfer Automated Retrieval System (TEKTRAN)

Organic weed control research was conducted in southeast Oklahoma to determine the effect of broadcast over-the-top applications of acetic acid (vinegar) on weed control efficacy, crop injury and onion yields. The experiment included 6 weed control treatments (2 application volumes, 2 hand-weeding ...

206

Screening for cervical neoplasia in a developing country utilizing cytology, cervicography and the acetic acid test  

Microsoft Academic Search

Objective: To compare three screening tests for cervical neoplasia. Method: Women (6301) were screened simultaneously with cytology, cervicography and the acetic acid test (AAT). Biopsies were taken from the acetowhite lesions and every fifth seemingly normal cervix. Positive cases (both at screening and histology) were referred for colposcopy. The histology results served as the golden standard. Results: Cytology was positive

H. S. Cronjé; B. F. Cooreman; E. Beyer; R. H. Bam; B. D. Middlecote; P. D. J. Divall

2001-01-01

207

Effect of conjugated linoleic acid immobilization on the hemocompatibility of cellulose acetate membrane  

Microsoft Academic Search

Conjugated linoleic acid (CLA) was covalently immobilized onto cellulose acetate (CA) membranes. The effects of CLA immobilization on the blood coagulation, platelet aggregation, and oxidative stress were evaluated using human blood. The resulting CLA grafting CA membranes were characterized with X-ray photoelectronic spectroscopy (XPS). The complete blood count (CBC) and coagulation time (CT) was evaluated in vitro for the hemocompatibility.

F.-C. Kung; M.-C. Yang

2006-01-01

208

A specific radioimmunoassay for nanogram quantities of the auxin, indole-3-acetic acid  

Microsoft Academic Search

We have developed a specific radioimmunoassay [RIA] for indole-3-acetic acid (IAA) in the 0.2 ng to 12 ng range which, in principle, can be extended to other indole auxins as well. Methods are presented for obtaining suitable antibody, for the RIA procedure, and for measuring IAA in methanolic extracts of plant tissues. Antibody specific for IAA was obtained from rabbits

William Pengelly; Frederick Meins

1977-01-01

209

( S)- ?-methoxyphenyl acetic acid : a new NMR chiral shift reagent for the stereochemical analysis of sulfoxides  

Microsoft Academic Search

The use of (S)-?-methoxyphenyl acetic acid (MPAA) as a general chiral 1H NMR shift reagent for the stereochemical analysis of sulfoxides is demonstrated. Using this methodology, both the enantiomeric purity and the absolute configuration of a wide variety of sulfoxides can be determined.

Herbert L. Holland; Frances M. Brown

1995-01-01

210

Effects of Trimetazidine on Acetic Acid-Induced Colitis in Female Swiss Rats  

Microsoft Academic Search

Induction of colitis by acetic acid (A A) in the rat is widely used experimental model of inflammatory bowel disease (IBD) and ulcerations. AA as an irritant induces colitis involving infiltration of colonic mucosa with neutrophils and increased production of inflammatory mediators, such as hydrogen peroxide (H 2 O 2 ), nitric oxide (NO), myeloperoxidase activity (MPO), and tumor necrosis

Filiz Kuralay; Co?kun Yildiz; Omer Ozutemiz; Huray Islekel; Sezer Caliskan; Basak Bingol; Sermin Ozkal

2003-01-01

211

Extraction of formic and acetic acids from aqueous solution by dynamic headspace-needle trap extraction  

Microsoft Academic Search

A combined method of dynamic headspace-needle trap sample preparation and gas chromatography for the determination of formic and acetic acids in aqueous solution was developed in this study. A needle extraction device coupled with a gas aspirating pump was intended to perform sampling and preconcentration of target compounds from aqueous sample before gas chromatographic analysis. The needle trap extraction (NTE)

Da-Wei Lou; Xinqing Lee; Janusz Pawliszyn

2008-01-01

212

Biosynthesis of Indole3Acetic Acid by the Gall-inducing Fungus Ustilago esculenta  

Microsoft Academic Search

Ustilago esculenta incites the formation of an edible gall and prevents inflorescence and seed production in the aquatic perennial grass, Zizania latifolia. As compared to the healthy tissues, the edible galls had higher amounts of indole-3-acetic acid (IAA), which could be synthesized from the host plant and\\/or the fungal pathogen. In this study we investigated the ability for IAA production

2004-01-01

213

Effects of acetic and butyric acids on solvents production by Clostridium acetobutylicum  

Microsoft Academic Search

The fermentation of glucose by Clostridium acetobutylicum on a synthetic medium is carried out with a conversion of carbon source into solvents of 32 %. The ratio of butanol, acetone and ethanol products is approximately 0.6 - 1.9 - 6. The synthetic medium supplemented with acetic acid at a concentration of 2 g\\/l increases acetone formation and the ratio of

J. R. Martin; H. Petitdemange; J. Ballongue; R. Gay

1983-01-01

214

SALT EFFECT IN LIQUID-LIQUID EQUILIBRIA OF ACETIC ACID-WATER-BENZENE SYSTEM  

Microsoft Academic Search

The effect of sodium sulphate, potassium-sulphate and potassium chloride on the distribution of acetic acid between benzene and water at 35°C is reported. Distribution data of the three quaternaries have been determined at salt saturation and unsaturation in each case, as well as the basic ternary in the absence of salt at that temperature. The simple method of Setschenov is

A. S. NARAYANA; R. NISCHAL; R. PATEL; K. G. PARIKH; R. K. SINGH

1990-01-01

215

The Biological Evaluation of Poly (Vinyl Acetate-Co-Crotonic Acid) Ionomer Hydrogel Coatings.  

National Technical Information Service (NTIS)

Poly(vinyl acetate-co-2%-crotonic acid) 60% sodium ionomer hydrogel was found to be the most thromboresistant hydrogel evaluated in our screening studies. The ionomer hydrogel was graft-coated onto substrate surfaces from an ethanol solution of its monome...

W. F. Beach D. D. Stewart

1980-01-01

216

Improved synthesis of 3-(dialkylaminomethyl)-indole in acetic acid aqueous solution under ultrasound irradiation.  

PubMed

Synthesis of Mannich bases related to gramine via Mannich reaction of secondary amine, formaldehyde and indole or N-methylindole can be carried out in 69-98% yields in acetic acid aqueous solution at 35°C under ultrasound irradiation. Compared with the method using stirring, the present procedure provided several advantages such as milder conditions, shorter reaction time and higher yield. PMID:20646952

Li, Ji-Tai; Sun, Shao-Feng; Sun, Ming-Xuan

2010-06-02

217

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

218

Active specie on vanadium-containing catalysts for the selective oxidation of ethane to acetic acid  

Microsoft Academic Search

Catalytic experiments on pure VPO phases and titania supported VPOx and VOx are presented for the selective oxidation of ethane to acetic acid. The effects of temperature, pressure, contact time and feed conditions are examined. The characterization of catalysts by several methods shows that different specie are present on titania according to the loading V\\/Ti. The correlation with catalytic results

L. Tessier; E. Bordes; M. Gubelmann-Bonneau

1995-01-01

219

Impact of acetic acid concentration of fermented liquid feed on growth performance of piglets  

Microsoft Academic Search

Feeding fermented liquid feed (FLF) to pigs has proven to benefit gastrointestinal health of the animals. However, growth performance data of piglets and growing pigs fed FLF are variable and often a lower feed intake compared to feeding non-FLF or dry feed has been observed. Accumulation of microbial metabolites, namely acetic acid, possibly in combination with low feed pH, has

Nuria Canibe; Anni Øyan Pedersen; Bent Borg Jensen

2010-01-01

220

Acetic Acid Digestion of High-Carbonate Substrates: An Aid to Sorting Aquatic Invertebrate Samples  

Microsoft Academic Search

Soaking high-carbonate sediment samples in 5% acetic acid reduces initial sample volumes; sorting times per unit of original volume and per organism also declined significantly compared with untreated samples. This procedure speeds the sorting of invertebrate samples, especially when similar specific gravities of organisms and substrates render useless the techniques of flotation and elutriation.

Amy Odell Daraghy; Roxanne Conrow; William F. Loftus

1988-01-01

221

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

222

Acetals and Ketals.  

National Technical Information Service (NTIS)

Thirteen open-chain simple cyclic and spirocyclic acetals and ketals were studied. The synthesis of all the cyclic compounds was accomplished by an alcoholysis reaction. The infrared and proton magnetic resonance spectra were measured and correlated. (Aut...

J. Radell R. E. Rondeau

1970-01-01

223

Sodium Acetate Hand Warmers  

NSDL National Science Digital Library

In this activity, sodium acetate hand warmers are used to introduce learners to supersaturated solutions, crystallization, and exothermic reactions. This activity guide includes background information, extension ideas, and resources.

Johnson, Jill

2006-01-01

224

Kinetics of the Methanogenic Fermentation of Acetate  

PubMed Central

Inhibition of the fermentation of acetate to methane and carbon dioxide by acetate was analyzed with an acetate-acclimatized sludge and with Methanosarcina barkeri Fusaro under mesophilic conditions. A second-order substrate inhibition model, qch4 = qmS/[Ks + S + (S2/Ki)], where S was the concentration of undissociated acetic acid, not ionized acetic acid, could be applicable in both cases. The analysis resulted in substrate saturation constants, Ks, of 4.0 ?M for the acclimatized sludge and 104 ?M for M. barkeri. The threshold concentrations of undissociated acetic acid when no further acetate utilization was observed were 0.078 ?M (pH 7.50) for the acclimatized sludge and 4.43 ?M (pH 7.45) for M. barkeri. These kinetic results suggested that the concentration of undissociated acetic acid became a key factor governing the actual threshold acetate concentration for acetate utilization and that the acclimatized sludge in which Methanothrix spp. appeared dominant could utilize acetate better and survive at a lower concentration of undissociated acetic acid than could M. barkeri. Images

Fukuzaki, Satoshi; Nishio, Naomichi; Nagai, Shiro

1990-01-01

225

Calibration and intercomparison of acetic acid measurements using proton transfer reaction mass spectrometry (PTR-MS)  

NASA Astrophysics Data System (ADS)

Acetic acid is one of the most abundant organic acids in the ambient atmosphere, with maximum mixing ratios reaching into the tens of parts per billion by volume (ppbv) range. The identities and associated magnitudes of the major sources and sinks for acetic acid are poorly characterized, due in part to the limitation in available measurement techniques. This paper demonstrates that Proton Transfer Reaction Mass Spectrometry (PTR-MS) can reliably quantify acetic acid vapor in ambient air. Three different PTR-MS configurations were calibrated at low ppbv mixing ratios using permeation tubes, which yielded calibration factors between 7.0 and 10.9 normalized counts per second per ppbv (ncps ppbv-1) at a drift tube field strength of 132 townsend (Td). Detection limits ranged from 0.06 to 0.32 ppbv with dwell times of 5 s. These calibration factors showed negligible humidity dependence. Using the experimentally determined calibration factors, PTR-MS measurements of acetic acid during the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) campaign were validated against results obtained using Mist Chambers coupled with Ion Chromatography (MC/IC). An orthogonal least squares linear regression of paired data yielded a slope of 1.14 ± 0.06 (2?), an intercept of 0.049 ± 20 (2?) ppbv, and an R2 of 0.78. The median mixing ratio of acetic acid on Appledore Island, ME during the ICARTT campaign was 0.530 ± 0.025 ppbv with a minimum of 0.075 ± 0.004 ppbv, and a maximum of 3.555 ± 0.171 ppbv.

Haase, K. B.; Keene, W. C.; Pszenny, A. A. P.; Mayne, H. R.; Talbot, R. W.; Sive, B. C.

2012-07-01

226

Calibration and intercomparison of acetic acid measurements using proton transfer reaction mass spectrometry (PTR-MS)  

USGS Publications Warehouse

Acetic acid is one of the most abundant organic acids in the ambient atmosphere, with maximum mixing ratios reaching into the tens of parts per billion by volume (ppbv) range. The identities and associated magnitudes of the major sources and sinks for acetic acid are poorly characterized, due in part to the limitation in available measurement techniques. This paper demonstrates that Proton Transfer Reaction Mass Spectrometry (PTR-MS) can reliably quantify acetic acid vapor in ambient air. Three different PTR-MS configurations were calibrated at low ppbv mixing ratios using permeation tubes, which yielded calibration factors between 7.0 and 10.9 normalized counts per second per ppbv (ncps ppbv?1) at a drift tube field strength of 132 townsend (Td). Detection limits ranged from 0.06 to 0.32 ppbv with dwell times of 5 s. These calibration factors showed negligible humidity dependence. Using the experimentally determined calibration factors, PTR-MS measurements of acetic acid during the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) campaign were validated against results obtained using Mist Chambers coupled with Ion Chromatography (MC/IC). An orthogonal least squares linear regression of paired data yielded a slope of 1.14 ± 0.06 (2?), an intercept of 0.049 ± 20 (2?) ppbv, and an R2 of 0.78. The median mixing ratio of acetic acid on Appledore Island, ME during the ICARTT campaign was 0.530 ± 0.025 ppbv with a minimum of 0.075 ± 0.004 ppbv, and a maximum of 3.555 ± 0.171 ppbv.

Haase, K. B.; Keene, W. C.; Pszenny, A. A. P.; Mayne, H. R.; Talbot, R. W.; Sive, B. C.

2012-01-01

227

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

228

Loading of amphipathic weak acids into liposomes in response to transmembrane calcium acetate gradients  

Microsoft Academic Search

We describe a novel procedure to load amphipathic weak acid molecules into preformed liposomes. Differences in calcium acetate concentrations across the liposomal membrane induce an increase of the internal pH. This pH imbalance serves as an efficient driving force to load and accumulate weak acids (5(6)-carboxyfluorescein and nalidixic acid) inside the lipid vesicles. The mechanism of loading and the relevance

Stéphane Clerc; Yechezkel Barenholz

1995-01-01

229

A Study of Polydimethylsiloxane\\/Aromatic Polyamide Laminated Membranes for Separation of Acetic Acid\\/Water Mixtures by Pervaporation Process  

Microsoft Academic Search

Separation of acetic acid\\/water mixtures by pervaporation was attempted over a range of compositions using polydimethylsiloxane (PDMS), aromatic polyamide (PA), and laminated polydimethylsiloxane-aromatic polyamide membranes. PDMS membranes are hydrophobic and acetic acid selective, whereas PA membranes are hydrophilic and water selective. When PDMS and PA membranes were laminated, with PDMS on the top side and in contact with the feed,

SHENGZHI DENG; S. SOURIRAJAN; T. MATSUURA

1994-01-01

230

Microbial process for the preparation of acetic acid as well as solvent for its extraction from the fermentation broth  

DOEpatents

A modified water-immiscible solvent useful in the extraction of acetic acid from aqueous streams is a substantially pure mixture of isomers of highly branched di-alkyl amines. This solvent is substantially devoid of mono-alkyl amines and alcohols. Solvent mixtures formed of such a modified solvent with a desired cosolvent, preferably a low boiling hydrocarbon which forms an azeotrope with water are useful in the extraction of acetic acid from aqueous gaseous streams. An anaerobic microbial fermentation process for the production of acetic acid employs such solvents, under conditions which limit amide formation by the solvent and thus increase the efficiency of acetic acid recovery. Methods for the direct extraction of acetic acid and the extractive fermentation of acetic acid also employ the modified solvents and increase efficiency of acetic acid production. Such increases in efficiency are also obtained where the energy source for the microbial fermentation contains carbon dioxide and the method includes a carbon dioxide stripping step prior to extraction of acetic acid in solvent.

Gaddy, James L. (Fayetteville, AR); Clausen, Edgar C. (Fayetteville, AR); Ko, Ching-Whan (Fayetteville, AR); Wade, Leslie E. (Corpus Christi, TX); Wikstrom, Carl V. (Fayetteville, AR)

2002-01-01

231

Acetic acid production of Vibrio halioticoli from alginate: a possible role for establishment of abalone– V. halioticoli association  

Microsoft Academic Search

Acetic acid, which is converted from cellulose by means of the metabolism of their gut microbes, is an important oxidizable energy source and precursors of anabolism in ruminant animals and xylophagus insects. However, acetic acid production from algal polysaccharides by means of the metabolism of gut microbes of marine herbivorous invertebrates is not well studied. Abundance of Vibrio halioticoli, which

Tomoo Sawabe; Naka Setoguchi; Sahoko Inoue; Reiji Tanaka; Masashi Ootsubo; Mamoru Yoshimizu; Yoshio Ezura

2003-01-01

232

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

233

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

234

Analysis of vaginal acetic acid in patients undergoing treatment for bacterial vaginosis.  

PubMed

A "gold standard" method for the diagnosis of bacterial vaginosis (BV) is lacking. The clinical criteria described by the Amsel technique are subjective and difficult to quantify. Alternatively, the reading of Gram-stained vaginal smears by scoring techniques such as those that use the Nugent or Hay-Ison scoring systems is again subjective, requires expert personnel to perform the reading, and is infrequently used clinically. Recently, a new diagnostic device, the Osmetech Microbial Analyzer--Bacterial Vaginosis (OMA-BV), which determines a patient's BV status on the basis of measurement of the amount of acetic acid present in a vaginal swab specimen, was approved by the Food and Drug Administration. The present study uses the conducting polymer gas-sensing technology of OMA-BV to measure the concentration of acetic acid in the headspace above vaginal swab specimens from patients undergoing treatment for BV with metronidazole. In 97.8% of the cases the level of acetic acid detected fell sharply during the treatment period, crossing from above to below the diagnostic threshold of 900 ppm. The diagnosis obtained on the basis of the level of vaginal acetic acid was compared with the diagnoses obtained by use of the Amsel criteria and the Nugent scoring system both at the time of initial entry into the study and at the repeat samplings on days 7 and 14. The results obtained with OMA-BV showed overall agreements compared with the results of the Amsel and Nugent tests of 98 and 94%, respectively, for the 34 patients monitored through the treatment process. This provides further evidence that the measurement of vaginal acetic acid by headspace analysis with conducting polymer sensors is a valid alternative to present tests for the diagnosis of BV. PMID:15528711

Chaudry, Amjad N; Travers, Paul J; Yuenger, Jeffrey; Colletta, Lorraine; Evans, Phillip; Zenilman, Jonathan M; Tummon, Andrew

2004-11-01

235

Analysis of Vaginal Acetic Acid in Patients Undergoing Treatment for Bacterial Vaginosis  

PubMed Central

A “gold standard” method for the diagnosis of bacterial vaginosis (BV) is lacking. The clinical criteria described by the Amsel technique are subjective and difficult to quantify. Alternatively, the reading of Gram-stained vaginal smears by scoring techniques such as those that use the Nugent or Hay-Ison scoring systems is again subjective, requires expert personnel to perform the reading, and is infrequently used clinically. Recently, a new diagnostic device, the Osmetech Microbial Analyzer—Bacterial Vaginosis (OMA-BV), which determines a patient's BV status on the basis of measurement of the amount of acetic acid present in a vaginal swab specimen, was approved by the Food and Drug Administration. The present study uses the conducting polymer gas-sensing technology of OMA-BV to measure the concentration of acetic acid in the headspace above vaginal swab specimens from patients undergoing treatment for BV with metronidazole. In 97.8% of the cases the level of acetic acid detected fell sharply during the treatment period, crossing from above to below the diagnostic threshold of 900 ppm. The diagnosis obtained on the basis of the level of vaginal acetic acid was compared with the diagnoses obtained by use of the Amsel criteria and the Nugent scoring system both at the time of initial entry into the study and at the repeat samplings on days 7 and 14. The results obtained with OMA-BV showed overall agreements compared with the results of the Amsel and Nugent tests of 98 and 94%, respectively, for the 34 patients monitored through the treatment process. This provides further evidence that the measurement of vaginal acetic acid by headspace analysis with conducting polymer sensors is a valid alternative to present tests for the diagnosis of BV.

Chaudry, Amjad N.; Travers, Paul J.; Yuenger, Jeffrey; Colletta, Lorraine; Evans, Phillip; Zenilman, Jonathan M.; Tummon, Andrew

2004-01-01

236

The Formation of Acetic Acid (CH3COOH) in Interstellar Ice Analogs  

NASA Astrophysics Data System (ADS)

Binary ice mixtures of methane (CH4) and carbon dioxide (CO 2) ices were irradiated at 12 K with energetic electrons to mimic the energy transfer processes that occur in the track of the trajectories of MeV cosmic-ray particles. The formation of trans-acetic acid (CH3COOH) was established through the appearance of new bands in the infrared spectrum at 1780, 1195, 1160, 1051, and 957 cm-1 two dimeric forms of acetic acid were assigned via absorptions at 1757 and 1723 cm-1 . During warm-up of the ice sample, the mass spectrometer recorded peaks of m/z values of 60 and 45 associated with the C2H 4O2+ and COOH+ molecular ion and fragment, respectively. The kinetic fits of the column densities of the acetic acid molecule suggest that the initial step of the formation process appears to be the cleavage of a carbon-hydrogen bond from methane to generate the methyl radical plus atomic hydrogen. The hydrogen atom holds excess kinetic energy allowing it to overcome entrance barriers required to add to a carbon dioxide molecule, generating the carboxyl radical (HOCO). This radical can recombine with the methyl radical to form acetic acid molecule. Similar processes are expected to form acetic acid in the interstellar medium, thus providing alternatives to gas-phase processes for the generation of complex chemical species whose fractional abundances compared to molecular hydrogen of typically a few×10-9 cannot be accounted for by solely gas-phase chemistry.

Bennett, Chris J.; Kaiser, Ralf I.

2007-05-01

237

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

238

Expanded scope of synthetic bacteriochlorins via improved acid catalysis conditions and diverse dihydrodipyrrin-acetals.  

PubMed

Bacteriochlorins are attractive candidates for a wide variety of photochemical studies owing to their strong absorption in the near-infrared spectral region. The prior acid-catalysis conditions [BF(3) x O(Et)(2) in CH(3)CN at room temperature] for self-condensation of a dihydrodipyrrin-acetal (bearing a geminal dimethyl group in the pyrroline ring) typically afforded a mixture of three macrocycles: the expected 5-methoxybacteriochlorin (MeOBC-type), a 5-unsubstituted bacteriochlorin (HBC-type), and a free base B,D-tetradehydrocorrin (TDC-type). Here, a broad survey of >20 acids identified four promising acid catalysis conditions of which TMSOTf/2,6-di-tert-butylpyridine in CH(2)Cl(2) at room temperature was most attractive owing to formation of the 5-methoxybacteriochlorin as the sole macrocycle regardless of the pyrrolic substituents in the dihydrodipyrrin-acetal (electron-withdrawing, electron-donating, or no substituent). Eleven new dihydrodipyrrin-acetals were prepared following standard routes. Application of the new acid catalysis conditions has afforded diverse bacteriochlorins (e.g., bearing alkyl/ester, aryl/ester, diester, and no substituents) in a few days from commercially available starting materials. Consideration of the synthetic steps and yields for formation of the dihydrodipyrrin-acetal and bacteriochlorin underpins evaluation of synthetic plans for early installation of bacteriochlorin substituents via the dihydrodipyrrin-acetal versus late installation via derivatization of beta-bromobacteriochlorins. Treatment of the 5-methoxybacteriochlorins with NBS gave regioselective 15-bromination when no pyrrolic substituents were present or when each pyrrole contained two substituents; on the other hand, the presence of a beta-ethoxycarbonyl group caused loss of regioselectivity. The 15 new bacteriochlorins prepared herein exhibit a long-wavelength absorption band in the range 707-759 nm, providing tunable access to the near-infrared region. Taken together, this study expands the scope of available bacteriochlorins for fundamental studies and diverse applications. PMID:20088604

Krayer, Michael; Ptaszek, Marcin; Kim, Han-Je; Meneely, Kelly R; Fan, Dazhong; Secor, Kristen; Lindsey, Jonathan S

2010-02-19

239

The thermal conductivity and viscosity of acetic acid-water mixtures  

NASA Astrophysics Data System (ADS)

The viscosity and thermal conductivity of acetic acid water mixtures were measured over the entire composition range and at temperatures ranging from 293 to 453 K. Viscosity measurements were performed with a high-pressure viscometer and thermal conductivity was measured using a modified transient hot-wire technique. A mercury filled. glass capillary was used as the insulated hot wire in the measurements. The l iscosity data showed unusual trends with respect to composition. At it given temperature. the viscosity was seen to increase with increasing acid concentration, attain a maximum. and then decrease. The thermal conductivity, on the other hand, decreased monotonically with acid concentration. A generalized corresponding-states principle using water and acetic acid as the reference fluids was used to predict both viscosity and thermal conductivity with considerable sucres.

Bleazard, J. G.; Sun, T. F.; Teja, A. S.

1996-01-01

240

Importance of secondary sources in the atmospheric budgets of formic and acetic acids  

NASA Astrophysics Data System (ADS)

We present a detailed budget of formic and acetic acids, two of the most abundant trace gases in the atmosphere. Our bottom-up estimate of the global source of formic and acetic acids are ~1200 and ~1400 Gmol yr-1, dominated by photochemical oxidation of biogenic volatile organic compounds, in particular isoprene. Their sinks are dominated by wet and dry deposition. We use the GEOS-Chem chemical transport model to evaluate this budget against an extensive suite of measurements from ground, ship and satellite-based Fourier transform spectrometers, as well as from several aircraft campaigns over North America. The model captures the seasonality of formic and acetic acids well but generally underestimates their concentration, particularly in the Northern midlatitudes. We infer that the source of both carboxylic acids may be up to 50% greater than our estimate and report evidence for a long-lived missing secondary source of carboxylic acids that may be associated with the aging of organic aerosols. Vertical profiles of formic acid in the upper troposphere support a negative temperature dependence of the reaction between formic acid and the hydroxyl radical as suggested by several theoretical studies.

