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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

Genera and species in acetic acid bacteria  

Microsoft Academic Search

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\\

Yuzo Yamada; Pattaraporn Yukphan

2008-01-01

3

Vesicles protect activated acetic acid.  

PubMed

Abstract Methyl thioacetate, or activated acetic acid, has been proposed to be central to the origin of life and an important energy currency molecule in early cellular evolution. We have investigated the hydrolysis of methyl thioacetate under various conditions. Its uncatalyzed rate of hydrolysis is about 3 orders of magnitude faster (K=0.00663 s(-1); 100°C, pH 7.5, concentration=0.33 mM) than published rates for its catalyzed production, making it unlikely to accumulate under prebiotic conditions. However, our experiments showed that methyl thioacetate was protected from hydrolysis when inside its own hydrophobic droplets. Further, we found that methyl thioacetate protection from hydrolysis was also possible in droplets of hexane and in the membranes of nonanoic acid vesicles. Thus, the hydrophobic regions of prebiotic vesicles and early cell membranes could have offered a refuge for this energetic molecule, increasing its lifetime in close proximity to the reactions for which it would be needed. This model of early energy storage evokes an additional critical function for the earliest cell membranes. PMID:25280019

Todd, Zoe R; House, Christopher H

2014-10-01

4

Acetic acid production from food wastes using yeast and acetic acid bacteria micro-aerobic fermentation.  

PubMed

In this study, yeast and acetic acid bacteria strains were adopted to enhance the ethanol-type fermentation resulting to a volatile fatty acids yield of 30.22 g/L, and improve acetic acid production to 25.88 g/L, with food wastes as substrate. In contrast, only 12.81 g/L acetic acid can be obtained in the absence of strains. The parameters such as pH, oxidation reduction potential and volatile fatty acids were tested and the microbial diversity of different strains and activity of hydrolytic ferment were investigated to reveal the mechanism. The optimum pH and oxidation reduction potential for the acetic acid production were determined to be at 3.0-3.5 and -500 mV, respectively. Yeast can convert organic matters into ethanol, which is used by acetic acid bacteria to convert the organic wastes into acetic acid. The acetic acid thus obtained from food wastes micro-aerobic fermentation liquid could be extracted by distillation to get high-pure acetic acid. PMID:25416587

Li, Yang; He, Dongwei; Niu, Dongjie; Zhao, Youcai

2015-05-01

5

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

6

Overview on mechanisms of acetic acid resistance in acetic acid bacteria.  

PubMed

Acetic acid bacteria (AAB) are a group of gram-negative or gram-variable bacteria which possess an obligate aerobic property with oxygen as the terminal electron acceptor, meanwhile transform ethanol and sugar to corresponding aldehydes, ketones and organic acids. Since the first genus Acetobacter of AAB was established in 1898, 16 AAB genera have been recorded so far. As the main producer of a world-wide condiment, vinegar, AAB have evolved an elegant adaptive system that enables them to survive and produce a high concentration of acetic acid. Some researches and reviews focused on mechanisms of acid resistance in enteric bacteria and made the mechanisms thoroughly understood, while a few investigations did in AAB. As the related technologies with proteome, transcriptome and genome were rapidly developed and applied to AAB research, some plausible mechanisms conferring acetic acid resistance in some AAB strains have been published. In this review, the related mechanisms of AAB against acetic acid with acetic acid assimilation, transportation systems, cell morphology and membrane compositions, adaptation response, and fermentation conditions will be described. Finally, a framework for future research for anti-acid AAB will be provided. PMID:25575804

Wang, Bin; Shao, Yanchun; Chen, Fusheng

2015-02-01

7

Tested Demonstrations: Buffer Capacity of Various Acetic Acid-Sodium Acetate Systems: A Lecture Experiment.  

ERIC Educational Resources Information Center

Background information and procedures are provided for a lecture experiment which uses indicators to illustrate the concept of differing buffer capacities by titrating acetic acid/sodium acetate buffers with 1.0 molar hydrochloric acid and 1.0 molar sodium hydroxide. A table with data used to plot the titration curve is included. (JN)

Donahue, Craig J.; Panek, Mary G.