Paulot, F.; Wunch, D.; Crounse, J. D.; Toon, G. C.; Millet, D. B.; Decarlo, P. F.; Vigouroux, C.; Deutscher, N. M.; González Abad, G.; Notholt, J.; Warneke, T.; Hannigan, J. W.; Warneke, C.; de Gouw, J. A.; Dunlea, E. J.; de Mazière, M.; Griffith, D. W. T.; Bernath, P.; Jimenez, J. L.; Wennberg, P. O.

2011-03-01

241

Importance of secondary sources in the atmospheric budgets of formic and acetic acids  

NASA Astrophysics Data System (ADS)

We present a detailed budget of formic and acetic acids, two of the most abundant trace gases in the atmosphere. Our bottom-up estimate of the global source of formic (acetic) acid is ~ 1200 (1400) Gmol/yr, dominated by photochemical oxidation of biogenic volatile organic compounds, in particular isoprene. Their sinks are dominated by wet and dry deposition. We use the GEOS-Chem chemical transport model to evaluate this budget against an extensive suite of measurements from ground, ship and satellite-based Fourier transform spectrometers, as well as from several aircraft campaigns over North America. The model captures the seasonality of formic and acetic acids well but generally underestimates their concentration, particularly in the Northern midlatitudes. We infer that the source of both carboxylic acids may be up to 50% greater than our estimate and report evidence for a long-lived missing secondary source of carboxylic acids that could be associated with the aging of organic aerosols. Vertical profiles of formic acid in the upper troposphere support a negative temperature dependence of the reaction between formic acid and the hydroxyl radical as suggested by several theoretical studies.

Paulot, F.; Wunch, D.; Crounse, J.; Millet, D. B.; Decarlo, P. F.; Vigouroux, C.; Deutscher, N. M.; Gonzalez Abad, G.; Toon, G. C.; Notholt, J.; Warneke, T.; Hannigan, J. W.; Warneke, C.; de Gouw, J. A.; Dunlea, E.; de Maziere, M. M.; Griffith, D. W.; Bernath, P. F.; Jimenez, J. L.; Wennberg, P. O.

2010-12-01

242

Importance of secondary sources in the atmospheric budgets of formic and acetic acids  

NASA Astrophysics Data System (ADS)

We present a detailed budget of formic and acetic acids, two of the most abundant trace gases in the atmosphere. Our bottom-up estimate of the global source of formic and acetic acids are ~1200 and ~1400 Gmol/yr, dominated by photochemical oxidation of biogenic volatile organic compounds, in particular isoprene. Their sinks are dominated by wet and dry deposition. We use the GEOS-Chem chemical transport model to evaluate this budget against an extensive suite of measurements from ground, ship and satellite-based Fourier transform spectrometers, as well as from several aircraft campaigns over North America. The model captures the seasonality of formic and acetic acids well but generally underestimates their concentration, particularly in the Northern midlatitudes. We infer that the source of both carboxylic acids may be up to 50% greater than our estimate and report evidence for a long-lived missing secondary source of carboxylic acids that may be associated with the aging of organic aerosols. Vertical profiles of formic acid in the upper troposphere support a negative temperature dependence of the reaction between formic acid and the hydroxyl radical as suggested by several theoretical studies.

Paulot, F.; Wunch, D.; Crounse, J. D.; Toon, G. C.; Millet, D. B.; Decarlo, P. F.; Vigouroux, C.; Deutscher, N. M.; González Abad, G.; Notholt, J.; Warneke, T.; Hannigan, J. W.; Warneke, C.; de Gouw, J. A.; Dunlea, E. J.; de Mazière, M.; Griffith, D. W. T.; Bernath, P.; Jimenez, J. L.; Wennberg, P. O.

2010-10-01

243

Microwave Spectroscopy and Proton Transfer Dynamics in the Formic Acid-Acetic Acid Dimer  

NASA Astrophysics Data System (ADS)

The rotational spectrum of the doubly hydrogen-bonded {hetero} dimer formed between formic acid and acetic acid has been recorded between 4 and 18 GHz using a pulsed-nozzle Fourier transform microwave spectrometer. Each rigid-molecule rotational transition is split into four as a result of two concurrent tunnelling motions, one being proton transfer between the two acid molecules, and the other the torsion/rotation of the methyl group within the acetic acid. We present a full assignment of the spectrum for {J} = 1 to {J} = 7 for these four torsion/tunnelling states. Spectra have been observed for the main isotopic species, with deuterium substitution at the C of the formic acid and all 13C species in natural abundance, The observed transitions are fitted to within a few kilohertz using a molecule-fixed effective rotational Hamiltonian for the separate {A} and {E} vibrational species of the G12 permutation-inversion group which is applicable to this complex. To reduce the effects of internal angular momentum, a non-principal axis system is used throughout. Interpretation of the internal motion uses an internal-vibration and overall rotation scheme, and full sets of rotational and centrifugal distortion constants are determined. The proton tunnelling rates and the internal angular momentum of the methyl group in the {E} states is interpreted in terms of a dynamical model which involves coupled proton transfer and internal rotation. The resulting potential energy surface not only describes these internal motions, but can also explain the observed shifts in rotational constants between {A} and {E} species, and the deviations of the tunnelling frequencies from the expected 2:1 ratio. It also permits the determination of spectral constants free from the contamination effects of the internal dynamics. M.C.D. Tayler, B. Ouyang and B.J. Howard, J. Chem. Phys., {134}, 054316 (2011).

Howard, B. J.; Steer, E.; Page, F.; Tayler, M.; Ouyang, B.; Leung, H. O.; Marshall, M. D.; Muenter, J. S.

2012-06-01

244

Interaction of ethylene with indole-3-acetic acid in regulation of rooting in pea cuttings  

Microsoft Academic Search

Cuttings of pea (Pisum sativum L. cv Marma) were treated with 1-aminocyclopropane-l-carboxylic acid (ACC). This treatment caused increased ethylene production and reduction of root formation. The effect of 0.1 mM ACC on the level of endogenous indole-3-acetic acid (IAA) in the rooting zone and in the shoot apex was analyzed by gas chromatography-single ion monitoring mass spectrometry or by high

A.-C. Nordstrom; L. Eliasson

1993-01-01

245

2,2,3-trimethylbutane and differently-branched hydrocarbons through hydrogenation of trialkyl acetic acid  

Microsoft Academic Search

This report described a method of producing Triptan (2,2,3-trimethylbutane). The starting material was diisopropyl ketone (Isobutyron). It was transformed into dimethylisopropyl acetic acid by first chlorinating the starting material and then treating it with a water-free alkali (sodium hydroxide) in a benzene solution containing a small amount of sodium metal to tie up any remaining water. The acid crystallized out

Bueren

1944-01-01

246

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

247

Pentose oxidation by acetic Acid bacteria led to a finding of membrane-bound purine nucleosidase.  

PubMed

D-Ribose and 2-deoxy-D-ribose were oxidized to 4-keto-D-ribonate and 2-deoxy-4-keto-D-ribonate respectively by oxidative fermentation, and the chemical structures of the oxidation products were confirmed to be as expected. Both pentoses are important sugar components of nucleic acids. When examined, purine nucleosidase activity predominated in the membrane fraction of acetic acid bacteria. This is perhaps the first finding of membrane-bound purine nucleosidase. PMID:23649247

Adachi, Osao; Hours, Roque A; Akakabe, Yoshihiko; Shinagawa, Emiko; Ano, Yoshitaka; Yakushi, Toshiharu; Matsushita, Kazunobu

2013-05-07

248

Modeling of yeast Brettanomyces bruxellensis growth at different acetic acid concentrations under aerobic and anaerobic conditions  

Microsoft Academic Search

Glucose utilization by Brettanomyces bruxellensis at different acetic acid concentrations under aerobic and anaerobic conditions was investigated. The presence of the organic\\u000a acid disturbs the growth and fermentative activity of the yeast when its concentration exceeds 2 g l?1. A mathematical model is proposed for the kinetic behavior analysis of yeast growing in batch culture. A Matlab algorithm\\u000a was used for estimation

Garcia Alvarado Yahara; Mendez Ancona Javier; Mata Jimenez Marco Tulio; Gómez Rodriguez Javier; Aguilar Uscanga Maria Guadalupe

2007-01-01

249

Analysis of the stable carbon isotope composition of formic and acetic acids.  

PubMed

Formic and acetic acids are ubiquitous in the environment and in many biological processes. Analysis of the stable carbon isotope composition (?(13)C) of formic and acetic acids is important to understanding their biogeochemical cycles. However, it has been faced with poor accuracy and high detection limits due to their low carbon number, high hydrophilicity, and semi-volatility. Here we developed an analytical technique by needle trap and gas chromatography-isotope ratio mass spectrometry (GC-IRMS). The organic acids in aqueous solution were extracted using a NeedlEx needle through purge-and-trap and were analyzed by GC-IRMS for ?(13)C. The procedures incur no isotope fractionation. Defined as the point at which the mean ?(13)C is statistically the same as the given value and the analytical error starts rising, the method's detection limits are 200 and 100 mg/L for formic and acetic acids, respectively, with an uncertainty of approximately 0.5‰ in direct extraction and analysis. They were lowered to 1 mg/L with precision of 0.9‰ after samples were subjected to preconcentration. The method was successfully applied to natural samples as diverse as precipitation, vinegars, ant plasma, and vehicle exhaust, which vary considerably in concentration and matrix of the organic acids. It is applicable to the organic acids in not only aqueous solution but also gaseous phase. PMID:23395975

Lee, Xinqing; Zhang, Like; Huang, Daikuan; An, Ning; Yang, Fang; Jiang, Wei; Fang, Bin

2013-02-08

250

Genomic Expression Program Involving the Haa1p-Regulon in Saccharomyces cerevisiae Response to Acetic Acid  

PubMed Central

Abstract The alterations occurring in yeast genomic expression during early response to acetic acid and the involvement of the transcription factor Haa1p in this transcriptional reprogramming are described in this study. Haa1p was found to regulate, directly or indirectly, the transcription of approximately 80% of the acetic acid-activated genes, suggesting that Haa1p is the main player in the control of yeast response to this weak acid. The genes identified in this work as being activated in response to acetic acid in a Haa1p-dependent manner include protein kinases, multidrug resistance transporters, proteins involved in lipid metabolism, in nucleic acid processing, and proteins of unknown function. Among these genes, the expression of SAP30 and HRK1 provided the strongest protective effect toward acetic acid. SAP30 encode a subunit of a histone deacetylase complex and HRK1 encode a protein kinase belonging to a family of protein kinases dedicated to the regulation of plasma membrane transporters activity. The deletion of the HRK1 gene was found to lead to the increase of the accumulation of labeled acetic acid into acid-stressed yeast cells, suggesting that the role of both HAA1 and HRK1 in providing protection against acetic acid is, at least partially, related with their involvement in the reduction of intracellular acetate concentration.

Becker, Jorg D.; Sa-Correia, Isabel

2010-01-01

251

Physicochemical characterization and antibacterial property of chitosan acetates  

Microsoft Academic Search

In a new approach to the preparation of solid chitosan acetate, the dependence of solubility of chitsoan acetate on the mole ratio of acetic acid to GlcN residues of chitosan was evaluated from turbidity. The structure of the product chitosan acetate was characterized by titration and FT-IR. It was demonstrated that the chitosan acetate with high solubility retained the structure

Yan Li; Xi Guang Chen; Nan Liu; Cheng Sheng Liu; Chen Guang Liu; Xiang Hong Meng; Le Jun Yu; John F. Kenendy

2007-01-01

252

Oxygen-dependent catabolism of indole-3-acetic acid in Bradyrhizobium japonicum.  

PubMed Central

Some strains of Bradyrhizobium japonicum have the ability to catabolize indole-3-acetic acid (IAA). Examination of this catabolism in strain 110 by in vivo experiments has revealed an enzymatic activity catalyzing the degradation of IAA and 5-hydroxy-indole-3-acetic acid. The activity requires addition of the substrates for induction and is oxygen dependent. The highest activity is obtained when the concentration of inducer is 0.2 mM. Spectrophotometric data are consistent with the suggestion that the indole ring is broken during degradation of IAA. We hypothesize that the enzyme catalyzes an oxygen-consuming opening of the indole ring analogous to the one catalyzed by tryptophan 2,3-dioxygenase. The pattern of metabolite usage by known tryptophan-auxotrophic mutants and studies of metabolites by high-performance liquid chromatography indicate that anthranilic acid is a terminal degradation product in the proposed pathway.

Egebo, L A; Nielsen, S V; Jochimsen, B U

1991-01-01

253

Chemiluminometric determination of the pesticide 3-indolyl acetic acid by a flow injection analysis assembly.  

PubMed

A new method is proposed for the chemiluminescent determination of the pesticide 3-indolyl acetic acid by means of an flow injection analysis system. The chemiluminescence emission is obtained by oxidation of the analyte with Ce (IV) in nitric acid and presence of beta-cyclodextrine. The continuous-flow method allows the determination of 159samplesh(-1) of 3-indolyl acetic acid in an interval of concentrations over the range 0.5-15.0mgl(-1). The limit of detection was 0.1mugl(-1) and the R.S.D. (n, 17) at 2.0mgl(-1) of the pesticide level was 2.7%. The method was applied to water samples. PMID:19071306

Neves, A I Pimentel; Albert-García, J R; Calatayud, J Martínez

2006-05-24

254

Host-guest stabilized room temperature phosphorescence in beta-cyclodextrin/ bromoalcohol solutions from 2-naphthyl-oxy-acetic acid and 1-naphthyl-acetic acid.  

PubMed

Room temperature phosphorescence (RTP) from 2-naphthyl-oxy-acetic acid (NOA) and 1-naphthyl-acetic acid (NAA), with stabilization by use of beta-cyclodextrin (beta-CD) as a host system, has been examined. 2-Bromoethanol and 2,3-dibromopropanol have been evaluated as external heavy atom perturbers to enhance the rate of intersystem crossing and, consequently, populating the triplet state for phosphorescence emission. The deoxygenation of the solutions was achieved chemically by use of sodium sulphite. The spectral characteristics of the phosphorescence emission from these relatively polar compounds and the optimization of the chemical variables involved are reported. The role of the bulkiness of the bromoalcohol employed, in comparison with the unoccupied space of the interior of the cyclodextrin cavity by the guest, is an important factor in the attainment of an effective RTP emission, and should be taken into account in the selection of the appropriate external heavy atom for the observation of RTP from other organic molecules of interest by this approach. 2,3-Dibromopropanol seems a more adequate bromoalcohol than 2-bromoethanol for the observation of RTP emission in the systems investigated. PMID:18965836

de la Pena, A M; Salinas, F; Gomez, M J; Sanchez-Pena, M; Duran-Meras, I

1993-11-01

255

Clostridium strain which produces acetic acid from waste gases  

DOEpatents

A method and apparatus are disclosed 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. 4 figs.

Gaddy, J.L.

1997-01-14

256

Kolbe electrolysis of acetic acid in a polymer electrolyte membrane reactor  

SciTech Connect

A polymer electrolyte membrane (PEM) reactor is described for use in Kolbe electrolysis: the anodic oxidation of an alkyl carboxylic acid with subsequent decarboxylation and coupling to yield a dimer, 2RCOOH {r_arrow} R-R + 2CO{sub 2} + 2e{sup {minus}} + 2H{sup +}. Platinized Nafion 117 is the PEM and functions simultaneously as the electrolyte and separator. Results demonstrating the feasibility of Kolbe electrolysis in a PEM reactor are presented for the oxidation of gaseous acetic acid (in a nitrogen diluent) to ethane and carbon dioxide, with hydrogen evolution at the counter electrode. The investigation includes the following effects on current density, current efficiency, and product selectivity: acetic acid partial pressure (P{sub total} {approx} 1 atm), cell voltage and temperature, phase of the catholyte (liquid water or humidified nitrogen), and the procedure used to prepare the membrane-electrode assembly. Current densities from 0.06 to 0.4 A/cm{sup 2} with Kolbe current efficiencies of 10 to 90% were obtained for cell voltages ranging from 4 to 10 V. The best results were obtained using PEMs platinized by a nonequilibrium impregnation-reduction method; a 75% current efficiency at 0.3 A/cm{sup 1} with a cell voltage of 6 V were measured at the following reaction conditions: 42 C reactor, 58 mm Hg acetic acid (50 C acetic acid dew point), and 42 C liquid water to the cathode. These initial results are encouraging for Kolbe electrolysis in a PEM cell; additional work, however, is needed to determine if the PEM strategy may be employed using a liquid-phase reactant. In addition, optimal reaction conditions and downstream mass-transfer separation requirements remain to be determined, both of which are reactant specific.

Hicks, M.T.; Fedkiw, P.S. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Chemical Engineering

1998-11-01

257

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

258

Uncoupling by acetic acid limits growth of and acetogenesis by Clostridium thermoaceticum  

SciTech Connect

The internal pH of growing cells was measured and compared with that of nongrowing cells incubated in the absence of acetic acid. Growing cells maintained an interior about 0.6 pH units more alkaline than the exterior throughout most of batch growth (i.e., ..delta..pH = 0.6). The transmembrane electrical potential (..delta.. PSI) was also measured and was found to decrease from 140 mV at pH 7 at the beginning of growth to 80 mV when the medium had reached pH 5. The proton motive force, therefore, was 155 mV at pH 7, decreasing to 120 mV at pH 5. When further fermentation acidifed the medium below pH 5, both the ..delta..pH and the ..delta.. PSI collapsed, indicating that these cells require an internal pH of at least 5.5 to 5.7. Cells harvested from stationary phase and suspended in citrate-phosphate buffer maintained a ..delta..pH of 1.5 at external pH 5.0. This ..delta..pH was dissipated by acetic acid (at the concentrations found in the growth medium) and other weak organic acids, as well as by ionophores and inhibitors of glycolysis and of the H/sup +/-ATOase. Nongrowing cells had a ..delta.. PSI which ranged from about 116 mV at external pH 7 to about 55 mV at external pH 5 and which also was sensitive to ionophores. Since acetic acid, in its un-ionized form, diffuses passively across the cytoplasmic membrane, it effectively renders the membrane permeable to protons. It therefore seems unlikely that mutations at one or a few loci would result in C. thermoaceticum cells significantly more acetic acid tolerant than their parental type.

Baronofsky, J.J.; Schreurs, W.J.A.; Kashket, E.R.

1984-12-01

259

The potential of ¹¹C-acetate PET for monitoring the Fatty acid synthesis pathway in Tumors.  

PubMed

Positron emission tomography (PET) is a molecular imaging modality that provides the opportunity to rapidly and non-invasively visualize tumors derived from multiple organs. In order to do so, PET utilizes radiotracers, such as ¹?F-FDG and ¹¹C-acetate, whose uptake coincides with altered metabolic pathways within tumors. Increased expression and activity of enzymes in the fatty acid synthesis pathway is a frequent hallmark of cancer cells. As a result, this pathway has become a prime target for therapeutic intervention. Although multiple drugs have been developed that both directly and indirectly interfere with fatty acid synthesis, an optimal means to assess their efficacy is lacking. Given that ¹¹Cacetate is directly linked to the fatty acid synthesis pathway, this probe provides a unique opportunity to monitor lipogenic tumors by PET. Herein, we review the relevance of the fatty acid synthesis pathway in cancer. Furthermore, we address the potential utility of ¹¹C-acetate PET in imaging tumors, especially those that are not FDG-avid. Last, we discuss several therapeutic interventions that could benefit from ¹¹C-acetate PET to monitor therapeutic response in patients with certain types of cancers. PMID:23597406

Deford-Watts, Laura M; Mintz, Akiva; Kridel, Steven J

2013-03-01

260

Novel wine yeast with mutations in YAP1 that produce less acetic acid during fermentation.  

PubMed

Acetic acid, a byproduct formed during yeast alcoholic fermentation, is the main component of volatile acidity (VA). When present in high concentrations in wine, acetic acid imparts an undesirable 'vinegary' character that results in a significant reduction in quality and sales. Previously, it has been shown that saké yeast strains resistant to the antifungal cerulenin produce significantly lower levels of VA. In this study, we used a classical mutagenesis method to isolate a series of cerulenin-resistant strains, derived from a commercial diploid wine yeast. Four of the selected strains showed a consistent low-VA production phenotype after small-scale fermentation of different white and red grape musts. Specific mutations in YAP1, a gene encoding a transcription factor required for oxidative stress tolerance, were found in three of the four low-VA strains. When integrated into the genome of a haploid wine strain, the mutated YAP1 alleles partially reproduced the low-VA production phenotype of the diploid cerulenin-resistant strains, suggesting that YAP1 might play a role in (regulating) acetic acid production during fermentation. This study offers prospects for the development of low-VA wine yeast starter strains that could assist winemakers in their effort to consistently produce wine to definable quality specifications. PMID:23146134

Cordente, Antonio G; Cordero-Bueso, Gustavo; Pretorius, Isak S; Curtin, Christopher D

2012-11-12

261

Metabolomic study of interactive effects of phenol, furfural, and acetic acid on Saccharomyces cerevisiae.  

PubMed

Metabolic profiling was carried out to investigate the interactive effects of three representative inhibitors (furfural, phenol, and acetic acid) in lignocellulosic hydrolysate on Saccharomyces cerevisiae during ethanol fermentation. Our results revealed that three inhibitors exhibited significantly synergistic effects on the growth, fermentation, and some metabolites of yeast. Acetic acid exerted the most severe effects on yeast in the combination of three inhibitors, enhancing amino acids metabolism and inhibiting central carbon metabolism. The effects on yeast cells by acetic acid were enhanced by the presence of phenol and furfural, which might be owing to the loss of membrane integrity and the inhibition on metabolism. Further investigation indicated that the combination of inhibitors also exhibited antagonistic effects mainly on threonine, cadaverine, inositol, and tryptophan, weakening or reversing the effects of individual inhibitor. It might be due to the more severe damage by the combined inhibitors, and different repairing mechanism of cells in the presence of individual and combined inhibitors. Better understanding of the synergistic and antagonistic effects of the inhibitors will be helpful for the improvement of tolerant strains and the optimization of lignocellulosic fermentation. PMID:21978393

Ding, Ming-Zhu; Wang, Xin; Yang, Yang; Yuan, Ying-Jin

2011-10-01

262

Metabolism of Indole-3-acetic Acid: IV. Biological Properties of Amino Acid Conjugates.  

PubMed

The biological activity of 20 l-alpha-amino acid conjugates of indole-3-acetic acid (IAA) to stimulate cell elongation of Avena sativa coleoptile sections and to stimulate growth of soybean cotyledon tissue cultures has been examined at concentrations of 10(-4) to 10(-7)m. In the Avena coleoptile test, most of the amino acid conjugates stimulated elongation. Several of the conjugates stimulated as much elongation as IAA but their half-maximum concentrations tended to be higher. Some of the more active conjugates were alanine, glycine, lysine, serine, aspartic acid, cystine, cysteine, methionine, and glutamic acid.In the soybean cotyledon tissue culture test, all of the l-alpha-amino acid conjugates of IAA stimulated growth except for the phenylalanine, histidine, and arginine conjugates. Most of the conjugates produced responses at least as great as that caused by IAA. Conjugates with half-maximum concentrations lower than IAA included cysteine, cystine, methionine, and alanine. These conjugates exceed the IAA-induced callus growth at all tested concentrations. Other conjugates significantly better than IAA at 10(-6)m were serine, glycine, leucine, proline, and threonine. PMID:16659795

Feung, C S; Hamilton, R H; Mumma, R O

1977-01-01

263

The adsorption of acetic acid on clean and oxygen-covered Au/Pd(100) alloy surfaces  

NASA Astrophysics Data System (ADS)

The adsorption of acetic acid is studied on clean and oxygen-covered Au/Pd(100) alloys as a function of gold content by temperature-programmed desorption and reflection-absorption infrared spectroscopy. Au/Pd(100) forms ordered alloys such that, for gold coverages above ~ 0.5 monolayers, only isolated palladium atoms surrounded by gold nearest neighbors are present. Predominantly molecular acetic acid forms on Au/Pd(100) alloy surfaces for gold coverages greater than ~ 0.56 ML, and desorbs with an activation energy of ~ 59 kJ/mol. Heating this surface also forms some ?1-acetate species which decompose to form CO and hydrogen. On alloy surfaces with palladium-palladium bridge sites, ?1-acetate species initially form, but rapidly convert into ?2-species. They thermally decompose to form CO and hydrogen, with a small portion rehydrogenating to form acetic acid between 280 and 321 K depending on gold coverage. The presence of oxygen on both Pd(100) and Au/Pd(100) alloys facilitates acetate dehydrogenation so that only ?2-acetate species form on these surfaces. The presence of oxygen also serves to stabilize the acetate species.

Li, Zhenjun; Tysoe, Wilfred T.

2012-12-01

264

The conjugated auxin indole-3-acetic acid-aspartic acid promotes plant disease development.  

PubMed

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

González-Lamothe, Rocío; El Oirdi, Mohamed; Brisson, Normand; Bouarab, Kamal

2012-02-28

265

Dynamics of indole-3-acetic acid during germination of Picea abies seeds.  

PubMed

High performance liquid chromatography and combined gas chromatography-mass spectrometry were used to identify indole-3-acetic acid (IAA) and indole-3-ethanol as endogenous constituents of germinating Norway spruce (Picea abies (L.) Karst.) seeds. Indole-3-methanol was tentatively identified by multiple ion monitoring. The free IAA content of the seeds rose from about 20 ng g(-1) to about 60 ng g(-1) (dry weight) during the first five days of germination and thereafter declined to around 20 ng g(-1). Indole-3-acetic acid released by alkaline hydrolysis, which was initially present at about 110 ng g(-1), decreased to 5-10 ng g(-1) during the first week of germination. The IAA content of seed lots differing in germination behavior was investigated. The findings are discussed in relation to the metabolism of IAA in conifer seeds. PMID:14975830

Sandberg, G; Ernstsen, A

1987-06-01

266

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

PubMed

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 O-H···O and intramolecular C-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. PMID:23466319

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

2013-02-09

267

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

268

Study of acetic acid production by immobilized acetobacter cells: oxygen transfer  

Microsoft Academic Search

The immobilization of living Acetobacter cells by adsorption onto a large-surface-area ceramic support was studied in a pulsed flow reactor. The high oxygen transfer capability of the reactor enabled acetic acid production rates up to 10.4 g\\/L\\/h to be achieved. Using a simple mathematical model incorporating both internal and external mass transfer coefficients, it was shown that oxygen transfer in

C. Ghommidh; J. M. Navarro; G. Durand

1982-01-01

269

Relation of Dietary Acetate and Lactates to Dry Matter Intake and Volatile Fatty Acid Metabolism1  

Microsoft Academic Search

Effects of feeding lactates and acetate supplemental to a basal ration of two-thirds sorghum silage and one-third mixture of beet pulp and soybean oil meal were deter- mined, using five heifers in a 5 × 5 Latin- square design. Rations were fed ad libitum. Lactates were added to give 9.0% lactic acid equivalent in the ration dry matter (HL) and

S. H. Senel; F. G. Owen

1966-01-01

270

Central hypotensive effects of imidazole acetic acid and rolipram (ZK 62 711) in rats  

Microsoft Academic Search

In urethane-anaesthetized rats the administration of imidazole acetic acid (IAA), 34–272 ?g per rat intracerebroventricularly (i.c.v.), induced a dose-related fall in blood pressure. Rolipram (ZK 62 711), a potent and selective inhibitor of cyclic AMP phosphodiesterase (cAMP-PDE), also lowered the blood pressure in a dose-dependent manner when administered at the doses of 1–64 ?g per rat i.c.v. A subhypotensive dose

H. Karppanen; Pirkko Paakkari; Anna-Liisa Orma; I. Paakkari

1979-01-01

271

Temperature-Sensitive Plant Cells with Shunted Indole3Acetic Acid Conjugation  

Microsoft Academic Search

Cells of henbane (Hyoscyamus muticus L.) grow indefinitely in culture without exogenous auxin. Cells of its temperature-sensitive variant XIlB2 grow like the wild type at 26OC but die rapidly at 33°C unless auxin is added to the medium. Despite this temperature- sensitive auxin auxotrophy, XllB2 produces wild-type amounts of indole-3-acetic acid (IAA). IAA is the predominant auxin and is important

Jiirg H. Oetiker; Ceorg Aeschbacher

1997-01-01

272

Sequential induction of the ethylene biosynthetic enzymes by indole-3-acetic acid in etiolated peas  

Microsoft Academic Search

Ethylene induced an increase in the accumulation of 1-aminocyclopropane-1-carboxylate (ACC) oxidase transcript level and enzyme activity in the first internode of 5- to 6-day-old etiolated pea (Pisum sativum L.) seedlings. Indole-3-acetic acid (IAA), which stimulates ethylene production by enhancing ACC synthase activity, also caused an increase in ACC oxidase transcript and activity levels. The IAA-induced increase in ACC oxidase mRNA

Scott C. Peck; Hans Kende

1995-01-01

273

Tachyphylaxis in 12-0-Tetradecanoylphorbol Acetate and Arachidonic Acid-Induced Ear Edema  

Microsoft Academic Search

12-0-Tetradecanoylphorbol acetate (TPA) applied to mouse ears rapidly induces an edema which is maximal by 6 hr but has substantially waned by 24 hr. (This is in contrast to many inflammatory agents that cause a prolonged edema lasting many days.) Reapplication of TPA at 16-24 hr will not provoke a second edematous response although increased erythema is evident. Arachidonic acid

John M. Young; Bonnie M. Wagner; Doreen A. Spires

1983-01-01

274

Direct catalytic conversion of methane to acetic acid in an aqueous medium  

Microsoft Academic Search

ALTHOUGH methane is the most-abundant of alkanes, hazards of handling and distribution prevent known methane reserves1,2 from being fully exploited. Moreover, it is the least reactive alkane, so whereas selective conversion to more useful chemical products would be of great value, it is difficult to achieve. A useful target molecule for methane conversion is acetic acid, but existing approaches to

Minren Lin; Ayusman Sen

1994-01-01

275

(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

276

Indole3-acetic acid production from indole-3-acetonitrile in Bradyrhizobium  

Microsoft Academic Search

Bradyrhizobium japonicum USDA 110, Bradyrhizobium elkanii USDA 76 and two Bradyrhizobium sp. strains, BTA-1 and BGA-1, produced indole-3-acetamide (IAM). IAM is a characteristic intermediate in indole-3-acetic acid production from tryptophan by the tryptophan-2-monooxygenase (TMO) pathway, by other bacteria, such as Agrobacterium tumefaciens and Pseudomonas savastanoi. However, none of these strains showed any TMO activity. Moreover, the TMO gene could not

Mariá C. Vega-Hernández; Milagros León-Barrios; Ricardo Pérez-Galdona

2002-01-01

277

MoVO-based catalysts for the oxidation of ethane to ethylene and acetic acid  

Microsoft Academic Search

The influence of niobium and\\/or palladium in MoV0.4Ox on both solid state chemistry and catalytic properties in the oxidation of ethane to acetic acid and ethylene is examined. Catalysts without molybdenum (VNb0.31Pd3e-4Ox) are also studied for comparison. The structural properties of the precursors and of the catalysts obtained by calcination of precursors at 350 and 400°C are studied by X-ray

Martial Roussel; Michel Bouchard; Khalid Karim; Saleh Al-Sayari; Elisabeth Bordes-Richard

2006-01-01

278

Oxidation of ethane to ethylene and acetic acid by MoVNbO catalysts  

Microsoft Academic Search

The influence of niobium on the physicochemical properties of the MoVO system and on its catalytic properties in the oxidation of ethane to ethylene and acetic acid is examined. Solids based on MoV0.4Ox and MoV0.4Nb0.12Oy composition and calcined at 350 or 400°C were studied by X-ray diffraction, and by laser Raman and X-ray photoelectron spectroscopies. Their reactivity during reduction and

M. Roussel; M. Bouchard; E. Bordes-Richard; K. Karim; S. Al-Sayari

2005-01-01

279

Brettanomyces bruxellensis : effect of oxygen on growth and acetic acid production  

Microsoft Academic Search

The influence of the oxygen supply on the growth, acetic acid and ethanol production by Brettanomyces bruxellensis in a glucose medium was investigated with different air flow rates in the range 0-300 l h-1 (0-0.5 vvm). This study shows that growth of this yeast is stimulated by moderate aeration. The optimal oxygen supply for cellular synthesis was an oxygen transfer

M. G. Aguilar Uscanga; M.-L. Délia; P. Strehaiano

2003-01-01

280

Evaluation of adsorption effects on measurements of ammonia, acetic acid, and methanol  

Microsoft Academic Search

We examined how adsorption and desorption of gases from inlets and a cell could affect the accuracy of closed-cell FTIR measurements of carbon dioxide (CO2), carbon monoxide (CO), methane (CH4), nitric oxide (NO), nitrogen dioxide (NO2), methanol (CH3OH), acetic acid (CH3COOH), and ammonia (NH3). When standards were delivered to the cell through a stainless steel inlet, temporarily reduced transmission was

R. J. Yokelson; T. J. Christian; I. T. Bertschi; W. M. Hao

2003-01-01

281

Interactions of human serum albumin with retinoic acid, retinal and retinyl acetate  

Microsoft Academic Search

Human serum albumin (HSA), a major plasma protein and plasma-derived therapeutic, interacts with a wide variety of drugs and native plasma metabolites. In this study the interactions between HSA and small lipophilic molecules all-trans retinoic acid (RA), all-trans retinaldehyde (retinal, RAL) and all-trans retinyl acetate (RAC) were investigated by UV–vis absorption spectroscopy, fluorescence spectroscopy and circular dichroism (CD). This paper

Elena Karnaukhova

2007-01-01

282

Indole3-acetic Acid Sensitization of Phytochrome-Controlled Growth of Coleoptile Sections  

Microsoft Academic Search

Addition of 6 mu M indole-3-acetic acid (IAA) to incubation buffer increases the sensitivity of coleoptile sections cut from dark-grown Avena sativa L. cv. Lodi to red light by a factor of 10,000, relative to the response in the absence of added IAA, without changing the maximum amount of light-induced growth. From 0.03 to 4 mu M IAA sections show

James R. Shinkle; Winslow R. Briggs

1984-01-01

283

Effect of oleic acid plasticizer on chitosan–lithium acetate solid polymer electrolytes  

Microsoft Academic Search

Plasticized polymer electrolytes composed of chitosan as the host polymer, oleic acid (OA) as the plasticizer and lithium acetate (LiOAc) as the doping salt were prepared by the solution cast technique. These complexes with different amounts of salts and plasticizers were investigated as possible ionic conducting polymers. The highest ionic conductivity of the plasticized chitosan–LiOAc was ?10?5 Scm?1 for the

M. Z. A. Yahya; A. K. Arof

2003-01-01

284

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

285

Indole3-acetic acid in microbial and microorganism-plant signaling  

Microsoft Academic Search

Diverse bacterial species possess the ability to produce the auxin phytohormone indole-3-acetic acid (IAA). Different biosynthesis pathways have been identified and redundancy for IAA biosynthesis is widespread among plant-associated bacteria. Interactions between IAA-producing bacteria and plants lead to diverse outcomes on the plant side, varying from pathogenesis to phytostimulation. Reviewing the role of bacterial IAA in different microorganism-plant interactions highlights

Stijn Spaepen; Jos Vanderleyden; Roseline Remans

2007-01-01

286

Improving the environmental profile of wood panels via co-production of ethanol and acetic acid.  

PubMed

The oriented strand board (OSB) biorefinery is an emerging technology that could improve the building, transportation, and chemical sectors' environmental profiles. By adding a hot water extraction stage to conventional OSB panel manufacturing, hemicellulose polysaccharides can be extracted from wood strands and converted to renewably sourced ethanol and acetic acid. Replacing fossil-based gasoline and acetic acid has the potential to reduce greenhouse gas (GHG) emissions, among other possible impacts. At the same time, hemicellulose extraction could improve the environmental profile of OSB panels by reducing the level of volatile organic compounds (VOCs) emitted during manufacturing. In this study, the life cycle significance of such GHG, VOC, and other emission reductions was investigated. A process model was developed based on a mix of laboratory and industrial-level mass and energy flow data. Using these data a life cycle assessment (LCA) model was built. Sensitive process parameters were identified and used to develop a target production scenario for the OSB biorefinery. The findings suggest that the OSB biorefinery's deployment could substantially improve human and ecosystem health via reduction of select VOCs compared to conventionally produced OSB, gasoline, and acetic acid. Technological advancements are needed, however, to achieve desirable GHG reductions. PMID:21967719

Earles, J Mason; Halog, Anthony; Shaler, Stephen

2011-10-17

287

Dual Antiplatelet Regime Versus Acetyl-acetic Acid for Carotid Artery Stenting  

SciTech Connect

Carotid artery stenting has been proposed as an option treatment of carotid artery stenosis. The aim of this single-institution study is to compare the dual-antiplatelet treatment and heparin combined with acetyl-acetic acid, in patients who underwent carotid artery stenting. We compared 2 groups of 50 patents each who underwent carotid artery stenting for primary atherosclerotic disease. Group A received heparin for 24 h combined with 325 mg acetyl-acetic acid and group B received 250 mg ticlopidine twice a day combined with 325 mg acetyl-acetic acid. Outcome measurements included 30-day bleeding and neurological complications and 30-day thrombosis/occlusion rates. The neurological complications were 16% in group A and 2% in group B (p < 0.05). Bleeding complications occurred in 4% in group A and 2% in group B (p > 0.05). The 30-day thrombosis/occlusion rate was 2% in group A and 0% in group B (p > 0.05). Dual antiplatelet treatment is recommended in all patients undergoing carotid artery stenting.

Dalainas, Ilias, E-mail: hdlns@freemail.gr; Nano, Giovanni; Bianchi, Paolo; Stegher, Silvia; Malacrida, Giovanni; Tealdi, Domenico G. [University of Milan, Istituto Policlinico San Donato, 1st Unit of Vascular Surgery (Italy)

2006-08-15

288

Intermolecular proton-transfer in acetic acid clusters induced by vacuum-ultraviolet photoionization  

NASA Astrophysics Data System (ADS)

Infrared (IR) spectroscopy based on vacuum-ultraviolet one-photon ionization detection was carried out to investigate geometric structures of neutral and cationic clusters of acetic acid: (CH3COOH)2, CH3COOH-CH3OH, and CH3COOH-H2O. All the neutral clusters have cyclic-type intermolecular structures, in which acetic acid and solvent molecules act as both hydrogen donors and acceptors, and two hydrogen-bonds are formed. On the other hand, (CH3COOH)2+ and (CH3COOH-CH3OH)+ form proton-transferred structures, where the acetic acid moiety donates the proton to the counter molecule. (CH3COOH-H2O)+ has a non-proton-transferred structure, where CH3COOH+ and H2O are hydrogen-bonded. The origin of these structural differences among the cluster cations is discussed with the relative sizes of the proton affinities of the cluster components and the potential energy curves along the proton-transfer coordinate.

Ohta, Keisuke; Matsuda, Yoshiyuki; Mikami, Naohiko; Fujii, Asuka

2009-11-01

289

Energy metabolism of a unique acetic acid bacterium, Asaia bogorensis, that lacks ethanol oxidation activity.  

PubMed

Acetic acid bacteria (AAB) are known as a vinegar producer on account of their ability to accumulate a high concentration of acetic acid due to oxidative fermentation linking the ethanol oxidation respiratory chain. Reactions in oxidative fermentation cause poor growth because a large amount of the carbon source is oxidized incompletely and the harmful oxidized products are accumulated almost stoichiometrically in the culture medium during growth, but a newly identified AAB, Asaia, has shown unusual properties, including scanty acetic acid production and rapid growth, as compared with known AAB as Acetobacter, Gluconobacter, and Gluconacetobacter. To understand these unique properties of Asaia in more detail, the respiratory chain and energetics of this strain were investigated. It was found that Asaia lacks quinoprotein alcohol dehydrogenase, but has other sugar and sugar alcohol-oxidizing enzymes specific to the respiratory chain of Gluconobacter, especially quinoprotein glycerol dehydrogenase. It was also found that Asaia has a cyanide-sensitive cytochrome bo(3)-type ubiquinol oxidase as sole terminal oxidase in the respiratory chain, and that it exhibits a higher H(+)/O ratio. PMID:18391448

Ano, Yoshitaka; Toyama, Hirohide; Adachi, Osao; Matsushita, Kazunobu

2008-04-07

290

Acetic acid and lithium chloride effects on hydrothermal carbonization of lignocellulosic biomass.  

PubMed

As a renewable non-food resource, lignocellulosic biomass has great potential as an energy source or feedstock for further conversion. However, challenges exist with supply logistics of this geographically scattered and perishable resource. Hydrothermal carbonization treats any kind of biomass in 200 to 260°C compressed water under an inert atmosphere to produce a hydrophobic solid of reduced mass and increased fuel value. A maximum in higher heating value (HHV) was found when 0.4 g of acetic acid was added per g of biomass. If 1g of LiCl and 0.4 g of acetic acid were added per g of biomass to the initial reaction solution, a 30% increase in HHV was found compared to the pretreatment with no additives, along with greater mass reduction. LiCl addition also reduces reaction pressure. Addition of acetic acid and/or LiCl to hydrothermal carbonization each contribute to increased HHV and reduced mass yield of the solid product. PMID:21411315

Lynam, Joan G; Coronella, Charles J; Yan, Wei; Reza, Mohammad T; Vasquez, Victor R

2011-02-13

291

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.

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

2013-01-01

292

Response surface methodological approach for Rhizomucor miehei lipase-mediated esterification of ?-terpineol with propionic acid and acetic anhydride  

Microsoft Academic Search

Esterification of ?-terpineol with acetic anhydride or propionic acid mediated by Rhizomucor miehei lipase was subjected to a response surface study in order to optimize conditions for maximum esterification. The variables\\u000a were enzyme\\/substrate (acid) ratio, ?-terpineol concentration and incubation period using lipase from R. miehei. Between acetic anhydride and propionic acid, the former showed better yields at lower enzyme\\/substrate ratios

Pramila Rao; Soundar Divakar

2002-01-01

293

SEPARATING, CHARACTERIZATION AND APPLICATION OF ALFA GRASS (Stipa tenacissima) CHEMICAL COMPONENTS 1. PULPING OF ALFA GRASS WITH FORMIC ACID\\/ACETIC ACID MIXTURE  

Microsoft Academic Search

The pulping of Alfa grass at atmospheric pressure using a mixture of formic acid\\/acetic acid\\/water was investigated. Different pulping variables were studied, especially the percentage of formic acid, acetic acid and water, pulping time, the liquor to fibre ratio and impregnation time. The obtained unbleached pulps were analysed in accordance with the Kappa number and the degree of polymerisation. The

Houcine Ammar; Hichem Mallek; Fatma Abdelkefi; Bouchra Benjelloun-Mlayeh; Rachid El Gharbi

294

Reactive uptake of acetic acid on calcite and nitric acid reacted calcite aerosol in an environmental reaction chamber.  

PubMed

The heterogeneous chemistry of gas-phase acetic acid with CaCO(3)(calcite) aerosol was studied under varying conditions of relative humidity (RH) in an environmental reaction chamber. Infrared spectroscopy showed the loss of gas-phase reactant and the appearance of a gaseous product species, CO(2). The acetic acid is observed to adsorb onto the calcite aerosol through both a fast and a slow uptake channel. While the fast channel is relatively independent of RH, the slow channel exhibits enhanced uptake and reaction as the RH is increased. In additional experiments, the calcite aerosol was exposed to both nitric and acetic acids in the presence of water vapor. The rapid conversion of the particulate carbonate to nitrate and subsequent deliquescence significantly enhances the uptake and reaction of acetic acid. These results suggest a possible mechanism for observed correlations between particulate nitrate and organic acids in the atmosphere. Calcium rich mineral dust may be an important sink for simple organic acids. PMID:18075693

Prince, Amy Preszler; Kleiber, Paul D; Grassian, Vicki H; Young, Mark A

2007-11-21

295

Physicochemical interactions of the isomers of aminobenzoic acid with sodium acetate in solid-matrix room-temperature luminescence spectroscopy  

SciTech Connect

The room-temperature fluorescence and room-temperature phosphorescence quantum yields of the isomers of aminobenzoic acid adsorbed on sodium acetate were obtained. These data were correlated with solution fluorescence data and diffuse reflectance infrared spectral data from the three isomers. The results yielded insights into the bonding interactions of the aminobenzoic acid isomers with sodium acetate. In particular, the specific structural and bonding characteristics of the isomers with sodium acetate were very important in determining whether a high room-temperature phosphorescence quantum yield would be obtained from a given isomer.

Ramasamy, S.M.; Hurtubise, R.J. (Univ. of Wyoming, Laramie (United States))

1990-01-01

296

Bacterial strains from human feces that reduce CO2 to acetic acid.  

PubMed Central

We used dilutions of fecal suspensions from a human volunteer to enrich cultures for bacteria that reduce CO2 to acetate in the colon. The soluble enrichment substrates used were glucose, methanol, formate, and vanillate, which were used with a gas phase that contained 80% N2 and 20% CO2. The gaseous enrichment substrates used were 80% H2-20% CO2 and 50% CO-50% CO2. We isolated three different strains that produced acetate from CO2. One strain produced acetate from methanol, vanillate, H2-CO2, glucose, and other sugars. The other two strains did not form acetate from methanol or vanillate. Both of the latter strains formed acetate from glucose and other sugars, but only one of these strains formed acetate from H2-CO2. Both of these strains cometabolized formate. However, none of the enrichment cultures or pure cultures used CO or formate as a substrate for growth. The two strains that produced acetate from H2 and CO2 grew slowly when the gases alone were used as substrates, but they rapidly cometabolized H2 and CO2 when they were grown with organic substrates. The ability of all of the strains to produce acetate from CO2 and/or other one-carbon precursors was verified by determining the radioactivity of the methyl and carboxyl groups of the acetate formed after growth with 14CO2 or other radioactively labeled one-carbon precursors.

Wolin, M J; Miller, T L

1993-01-01

297

Attractiveness to mexican fruit flies of combinations of acetic acid with ammonium\\/amino attractants with emphasis on effects of hunger  

Microsoft Academic Search

Ammonium acetate was more attractive than other ammonium salts to Mexican fruit flies (Anastrepha ludens) in an orchard test. We hypothesized that acetic acid enhanced the attractiveness of ammonia in the orchard test and that acetic acid may similarly enhance attractiveness of AMPu, an attractant consisting of a mixture of ammonium bicarbonate or ammonium carbonate, methylamine HCl, and putrescine. In

D. C. Robacker; D. S. Moreno; A. B. Demilo

1996-01-01

298

Oxime Acetates: Substrates for Acetylcholinesterase.  

National Technical Information Service (NTIS)

Oxime acetates function as typical substrates for acetylcholinesterase (AChE). Both syn 3- and syn 4-PAM acetates are rapidly hydrolyzed. Both are highly water soluble and give large changes in molar absorbance upon hydrolysis. Hence, they have potential ...

G. M. Steinberg J. P. Maddox L. J. Szafraniec L. M. Berkowitz N. C. Thomas

1971-01-01

299

Support and promoter effects in the selective oxidation of ethane to acetic acid catalyzed by Mo-V-Nb oxides  

Microsoft Academic Search

Catalysts based on Mo-V-Nb oxides were examined in bulk and supported forms for the oxidation of ethane to ethene and acetic acid. Bulk Mo0.61V0.31Nb0.08Ox powders showed rates and selectivities similar to those in previous reports. Precipitation in the presence of colloidal TiO2 led to a 10-fold increase in ethene and acetic acid rates (per active oxide) without significant changes in

Xuebing Li; Enrique Iglesia

2008-01-01

300

Anodic oxidation of 3,4-dihydroxyphenylacetic acid on carbon electrodes in acetic acid solutions.  

PubMed

The electrochemical oxidation of 3,4-dihydroxyphenylacetic acid (DOPAC) on a carbon fiber microelectrode (CF) and a glassy carbon macroelectrode (GC) in glacial acetic acid solutions was investigated using voltammetric techniques. Voltammograms recorded at these electrodes show well-defined single waves or peaks. The proposed mechanism of the anodic oxidation of DOPAC consists of two successive one-electron one-proton steps. The loss of the first electron proceeds irreversibly and determines the overall rate of the electrode process. This stage is accompanied by the generation of an unstable phenoxyl radical in position 4 of the aromatic ring. The second stage of the electrode reaction produces substituted orto-quinone as the final product of the electrode process of DOPAC. DOPAC exhibits more antioxidative power than synthetic BHT and can be useful in food protection against reactive oxygen species. The results presented can help to explain biochemical and antioxidative properties of DOPAC in a living cell and can be useful in determination of this compound in real samples. PMID:20004625

Michalkiewicz, Slawomir; Skorupa, Agata

2009-12-03

301

Kallolide A acetate pyrazoline  

PubMed Central

In the crystal structure of kallolide A acetate pyrazoline [systematic name: 7-methyl-16-oxo-4,10-bis­(prop-1-en-2-yl)-17,18-dioxa-14,15-diaza­tetra­cyclo­[9.4.2.16,9.01,12]octa­deca-6,8,14-trien-5-yl acetate], C23H28N2O5, there is a 12-member­ed carbon macrocyclic structure. In addition, there is a tris­ubstituted furan ring, an approximately planar ?-lactone ring [maximum deviation of 0.057?(3)?Å] and a pyraz­oline ring, the latter in an envelope conformation. The pyrazoline and the ?-lactone rings are fused in a cis configuration. In the crystal, mol­ecules are linked by weak C—H?O inter­actions, forming a two-dimensional network parallel to (001). An intra­molecular C—H?O hydrogen bond is also present.

Rodriguez-Escudero, Idaliz; Marrero, Jeffrey; Rodriguez, Abimael D.

2012-01-01

302

Involvement of yeast HSP90 isoforms in response to stress and cell death induced by acetic acid.  

PubMed

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, Belém; Fernandes, Angela; Carreto, Laura; Rodrigues, Fernando; Holcik, Martin; Santos, Manuel A S; Ludovico, Paula

2013-08-15

303

Intramolecular carbon isotopic analysis of acetic acid by direct injection of aqueous solution  

Microsoft Academic Search

We report an improved method for determining the intramolecular carbon isotopic composition of acetate using direct injection of aqueous samples. The system builds upon prior work that established pyrolytic conditions for online analysis and represents a significant advance in that it requires minimal preparation for samples containing as little as 1mM sodium acetate in aqueous solution. The technique is applicable

Burt Thomas; Katherine H. Freeman; Michael A. Arthur

2009-01-01

304

Plasma acetate turnover and oxidation.  