1985-01-01

8

Mesoxalaldehyde acetals  

SciTech Connect

The treatment of methylglyoxal acetals by alkyl nitrites in the presence of the corresponding aliphatic alcohols and hydrochloric acid leads to the formation of linear mesoxalaldehyde acetals, whose structure was established by NMR spectroscopy and mass spectrometry. The major pathways for the decomposition of these molecules upon electron impact were established.

Gordeeva, G.N.; Kalashnikov, S.M.; Popov, Yu.N.; Kruglov, E.A.; Imashev, U.B.

1987-11-10

9

Asymmetric Hydrogenation of Itaconic Acid and Enol Acetate Derivatives with  

E-print Network

. A variety of chiral 2-substituted succinic acids and chiral acetates have been obtained in excellent ee)- acrylates.3b Herein we report the applications of TangPhos in asymmetric hydrogenation of itaconic acid of acyclic enol acetates bearing aromatic substituents. Chiral 2-substituted succinic acids have attracted

Zhang, Xumu

10

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

NASA Technical Reports Server (NTRS)

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

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

1988-01-01

11

Characterization of acetic acid bacteria in “traditional balsamic vinegar”  

Microsoft Academic Search

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

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

2006-01-01

12

Original article Ethanol and acetic-acid tolerances  

E-print Network

Original article Ethanol and acetic-acid tolerances in Drosophila melanogaster: similar maternal) Summary - Ethanol and acetic-acid tolerances were studied in a cross between 2 geo- graphic races disappeared in the F2. Further investigations demonstrated that for ethanol tolerance, the large difference

Paris-Sud XI, Université de

13

Micelles Protect and Concentrate Activated Acetic Acid  

NASA Astrophysics Data System (ADS)

As more and more exoplanets are discovered and the habitability of such planets is considered, one can turn to searching for the origin of life on Earth in order to better understand what makes a habitable planet. Activated acetic acid, or methyl thioacetate, has been proposed to be central to the origin of life on Earth, and also as an important energy currency molecule in early cellular evolution. We have investigated the hydrolysis of methyl thioacetate under various conditions. Its uncatalyzed rate of hydrolysis is about three orders of magnitude faster (K = 0.00663 s^-1; 100°C, pH 7.5, concentration = 0.33mM) than published rates for its catalyzed production making it unlikely to accumulate under prebiotic conditions. However, we also observed that methyl thioacetate was protected from hydrolysis when inside its own hydrophobic droplets. We found that methyl thioacetate protection from hydrolysis was also possible in droplets of hexane and in the membranes of nonanoic acid micelles. Thus, the hydrophobic regions of prebiotic micelles and early cell membranes could have offered a refuge for this energetic molecule increasing its lifetime in close proximity to the reactions for which it would be needed. Methyl thioacetate could thus be important for the origin of life on Earth and perhaps for better understanding the potential habitability of other planets.

Todd, Zoe; House, C.

2014-01-01

14

Original article Effect of indole-3-acetic acid (plant auxin)  

E-print Network

Original article Effect of indole-3-acetic acid (plant auxin) on the preservation at 15 °C of boar; Effet de l'auxine végétale, l'acide 3-indole-acétique, sur la conservation du sperme de verrat pourl

Paris-Sud XI, Université de

15

SOLVENT EXTRACTION OF WASTEWATERS FROM ACETIC-ACID MANUFACTURE  

EPA Science Inventory

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

16

Degradation by acetic acid for crystalline Si photovoltaic modules  

NASA Astrophysics Data System (ADS)

The degradation of crystalline Si photovoltaic modules during damp-heat test was studied using some test modules with and without polymer film insertion by observing electrical and electroluminescence properties and by chemical analyses. Acetic acid generated by the hydrolysis decomposition of ethylene vinyl acetate used as an encapsulant is the main origin of degradation. The change in electroluminescence images is explained on the basis of the corrosion of electrodes by acetic acid. On the other hand, little change was observed at the pn junction even after damp-heat test for a long time. Therefore, carrier generation occurs even after degradation; however, such generated carriers cannot be collected owing to corrosion of electrodes. The guiding principle that module structure and module materials without saving acetic acid into the modules was obtained.