PubMed Central

Plasma acetate turnover and oxidation were determined in 11 healthy subjects by the constant infusion of a trace amount of [1-14C]acetate for 6 h. The subjects ages ranged from 22 to 57 yr. There was a positive correlation (P less than 0.001) between plasma acetate concentration and turnover rate, and a negative correlation (P less than 0.001) between turnover and age. The plasma acetate concentration in the subjects 22--28 yr old was 0.17 vs. 0.13 mM (P less than 0.02) in subjects 40--57 yr old. The plasma acetate turnover rate was also greater in the younger age group (8.23 +/- 0.66 vs. 4.98 +/- 0.64 mumol/min . kg, P less than 0.01). Approximately 90% of the plasma acetate turnover was immediately oxidized to CO2 in both age groups, however, 13.2 +/- 0.89% of the CO2 output in the younger group was derived from plasma acetate oxidation compared to 7.9 +/- 0.94% in the older group (P less than 0.01). The mean plasma acetate concentration, turnover, and oxidation in six cancer patients 47--63 yr old were similar to the values observed in the age-matched healthy subjects. Uptake or output of acetate by various tissues was measured by arterial-venous plasma acetate concentration differences. In seven of eight subjects undergoing elective surgery, the arterial-portal venous concentration difference was negative, which indicated that the gastrointestinal tract can contribute to plasma acetate production. Uptake of plasma acetate by both the leg and liver appeared to be dictated by the arterial acetate concentration. Net production of acetate by both the leg and liver was most often observed at arterial plasma acetate concentrations less than 0.08 mM.

Skutches, C L; Holroyde, C P; Myers, R N; Paul, P; Reichard, G A

1979-01-01

305

Purification and partial characterization of acetic acid esterase from malted finger millet (Eleusine coracana, Indaf-15).  

PubMed

Acetic acid esterase (EC 3.1.1.6) cleaves the acetyl groups substituted at O-2/O-3 of the xylan backbone of arabinoxylans and is known to modulate their functional properties. To date, this enzyme from cereals has not received much attention. In the present study, acetic acid esterase from 72 h ragi malt was isolated and purified to apparent homogeneity by a four-step purification, i.e., ammonium sulfate precipitation, DEAE-cellulose, Sephacryl S-200, and phenyl-Sepharose column chromatography, with a recovery of 0.36% and a fold purification of 34. The products liberated from alpha-NA and PNPA by the action of purified ragi acetic acid esterase were authenticated by ESI-MS and 1H NMR. The pH and temperature optima of the enzyme were found to be 7.5 and 45 degrees C, respectively. The enzyme is stable in the pH range of 6.0-9.0 and temperature range of 30-40 degrees C. The activation energy of the enzymatic reaction was found to be 7.29 kJ mol-1. The apparent Km and Vmax of the purified acetic acid esterase for alpha-NA were 0.04 microM and 0.175 microM min-1 mL-1, respectively. The molecular weight of the native enzyme was found to be 79.4 kDa by GPC whereas the denatured enzyme was found to be 19.7 kDa on SDS, indicating it to be a tetramer. EDTA, citric acid, and metal ions such as Fe+3 and Cu+2 increased the activity while Ni+2, Ca+2, Co+2, Ba+2, Mg+2, Mn+2, Zn+2, and Al+3 reduced the activity. Group-specific reagents such as eserine and PCMB at 25 mM concentration completely inhibited the enzyme while iodoacetamide did not have any effect. Eserine was found to be a competitive inhibitor. PMID:17263491

Latha, G Madhavi; Muralikrishna, G

2007-02-01

306

Effect of acetic acid on Saccharomyces carlsbergensis ATCC 6269 batch ethanol production monitored by flow cytometry.  

PubMed

Bioethanol produced from lignocellulosic materials has been considered a sustainable alternative fuel. Such type of raw materials have a huge potential, but their hydrolysis into mono-sugars releases toxic compounds such as weak acids, which affect the microorganisms' physiology, inhibiting the growth and ethanol production. Acetic acid (HAc) is the most abundant weak acid in the lignocellulosic materials hydrolysates. In order to understand the physiological changes of Saccharomyces carlsbergensis when fermenting in the presence of different acetic acid (HAc) concentrations, the yeast growth was monitored by multi-parameter flow cytometry at same time that the ethanol production was assessed. The membrane potential stain DiOC(6)(3) fluorescence intensity decreased as the HAc concentration increased, which was attributed to the plasmic membrane potential reduction as a result of the toxic effect of the HAc undissociated form. Nevertheless, the proportion of cells with permeabilized membrane did not increase with the HAc concentration increase. Fermentations ending at lower external pH and higher ethanol concentrations depicted the highest proportions of permeabilized cells and cells with increased reactive oxygen species levels. Flow cytometry allowed monitoring, near real time (at-line), the physiological states of the yeast during the fermentations. The information obtained can be used to optimize culture conditions to improve bioethanol production. PMID:22971830

Freitas, Cláudia; Neves, Elisabete; Reis, Alberto; Passarinho, Paula C; da Silva, Teresa Lopes

2012-09-13

307

Gluconacetobacter kakiaceti sp. nov., an acetic acid bacterium isolated from a traditional Japanese fruit vinegar.  

PubMed

Two novel acetic acid bacteria, strains G5-1(T) and I5-1, were isolated from traditional kaki vinegar (produced from fruits of kaki, Diospyros kaki Thunb.), collected in Kumamoto Prefecture, Japan. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strains G5-1(T) and I5-1 formed a distinct subline in the genus Gluconacetobacter and were closely related to Gluconacetobacter swingsii DST GL01(T) (99.3% 16S rRNA gene sequence similarity). The isolates showed 96-100% DNA-DNA relatedness with each other, but <53% DNA-DNA relatedness with closely related members of the genus Gluconacetobacter. The isolates could be distinguished from closely related members of the genus Gluconacetobacter by not producing 2- and 5-ketogluconic acids from glucose, producing cellulose, growing without acetic acid and with 30% (w/v) d-glucose, and producing acid from sugars and alcohols. Furthermore, the genomic DNA G+C contents of strains G5-1(T) and I5-1 were a little higher than those of their closest phylogenetic neighbours. On the basis of the phenotypic characteristics and phylogenetic position, strains G5-1(T) and I5-1 are assigned to a novel species, for which the name Gluconacetobacter kakiaceti sp. nov. is proposed; the type strain is G5-1(T) (=JCM 25156(T)=NRIC 0798(T)=LMG 26206(T)). PMID:21841006

Iino, Takao; Suzuki, Rei; Tanaka, Naoto; Kosako, Yoshimasa; Ohkuma, Moriya; Komagata, Kazuo; Uchimura, Tai

2011-08-12

308

Benzylidene acetal type bridged nucleic acids: changes in properties upon cleavage of the bridge triggered by external stimuli.  

PubMed

Four classes of benzylidene acetal type bridged nucleic acids (BA-BNAs) were designed with 2',4'-bridged structures that cleaved upon exposure to appropriate external stimuli. Cleavage of 6-nitroveratrylidene and 2-nitrobenzylidene acetal type BNA bridges occurred upon photoirradiation and subsequent treatment with thiol caused changes in secondary structure to afford 4'-C-hydroxymethyl RNA. Benzylidene and 4-nitrobenzylidene acetal type BNA responded to acids and reducing agents, respectively, resulting in hydrolysis of the acetal-bridged structure. Cleavage of the bridge removed sugar conformational restrictions and changed the duplex- and triplex-forming properties of the BNA-modified oligonucleotides. Moreover, oligonucleotides incorporating a single BA-BNA modification had considerably improved stability toward 3'-exonuclease, which was lost upon cleavage of the bridge. Thus, these new BNAs may be useful as therapeutic and detection tools by sensing various environments. PMID:21644240

Morihiro, Kunihiko; Kodama, Tetsuya; Obika, Satoshi

2011-06-03

309

A PCR assay for detection of acetic acid-tolerant lactic acid bacteria in acidic food products.  

PubMed

A PCR assay for the detection of acetic acid-tolerant lactic acid bacteria in the genera of Lactobacillus and Pediococcus was developed in this study. Primers targeting the bacterial 16S rRNA gene were newly designed and used in this PCR assay. To determine the specificity of the assay, 56 different bacterial strains (of 33 genera), 2 fungi, 3 animals, and 4 plants were tested. Results were positive for most tested bacterial members of 16S rRNA gene-based phylogenetic groups (classified in the Lactobacillus casei and Pediococcus group), including Lactobacillus fructivorans, Lactobacillus brevis, Lactobacillus buchneri, Lactobacillus plantarum, and Lactobacillus paracasei. For all other bacterial strains and eukaryote tested, results were negative. Bacterial DNA for PCR was prepared with a simple procedure with the use of Chelex 100 resin from culture after growth in deMan Rogosa Sharpe broth (pH 6.0). To test this PCR assay for the monitoring of the acetic acid-tolerant lactic acid bacteria, L. fructivorans was inoculated into several acidic food as an indicator. Before the PCR, the inoculation of 10 to 50 CFU of bacteria per g of food was followed by a 28-h enrichment culture step, and the PCR assay allowed the detection of bacterial cells. Including the enrichment culture step, the entire PCR detection process can be completed within 30 h. PMID:15035383

Nakano, Shigeru; Matsumura, Atsushi; Yamada, Toshihiro

2004-03-01

310

1-[3-(4-Nitro-phen-yl)propano-yl]urea acetic acid monosolvate  

PubMed Central

The title compound, C10H11N3O4·C2H4O2, was prepared by an electrochemical technique. In the crystal, acetic acid mol­ecules are involved in hydrogen bonding to two separate propano­ylurea mol­ecules, acting as a donor in an O—H?O inter­action and as an acceptor in two N—H?O inter­actions. The propano­ylurea mol­ecules inter­act with each other via N—H?O hydrogen bonds. C—H?O inter­actions also stabilize the crystal structure.

Merzouki, Soraya; Mouats, Chabane; Bendeif, El-Eulmi; Pillet, Sebastien; Bouchouit, Karim

2011-01-01

311

1-[3-(4-Nitro-phen-yl)propano-yl]urea acetic acid monosolvate.  

PubMed

The title compound, C(10)H(11)N(3)O(4)·C(2)H(4)O(2), was prepared by an electrochemical technique. In the crystal, acetic acid mol-ecules are involved in hydrogen bonding to two separate propano-ylurea mol-ecules, acting as a donor in an O-H?O inter-action and as an acceptor in two N-H?O inter-actions. The propano-ylurea mol-ecules inter-act with each other via N-H?O hydrogen bonds. C-H?O inter-actions also stabilize the crystal structure. PMID:22219927

Merzouki, Soraya; Mouats, Chabane; Bendeif, El-Eulmi; Pillet, Sebastien; Bouchouit, Karim

2011-10-08

312

Structural characterization and auxin properties of dichlorinated indole-3-acetic acids  

Microsoft Academic Search

The dichlorinated indole-3-acetic acids: 4,5-Cl2-IAA, 4,6-Cl2-IAA, 4,7-Cl2-IAA, 5,6-Cl2-IAA, 5,7-Cl2-IAA and 6,7-Cl2-IAA were synthesized and characterized by X-ray structure analysis to unambiguously identify the substances for bioassays required to establish structure activity relationships of auxins and their analogues. Straight-growth tests were performed on Avena sativa coleoptiles to correlate their auxin activity with molecular properties which could reveal information on the topology

Snježana Antoli´; Branka Salopek; Biserka Koji?-Prodi?; Volker Magnus; Jerry D. Cohen

1999-01-01

313

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

314

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

315

Shape-controlled synthesis of octahedral ?-NaYF 4 and its rare earth doped submicrometer particles in acetic acid  

Microsoft Academic Search

Submicrometer sized pure cubic phase, Eu3+ doped, and Yb3+\\/Er3+ co-doped ?-NaYF4 particles with octahedral morphology have been prepared in acetic acid. The acetate anion plays a critical role in the formation\\u000a of such symmetric octahedral structures through its selective adsorption on the (111) faces of the products. The size of the\\u000a as-prepared octahedra can be tuned by varying the amount

Li Gao; Xin Ge; Zhanli Chai; Guohai Xu; Xin Wang; Cheng Wang

2009-01-01

316

Room-temperature luminescence properties of rho-aminobenzoic acid adsorbed on sodium acetate-sodium chloride mixtures  

Microsoft Academic Search

Room-temperature fluorescence and phosphorescence quantum yield, triplet formation efficiency, and phosphorescence lifetime values were obtained for the anion of rho-aminobenzoic acid adsorbed on sodium acetate and several sodium acetate-sodium chloride mixtures. From these data, rate constants for phosphorescence and for radiationless transition from the triplet state were obtained. The results revealed that several factors are important for maximum room-temperature phosphorescence

S. M. Ramasamy; R. J. Hurtubise

1987-01-01

317

Fatty acid synthesis in the oil palm ( Elaeis guineensis ): Incorporation of acetate by tissue slices of the developing fruit  

Microsoft Academic Search

Oil palm (E. guineensis) fruits at three stages of development were studied. At week 12–13 after anthesis, the endosperm had started accumulating\\u000a oil and tissue slices incorporated [1-14C] acetate into fatty acids which resembled those found in the mature endosperm. The mesocarp contained very little oil and\\u000a incorporated acetate into polar lipids. At week 16–17, the mesocarp started to accumulate

Khaik-Cheang Oo; Sau-Keen Teh; Hun-Teik Khor; Augustine S. H. Ong

1985-01-01

318

Different Temperature Optima for Methane Formation When Enrichments from Acid Peat Are Supplemented with Acetate or Hydrogen  

PubMed Central

Laboratory studies of methane formation in peat samples from an acid subarctic mire in Sweden indicated the presence of a low-temperature-adapted methanogenic flora. Enrichment culture studies with ethanol, acetate, hydrogen, or a combination of these as substrate for methane formation provided evidence for the existence of two different methanogenic populations in the peat: one, unaffected by hydrogen and using acetate, with a temperature optimum at 20°C; the other, oxidizing hydrogen, with a temperature optimum at ca. 28°C.

Svensson, Bo H.

1984-01-01

319

Observation of SERS of picolinic acid and nicotinic acid using cellulose acetate films doped with Ag fine particles  

NASA Astrophysics Data System (ADS)

Surface enhanced Raman (SER) spectra of picolinic acid and nicotinic acid were observed using cellulose acetate (CA) films doped with Ag fine particles. The spectra obtained match those reported for silver colloids though some differences in SER band intensity were observed. The ease of preparation and handling of the CA film method renders it more useful than the colloid method for the observation of SER spectra.

Imai, Yoshika; Kurokawa, Yoichi; Hara, Masaru; Fukushima, Michiko

1997-10-01

320

A solvent extraction approach to recover acetic acid from mixed waste acids produced during semiconductor wafer process  

Microsoft Academic Search

Recovery of acetic acid (HAc) from the waste etching solution discharged from silicon wafer manufacturing process has been attempted by using solvent extraction process. For this purpose 2-ethylhexyl alcohol (EHA) was used as organic solvent. In the pre-treatment stage >99% silicon and hydrofluoric acid was removed from the solution by precipitation. The synthesized product, Na2SiF6 having 98.2% purity was considered

Chang-Hoon Shin; Ju-Yup Kim; Jun-Young Kim; Hyun-Sang Kim; Hyang-Sook Lee; Debasish Mohapatra; Jae-Woo Ahn; Jong-Gwan Ahn; Wookeun Bae

2009-01-01

321

Carriers for abscisic acid and indole-3-acetic acid in primary roots: their regional localisation and thermodynamic driving forces  

Microsoft Academic Search

A carrier for the uptake of abscisic acid (ABA) is present in the tips and elongating zones of primary roots of both leguminous (runner bean, French bean, pea) and non-leguminous (sunflower, maize) seedlings. No ABA carrier was present in more mature root regions. For indole-3-acetic acid both carrier-mediated uptake and a 2,3,5-triiodobenzoate-sensitive efflux component are present in growing and in

M. C. Astle; P. H. Rubery

1983-01-01

322

Lateral root formation in rice ( Oryza Sativa L.): differential effects of indole-3-acetic acid and indole-3-butyric acid  

Microsoft Academic Search

Comparative effects of indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) on lateral root (LR) formation were studied using 2-day-old seedlings of IR8 rice (Oryza sativa L.). Results showed that IBA at all concentrations (0.8–500 nmol\\/L) increased the number of LRs in the seminal root. However exogenous IAA, failed to increase the number of LRs. On the other hand, both IBA

Shucai Wang; Shin Taketa; Masahiko Ichii; Langlai Xu; Kai Xia; Xie Zhou

2003-01-01

323

Azospirillum brasilense Produces the Auxin-Like Phenylacetic Acid by Using the Key Enzyme for Indole3Acetic Acid Biosynthesis  

Microsoft Academic Search

Received 23 August 2004\\/Accepted 28 October 2004 An antimicrobial compound was isolated from Azospirillum brasilense culture extracts by high-performance liquid chromatography and further identified by gas chromatography-mass spectrometry as the auxin-like molecule, phenylacetic acid (PAA). PAA synthesis was found to be mediated by the indole-3-pyruvate decar- boxylase, previously identified as a key enzyme in indole-3-acetic acid (IAA) production in A.

E. Somers; D. Ptacek; P. Gysegom; M. Srinivasan; J. Vanderleyden

2005-01-01

324

Effects of indole-3-acetic acid on croton oil- and arachidonic acid-induced mouse ear edema  

Microsoft Academic Search

The indole-3-acetic acid (IAA) is a plant growth hormone (auxin) being considered as a tryptophan metabolite in animals. The main purpose of this work was to verify IAA's topical anti-inflammatory action using croton oil- or arachidonic acid-induced mouse ear edema, in comparison to known anti-inflammatory agents. IAA antioxidant activity was also verified by measuring the inhibition of brain homogenate lipid

L. H. Jones; D. S. P. Abdalla; J. C. Freitas

1995-01-01

325

Biosynthesis of Indole-3-Acetic Acid by the Pine Ectomycorrhizal Fungus Pisolithus tinctorius  

PubMed Central

Previous work has indicated that anatomical and morphological changes (stunting and dichotomy) in roots of various conifers may be influenced by plant-growth-regulating substances secreted by mycorrhizae. Indole-3-acetic acid (IAA) has been tentatively identified as a major auxin produced by some selected ectomycorrhizae. We report the isolation and detection of IAA as a secondary metabolite from Pisolithus tinctorius by thin-layer chromatography, high-performance liquid chromatography (HPLC), enzyme-linked immunosorbent (monoclonal antibody) assay (ELISA), and unequivocal identification by gas chromatography-mass spectrometry (GC-MS). The thin-layer chromatography methods for auxin isolation described here are novel, with the use of heptane-acetone-glacial acetic acid as the migrating solvent and formaldehyde, H2SO4, and vanadate in detection. The acidic extract of the culture supernatant was methylated with ethereal diazomethane to detect IAA as methyl-3-IAA by HPLC, ELISA, and GC-MS. The quantitative amount of IAA detected ranged from 4 to 5 ?mol liter?1 by HPLC and ELISA. Another unidentified metabolite was detected by GC-MS with a typical indole nucleus (m/z = 130), indicating that it could be an intermediate in auxin metabolism. Plant response (Pseudotsuga menziesii, Douglas fir) was monitored upon inoculation of P. tinctorius and l-tryptophan. There was a consistent increase in plant height and stem diameter as a result of the two treatments, with statistical differences in dry weights of the shoots and roots. Images

Frankenberger, W. T.; Poth, M.

1987-01-01

326

Hydrogen-bonding interactions in (3,4-dimethoxyphenyl)acetic acid monohydrate.  

PubMed

The crystal structure of the title compound, C(10)H(12)O(4).H(2)O, consists of (3,4-dimethoxyphenyl)acetic acid and water molecules linked by O-H...O hydrogen bonds to form cyclic structures with graph-set motifs R(1)(2)(5) and R(4)(4)(12). These hydrogen-bond patterns result in a three-dimensional network with graph-set motifs R(4)(4)(20) and R(4)(4)(22), and the formation of larger macrocycles, respectively. The C-C bond lengths and the endocyclic angles of the benzene ring show a noticeable asymmetry, which is connected with the charge-transfer interaction of the carboxyl or methoxy groups and the benzene ring. The title compound is one of the simple carboxylic acid systems that form hydrates. Thus, the significance of this study lies in the analysis of the interactions in this structure and the aggregations occurring via hydrogen bonds in two crystalline forms of (3,4-dimethoxyphenyl)acetic acid, namely the present hydrate and the anhydrous form [Chopra, Choudhury & Guru Row (2003). Acta Cryst. E59, o433-o434]. The correlation between the IR spectrum of this compound and its structural data are also discussed. PMID:18599976

Hachu?a, Barbara; Nowak, Maria; Kusz, Joachim

2008-06-07

327

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

NASA Astrophysics Data System (ADS)

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.

1990-09-01

328

Activity, distribution and function of indole-3-acetic acid biosynthetic pathways in bacteria.  

PubMed

The capacity to produce the phytohormone indole-3-acetic acid (IAA) is widespread among bacteria that inhabit diverse environments such as soils, fresh and marine waters, and plant and animal hosts. Three major pathways for bacterial IAA synthesis have been characterized that remove the amino and carboxyl groups from the ?-carbon of tryptophan via the intermediates indolepyruvate, indoleacetamide, or indoleacetonitrile; the oxidized end product IAA is typically secreted. The enzymes in these pathways often catabolize a broad range of substrates including aromatic amino acids and in some cases the branched chain amino acids. Moreover, expression of some of the genes encoding key IAA biosynthetic enzymes is induced by all three aromatic amino acids. The broad distribution and substrate specificity of the enzymes suggests a role for these pathways beyond plant-microbe interactions in which bacterial IAA has been best studied. PMID:22978761

Patten, Cheryl L; Blakney, Andrew J C; Coulson, Thomas J D

2012-09-15

329

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

330

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

331

Calcium Magnesium Acetate at Lower-Production Cost: Production of CMA Deicer from Cheese Whey.  

National Technical Information Service (NTIS)

Calcium magnesium acetate (CMA), a mixture of calcium acetate and magnesium acetate, is used as an environmentally benign roadway deicer. The present commercial CMA deicer made from glacial acetic acid and dolomitic lime or limestone is expensive compared...

H. Zhu S. T. Yang W. Qin Y. Huang Y. L. Huang Z. Jin

1999-01-01

332

Factors involved in the anti-cancer activity of the investigational agents LM985 (flavone acetic acid ester) and LM975 (flavone acetic acid).  

PubMed Central

LM985 has been shown previously to hydrolyse to flavone acetic acid (LM975) in mouse plasma and to produce significant anti-tumour effects in transplantable mouse colon tumours (MAC). It has undergone Phase I clinical trials and dose limiting toxicity was acute reversible hypotension. Substantially higher doses of LM975 can be given clinically without dose limiting toxicity. We have investigated the activity of LM975 against a panel of MAC tumours and also the in vitro cytotoxicity of both LM985 and LM975 in two cell lines derived from MAC tumours. LM985 is considerably more cytotoxic than LM975 in vitro but increased length of exposure to LM975 results in improved activity. Single in vivo injection of LM975 showed no activity against the ascitic tumour MAC 15A, moderate activity against the s.c. poorly differentiated tumour MAC 13 and produced a significant growth delay in the well differentiated MAC 26. These latter responses were considerably enhanced by repeated injection 7 days later. Pharmacokinetic studies in mice following i.p. injection of LM985 demonstrated rapid degradation of LM985 to LM975 in the peritoneum. Length of exposure as well as drug concentration appear important factors in determining anti-tumour responses.

Bibby, M. C.; Double, J. A.; Phillips, R. M.; Loadman, P. M.

1987-01-01

333

Acetic acid production from lactose by an anaerobic thermophilic coculture immobilized in a fibrous-bed bioreactor.  

PubMed

An anaerobic thermophilic coculture consisting of a heterofermentative bacterium (Clostridium thermolacticum) and a homoacetogen (Moorella thermoautotrophica) was developed for acetic acid production from lactose and milk permeate. The fermentation kinetics with free cells in conventional fermentors and immobilized cells in a recycle batch fibrous-bed bioreactor were studied. The optimal conditions for the cocultured fermentation were found to be 58 degrees C and pH 6.4. In the free-cell fermentation, C. thermolacticum converted lactose to acetate, ethanol, lactate, H(2) and CO(2), and the homoacetogen then converted lactate, H(2), and CO(2) to acetate. The overall acetate yield from lactose ranged from 0.46 to 0.65 g/g lactose fermented, depending on the fermentation conditions. In contrast, no ethanol was produced in the immobilized-cell fermentation, and the overall acetate yield from lactose increased to 0.8-0.96 g/g lactose fermented. The fibrous-bed bioreactor also gave a higher final acetate concentration (up to 25. 5 g/L) and reactor productivity (0.18-0.54 g/L/h) as compared to those from the free-cell fermentation (final acetate concentration, 15 g/L; productivity, 0.06-0.08 g/L/h). The superior performance of the fibrous-bed bioreactor was attributed to the high cell density (20 g/L) immobilized in the fibrous-bed and adaptation of C. thermolacticum cells to tolerate a higher acetate concentration. The effects of yeast extract and trypticase as nutrient supplements on the fermentation were also studied. For the free-cell fermentation, nutrient supplementation was necessary for the bacteria to grow in milk permeate. For the immobilized-cell fermentation, plain milk permeate gave a high acetate yield (0.96 g/g), although the reactor productivity was lower than those with nutrient supplementation. Balanced growth and fermentation activities between the two bacteria in the coculture are important to the quantitative conversion of lactose to acetic acid. Lactate and hydrogen produced by C. thermolacticum must be timely converted to acetic acid by the homoacetogen to avoid inhibition by these metabolites. PMID:11101328

Talabardon, M; Schwitzguébel, J P; Péringer, P; Yang, S T

334

The role of glass composition in the behaviour of glass acetic acid and glass lactic acid cements.  

PubMed

Cements have recently been described, made from glass ionomer glass reacted with acetic and lactic acid instead of polymeric carboxylic acid. From their behaviour a theory relating to a possible secondary setting mechanism of glass ionomer has been adduced. However, only one glass (G338) was used throughout. In this study a much simpler glass ionomer glass (MP4) was compared with G338. This produced very different results. With acetic acid G338 formed cement which became resistant to water over a period of hours, as previously reported, MP4 formed cement which was never stable to water. With lactic acid G338 behaved similarly to G338 with acetic acid, again as reported, but MP4 produced a cement which was completely resistant to water at early exposure and unusually became slightly less resistant if exposure was delayed for 6 h or more. These findings indicate that the theories relating to secondary setting in glass ionomer maturation may need revision. PMID:17619992

Shahid, Saroash; Billington, R W; Pearson, G J

2007-07-10

335

Methane reacts with heteropolyacids chemisorbed on silica to produce acetic acid under soft conditions.  

PubMed

Selective functionalization of methane at moderate temperature is of crucial economic, environmental, and scientific importance. Here, we report that methane reacts with heteropolyacids (HPAs) chemisorbed on silica to produce acetic acid under soft conditions. Specially, when chemisorbed on silica, H(4)SiW(12)O(40), H(3)PW(12)O(40), H(4)SiMo(12)O(40), and H(3)PMo(12)O(40) activate the primary C-H bond of methane at room temperature and atmospheric pressure. With these systems, acetic acid is produced directly from methane, in a single step, in the absence of Pd and without adding CO. Extensive surface characterization by solid-state NMR spectroscopy, IR spectroscopy, cyclic voltammetry, and X-ray photoelectron spectroscopy suggests that C-H activation of methane is triggered by the protons in the HPA-silica interface with concerted reduction of the Keggin cage, leading to water formation and hydration of the interface. This is the simplest and mildest way reported to date to functionalize methane. PMID:23268596

Sun, Miao; Abou-Hamad, Edy; Rossini, Aaron J; Zhang, Jizhe; Lesage, Anne; Zhu, Haibo; Pelletier, Jeremie; Emsley, Lyndon; Caps, Valerie; Basset, Jean-Marie

2013-01-03

336

Dissociative electron-ion recombination of the interstellar species protonated glycolaldehyde, acetic acid, and methyl formate.  

PubMed

Recently, methyl formate, glycolaldehyde, and acetic acid have been detected in the Interstellar Medium, ISM. The rate constants, ?(e), for dissociative electron-ion recombination of protonated gycolaldehyde, (HOCH(2)CHO)H(+), and protonated methyl formate, (HCOOCH(3))H(+), have been determined at 300 K in a variable temperature flowing afterglow using a Langmuir probe to obtain the electron density. The recombination rate constants at 300 K are 3.2 × 10(-7) cm(3) s(-1) for protonated methyl formate and 7.5 × 10(-7) cm(3) s(-1) for protonated glycolaldehyde. The recombination rate constant of protonated acetic acid could not be directly measured, but it appears to have a rate constant, ?(e), on the 10(-7) cm(3) s(-1) scale. Several high- and low-temperature measurements for protonated methyl formate were made. In addition, an ?(e) measurement at 220 K for protonated glycolaldehyde was performed. The astrochemical implications of the rates of recombination, ?(e), and protonation routes are discussed. PMID:22335483

Lawson, Patrick A; Osborne, David S; Adams, Nigel G

2012-03-12

337

Azithromycin and erythromycin ameliorate the extent of colonic damage induced by acetic acid in rats  

SciTech Connect

Ulcerative colitis is a common inflammatory bowel disease (IBD) of unknown etiology. Recent studies have revealed the role of some microorganisms in the initiation and perpetuation of IBD. The role of antibiotics in the possible modulation of colon inflammation is still uncertain. In this study, we evaluated the effects of two macrolides, namely azithromycin and erythromycin, at different doses on the extent and severity of ulcerative colitis caused by intracolonic administration of 3% acetic acid in rats. The lesions and the inflammatory response were assessed by histology and measurement of myeloperoxidase (MPO) activity, nitric oxide synthetase (NOS) and tumor necrosis factor alpha (TNF{alpha}) in colonic tissues. Inflammation following acetic acid instillation was characterized by oedema, diffuse inflammatory cell infiltration and necrosis. Increase in MPO, NOS and TNF{alpha} was detected in the colonic tissues. Administration of either azithromycin or erythromycin at different dosage (10, 20 and 40 mg/kg orally, daily for 5 consecutive days) significantly (P < 0.05) reduced the colonic damage, MPO and NOS activities as well as TNF{alpha} level. This reduction was highly significant with azithromycin when given at a dose of 40 mg/kg. It is concluded that azithromycin and erythromycin may have a beneficial therapeutic role in ulcerative colitis.

Mahgoub, Afaf [Department of Pharmacology, College of Medicine, King Saud University, Riyadh 11461 (Saudi Arabia)]. E-mail: afaf_mahgoub@yahoo.com; El-Medany, Azza [Department of Pharmacology, College of Medicine, King Saud University, Riyadh 11461 (Saudi Arabia); Mustafa, Ali [Department of Pharmacology, College of Medicine, King Saud University, Riyadh 11461 (Saudi Arabia); Arafah, Maha [Department of Pathology, College of Medicine, King Saud University, Riyadh 11461 (Saudi Arabia); Moursi, Mahmoud [Central Laboratories, Ministry of Health, Riyadh (Saudi Arabia)

2005-05-15

338

Modified (n, 0) BN nanotubes (n = 3-10) by acetic acids: DFT studies  

NASA Astrophysics Data System (ADS)

Covalent additions of one acetic acid molecular group to the tips of eight (n, 0) boron nitride nanotubes (n = 3-10) have been investigated by density functional theory (DFT) calculations. The results indicated that the properties of pristine and modified models detect almost similar effects by widening the nanotubes. The values of dipole moments and energy gaps have been increased for wider nanotubes. Comparing to the pristine models, the values of dipole moments and energy gaps show different properties for the models of two types of modifications. The values of binding energies have not been significantly changed for wider nanotubes. The atomic scale properties have been also investigated by computations of quadrupole coupling constants, in which the most significant effects of modifications have been observed for the atoms close to the modified regions. And finally, the properties for carbon atoms of methyl groups and oxygen atoms of carbonyl groups of the acetic acid molecular groups have been notably changed among the investigated modified BNNTs.

Mirzaei, Mahmoud; Yousefi, Mohammad

2013-03-01

339

Enhancement of the wet properties of transparent chitosan-acetic-acid-salt films using microfibrillated cellulose.  

PubMed

This report presents a new route to enhance the wet properties of chitosan-acetic-acid-salt films using microfibrillated cellulose (MFC). The enhancement makes it easier to form chitosan-acetic-acid-salt films into various shapes at room temperature in the wet state. Chitosan with MFC was compared with the well-known buffer treatment. It was observed that films containing 5 wt % MFC were visually identical to the buffered/unbuffered films without MFC. Field-emission scanning electron microscopy indicated that MFC formed a network with uniformly distributed fibrils and fibril bundles in the chitosan matrix. The addition of MFC reduced the risk of creases and deformation in the wet state because of a greater wet stiffness. The wet films containing MFC were also extensible. Although the stiffness, strength and extensibility were highest for the buffered films, the wet strength of the MFC-containing unbuffered films was sufficient for wet forming operations. The effects of MFC on the mechanical properties of the dry chitosan films were small or absent. It was concluded that the addition of MFC is an acceptable alternative to buffering for shaping chitosan films/products in the wet state. The advantages are that the "extra" processing step associated with buffering is unnecessary and that the film matrix remains more water-soluble. PMID:17645308

Nordqvist, David; Idermark, Johan; Hedenqvist, Mikael S; Gällstedt, Mikael; Ankerfors, Mikael; Lindström, Tom

2007-07-24

340

?-(Acetic acid)-di-?-chlorido-bis[tri-phenyl-tellurium(IV)] monohydrate  

PubMed Central

The asymmetric unit of the title compound, C38H34Cl2O2Te2·H2O, contains two independent TeIV cations, each coordinated by three phenyl ligands, two Cl? anions and one acetic acid mol­ecule in a distorted octa­hedral C3Cl2O geometry; the longer Te?Cl distances ranging from 3.2007?(11) to 3.4407?(11)?Å and the longer Te?O distances of 3.067?(3) and 3.113?(3)?Å indicate the weak bridge coordination. The Cl? anion and acetic acid mol­ecule bridge the two independent TeIV cations, forming the dimeric complex mol­ecule, in which the Te?Te separation is 3.7314?(4)?Å. In the crystal, the water molecules of crystallization link the TeIV complex mol­ecules into chains running along the b-axis direction via O—H?O and O—H?Cl hydrogen bonds.

Hu, Feng; Xu, Chao; Shi, Hua-Tian; Chen, Qun; Zhang, Qian-Feng

2013-01-01

341

Experimental densities of binary mixtures: Acetic acid with benzene at several temperatures  

NASA Astrophysics Data System (ADS)

Hydrocarbons are the most commonly used chemicals in the hydrocarbon processing industries. The knowledge of thermodynamic properties of various binary organic or inorganic mixtures is essential in many practical aspects concerning the mass transport and fluid flow. Such properties are important from the fundamental point of view to understand their mixing behaviour (molecular interactions), as well for practical applications (e.g. in the petrochemical industry). The density of acetic acid-benzene mixtures at several temperatures (T = 296.15, 302.15, 308.15, 314.15 and 319.15 K) were measured over the whole composition range and atmospheric pressure, along with the physical-chemical properties of the pure components (e.g. density, viscosity, refractive index at 298.15 K). The excess molar volumes at the above-mentioned temperatures were calculated from experimental data and fitted by using a new polynomial equation comparing the results with the known equation of Redlich-Kister. The excess volumes for acetic acid with benzene were positive and increase with the temperature. Results were analyzed in terms of molecular interactions. This research was financed by the postdoc grant PERFORM-ERA-ID 57649.

Bolat, Georgiana; Sutiman, Daniel; Lisa, Gabriela

2011-03-01

342

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

343

Ameyamaea chiangmaiensis gen. nov., sp. nov., an acetic acid bacterium in the alpha-Proteobacteria.  

PubMed

Two isolates, AC04(T) and AC05, were isolated from the flowers of red ginger collected in Chiang Mai, Thailand. In phylogenetic trees based on 16S rRNA gene sequences, the two isolates were included within a lineage comprised of the genera Acidomonas, Gluconacetobacter, Asaia, Kozakia, Swaminathania, Neoasaia, Granulibacter, and Tanticharoenia, and they formed an independent cluster along with the type strain of Tanticharoenia sakaeratensis. The calculated pair-wise sequence similarities of isolate AC04(T) were 97.8-92.5% to the type strains of the type species of the 11 genera of acetic acid bacteria. The DNA base composition was 66.0-66.1 mol % G+C with a range of 0.1 mol %. A single-stranded, labeled DNA from isolate AC04(T) presented levels of DNA-DNA hybridization of 100, 85, 4, and 3% respectively to DNAs from isolates AC04(T) and AC05 and the type strains of Tanticharoenia sakaeratensis and Gluconacetobacter liquefaciens. The two isolates were unique morphologically in polar flagellation and physiologically in intense acetate oxidation to carbon dioxide and water and weak lactate oxidation. The intensity in acetate oxidation almost equaled that of the type strain of Acetobacter aceti. The two isolates had Q-10. Isolate AC04(T) was discriminated from the type strains of the type species of the 11 genera by 16S rRNA gene restriction analysis using restriction endonucleases TaqI and Hin6I. The unique phylogenetic, genetic, morphological, physiological, and biochemical characteristics obtained indicate that the two isolates can be classified into a separate genus, and Ameyamaea chiangmaiensis gen. nov., sp. nov. is proposed. The type strain is isolate AC04(T) (=BCC 15744(T), =NBRC 103196(T)), which has a DNA G+C content of 66.0 mol %. PMID:19809199

Yukphan, Pattaraporn; Malimas, Taweesak; Muramatsu, Yuki; Takahashi, Mai; Kaneyasu, Mika; Potacharoen, Wanchern; Tanasupawat, Somboon; Nakagawa, Yasuyoshi; Hamana, Koei; Tahara, Yasutaka; Suzuki, Ken-ichiro; Tanticharoen, Morakot; Yamada, Yuzo

2009-10-07

344

Influence of heated vegetable oils and ??tocopheryl acetate supplementation on ??tocopherol, fatty acids and lipid peroxidation in chicken muscle  

Microsoft Academic Search

1. Chicks were fed on diets containing fresh, heated or ??tocopheryl acetate?supplemented heated vegetable oils. The effects on ??tocopherol status, and on the fatty acid composition and oxidative stability of thigh and breast muscle were determined.2. Plasma ??tocopherol was significantly correlated with ??tocopherol concentrations in thigh and breast muscle.3. The fatty acid profiles of muscle lipids reflected dietary fatty acid

P. J. A. Sheehy; P. A. Morrissey; A. Flynn

1993-01-01

345

Role of organic acids (formic, acetic, pyruvic and oxalic) in the formation of cloud condensation nuclei (CCN): a review  

Microsoft Academic Search

Although it is believed that organic aerosols play a key role in cloud nucleation and make an important contribution to the cloud condensation nuclei (CCN) population, their specific species remain poorly characterized. This paper reviews the current knowledge of organic acids (mainly formic, acetic, pyruvic and oxalic acids). Without specification, organic acids in this paper refer to these four organic

Shaocai Yu

2000-01-01

346

Aerobic oxidation of ethane to acetic acid catalyzed by N,N?-dihydroxypyromellitimide combined with Co species  

Microsoft Academic Search

Aerobic oxidation of ethane to acetic acid was successfully performed through a catalytic radical process using N,N?-dihydroxypyromellitimide (NDHPI) combined with a Co(II) salt in acetonitrile or propionic acid. The turnover number of NDHPI reached 9.5 in acetonitrile and 15.3 in propionic acid.

Akihiro Shibamoto; Satoshi Sakaguchi; Yasutaka Ishii

2002-01-01

347

Energy Requirements for Fatty Acid and Glycerolipid Biosynthesis from Acetate by Isolated Pea Root Plastids 1  

PubMed Central

Fatty acid and glycerolipid biosynthesis from [14C]acetate by isolated pea root plastids is completely dependent on exogenously supplied ATP. CTP, GTP, and UTP are ineffective in supporting fatty acid biosynthesis, all resulting in <3% of the activity obtained with ATP. However, ADP alone or in combination with inorganic phosphate (Pi) or pyrophosphate (PPi) gave up to 28% of the ATP control activity, whereas AMP + PPi, PPi alone, or Pi alone were ineffective in promoting fatty acid biosynthesis. The components of the dihydroxyacetonephosphate (DHAP) shuttle (DHAP, oxaloacetate, and Pi), which promote intraplastidic ATP synthesis, restored 41% of the control ATP activity, whereas the omission of any of the shuttle components abolished this activity. When the DHAP shuttle components were supplemented with ADP, the rate of fatty acid biosynthesis was completely restored to that observed in the presence of ATP. Under the conditions of ADP + DHAP shuttle-driven fatty acid biosynthesis, exogenously supplied ATP gave only a 6% additional stimulation of activity. In general, variations in the energy source had only small effects on the proportions of radioactive fatty acids and glycerolipids synthesized. Most notably, higher amounts of radioactive oleic acid, free fatty acids, and diacylglycerol and lower amounts of phosphatidic acid were observed when ADP and/or the DHAP shuttle were substituted for ATP. The results presented here indicate that, although isolated pea root plastids readily utilize exogenously supplied ATP for fatty acid biosynthesis, these plastids can also synthesize sufficient ATP when provided with the appropriate cofactors.

Kleppinger-Sparace, Kathryn F.; Stahl, Richard J.; Sparace, Salvatore A.

1992-01-01

348

Helpfulness of the combination of acetic acid and FICE in the detection of Barrett's epithelium and Barrett's associated neoplasias  

PubMed Central

AIM: To investigate the mucosal morphology in Barrett’s oesophagus by chromo and magnifying endoscopy. METHODS: A prospective pilot study at a tertiary medical centre was conducted to evaluate the use of acetic acid pulverisation combined with virtual chromoendoscopy using Fujinon intelligent chromoendoscopy (FICE) for semiological characterization of the mucosal morphology in Barrett’s oesophagus and its neoplastic complications. Upper endoscopy using high definition white light, 2% acid acetic pulverisation and FICE with high definition videoendoscopy were performed in 20 patients including 18 patients who presented with aspects of Barrett’s oesophagus at endoscopy examination. Two patients used as controls had normal endoscopy and histological results. Prospectively, videos were watched blind from histological results by three trained FICE technique endoscopists. RESULTS: The videos of patients with high-grade dysplasia showed an irregular mucosal pattern in 14% using high definition white light endoscopy and in 100% using acid acetic-FICE combined. Videos did not identify irregular vascular patterns using high definition white light endoscopy, while acid acetic-FICE combined visualised one in 86% of cases. CONCLUSION: Combined acetic acid and FICE is a promising method for screening high-grade dysplasia and early cancer in Barrett’s oesophagus.

Camus, Marine; Coriat, Romain; Leblanc, Sarah; Brezault, Catherine; Terris, Benoit; Pommaret, Elise; Gaudric, Marianne; Chryssostalis, Ariane; Prat, Frederic; Chaussade, Stanislas

2012-01-01

349

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

PubMed

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

1997-07-01

350

Gluconacetobacter maltaceti sp. nov., a novel vinegar producing acetic acid bacterium.  

PubMed

Comparison of HaeIII- and HpaII-restriction profiles of PCR-amplified 16S-23S rDNA ITS regions of Gluconacetobacter sp. LMG 1529(T) and SKU 1109 with restriction profiles of reference strains of acetic acid bacteria described by Tr?ek and Teuber [34] revealed the same but unique restriction profiles for LMG 1529(T) and SKU 1109. Further analyses of nearly complete 16S rRNA gene sequences, nearly complete 16S-23S rDNA ITS sequences, as well as concatenated partial sequences of the housekeeping genes dnaK, groEL and rpoB, allocated both strains to a single phylogenetic cluster well separated from the other species of the genus Gluconacetobacter. DNA-DNA hybridizations confirmed their novel species identity by 73% DNA-DNA relatedness between both strains, and values below the species level (<70%) between SKU 1109 and the type strains of the closest phylogenetic neighbors. The classification of strains LMG 1529(T) and SKU 1109 into a single novel species was confirmed also by AFLP and (GTG)(5)-PCR DNA fingerprinting data, as well as by phenotypic data. Strains LMG 1529(T) and SKU 1109 can be differentiated from their closely related Gluconacetobacter species, Gluconacetobacter entanii and Gluconacetobacter hansenii, by their ability to form 2-keto-d-gluconic acid from d-glucose, their ability to use d-mannitol, d-gluconate and glycerol as carbon source and form acid from d-fructose, and their ability to grow without acetic acid. The major fatty acid of LMG 1529(T) and SKU 1109 is C(18:1?7c) (60.2-64.8%). The DNA G+C content of LMG 1529(T) and SKU 1109 is 62.5 and 63.3mol% respectively. The name Gluconacetobacter maltaceti sp. nov. is proposed. The type strain is LMG 1529(T) (=NBRC 14815(T)=NCIMB 8752(T)). PMID:23273842

Slapšak, Nina; Cleenwerck, Ilse; De Vos, Paul; Tr?ek, Janja

2012-12-27

351

Synthesis and antiradical/antioxidant activities of caffeic acid phenethyl ester and its related propionic, acetic, and benzoic acid analogues.  

PubMed

Caffeic acid phenethyl ester (CAPE) is a bioactive component isolated from propolis. A series of CAPE analogues was synthesized and their antiradical/antioxidant effects analyzed. The effect of the presence of the double bond and of the conjugated system on the antioxidant effect is evaluated with the analogues obtained from 3-(3,4-dihydroxyphenyl) propanoic acid. Those obtained from 2-(3,4-dihydroxyphenyl) acetic acid and 3,4-dihydroxybenzoic acid allow the evaluation of the effect of the presence of two carbons between the carbonyl and aromatic system. PMID:23222926

LeBlanc, Luc M; Paré, Aurélie F; Jean-François, Jacques; Hébert, Martin J G; Surette, Marc E; Touaibia, Mohamed

2012-12-10

352

Inhibition of Methanogenesis from Acetate in Granular Sludge by Long-Chain Fatty Acids  

PubMed Central

The effect of four saturated long-chain fatty acids (caprylic, capric, lauric, and myristic) and one unsaturated long-chain fatty acid (oleic) on the microbial formation of methane from acetate was investigated in batch anaerobic toxicity assays. The tests were carried out with granular sludge from an upflow anaerobic sludge bed reactor. In this sludge, Methanothrix spp. are the predominant acetoclastic methanogens. Lauric acid appeared to be the most versatile inhibitor: inhibition started at 1.6 mM, and at 4.3 mM the maximum specific acetoclastic methanogenic activity had been reduced to 50%. Caprylic acid appeared to be only slightly inhibitory. Oleic acid was almost as inhibitory as lauric acid. Although adsorption of the inhibitor on the cell wall might play an important role in the mechanism of inhibition, the inhibition was found to be correlated with concentration rather than with the amount per unit of biomass. In practical situations, as in anaerobic waste treatment processes, synergism can be expected to enhance the inhibition of methanogenesis. In the present research a background concentration of lauric acid below its MIC strongly enhanced the toxicity of capric acid and (to an even greater extent) myristic acid.

Koster, Iman W.; Cramer, Albertus

1987-01-01

353

Apparent molar volumes and heat capacities of aqueous acetic acid and sodium acetate at temperatures from T = 278.15 K to T = 393.15 K at the pressure 0.3 5 MPa  

Microsoft Academic Search

Apparent molar volumes V?and heat capacities Cp , ?of aqueous solutions of acetic acid (CH3CO2H) and sodium acetate (CH3CO2Na) , and Cp , ?for hydrochloric acid (HCl) and sodium hydroxide (NaOH) were determined at temperatures from T= 278.15 K to T= 393.15 K at the pressure 0.35MPa. Apparent molar volumes were obtained from density measurements using an Anton Paar vibrating-tube

K. Ballerat-Busserolles; T. D. Ford; T. G. Call; E. M. Woolley

1999-01-01

354

Acetate metabolism in Methanosarcina barkeri  

Microsoft Academic Search

Methanosarcina barkeri was grown by acetate fermentation in complex medium (N2 gas phase). The molar growth yield was 1.6–1.9 g cells\\/mol methane formed. Under these conditions 63–82% of the methane produced byMethanosarcina strains was derived from the methyl carbon of acetate, indicating that some methane was derived from other media components. Growth was not demonstrated in complex media lacking acetate

P. J. Weimer; J. G. Zeikus

1978-01-01

355

Production of indole-3-acetic acid, aromatic amino acid aminotransferase activities and plant growth promotion by Pantoea agglomerans rhizosphere isolates  

Microsoft Academic Search

The production of auxins, such as indole-3-acetic acid (IAA), by rhizobacteria has been associated with plant growth promotion,\\u000a especially root initiation and elongation. Six indole-producing bacteria isolated from the rhizosphere of legumes grown in\\u000a Saskatchewan soils and identified as Pantoea agglomerans spp. were examined for their ability to promote the growth of canola, lentil and pea under gnotobiotic conditions and

Elena Sergeeva; Danielle L. M. Hirkala; Louise M. Nelson

2007-01-01

356

Kozakia baliensis gen. nov., sp. nov., a novel acetic acid bacterium in the alpha-proteobacteria.  

PubMed

Four bacterial strains were isolated from palm brown sugar and ragi collected in Bali and Yogyakarta, Indonesia, by an enrichment culture approach for acetic acid bacteria. Phylogenetic analysis based on 16S rRNA gene sequences showed that the four isolates constituted a cluster separate from the genera Acetobacter, Gluconobacter, Acidomonas, Gluconacetobacter and Asaia with a high bootstrap value in a phylogenetic tree. The isolates had high values of DNA-DNA similarity (78-100%) between one another and low values of the similarity (7-25%) to the type strains of Acetobacter aceti, Gluconobacter oxydans, Gluconacetobacter liquefaciens and Asaia bogorensis. The DNA base composition of the isolates ranged from 56.8 to 57.2 mol% G+C with a range of 0-4 mol%. The major quinone was Q-10. The isolates oxidized acetate and lactate to carbon dioxide and water, but the activity was weak, as with strains of Asaia bogorensis. The isolates differed from Asaia bogorensis strains in phenotypic characteristics. The name Kozakia baliensis gen. nov., sp. nov., is proposed for the four isolates. Strain Yo-3T (= NRIC 0488T = JCM 11301T = IFO 16664T = DSM 14400T) was isolated from palm brown sugar collected in Bali, Indonesia, and was designated as the type strain. PMID:12054243

Lisdiyanti, Puspita; Kawasaki, Hiroko; Widyastuti, Yantyati; Saono, Susono; Seki, Tatsuji; Yamada, Yuzo; Uchimura, Tai; Komagata, Kazuo

2002-05-01

357

Re-characterisation of Saccharomyces cerevisiae Ach1p: fungal CoA-transferases are involved in acetic acid detoxification.  

PubMed

Saccharomyces cerevisiae and Neurospora crassa mutants defective in the so-called acetyl-CoA hydrolases Ach1p and Acu-8, respectively, display a severe growth defect on acetate, which is most strongly pronounced under acidic conditions. Acetyl-CoA hydrolysis is an energy wasting process and therefore denoted as a biochemical conundrum. Acetyl-CoA hydrolases show high sequence identity to the CoA-transferase CoaT from Aspergillus nidulans. Therefore, we extensively re-characterised the yeast enzyme. Ach1p showed highest specific activity for the CoASH transfer from succinyl-CoA to acetate and only a minor acetyl-CoA-hydrolase activity. Complementation of an ach1 mutant with the coaT gene reversed the growth defect on acetate confirming the in vivo function of Ach1p as a CoA-transferase. Our results imply that Ach1p is involved in mitochondrial acetate detoxification by a CoASH transfer from succinyl-CoA to acetate. Thereby, Ach1p does not perform the energy wasting hydrolysis of acetyl-CoA but conserves energy by the detoxification of mitochondrial acetate. PMID:19298859

Fleck, Christian B; Brock, Matthias

2009-03-17

358

Influence of lactate and acetate salt adaptation on Salmonella Typhimurium acid and heat resistance.  

PubMed

The aim of the present study was to determine the survival of Salmonella Typhimurium adapted with sodium lactate (NaL), potassium lactate/sodium acetate mixture (KL/NaA) or sodium acetate (NaA) in simulated gastric fluid (SGF) and during heat treatment. NaL-, KL/NaA- and NaA-adapted cells were prepared by incubating in tryptic soy broth (TSB) containing these salts at 5, 5 and 3% (w/v) concentration levels, respectively, for 24 h at 37 °C. The Baranyi model was used to compare the growth kinetic parameters of adapted cells. The acid and heat resistance of adapted cells were determined by incubating in SGF (pH 2.04) at 37 °C and in TSB at 55.8, 57.8 and 59.8 °C, respectively. Adapted cells had significantly (P < 0.05) longer lag phase duration (LPD) and slower maximum growth rate (MGR) than non-adapted cells. The acid resistance of KL/NaA-adapted cells was not significantly (P > 0.05) different from that of non-adapted cells. NaL-adapted cells were more susceptible to the low pH environment, whereas NaA-adapted cells showed enhanced acid resistance compared to non-adapted and other adapted cells. Unlike acid resistance, both NaL- and NaA-adapted cells showed enhanced heat resistance with increased D-values, regardless of treatment temperatures. Thus, this study indicates that adaptation of S. Typhimurium to 5% NaL or 3% NaA could enhance their ability to survive thermal processes or in the human stomach, possibly increasing the risk of Salmonella outbreaks. PMID:22365359

Yuan, Wenqian; Ágoston, Réka; Lee, Dongwon; Lee, Seung-Cheol; Yuk, Hyun-Gyun

2012-01-03

359

Sol-gel processing of yttria-stabilized zirconia films derived from the zirconium n -butoxide-acetic acid-nitric acid-water-isopropanol system  

Microsoft Academic Search

A stable yttria-stabilized zirconia (YSZ) sol has been synthesized by the controlled hydrolysis of zirconium n-butoxide. Acetic acid and nitric acid were used as chelating agent and catalyst, respectively. The addition of acetic acid and increasing the amount of nitric acids to the system significantly enhanced the sol stability. The viscosity of YSZ sol with the concentration less than 0.80

Seung-Goo Kim; Suk Woo Nam; Sung-Pil Yoon; Sang-Hoon Hyun; Jonghee Han; Tae-Hoon Lim; Seong-Ahn Hong

2004-01-01

360

Iron Dissolution of Dust Source Materials during Simulated Acidic Processing: The Effect of Sulfuric, Acetic, and Oxalic Acids.  

PubMed

Atmospheric organic acids potentially display different capacities in iron (Fe) mobilization from atmospheric dust compared with inorganic acids, but few measurements have been made on this comparison. We report here a laboratory investigation of Fe mobilization of coal fly ash, a representative Fe-containing anthropogenic aerosol, and Arizona test dust, a reference source material for mineral dust, in pH 2 sulfuric acid, acetic acid, and oxalic acid, respectively. The effects of pH and solar radiation on Fe dissolution have also been explored. The relative capacities of these three acids in Fe dissolution are in the order of oxalic acid > sulfuric acid > acetic acid. Oxalate forms mononuclear bidentate ligand with surface Fe and promotes Fe dissolution to the greatest extent. Photolysis of Fe-oxalate complexes further enhances Fe dissolution with the concomitant degradation of oxalate. These results suggest that ligand-promoted dissolution of Fe may play a more significant role in mobilizing Fe from atmospheric dust compared with proton-assisted processing. The role of atmospheric organic acids should be taken into account in global-biogeochemical modeling to better access dissolved atmospheric Fe deposition flux at the ocean surface. PMID:23883276

Chen, Haihan; Grassian, Vicki H

2013-08-29

361

Nitrilase in Biosynthesis of the Plant Hormone Indole3Acetic Acid from Indole3Acetonitrile: Cloning of the Alcaligenes Gene and Site-Directed Mutagenesis of Cysteine Residues  

Microsoft Academic Search

Indole-3-acetic acid is the major auxin in most plants. In Cruciferae, including Brassicaceae, indole-3-acetic acid is synthesized from indole-3-acetonitrile by nitrilase, after indole-3-acetonitrile is formed from tryptophan via indole-3-acetaldoxime or indole glycosinolates as the intermediate. We cloned and sequenced the gene for nitrilase (EC 3.5.5.1), which catalyzes the hydrolysis of indole-3-acetonitrile to indole-3-acetic acid, from Alcaligenes faecalis JM3. The amino

Michihiko Kobayashi; Hiroshi Izui; Toru Nagasawa; Hideaki Yamada

1993-01-01

362

First European report of social wasps trapped in response to acetic acid, isobutanol, 2-methyl-2-propanol and heptyl butyrate in tests conducted in Hungary  

Microsoft Academic Search

Five species of social wasps were captured in trapping tests in Budapest (Hungary) that evaluated the attractiveness of acetic acid, isobutanol, 2-methyl-2-propanol, and heptyl butyrate. Both Vespula vulgaris (L.) and Vespula germanica (F.), were captured in traps baited with isobutanol, the combination of acetic acid and isobutanol, and the combination of acetic acid and 2-methyl-2- propanol. V. germanica did not

Peter J. LANDOLT; Miklos TÓTH; Júlia JÓSVAI

363

[Nomegestrol acetate: clinical pharmacology].  

PubMed

Progestogens are used in clinical practice in some conditions. Their effects depend on their chemical structure, pharmacokinetics, pharmacodynamics, with important differences among various progestogens. Generally, progestins are classified according to their parent molecule, of which often they keep some features. Derivatives of 19-nor-progesterone are characterized by high selectivity of action on progestin receptor. In particular, nomegestrol acetate (NomAc) shows an important progestational potency, neutral gluco-lipid profile, and antigonadotropic activity. It is used for treating menstrual cycle disorders and for hormone replacement therapy in menopause in association with an estrogen. In future, thanks to its antigonadotropic activity, NomAc will be used in estroprogestin combinations in fertile women, thus taking advantage of its tolerability profile and obtaining numerous non-contraceptive benefits as well. PMID:19749678

Lello, S

2009-10-01

364

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

365

Understanding the dissolution of ?-zein in aqueous ethanol and acetic acid solutions.  

PubMed

Zein is a corn prolamin that has broad industrial applications because of its unique physical properties. Currently, the high cost of extraction and purification, which is directly related to the dispersion of zein in different solvents, is the major bottleneck of the zein industry. Solution behaviors of zein have been studied for a long time. However, the physical nature of zein in different solvents remains unclear. In this study, small-angle X-ray scattering (SAXS), static light scattering (SLS), and rheology were combined to study the structure and protein-solvent interaction of ?-zein in both acetic acid and aqueous ethanol solutions. We found that the like-dissolve-like rule, the partial unfolding, and the protonation of zein are all critical to understanding the solution behaviors. Zein holds an elongated conformation (i.e., prolate ellipsoid) in all solutions, as revealed from SAXS data. There is an "aging effect" for zein in aqueous ethanol solutions, as evidenced by the transition of Newtonian rheological profiles for fresh zein solutions to the non-Newtonian shear thinning behavior for zein solutions after storage at room temperature for 24 h. Such shear thinning behavior becomes more pronounced for zein solutions at higher concentrations. The SLS results clearly show that acetic acid is a better solvent to dissolve zein than aqueous ethanol solution, as supported by a more negative second virial coefficient. This is majorly caused by the protonation of the protein, which was further verified by the dissolution of zein in water (a nonsolvent for zein) with the addition of acids. PMID:22973883

Li, Yunqi; Li, Ji; Xia, Qiuyang; Zhang, Boce; Wang, Qin; Huang, Qingrong

2012-09-24

366

Influence of environmental factors on the emissions of gaseous formic and acetic acids from orange (Citrus sinensis L.) foliage  

Microsoft Academic Search

Gaseous acids can be emitted as well as taken up by plant foliage, but little is known about the influence of environmental factors on the exchange process. In a laboratory study we investigated the short-term effects of temperature and light on the exchange of acetic and formic acids between orange foliage and the atmosphere. The results were compared with diurnal

Michael Staudt; Annette Wolf; Jürgen Kesselmeier

2000-01-01

367

Evidence That Isolated Chloroplasts Contain an Integrated Lipid-Synthesizing Assembly That Channels Acetate into Long-Chain Fatty Acids  

Microsoft Academic Search

High rates of light-dependent fatty acid synthesis from acetate were measured in isolated chloroplasts that were permeabilized to varying extents by resuspension in hypotonic reaction medium. The reactions in hypotonic medium unsupplemented with cofactors were linear with time and were directly proportional to chlorophyll concentration, suggesting that the enzymes and cofactors of fatty acid synthesis remained tightly integrated and thylakoid

P. Crattan Roughan; John B. Ohlrogge

368

Thermogravimetric analysis of the relationship among calcium magnesium acetate, calcium acetate and magnesium acetate  

Microsoft Academic Search

Thermal decomposition characteristic of calcium magnesium acetate (CMA), calcium acetate (CA) and magnesium acetate (MA) are investigated through thermogravimetric (TG) analysis at the heating rates of 5Kmin?1, 7.5Kmin?1, 10Kmin?1 and 15Kmin?1. After dehydration, the evaporation of carboxylic radical and carbon dioxide of CMA and CA exist in two separate segments, but for MA, this occurs together in just one segment

Shengli Niu; Kuihua Han; Chunmei Lu; Rongyue Sun

2010-01-01

369

Translocation of radiolabeled indole-3-acetic acid and indole-3-acetyl-myo-inositol from kernel to shoot of Zea mays L.  

PubMed

Either 5-[3H]indole-3-acetic acid (IAA) or 5-[3H]indole-3-acetyl-myo-inositol was applied to the endosperm of kernels of dark-grown Zea mays seedlings. The distribution of total radioactivity, radiolabeled indole-3-acetic acid, and radiolabeled ester conjugated indole-3-acetic acid, in the shoots was then determined. Differences were found in the distribution and chemical form of the radiolabeled indole-3-acetic acid in the shoot depending upon whether 5-[3H]indole-3-acetic acid or 5-[3H]indole-3-acetyl-myo-inositol was applied to the endosperm. We demonstrated that indole-3-acetyl-myo-inositol applied to the endosperm provides both free and ester conjugated indole-3-acetic acid to the mesocotyl and coleoptile. Free indole-3-acetic acid applied to the endosperm supplies some of the indole-3-acetic acid in the mesocotyl but essentially no indole-3-acetic acid to the coleoptile or primary leaves. It is concluded that free IAA from the endosperm is not a source of IAA for the coleoptile. Neither radioactive indole-3-acetyl-myo-inositol nor IAA accumulates in the tip of the coleoptile or the mesocotyl node and thus these studies do not explain how the coleoptile tip controls the amount of IAA in the shoot. PMID:11538236

Chisnell, J R; Bandurski, R S

1988-01-01

370

Translocation of radiolabeled indole-3-acetic acid and indole-3-acetyl-myo-inositol from kernel to shoot of Zea mays L  

SciTech Connect

Either 5-(/sup 3/H)indole-3-acetic acid (IAA) or 5-(/sup 3/H)indole-3-acetyl-myoinositol was applied to the endosperm of kernels of dark-grown Zea mays seedlings. The distribution of total radioactivity, radiolabeled indole-3-acetic acid, and radiolabeled ester conjugated indole-3-acetic acid, in the shoots was then determined. Differences were found in the distribution and chemical form of the radiolabeled indole-3-acetic acid in the shoot depending upon whether 5-(/sup 3/H)indole-3-acetic acid or 5-(/sup 3/H)indole-3-acetyl-myo-inositol was applied to the endosperm. We demonstrated that indole-3-acetyle-myo-inositol applied to the endosperm provides both free and ester conjugated indole-3-acetic acid to the mesocotyl and coleoptile. Free indole-3-acetic acid applied to the endosperm supplies some of the indole-3-acetic acid in the mesocotyl but essentially no indole-3-acetic acid to the coleoptile or primary leaves. It is concluded that free IAA from the endosperm is not a source of IAA for the coleoptile. Neither radioactive indole-3-acetyl-myo-inositol nor IAA accumulates in the tip of the coleoptile or the mesocotyl node and thus these studies do not explain how the coleoptile tip controls the amount of IAA in the shoot.

Chisnell, J.R.; Bandurski, R.S.

1988-01-01

371

Study of polydimethylsiloxane/aromatic polyamide laminated membranes for separation of acetic acid/water mixtures by pervaporation process  

SciTech Connect

Separation of acetic acid/water mixtures by pervaporation was attempted over a range of compositions using polydimethylsiloxane (PDMS), aromatic polyamide (PA), and laminated polydimethylsiloxane-aromatic polyamide membranes. PDMS membranes are hydrophobic and acetic acid selective, whereas PA membranes are hydrophilic and water selective. When PDMS and PA membranes were laminated, with PDMS on the top side and in contact with the feed, water selectivity of the bottom PA membrane was intensified. On the other hand, when the PA membrane was on the top side and in contact with the feed, the selectivity was lowered. 10 refs., 4 figs.

Deng, S.; Sourirajan, S.; Matsuura, T. (Univ. of Ottawa (Canada))

1994-06-01

372

Spectral fingerprint in X-ray absorption for hydrogen-bonded dimer formation of acetic acids in solution  

NASA Astrophysics Data System (ADS)

We have measured X-ray absorption spectra for acetic acid molecules in an organic solvent in order to study the effect of hydrogen-bonding formation. The spectral shapes distorted by saturation effect were compensated by using a new correction procedure for X-ray absorption based on the changes in the concentration of the samples. A resonance peak shift was observed when the acetic acid molecules formed a cyclic dimer in hexane solution, which is similar to the behavior of cluster molecules in vacuum. This is the first report on the XAS spectral changes due to cyclic dimer formation in a solution.

Horikawa, Y.; Arai, H.; Tokushima, T.; Shin, S.

2012-01-01

373

Variability of acid-base status in acetate-free biofiltration 84% versus bicarbonate dialysis.  

PubMed

The ultimate goal of hemodialysis (HD) treatment is to achieve the highest level of efficacy in the presence of maximal clinical tolerance. With an aim to offer good hemodynamic stability, as observed during the acetate-free biofiltration 14% (AFB 14%) to patients who are intolerant to bicarbonate dialysis (BD) and with less cost, we have developed since June 1994, a new HD technique, namely AFB 84%. This study was carried out to analyze acid-base variations during the AFB 84% in comparison to BD in hemodynamically stable patients on regular HD. This was a prospective randomized crossover study carried out on 12 patients (6 males and 6 females) for a total of 144 HD sessions (72 BD and 72 AFB 84%). Patients with decompensated cardiomyopathy, respiratory diseases or uncontrolled hypertension were not included in the trial. All the patients were treated with BD or AFB 84%; the latter is characterized by the absence of acetate in the dialysate and a complete correction of buffer balance by post-dilutional infusion of bicarbonate-based replacement solution. The comparison of pre-dialysis arterial acid-base and blood-gas parameters revealed no significant differences of pH, HCO(3)(-) and paCO(2) levels between the two techniques. Analysis of post-dialysis parameters showed that, among patients dialyzed with BD, there was over correction of metabolic acidosis with a tendency towards metabolic alkalosis. In contrast, in patients dialyzed with AFB 84%, we observed a significant improvement in pH and HCO(3)(-) levels but the increase in paCO(2) level was not significant. A comparison of these parameters between the two techniques showed statistically significant difference in pH, HCO(3)(-) and paCO(2) levels, but not for paO(2) level. AFB 84% can offer some important advantages with the complete absence of acetate from the substitution fluids, and permits a better correction of metabolic acidosis than BD, without causing alkalosis. PMID:18310870

Harzallah, Kais; Hichri, Nourredine; Mazigh, Chakib; Tagorti, Mohamed; Hmida, Ahmed; Hmida, Jalel

2008-03-01

374

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

375

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

NASA Astrophysics Data System (ADS)

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 6 -C 34 ), saturated normal , -dicarboxylic acids (C 4 -C 34 ), and isoprenoid acids (C 14 -C 21 , except C 18 ). Less dominant were aromatic acids, branched monocarboxylic acids (C 6 -C 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: 1. (a) the kerogen nucleus is mainly composed of long-chain polymethylene, cross-linked aliphatic structure from which protrude n -alkyl chains and minor amounts of isoprenoid and non-isoprenoid branched hydrocarbons; 2. (b) the periphery, compared to the nucleus, contains a greater proportion of n -alkyl and isoprenoid moieties, particularly the C 14 , C 16 , and C 18 n -alkyl chains as well as the C 15 and C 16 isoprenoid chains; 3. (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

376

Removal and recovery of furfural, 5-hydroxymethylfurfural, and acetic acid from aqueous solutions using a soluble polyelectrolyte.  

PubMed

In the cellulosic ethanol process, furfural, 5-hydroxymethylfurfural (HMF), and acetic acid are formed during the high temperature acidic pretreatment step needed to convert biomass into fermentable sugars. These compounds can inhibit cellulase enzymes and fermentation organisms at relatively low concentrations (? 1 g/L). Effective removal of these inhibitory compounds would allow the use of more severe pretreatment conditions to improve sugar yields and lead to more efficient fermentations; if recovered and purified, they could also be sold as valuable by-products. This study investigated the separation of aldhehydes (furfural and HMF) and organic acid (acetic acid) inhibitory compounds from simple aqueous solutions by using polyethyleneimene (PEI), a soluble cationic polyelectrolyte. PEI added to simple solutions of each inhibitor at a ratio of 1 mol of functional group to 1 mol inhibitor removed up to 89.1, 58.6, and 81.5 wt% of acetic acid, HMF, and furfural, respectively. Furfural and HMF were recovered after removal by washing the polyelectrolyte/inhibitor complex with dilute sulfuric acid solution. Recoveries up to 81.0 and 97.0 wt% were achieved for furfural and HMF, respectively. The interaction between PEI and acetic acid was easily disrupted by the addition of chloride ions, sulfate ions, or hydroxide ions. The use of soluble polymers for the removal and recovery of inhibitory compounds from biomass slurries is a promising approach to enhance the efficiency and economics of an envisioned biorefinery. PMID:21455937

Carter, Brian; Gilcrease, Patrick C; Menkhaus, Todd J

2011-04-14

377

Fermentation characteristics of Fusariumoxysporum grown on acetate.  

PubMed

In this study, the growth characteristics of Fusariumoxysporum were evaluated in minimal medium using acetate or different mixtures of acetate and glucose as carbon source. The minimum inhibitory concentration (MIC) of acetic acid that F.oxysporum cells could tolerate was 0.8%w/v while glucose was consumed preferentially to acetate. The activity of isocitrate lyase was high when cells were grown on acetate and acetate plus glucose indicating an activation of the glyoxylate cycle. Investigation of the metabolic fingerprinting and footprinting revealed higher levels of intracellular and extracellular TCA cycle intermediates when F.oxysporum cells were grown on mixtures of acetate and glucose compared to growth on only glucose. Our data support the hypothesis that a higher flux through TCA cycle during acetate consumption could significantly increase the pool of NADH, resulting in the activation of succinate-propionate pathway which consumes reducing power (NADH) via conversion of succinate to propionyl-CoA and produce propionate. PMID:18304808

Panagiotou, Gianni; Pachidou, Fotini; Petroutsos, Dimitris; Olsson, Lisbeth; Christakopoulos, Paul

2008-03-04

378

Ultrastructure of Sheep Primordial Follicles Cultured in the Presence of Indol Acetic Acid, EGF, and FSH  

PubMed Central

The aim of this study was to investigate the ultrastructural characteristics of primordial follicles after culturing of sheep ovarian cortical slices in the presence of indol acetic acid (IAA), Epidermal Growth Factor (EGF), and FSH. To evaluate ultrastructure of primordial follicles cultured in MEM (control) or in MEM containing IAA, EGF, and FSH, fragments of cultured tissue were processes for transmission electron microscopy. Except in the control, primordial follicles cultured in supplemented media for 6?d were ultrastructurally normal. They had oocyte with intact nucleus and the cytoplasm contained heterogeneous-sized lipid droplets and numerous round or elongated mitochondria with intact parallel cristae were observed. Rough endoplasmic reticulum (RER) was rarely found. The granulosa cells cytoplasm contained a great number of mitochondria and abundant RER. In conclusion, the presence of IAA, EGF, and FSH helped to maintain ultrastructural integrity of sheep primordial follicles cultured in vitro.

Andrade, Evelyn Rabelo; Maddox-Hyttel, Poul; Landim-Alvarenga, Fernanda Da Cruz; Viana Silva, Jose Roberto; Alfieri, Amauri Alcindo; Seneda, Marcelo Marcondes; Figueiredo, Jose Ricardo; Toniolli, Ricardo

2011-01-01

379

Utilization of Vinegar for Isolation of Cellulose Producing Acetic Acid Bacteria  

SciTech Connect

Wastes of traditionally fermented Turkish vinegar were used in the isolation of cellulose producing acetic acid bacteria. Waste material was pre-enriched in Hestrin-Schramm medium and microorganisms were isolated by plating dilution series on HS agar plates The isolated strains were subjected to elaborate biochemical and physiological tests for identification. Test results were compared to those of reference strains Gluconacetobacter xylinus DSM 46604, Gluconacetobacter hansenii DSM 5602 and Gluconacetobacter liquefaciens DSM 5603. Seventeen strains, out of which only three were found to secrete the exopolysaccharide cellulose. The highest cellulose yield was recorded as 0.263+-0.02 g cellulose L{sup -1} for the strain AS14 which resembled Gluconacetobacter hansenii in terms of biochemical tests.

Aydin, Y. Andelib; Aksoy, Nuran Deveci [Chemical Engineering Department of Istanbul Technical University, Ayazaga, Maslak, Istanbul, 34469 (Turkey)

2010-06-17

380

Ultrafine cellulose fibers produced by Asaia bogorensis, an acetic acid bacterium.  

PubMed

The ability to synthesize cellulose by Asaia bogorensis, a member of the acetic acid bacteria, was studied in two substrains, AJ and JCM. Although both strains have identical 16S rDNA sequence, only the AJ strain formed a solid pellicle at the air-liquid interface in static culture medium, and we analyzed this pellicle using a variety of techniques. In the presence of cellulase, glucose and cellobiose were released from the pellicle suggesting that it is made of cellulose. Field emission electron microscopy allowed the visualization of a 3D knitted structure with ultrafine microfibrils (approximately 5-20 nm in width) in cellulose from A. bogorensis compared with the 40-100 nm wide microfibrils observed in cellulose isolated from Gluconacetobacter xylinus, suggesting differences in the mechanism of cellulose biosynthesis or organization of cellulose synthesizing sites in these two related bacterial species. Identifying these differences will lead to a better understanding of cellulose biosynthesis in bacteria. PMID:21650167

Kumagai, Akio; Mizuno, Masahiro; Kato, Naoto; Nozaki, Kouichi; Togawa, Eiji; Yamanaka, Shigeru; Okuda, Kazuo; Saxena, Inder M; Amano, Yoshihiko

2011-06-17

381

Utilization of Vinegar for Isolation of Cellulose Producing Acetic Acid Bacteria  

NASA Astrophysics Data System (ADS)

Wastes of traditionally fermented Turkish vinegar were used in the isolation of cellulose producing acetic acid bacteria. Waste material was pre-enriched in Hestrin-Schramm medium and microorganisms were isolated by plating dilution series on HS agar plates The isolated strains were subjected to elaborate biochemical and physiological tests for identification. Test results were compared to those of reference strains Gluconacetobacter xylinus DSM 46604, Gluconacetobacter hansenii DSM 5602 and Gluconacetobacter liquefaciens DSM 5603. Seventeen strains, out of which only three were found to secrete the exopolysaccharide cellulose. The highest cellulose yield was recorded as 0.263+/-0.02 g cellulose L-1 for the strain AS14 which resembled Gluconacetobacter hansenii in terms of biochemical tests.

Aydin, Y. Andelib; Aksoy, Nuran Deveci

2010-06-01

382

Study of dynamic process of acetic acid induced-whitening in epithelial tissues at cellular level  

NASA Astrophysics Data System (ADS)

Acetic acid, inducing transient whitening (acetowhitening) when applied to epithelial tissues, is a commonly used contrast agent for detecting early cervical cancer. The goals of this research are to investigate the temporal characteristics of acetowhitening process in cervical epithelial tissue at cellular level and develop a clear understanding of the diagnostic information carried in the acetowhitening signal. A system measuring time-resolved reflectance was built to study the rising and decay processes of acetowhitening signal from the monolayered cell cultures of normal and cancerous cervical squamous cells. It is found that the dynamic processes of acetowhitening in normal and cancerous cells are significantly different. The results of this study provide insight valuable to further understand the acetowhitening process in epithelial cells and to encourage the development of an objective procedure to detect the early cervical cancers based on quantitative monitoring of the dynamic process of acetowhitening

Wu, Tao T.; Qu, Jianan Y.; Cheung, Tak Hong; Yim, So Fan; Wong, Yick Fu

2005-06-01

383

Wounding Nicotiana tabacum Leaves Causes a Decline in Endogenous Indole-3-Acetic Acid 1  

PubMed Central

We have previously observed that auxin can act as a repressor of the wound-inducible activation of a chimeric potato proteinase inhibitor II-CAT chimeric gene (pin2-CAT) in transgenic tobacco (Nicotiana tobacum) callus and in whole plants. Therefore, this study was designed to examine endogenous levels of indole-3-acetic acid (IAA) in plant tissues both before and after wounding. Endogenous IAA was measured in whole plant tissues by gas chromatography-mass spectrometry using an isotope dilution technique. 13C-Labeled IAA was used as an internal standard. The endogenous levels of IAA declined two- to threefold within 6 hours after a wound. The kinetics of auxin decline are consistent with the kinetics of activation of the pin2-CAT construction in the foliage of transgenic tobacco.

Thornburg, Robert W.; Li, Xiaoyue

1991-01-01

384

Indole-3-acetic acid-regulated genes in Rhizobium etli CNPAF512.  

PubMed

In the rhizosphere and their interaction with plants rhizobia encounter many different plant compounds, including phytohormones like auxins. Moreover, some rhizobial strains are capable of producing the auxin, indole-3-acetic acid (IAA). However, the role of IAA for the bacterial partner in the legume-Rhizobium symbiosis is not known. To identify the effect of IAA on rhizobial gene expression, a transposon (mTn5gusA-oriV) mutant library of Rhizobium etli, enriched for mutants that show differential gene expression under microaerobiosis and/or addition of nodule extracts as compared with control conditions, was screened for altered gene expression upon IAA addition. Four genes were found to be regulated by IAA. These genes appear to be involved in plant signal processing, motility or attachment to plant roots, clearly demonstrating a distinct role for IAA in legume-Rhizobium interactions. PMID:19087205

Spaepen, Stijn; Das, Frederik; Luyten, Ellen; Michiels, Jan; Vanderleyden, Jos

2008-12-11

385

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.

Ebaugh, David

2010-01-01

386

Stabilized Calcium Acetate Oil Dispersions.  

National Technical Information Service (NTIS)

A lubricating composition is imparted with improved load-carrying ability and anti-wear properties by incorporation of calcium acetate. The composition consists of a base lubricant, 0.1 to 50 percent by weight calcium acetate and 0.01 to 20 percent by wei...

R. H. Davis

1965-01-01

387

Lead Acetate, Radiotracer Metabolism Study.  

National Technical Information Service (NTIS)

Metabolic studies utilizing radiotracer techniques were applied to tissues from rats which had received 0 and 1000 ppm lead acetate (calculated as lead) for one month prior to the oral administration of 210 lead acetate. Seventy-two hours after administra...

D. C. Jessup

1967-01-01

388

Room-temperature luminescence properties of rho-aminobenzoic acid adsorbed on sodium acetate-sodium chloride mixtures  

SciTech Connect

Room-temperature fluorescence and phosphorescence quantum yield, triplet formation efficiency, and phosphorescence lifetime values were obtained for the anion of rho-aminobenzoic acid adsorbed on sodium acetate and several sodium acetate-sodium chloride mixtures. From these data, rate constants for phosphorescence and for radiationless transition from the triplet state were obtained. The results revealed that several factors are important for maximum room-temperature phosphorescence for the anion of rho-aminobenzoic acid. One of the most important conditions for strong room-temperature phosphorescence of the anion was how efficiently the matrix was packed with sodium acetate molecules. The same general conclusion was found for room-temperature fluorescence, but the phosphorescence quantum yield increased more dramatically than the fluorescence quantum yield.

Ramasamy, S.M.; Hurtubise, R.J.

1987-09-01

389

Acetate oxidation to CO 2 via a citric acid cycle involving an ATP-citrate lyase: a mechanism for the synthesis of ATP via substrate level phosphorylation in Desulfobacter postgatei growing on acetate and sulfate  

Microsoft Academic Search

Desulfobacter postgatei is an acetate-oxidizing, sulfate-reducing bacterium that metabolizes acetate via the citric acid cycle. The organism has been reported to contain a si-citrate synthase (EC 4.1.3.7) which is activated by AMP and inorganic phosphate. It is show now, that the enzyme mediating citrate formation is an ATP-citrate lyase (EC 4.1.3.8) rather than a citrate synthase. Cell extracts (160,000xg supernatant)

D. Möller; R. Schauder; G. Fuchs; R. K. Thauer

1987-01-01

390

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.

2012-01-01

391

Different response to acetic acid stress in Saccharomyces cerevisiae wild-type and l-ascorbic acid-producing strains.  

PubMed

Biotechnological processes are of increasing significance for industrial production of fine and bulk chemicals, including biofuels. Unfortunately, under operative conditions microorganisms meet multiple stresses, such as non-optimal pH, temperature, oxygenation and osmotic stress. Moreover, they have to face inhibitory compounds released during the pretreatment of lignocellulosic biomasses, which constitute the preferential substrate for second-generation processes. Inhibitors include furan derivatives, phenolic compounds and weak organic acids, among which acetic acid is one of the most abundant and detrimental for cells. They impair cellular metabolism and growth, reducing the productivity of the process: therefore, the development of robust cell factories with improved production rates and resistance is of crucial importance. Here we show that a yeast strain engineered to endogenously produce vitamin C exhibits an increased tolerance compared to the parental strain when exposed to acetic acid at moderately toxic concentrations, measured as viability on plates. Starting from this evidence, we investigated more deeply: (a) the nature and levels of reactive oxygen species (ROS); (b) the activation of enzymes that act directly as detoxifiers of reactive oxygen species, such as superoxide dismutase (SOD) and catalase, in parental and engineered strains during acetic acid stress. The data indicate that the engineered strain can better recover from stress by limiting ROS accumulation, independently from SOD activation. The engineered yeast can be proposed as a model for further investigating direct and indirect mechanism(s) by which an antioxidant can rescue cells from organic acid damage; moreover, these studies will possibly provide additional targets for further strain improvements. Copyright © 2013 John Wiley & Sons, Ltd. PMID:23847041

Martani, Francesca; Fossati, Tiziana; Posteri, Riccardo; Signori, Lorenzo; Porro, Danilo; Branduardi, Paola

2013-07-30

392

Growth inhibitory effect of grape phenolics against wine spoilage yeasts and acetic acid bacteria.  

PubMed

This paper investigates the in vitro antimicrobial potential of 15 grape phenolic compounds of various chemical classes (phenolic acids, stilbenes and flavonoids) using the broth microdilution method against yeasts and acetic acid bacteria frequently occurring in deteriorated wine. Pterostilbene (MICs=32-128 ?g/mL), resveratrol (MICs=256-512 ?g/mL) and luteolin (MICs=256-512 ?g/mL) are among six active compounds that possessed the strongest inhibitory effects against all microorganisms tested. In the case of phenolic acids, myricetin, p-coumaric and ferulic acids exhibited selective antimicrobial activity (MICs=256-512 ?g/mL), depending upon yeasts and bacteria tested. In comparison with potassium metabisulphite, all microorganisms tested were more susceptible to the phenolics. The results revealed the antibacterial and antiyeast effects against wine spoilage microorganisms of several highly potent phenolics naturally occurring in grapes. These findings also provide arguments for further investigation of stilbenes as prospective compounds reducing the need for the use of sulphites in winemaking. PMID:23334100

Pastorkova, E; Zakova, T; Landa, P; Novakova, J; Vadlejch, J; Kokoska, L

2013-01-02

393

Startup of anaerobic fluidized bed reactors with acetic acid as the substrate.  

PubMed

The startup of anaerobic fluidized bed reactors, which use Manville R-633 beads as the growth support media, acetate enriched bacterial culture as the inoculum, and acetic acid as the sole substrate, is studied. Tow startup strategies are evaluated: one based on maximum and stable substrate utilization and another based on maximum substrate loading controlled by reactor pH. The startup process is characterized using a number of operational parameters.The reactors again excellent total organic carbon (TOC) removal (i.e., > 97% at a feed concentration of 5000 mg TOC/L) and stable methane production (i.e., 0.90 L CH(4)/g TOC, where TOC(r) is TOC removed) at a early stage of the startup process, regardless of the strategies applied. The loading can be increased rapidly without the danger of being overloaded. Significant losses of growth support media and biomass caused by gas effervescence at higher loadings limits the maximum loading that can be safely applied during startup process.A high reactor immobilized biomass inventory is achievable using the porous growth support media (e.g., Manville 633 beads). A rapid increase in loading creates a substrate rich environment that yields more viable reactor biomass. Both substrate utilization rate (batch and continuous) and immobilized biomass inventory stabilize concomitantly at the late stage of the startup process, indicating the attainment of steady-state conditions in reactors. Therefore, they are better parameters that TOC removal and methane production for characterizing the entire startup process of aerobic fluidized bed reactor.The strategy based on maximum substrate loading controlled by reactor pH significantly shortens the startup time. In this case, the reactor attains steady-state conditions approximately 140 days after startup. On the other hand, a startup time of 200 days is required when the strategy based maximum substrate utilization is adopted. PMID:18609559

Hsu, Y; Shieh, W K

1993-02-01

394

Behavior of Lignin in Organic Acid Pulping. II Reaction of Phenylcoumarans and 1,2Diaryl1,3-Propanediols with Acetic Acid  

Microsoft Academic Search

In order to explain the behavior of phenylcoumaran and 1,2-diaryl-1,3-propanediol structures in acetic acid pulping, their lignin model dimers in the presence of creosol as a lignin aromatic nucleus model were cooked in 90% acetic acid at 180°C.About 50% of phenolic phenylcoumaran was consumed during a 3 hour reaction to yield phenylcoumarone, a stilbene derivative and a condensation product, but

Seiichi Yasuda

1988-01-01

395

Effects of Acid Adaptation of Escherichia coli O157:H7 on Efficacy of Acetic Acid Spray Washes To Decontaminate Beef Carcass Tissue  

PubMed Central

Exposure to low pH and organic acids in the bovine gastrointestinal tract may result in the induced acid resistance of Escherichia coli O157:H7 and other pathogens that may subsequently contaminate beef carcasses. The effect of acid adaptation of E. coli O157:H7 on the ability of acetic acid spray washing to reduce populations of this organism on beef carcass tissue was examined. Stationary-phase acid resistance and the ability to induce acid tolerance were determined for a collection of E. coli O157:H7 strains by testing the survival of acid-adapted and unadapted cells in HCl-acidified tryptic soy broth (pH 2.5). Three E. coli O157:H7 strains that were categorized as acid resistant (ATCC 43895) or acid sensitive (ATCC 43890) or that demonstrated inducible acid tolerance (ATCC 43889) were used in spray wash studies. Prerigor beef carcass surface tissue was inoculated with bovine feces containing either acid-adapted or unadapted E. coli O157:H7. The beef tissue was subjected to spray washing treatments with water or 2% acetic acid or left untreated. For strains ATCC 43895 and 43889, larger populations of acid-adapted cells than of unadapted cells remained on beef tissue following 2% acetic acid treatments and these differences remained throughout 14 days of 4°C storage. For both strains, numbers of acid-adapted cells remaining on tissue following 2% acetic acid treatments were similar to numbers of both acid-adapted and unadapted cells remaining on tissue following water treatments. For strain ATCC 43890, there was no difference between populations of acid-adapted and unadapted cells remaining on beef tissue immediately following 2% acetic acid treatments. These data indicate that adaptation to acidic conditions by E. coli O157:H7 can negatively influence the effectiveness of 2% acetic acid spray washing in reducing the numbers of this organism on carcasses.

Berry, Elaine D.; Cutter, Catherine N.

2000-01-01

396

Competitive fragmentation pathways of acetic acid dimer explored by synchrotron VUV photoionization mass spectrometry and electronic structure calculations.  

PubMed

In present study, photoionization and dissociation of acetic acid dimers have been studied with the synchrotron vacuum ultraviolet photoionization mass spectrometry and theoretical calculations. Besides the intense signal corresponding to protonated cluster ions (CH(3)COOH)(n)·H(+), the feature related to the fragment ions (CH(3)COOH)H(+)·COO (105 amu) via ?-carbon-carbon bond cleavage is observed. By scanning photoionization efficiency spectra, appearance energies of the fragments (CH(3)COOH)·H(+) and (CH(3)COOH)H(+)·COO are obtained. With the aid of theoretical calculations, seven fragmentation channels of acetic acid dimer cations were discussed, where five cation isomers of acetic acid dimer are involved. While four of them are found to generate the protonated species, only one of them can dissociate into a C-C bond cleavage product (CH(3)COOH)H(+)·COO. After surmounting the methyl hydrogen-transfer barrier 10.84 ± 0.05 eV, the opening of dissociative channel to produce ions (CH(3)COOH)(+) becomes the most competitive path. When photon energy increases to 12.4 eV, we also found dimer cations can be fragmented and generate new cations (CH(3)COOH)·CH(3)CO(+). Kinetics, thermodynamics, and entropy factors for these competitive dissociation pathways are discussed. The present report provides a clear picture of the photoionization and dissociation processes of the acetic acid dimer in the range of the photon energy 9-15 eV. PMID:23020332

Guan, Jiwen; Hu, Yongjun; Zou, Hao; Cao, Lanlan; Liu, Fuyi; Shan, Xiaobin; Sheng, Liusi

2012-09-28

397

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

398

L-ARGININE AUGMENTS THE ANTIOXIDANT EFFECT OF GARLIC AGAINST ACETIC ACID INDUCED ULCERATIVE COLITIS IN RATS  

Microsoft Academic Search

Garlic contains many sulfhydryl compounds that act as antioxidants. However, the role of nitric oxide (NO) in inflammation is controversial. The aim of the present study is to investigate the possible protective effect of garlic against acetic acid-induced ulcerative colitis in rats, as well as the probable modulatory effect of L- arginine (NO precursor) on garlic activity. Intra-rectal inoculation of

GAMAL ELDIN I. HARISA; OSAMA M. ABO-SALEM; EL-SAYED M. EL-SAYED; EHAB I. TAHA; NERMIN EL-HALAWANY

2009-01-01

399

Production of acetic acid by hydrothermal two-step process of vegetable wastes for use as a road deicer  

NASA Astrophysics Data System (ADS)

This study aimed to produce acetic acid from vegetable wastes by a new hydrothermal two-step process. A continuous flow reaction system with a maximum treatment capacity of 2 kg/h of dry biomass developed by us was used. Five kinds of vegetables of carrots, white radish, chinese cabbage, cabbage and potato were selected as the representation of vegetable wastes. First, batch experiments with the selected vegetables were performed under the condition of 300°C, 1 min for the first step, and 300°C, 1 min and 70% oxygen supply for the second step, which is the optimum condition for producing acetic acid in the case of using starch as test material. The highest yields of acetic acid from five vegetables were almost the same as those obtained from starch. Subsequently, similar the highest yield of acetic acid and experimental conditions from vegetables were also obtained successfully using the continuous flow reaction system. These results should be useful for developing an industrial scale process.

Jin, F.; Watanabe, Y.; Kishita, A.; Enomoto, H.; Kishida, H.

2008-07-01

400

Growth performance and immune response of channel catfish ( Ictalurus puctatus) fed diets containing graded levels of gossypol–acetic acid  

Microsoft Academic Search

This study was conducted to evaluate the effect of gossypol levels on growth performance, body composition, hematology, immune response and resistance of channel catfish to Edwadsiella ictaluri challenge. A purified basal diet supplemented with 0, 300, 600, 900, 1200 and 1500 mg of gossypol from gossypol–acetic acid was fed to juvenile channel catfish in quadruplicate aquaria to apparent satiation twice

Mediha Yildirim; Chhorn Lim; Peter J Wan; Phillip H Klesius

2003-01-01

401

Rebamipide Prevents Delay of Acetic Acid-Induced Gastric Ulcer Healing Caused by Helicobacter pylori Infection in Mongolian Gerbils  

Microsoft Academic Search

In this study, we examined the effect of rebamipide, a mucoprotective drug, on gastric ulcer healing in Mongolian gerbils infected with H. pylori. Male Mongolian gerbils were inoculated with H. pylori or vehicle alone 12 hr after the production of an acetic acid-induced gastric ulcer. On day 5, the gerbils inoculated with H. pylori were divided into three groups and

Toshio Watanabe; Kazuhide Higuchi; Masaki Hamaguchi; Tetsuya Tanigawa; Rikimon Wada; Kazunari Tominaga; Yasuhiro Fujiwara; Tetsuo Arakawa

2002-01-01

402

Effect of Dietary Supplementation with Rosemary Extract and ?-Tocopheryl Acetate on Lipid Oxidation in Eggs Enriched with ?3Fatty Acids  

Microsoft Academic Search

The antioxidant effect of dietary supple- mentation with 500 or 1,000 mg\\/kg of a commercial rose- mary extract vs. 200 mg\\/kg of ?-tocopheryl acetate (?- TA) on the lipid oxidative stability of ?3-fatty acid (FA)- enriched eggs was compared. Lipid oxidation was mea- sured in fresh eggs by the lipid hydroperoxide level and

J. Galobart; A. C. Barroeta; M. D. Baucells; R. Codony; W. Ternes

403

GROWTH PERFORMANCE AND IMMUNE RESPONSE OF CHANNEL CATFISH (ICTALURUS PUNCTATUS) FED DIETS CONTAINING GRADED LEVELS OF GOSSYPOL - ACETIC ACID  

Technology Transfer Automated Retrieval System (TEKTRAN)

A study was conducted to evaluate the effect of dietary gossypol levels on growth, hematology, immune response and resistance of channel catfish to Edwardsiella ictaluri. A purified basal diet supplemented with 0, 300, 600, 900, 1,200 and 1,500 mg gossypol from gossypol-acetic acid were fed to juven...

404

Production of Indole3Acetic Acid by Bradyrhizobium japonicum'. A Correlation with Genotype Grouping and Rhizobitoxine Production  

Microsoft Academic Search

Bioassays show that rhizobitoxine-producing strains of Bradyrhizobium japonicum excreted another phytotoxic compound into their culture fluid. This compound was purified and identifi- ed by HPLC and mass spectrometry as indole-3-acetic acid (IAA). The levels of IAA produced by the different strains of B. japonicum, for which the genotype groups have been determined with respect to the degree of base substitution

Kiwamu Minamisawa; Katsuhiko Fukai

405

Improved Monitoring of Female Codling Moth (Lepidoptera: Tortricidae) with Pear Ester Plus Acetic Acid in Sex Pheromone-treated Orchards  

Technology Transfer Automated Retrieval System (TEKTRAN)

Catch of codling moth, Cydia pomonella (L.), in clear delta traps baited with ethyl (E,Z)-2,4-decadienoate (pear ester, PE) and acetic acid (AA) in separate lures (PE+AA) was compared with catch in orange delta traps baited with a single lure containing PE and the sex pheromone, (E,E)-8,10-dodecadie...

406

Integrated phospholipidomics and transcriptomics analysis of Saccharomyces cerevisiae with enhanced tolerance to a mixture of acetic acid, furfural, and phenol  

Technology Transfer Automated Retrieval System (TEKTRAN)

A mixture of acetic acid, furfural and phenol (AFP), three representative lignocellulose derived inhibitors, significantly inhibited the growth and bioethanol production of Saccharomyces cerevisiae. In order to uncover mechanisms behind the enhanced tolerance of an inhibitor-tolerant S.cerevisiae s...

407

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

408

Characterization of bore pressure change effects on Matrimid ® fiber performance in pervaporation of acetic acid and water mixtures  

Microsoft Academic Search

A mathematical model was used to account for the bore pressure change effects observed for Matrimid® hollow fiber membranes to obtain the inherent water permeability and membrane selectivity in pervaporation of 20%wt acetic acid (HAc) and water mixtures. The modeled water flux was close to the experimental result for a large bore size fiber (bore size ?350?m) with 20cm length

Fangbin Zhou; William J. Koros

2006-01-01

409

FUNCTIONAL GENOMIC ANALYSIS OF THE AUXIN/INDOLE-3-ACETIC ACID GENE FAMILY MEMBERS IN ARABIDOPSIS THALIANA  

Technology Transfer Automated Retrieval System (TEKTRAN)

Auxin regulates various aspects of plant growth and development. The AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) genes encode short-lived transcriptional repressors that are targeted by the TRANSPORT INHIBITOR RESPONSE1/AUXIN RECEPTOR F-BOX proteins. The Aux/IAA proteins regulate auxin-mediated gene expres...

410

Evaluation of the effect of fluoride-containing acetic acid on NiTi wires.  

PubMed

The possibility of the formation of hydrofluoric acid by the reaction of fluoride with acetic acid seems natural in the oral cavity. The effect of an acidic fluoride solution on NiTi wires was investigated by testing microhardness and color changes on wires. For aesthetic reasons, the color change on wires was also evaluated. Wires were immersed in four different test solutions for 1 or 3 days. As-received wires were used as a reference. After immersion for 3 days, the microhardness of the tested wires increased 1.8% to 10.4% compared to that of their as-received state. Wires immersed in a higher NaF concentration, lower pH solution with longer immersion yielded a more corroded surface than those of the counter cases. Wires showed a different color after immersion. However, after 3 days in solutions of pH 4, wires showed an appreciable color change regardless of the products. In test solutions, 3M wires showed the highest volumetric and percentage (0.59 for 0.05%; 1.19 for 0.2% solution) weight loss and G&H wires showed the least volumetric and percentage (0.43 for 0.05%; 1.05 for 0.2% solution) weight loss among tested wires. In pH 6 solutions, wires lost weight and were under the detection limit of the testing machine. PMID:15389492

Kwon, Yong Hoon; Cho, Ho-Sung; Noh, Dong-Jin; Kim, Hyung-Il; Kim, Kyo-Han

2005-01-15

411

Calibration and intercomparison of acetic acid measurements using proton-transfer-reaction mass spectrometry (PTR-MS)  

NASA Astrophysics Data System (ADS)

Acetic acid is one of the most abundant organic acids in the ambient atmosphere, with maximum mixing ratios reaching into the tens of parts per billion by volume (ppbv) range. The identities and associated magnitudes of the major sources and sinks for acetic acid are poorly characterized, due in part to the limitations of available measurement techniques. This paper demonstrates that, when properly calibrated, proton-transfer-reaction mass spectrometry (PTR-MS) can be a valuable technique for fast response, accurate quantification of acetic acid in ambient air. Three different PTR-MS configurations were calibrated at low ppbv mixing ratios using permeation tubes, which yielded calibration factors between 7.0 and 10.9 normalized counts per second per ppbv (ncps ppbv-1) at a drift tube field strength of 132 Townsend (Td). Detection limits ranged from 0.06 to 0.32 ppbv with dwell times of 5 s. These calibration factors showed negligible humidity dependence. Acetic acid was measured with PTR-MS on Appledore B Island, ME, during the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) campaign and validated based on acetic acid measured in parallel using tandem mist chambers coupled with ion chromatography (MC/IC). Mixing ratios ranged from a minimum of 0.075 ± 0.004 ppbv to 3.555 ± 0.171 ppbv, with a median mixing ratio of 0.530 ± 0.025 ppbv. An orthogonal least squares linear regression of paired data yielded a slope of 1.14 ± 0.06 (2?), an intercept of 0.049 ± 0.020 (2?) ppbv, and an R2 of 0.78.

Haase, K. B.; Keene, W. C.; Pszenny, A. A. P.; Mayne, H. R.; Talbot, R. W.; Sive, B. C.

2012-11-01

412

Fragrance material review on 3-phenylpropyl acetate.  

PubMed

A toxicologic and dermatologic review of 3-phenylpropyl acetate when used as a fragrance ingredient is presented. 3-Phenylpropyl acetate is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 3-phenylpropyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, skin sensitization, and toxicokinetics data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al., 2012 for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22414651

McGinty, D; Letizia, C S; Api, A M

2012-03-04

413

Fragrance material review on anisyl acetate.  

PubMed

A toxicologic and dermatologic review of anisyl acetate when used as a fragrance ingredient is presented. Anisyl acetate is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for anisyl acetate were evaluated, then summarized, and includes: physical properties, skin irritation, skin sensitization, elicitation, and phototoxicity data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al., 2012 for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22414654

McGinty, D; Letizia, C S; Api, A M

2012-03-03

414

Fragrance material review on 4-methylbenzyl acetate.  

PubMed

A toxicologic and dermatologic review of 4-methylbenzyl acetate when used as a fragrance ingredient is presented. 4-Methylbenzyl acetate is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 4-methylbenzyl acetate were evaluated, then summarized, and includes: physical properties, skin irritation, skin sensitization, and elicitation data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22414643

McGinty, D; Letizia, C S; Api, A M

2012-03-05

415

The use of acetic acid as a source of carbon by cultured Chondrus crispus (Gigartinales, Rhodophyta) stackhouse  

Microsoft Academic Search

When growing seaweeds in tanks, pH and carbon source supply have to be controlled in order to maximize photosynthesis. pH can be controlled either by adding various inorganic acids which requires the extra addition of carbon, or by combining pH control and carbon source with for instance CO2 or an organic acid such as acetic acid (CH3COOH). We have found

Mireille A. Amat; Jean-Paul Braud

1993-01-01

416

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

417

Characterization of a recombinant flocculent Saccharomyces cerevisiae strain that co-ferments glucose and xylose: II. influence of pH and acetic acid on ethanol production.  

PubMed

The inhibitory effects of pH and acetic acid on the co-fermentation of glucose and xylose in complex medium by recombinant flocculent Saccharomyces cerevisiae MA-R4 were evaluated. In the absence of acetic acid, the fermentation performance of strain MA-R4 was similar between pH?4.0-6.0, but was negatively affected at pH?2.5. The addition of acetic acid to batch cultures resulted in negligible inhibition of several fermentation parameters at pH?6.0, whereas the interactive inhibition of pH and acetic acid on the maximum cell and ethanol concentrations, and rates of sugar consumption and ethanol production were observed at pH levels below 5.4. The inhibitory effect of acetic acid was particularly marked for the consumption rate of xylose, as compared with that of glucose. With increasing initial acetic acid concentration, the ethanol yield slightly increased at pH?5.4 and 6.0, but decreased at pH values lower than 4.7. Notably, ethanol production was nearly completely inhibited under low pH (4.0) and high acetic acid (150-200 mM) conditions. Together, these results indicate that the inhibitory effects of acetic acid and pH on ethanol fermentation by MA-R4 are highly synergistic, although the inhibition can be reduced by increasing the medium pH. PMID:23076570

Matsushika, Akinori; Sawayama, Shigeki

2012-10-18

418

Effect of acetic acid and pH on the cofermentation of glucose and xylose to ethanol by a genetically engineered strain of Saccharomyces cerevisiae.  

PubMed

A current challenge of the cellulosic ethanol industry is the effect of inhibitors present in biomass hydrolysates. Acetic acid is an example of one such inhibitor that is released during the pretreatment of hemicellulose. This study examined the effect of acetic acid on the cofermentation of glucose and xylose under controlled pH conditions by Saccharomyces cerevisiae 424A(LNH-ST), a genetically engineered industrial yeast strain. Acetic acid concentrations of 7.5 and 15 g L(-1), representing the range of concentrations expected in actual biomass hydrolysates, were tested under controlled pH conditions of 5, 5.5, and 6. The presence of acetic acid in the fermentation media led to a significant decrease in the observed maximum cell biomass concentration. Glucose- and xylose-specific consumption rates decreased as the acetic acid concentration increased, with the inhibitory effect being more severe for xylose consumption. The ethanol production rates also decreased when acetic acid was present, but ethanol metabolic yields increased under the same conditions. The results also revealed that the inhibitory effect of acetic acid could be reduced by increasing media pH, thus confirming that the undissociated form of acetic acid is the inhibitory form of the molecule. PMID:20402796

Casey, Elizabeth; Sedlak, Miroslav; Ho, Nancy W Y; Mosier, Nathan S

2010-03-10

419

Vanadium-molybdenum phosphates supported by TiO 2 -anatase as new catalysts for selective oxidation of ethane to acetic acid  

Microsoft Academic Search

Dispersion of vanadium and molybdenum phosphates on titanium oxide (anatase) below the monolayer gives good catalysts for direct oxidation of ethane to acetic acid. By comparison with the dispersion of only vanadium phosphate, the higher selectivity to acetic acid for vanadium and molybdenum phosphates has been explained by an interaction between molybdenum and vanadium as it can be deduced from

Magalie Roy; Michel Gubelmann-Bonneau; Hervé Ponceblanc; Jean-Claude Volta

1996-01-01

420

Short chain fatty acid distributions of enema samples from a sigmoidoscopy population: an association of high acetate and low butyrate ratios with adenomatous polyps and colon cancer  

Microsoft Academic Search

We investigated the distribution of short chain fatty acids (SCFA) in enema samples taken from subjects before sigmoidoscopy as an indicator of possible microbial community differences between subjects subsequently diagnosed as normal or having colonic disorders. The major SCFA in all groups were acetic, propionic, and butyric acids. A significantly higher ratio of acetate to total SCFA and lower ratio

G A Weaver; J A Krause; T L Miller; M J Wolin

1988-01-01

421

Lewis acid catalyzed intramolecular condensation of ynol ether-acetals. Synthesis of alkoxycycloalkene carboxylates.  

PubMed

Treatment of ynol ether-tethered dialkyl acetals with catalytic quantities of scandium triflate in CH(3)CN gives rise to five-, six-, and seven-membered alkoxycycloalkene carboxylates in good to excellent yields. Tri- and tetrasubstituted carbocyclic and heterocyclic alkenes may be formed by this method, and the products obtained may serve as useful intermediates for natural product synthesis. PMID:23170869

Tran, Vincent; Minehan, Thomas G

2012-11-21

422

Influence of Helicobacter pylori Infection on Healing and Relapse of Acetic Acid Ulcers in Mongolian Gerbils  

Microsoft Academic Search

Both Helicobacter pylori and NSAIDs play important roles in the healing and relapse of peptic ulcers in man. We examined how H. pylori infection, indomethacin, and their combination affects the healing of gastric ulcers and whether or not such factors provoke a relapse of healed gastric ulcers in Mongolian gerbils. Gastric ulcers were induced by serosal application of an acetic

Yoshihiro Keto; Misako Ebata; Kazuyoshi Tomita; Susumu Okabe

2002-01-01

423

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

424

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

425

Draft Guidance on Norethindrone Acetate Active ingredient ...  

Center for Drug Evaluation (CDER)

Text VersionPage 1. Contains Nonbinding Recommendations Draft Guidance on Norethindrone Acetate ... Active ingredient: Norethindrone Acetate ... More results from www.fda.gov/downloads/drugs/guidancecomplianceregulatoryinformation

426

Effects of Indole-3-Acetic Acid on the Transcriptional Activities and Stress Tolerance of Bradyrhizobium japonicum.  

PubMed

A genome-wide transcriptional profile of Bradyrhizobium japonicum, the nitrogen-fixing endosymbiont of the soybean plant, revealed differential expression of approximately 15% of the genome after a 1 mM treatment with the phytohormone indole-3-acetic acid (IAA). A total of 1,323 genes were differentially expressed (619 up-regulated and 704 down-regulated) at a two-fold cut off with q value ? 0.05. General stress response genes were induced, such as those involved in response to heat, cold, oxidative, osmotic, and desiccation stresses and in exopolysaccharide (EPS) biosynthesis. This suggests that IAA is effective in activating a generalized stress response in B. japonicum. The transcriptional data were corroborated by the finding that stress tolerance of B. japonicum in cell viability assays was enhanced when pre-treated with 1 mM IAA compared to controls. The IAA treatment also stimulated biofilm formation and EPS production by B. japonicum, especially acidic sugar components in the total EPS. The IAA pre-treatment did not influence the nodulation ability of B. japonicum. The data provide a comprehensive overview of the potential transcriptional responses of the symbiotic bacterium when exposed to the ubiquitous hormone of its plant host. PMID:24098533

Donati, Andrew J; Lee, Hae-In; Leveau, Johan H J; Chang, Woo-Suk

2013-10-02

427

Asaia siamensis sp. nov., an acetic acid bacterium in the alpha-proteobacteria.  

PubMed

Five bacterial strains were isolated from tropical flowers collected in Thailand and Indonesia by the enrichment culture approach for acetic acid bacteria. Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolates were located within the cluster of the genus Asaia. The isolates constituted a group separate from Asaia bogorensis on the basis of DNA relatedness values. Their DNA G+C contents were 58.6-59.7 mol%, with a range of 1.1 mol%, which were slightly lower than that of A. bogorensis (59.3-61.0 mol%), the type species of the genus Asaia. The isolates had morphological, physiological and biochemical characteristics similar to A. bogorensis strains, but the isolates did not produce acid from dulcitol. On the basis of the results obtained, the name Asaia siamensis sp. nov. is proposed for these isolates. Strain S60-1T, isolated from a flower of crown flower (dok rak, Calotropis gigantea) collected in Bangkok, Thailand, was designated the type strain ( = NRIC 0323T = JCM 10715T = IFO 16457T). PMID:11321102

Katsura, K; Kawasaki, H; Potacharoen, W; Saono, S; Seki, T; Yamada, Y; Uchimura, T; Komagata, K

2001-03-01

428

Effects of Indole-3-Acetic Acid on the Transcriptional Activities and Stress Tolerance of Bradyrhizobium japonicum  

PubMed Central

A genome-wide transcriptional profile of Bradyrhizobium japonicum, the nitrogen-fixing endosymbiont of the soybean plant, revealed differential expression of approximately 15% of the genome after a 1 mM treatment with the phytohormone indole-3-acetic acid (IAA). A total of 1,323 genes were differentially expressed (619 up-regulated and 704 down-regulated) at a two-fold cut off with q value ? 0.05. General stress response genes were induced, such as those involved in response to heat, cold, oxidative, osmotic, and desiccation stresses and in exopolysaccharide (EPS) biosynthesis. This suggests that IAA is effective in activating a generalized stress response in B. japonicum. The transcriptional data were corroborated by the finding that stress tolerance of B. japonicum in cell viability assays was enhanced when pre-treated with 1 mM IAA compared to controls. The IAA treatment also stimulated biofilm formation and EPS production by B. japonicum, especially acidic sugar components in the total EPS. The IAA pre-treatment did not influence the nodulation ability of B. japonicum. The data provide a comprehensive overview of the potential transcriptional responses of the symbiotic bacterium when exposed to the ubiquitous hormone of its plant host.

Donati, Andrew J.; Lee, Hae-In; Leveau, Johan H. J.; Chang, Woo-Suk

2013-01-01

429

The Promotion of Indole-3-acetic Acid Oxidation in Pea Buds by Gibberellic Acid and Treatment 1  

PubMed Central

Terminal buds of dark-grown pea (Pisum sativum) seedlings have an indole-3-acetic acid oxidase which does not require Mn2+ and 2,4-dichlorophenol as cofactors. Oxidase activity is at least 50 times higher in buds of tall peas than in dwarf seedlings. Administration of gibberellic acid to dwarf peas stimulates both growth and indoleacetic acid oxidase activity to the same levels as in tall seedlings. By contrast, indoleacetic acid oxidation assayed in the presence of Mn2+ and 2,4-dichlorophenol proceeds at similar rates regardless of gibberellin application. Treatment of tall peas with the growth retardant AMO-1618 reduces growth and oxidase activity. Such treated seedlings are indistinguishably dwarf. The enzyme does not appear to be polyphenol oxidase, nor do the results suggest that reduced activity in dwarf buds is due to higher levels of a dialyzable inhibitor. The peroxidative nature of the oxidase is probable.

Ockerse, Ralph; Waber, Jack

1970-01-01

430

Separation by extractive distillation of mixtures of alcohols and the esters of acetic acid. 1: Solvent selection  

Microsoft Academic Search

Isobaric 760-mm-Hg vapor-liquid equilibrium data were measured for the binary systems methyl acetate-methanol (1), ethyl acetate-ethanol (2), n-propanol-n-propyl acetate (3), and isopropanol-isopropyl acetate (4) by using a recirculation still designed in the present authors laboratory. The data were tested for experimental thermodynamic consistency, and were correlated by applying the van Laar and Wilson equations. The following minimum azeotropes were found:

E. Cepeda; J. M. Resa

1994-01-01

431

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.

2010-01-01

432

Methanogenesis from acetate: enrichment studies.  

PubMed Central

An acetate enrichment culture was initiated by inoculating anaerobic sludge from a mesophilic methane digestor into a mineral salts medium with calcium acetate as the sole carbon and energy source. This enrichment was maintained indefinitely by weekly transfer into medium of the same composition. A study of this enrichment disclosed an unexpected age-dependent inhibition of methanogenesis by H2 and formate which apparently differed from the inhibition by chloroform and benzyl viologen. This age-dependent inhibition indicated that microbial interactions of the mixed enrichment population may play a regulatory role in methane formation. Futhermore, stimulation of methanogenesis in the acetate enrichment by addition of yeast extract showed a nutrient limitation which indicated that syntrophic interactions leading to formation of growth factors may also occur. A model is presented to illustrate the possible interrelationships between methanogenic and nonmethanogenic bacteria in their growth and formation of methane and carbon dioxide from acetate. Images

Baresi, L; Mah, R A; Ward, D M; Kaplan, I R

1978-01-01

433

Kinetics of the methanogenic fermentation of acetate. [Methanosarcina barkeri  

SciTech Connect

Inhibition of the fermentation of acetate to methane and carbon dioxide by acetate was analyzed with an acetate-acclimatized sludge and with Methanosarcina barkeri Fusaro under mesophilic conditions. A second-order substrate inhibition model, q{sub CH{sub 4}} = q{sub m}S/(K{sub s} + S + (S{sup 2}/K{sub i})), where S was the concentration of undissociated acetic acid, not ionized acetic acid, could be applicable in both cases. The analysis resulted in substrate saturation constants, K{sub s}, of 4.0 {mu}M for the acclimatized sludge and 104 {mu}M for M. barkeri. The threshold concentrations of undissociated acetic acid when no further acetate utilization was observed were 0.078 {mu}M (pH 7.50) for the acclimatized sludge and 4.43 {mu}M (pH 7.45) for M. barkeri. These kinetic results suggested that the concentration of undissociated acetic acid became a key factor governing the actual threshold acetate concentration for acetate utilization and that the acclimatized sludge in which Methanothrix spp. appeared dominant could utilize acetate better and survive at a lower concentration of undissociated acetic acid than could M. barkeri.

Fukuzaki, Satoshi; Nishio, Naomichi; Nagai, Shiro (Hiroshima Univ. (Japan))

1990-10-01

434

Acetate catabolism by Methanosarcina barkeri  

SciTech Connect

Cell suspensions of Methanosarcina barkeri convert the carboxyl and methyl group carbons of acetate to carbon dioxide and methane at pH 6 under an atmosphere of 100% CO/sub 2/. The rate of loss of radioactivity from (1-/sup 14/C)acetate was over three times greater than that from (2-/sup 14/C)acetate under these conditions. Control experiments with both labeled substrates present showed that the rates were additive. Addition of a high level of 2-bromoethanesulfonate to selectively inhibit methane formation largely inhibited release of /sup 14/C from methyl-labeled acetate but only marginally decreased the rate of loss from (1-/sup 14/C)acetate. Thus, in the absence of the inhibitor loss of /sup 14/C from (1-/sup 14/C)acetate likely reflects an isotopic exchange reaction with CO/sub 2/ superimposed on the overall conversion of acetate to CO/sub 2/ and CH/sub 4/. The exchange reaction was inhibited by uncouplers such as 2,4-dinitrophenol, CCCP, and FCCP. Cells permeabilized by treatment with nonionic detergents or disrupted by passage through a French pressure cell failed to catalyze the exchange reaction. Exchange activity was not restored by addition of ATP or by use of (1-/sup 14/C)acetyl CoA as substrate. No evidence for involvement of carbon monoxide dehydrogenase in the exchange was found in these experiments when CO/sub 2/ was replaced by CO. However, the soluble extracts retained the ability to convert acetate to methane in the presence of H/sub 2/ and ATP.

Grahame, D.A.

1987-05-01

435

Metabolism of Tryptophan, Indole-3-acetic Acid, and Related Compounds in Parasitic Plants from the Genus Orobanche.  

PubMed

Metabolic reactions involving the aliphatic side chain of tryptophan were studied in the holoparasitic dicotyledonous plants Orobanche gracilis Sm., O. lutea Baumg., and O. ramosa L. Unlike known autotrophic plants, the parasite metabolized l-tryptophan directly to indole-3-carboxaldehyde, which was further converted to indole-3-methanol and indole-3-carboxylic acid. Independently, these metabolites were also formed from d-tryptophan, tryptamine, indole-3-lactic acid, and indole-3-acetic acid. As in autotrophic plants, tryptophan and tryptamine were also converted, via indole-3-acetaldehyde, to indole-3-acetic acid, indole-3-ethanol, and its glucoside. The branch of tryptophan metabolism relevant to auxin biogenesis and catabolism is, therefore, not rudimentary in Orobanche but even more complex than in autotrophic higher plants. PMID:16662308

Magnus, V; Simaga, S; Iskri?, S; Kveder, S

1982-04-01

436

Metabolism of Tryptophan, Indole-3-acetic Acid, and Related Compounds in Parasitic Plants from the Genus Orobanche  

PubMed Central

Metabolic reactions involving the aliphatic side chain of tryptophan were studied in the holoparasitic dicotyledonous plants Orobanche gracilis Sm., O. lutea Baumg., and O. ramosa L. Unlike known autotrophic plants, the parasite metabolized l-tryptophan directly to indole-3-carboxaldehyde, which was further converted to indole-3-methanol and indole-3-carboxylic acid. Independently, these metabolites were also formed from d-tryptophan, tryptamine, indole-3-lactic acid, and indole-3-acetic acid. As in autotrophic plants, tryptophan and tryptamine were also converted, via indole-3-acetaldehyde, to indole-3-acetic acid, indole-3-ethanol, and its glucoside. The branch of tryptophan metabolism relevant to auxin biogenesis and catabolism is, therefore, not rudimentary in Orobanche but even more complex than in autotrophic higher plants.

Magnus, Volker; Simaga, Sumski; Iskric, Sonja; Kveder, Sergije

1982-01-01

437

Sources and sinks of formic, acetic, and pyruvic acids over central Amazonia. 2. Wet season  

SciTech Connect

The authors determined the gas phase concentrations of formic (FA), acetic (AA), and pyruvic (PA) acids in the forest canopy, boundary layer, and free troposphere over the central Amazon Basin during the April-May segment of the 1987 wet season. At 150-m altitude in the boundary layer the daytime average concentrations were 430 {plus minus} 225, 340 {plus minus} 155, and 25 {plus minus} 15 ppt for FA, AA, and PA, respectively. These values were fivefold lower than those observed in the 1985 dry season. Concentrations measured near canopy top were not significantly different from boundary layer values (P = 0.10), while concentrations in the lower canopy were significantly less. Concentrations in the free troposphere (5 km) were lower than in the boundary layer and averaged 170 {plus minus} 40, 210 {plus minus} 40, and 15 {plus minus} 15 ppt for FA, AA, and PA, respectively. Fivefold enhancements of PA concentrations were observed in convective outflows at 5- to 6-km altitudes. Aerosol carboxylate concentrations were usually below the detection limit of 5-10 ppt. Preliminary branch enclosure measurements indicated significant direct emission of carboxylic acids by vegetation. A one-dimensional photochemical model for the canopy and the boundary layer was used to examine the contributions from various sources to the carboxylic acid budgets. Model results indicate that direct emissions from vegetation can account for most of the concentrations observed in the canopy. These emissions peak during the daytime hours, and 24-hour average upward fluxes at canopy top are 4.4 {times} 10{sup 9}, 3.7 {times} 10{sup 9}, and 2.8 {times} 10{sup 8} molecules cm{sup {minus}2} s{sup {minus}1} for FA, AA, and PA, respectively. However, direct emissions from vegetation can account for only a small fraction of the observed carboxylic acid concentrations in the boundary layer, suggesting a large contribution from atmospheric sources.

Talbot, R.W.; Beecher, K.M. (NASA Langley Research Center, Hampton, VA (USA)); Andreae, M.O.; Berresheim, H. (Florida State Univ., Tallahassee (USA)); Jacob, D.J. (Harvard Univ., Cambridge, MA (USA))

1990-09-20

438

Synthesis and in vitro antimicrobial activity of novel 2-(3-oxo-1,3-diarylpropylthio)acetic acid derivatives.  

PubMed

A series of novel 2-(3-oxo-1,3-diarylpropylthio)acetic acid derivatives (3a-l) were prepared by base catalyzed addition of thioglycolic acid to chalcones (1a-l). The antibacterial activities of synthesized compounds were screened against human pathogenic microorganisms by employing the disk-diffusion technique. For the active compounds, also minimum inhibitory concentrations (MICs) were determined. PMID:23061285

Gezegen, Hayreddin; Karaman, Isa; Ceylan, Mustafa; Dilmaç, Merve

439

Partially reduced heteropolyanions for the oxidative dehydrogenation of ethane to ethylene and acetic acid at atmospheric pressure  

Microsoft Academic Search

Niobium- and pyridine-exchanged salts of phosphomolybdic (NbPMo12Pyr) and phosphovanadomolybdic acids, NbPMo12Pyr and NbPMo11VPyr, respectively, were investigated as precursors to materials that catalyze the oxidative dehydrogenation of ethane to ethylene and acetic acid at atmospheric pressure. The effects of feed composition, steam flow, temperature, and precursor composition on catalytic activity and selectivity are presented for both ethane and ethylene oxidation. The

J. M. Galownia; A. P. Wight; A. Blanc; J. A. Labinger; M. E. Davis

2005-01-01

440

Effects of Lactic and Acetic Acid on Survival of Salmonella enteritidis During Refrigerated and Frozen Storage of Chicken Meats  

Microsoft Academic Search

Chicken leg and breast meat samples inoculated with Salmonella enteritidis [4–5 log most probable number (MPN)\\/cm2] were dipped into lactic acid (LA; 1% and 3%) and acetic acid (AA; 1% and 2%) solutions for 10 min. After packaging, samples\\u000a were stored at 4 °C (10 days) or ?18 °C (6 months). Immediately after dipping into 1% LA, 3% LA, 1% AA, and 2% AA solutions,

Serap Cosansu; Kamuran Ayhan

441

Effect of Chronic Dietary Treatment with Nicotinic Acid on the Development and Maintenance of Deoxycorticosterone-Acetate-Salt-Induced Hypertension  

Microsoft Academic Search

Chronic dietary administration of either \\/-tryptophan (5.0%) or nicotinic acid (5.0%) reduced the elevated blood pressure of rats with established, deoxycorticosterone-acetate (DOCA)-salt-induced hypertension without affecting either body weight or cardiac hypertrophy. In a second study, chronic dietary administration of nicotinic acid (2.5 and 5.0%) provided significant protection against the development of an elevated blood pressure in rats treated with DOCA

Melvin J. Fregly; Ora E. Lockley; Jose L. Torres; Robert Cade

1988-01-01

442

PREPARATION AND PROPERTIES OF WATER-SOLUBLE STARCH ACETATES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Starch acetates of degree of substitution (DS) 0-1.5 were prepared by heating dry corn starch, acetic acid and acetic anhydride in sealed 60 ul vessels at 180 degree C for 5 minutes. These reactions appeared to be homogeneous (clear) and proceeded to completion without added catalyst. Starch aceta...

443

Pathway of acetate assimilation in autotrophic and heterotrophic methanococci.  

PubMed Central

The autotroph Methanococcus maripaludis contained high levels of acetate-coenzyme A ligase, pyruvate synthase, pyruvate, water dikinase, pyruvate carboxylase, and the enzymes of the incomplete reductive tricarboxylic acid cycle. Phosphoenolpyruvate carboxykinase, citrate synthase, and isocitrate dehydrogenase were not detected. In contrast, the heterotroph Methanococcus sp. strain A3 contained acetate kinase, and acetate coenzyme A ligase was virtually absent.

Shieh, J S; Whitman, W B

1987-01-01

444

Pathway of acetate assimilation in autotrophic and heterotrophic methanococci.  

PubMed

The autotroph Methanococcus maripaludis contained high levels of acetate-coenzyme A ligase, pyruvate synthase, pyruvate, water dikinase, pyruvate carboxylase, and the enzymes of the incomplete reductive tricarboxylic acid cycle. Phosphoenolpyruvate carboxykinase, citrate synthase, and isocitrate dehydrogenase were not detected. In contrast, the heterotroph Methanococcus sp. strain A3 contained acetate kinase, and acetate coenzyme A ligase was virtually absent. PMID:3667534

Shieh, J S; Whitman, W B

1987-11-01

445

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

2012-10-29

446

Nutrient salts promote light-induced degradation of indole-3-acetic Acid in tissue culture media.  

PubMed

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, J R; Robacker, K M

1988-10-01

447

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

2013-09-24

448

Antiproliferative properties of flavone acetic acid (NSC 347512) (LM 975), a new anticancer agent.  

PubMed

The antiproliferative activity of flavone acetic acid (LM 975) was investigated on human adenocarcinoma cell lines (HCC-P2998, HCC-M1544, HCC-M1410, HT 29, LoVo), on a murine colon adenocarcinoma cell line (Colon 26), on murine pancreatic adenocarcinoma cells growing in primary culture (Pan 03) and on human normal fibroblasts (N1). No cytotoxic effects were found against human normal fibroblasts. LM 975 was active against murine adenocarcinoma Pan 03 and Colon 26, known to be sensitive in vivo too and, to variable extents, on human adenocarcinoma cell lines. LM 975 in vitro cytotoxic potency was relatively low. The high concentrations (1.0-1.4 mM) required to obtain a cytotoxic effect are, however, pharmacologically reasonable since they are comparable with drug plasma levels in mice or in patients treated with tolerable doses. After a relatively short LM 975 treatment (2 h) DNA, RNA and protein synthesis were inhibited in different proportions. In more se