Masuda, Atsushi; Uchiyama, Naomi; Hara, Yukiko

2015-04-01

17

Tetrazole acetic acid: Tautomers, conformers, and isomerization  

NASA Astrophysics Data System (ADS)

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

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

2014-02-01

18

Photoionization of small sodium-doped acetic acid clusters.  

PubMed

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. PMID:21384976

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

2011-03-01

19

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

20

Separation of acetic acid from xylose by nanofiltration  

Microsoft Academic Search

Lignocellulose has drawn great attention in the bioethanol industry as an alternative feedstock for ethanol production due to its renewability, abundance and non-food crop characteristics. Acid hydrolyzation of lignocellulose releases sugars (mainly d-xylose) and several derivatives. The sugars in the hydrolyzate are then converted into ethanol by fermentation. Since acetic acid is believed to be one of the inhibitors which

Yu-Hsiang Weng; Hwa-Jou Wei; Tsung-Yen Tsai; Wei-Hsi Chen; Tsong-Yang Wei; Wen-Song Hwang; Chia-Pao Wang; Chin-Pao Huang

2009-01-01

21

The effect of oral sodium acetate administration on plasma acetate concentration and acid-base state in horses  

PubMed Central

Aim Sodium acetate (NaAcetate) has received some attention as an alkalinizing agent and possible alternative energy source for the horse, however the effects of oral administration remain largely unknown. The present study used the physicochemical approach to characterize the changes in acid-base status occurring after oral NaAcetate/acetic acid (NAA) administration in horses. Methods Jugular venous blood was sampled from 9 exercise-conditioned horses on 2 separate occasions, at rest and for 24 h following a competition exercise test (CET) designed to simulate the speed and endurance test of 3-day event. Immediately after the CETs horses were allowed water ad libitum and either: 1) 8 L of a hypertonic NaAcetate/acetic acid solution via nasogastric tube followed by a typical hay/grain meal (NAA trial); or 2) a hay/grain meal alone (Control trial). Results Oral NAA resulted in a profound plasma alkalosis marked by decreased plasma [H+] and increased plasma [TCO2] and [HCO3-] compared to Control. The primary contributor to the plasma alkalosis was an increased [SID], as a result of increased plasma [Na+] and decreased plasma [Cl-]. An increased [Atot], due to increased [PP] and a sustained increase in plasma [acetate], contributed a minor acidifying effect. Conclusion It is concluded that oral NaAcetate could be used as both an alkalinizing agent and an alternative energy source in the horse. PMID:18096070

Waller, Amanda; Lindinger, Michael I

2007-01-01

22

Improvement of productivity in acetic acid fermentation with Clostridium thermoaceticum  

SciTech Connect

Production of acetic acid by a mutant strain of Clostridium thermoaceticum was compared in three types of membrane cell-recycle bioreactors. A modified fed-batch bioreactor (where the product is partially removed at the end of fermentation, but the cells are retained), and a two-stage CSTR (with product being removed continuously and the cells being recycled from the second to the first stage) resulted in better performance than a one-stage CSTR or batch fermenter. The difference in performance was greater at higher acetate concentration. With 45 g/L of glucose in the feed, productivity was 0.75-1.12 g/L-h and acetic acid concentrations were 34-38 g/L. This is more than double the batch system. The nutrient supply rate also appeared to have a strong influence on productivity of the microorganism.

Shah, M.M.; Cheryan, M. [Univ. of Illinois, Urbana, IL (United States)

1995-12-31

23

Acetic Acid Increases Stability of Silage under Aerobic Conditions  

PubMed Central

The effects of various compounds on the aerobic stability of silages were evaluated. It has been observed that inoculation of whole-crop maize with homofermentative lactic acid bacteria leads to silages which have low stability against aerobic deterioration, while inoculation with heterofermentative lactic acid bacteria, such as Lactobacillus brevis or Lactobacillus buchneri, increases stability. Acetic acid has been proven to be the sole substance responsible for the increased aerobic stability, and this acid acts as an inhibitor of spoilage organisms. Therefore, stability increases exponentially with acetic acid concentration. Only butyric acid has a similar effect. Other compounds, like lactic acid, 1,2-propanediol, and 1-propanol, have been shown to have no effect, while fructose and mannitol reduce stability. PMID:12514042

Danner, H.; Holzer, M.; Mayrhuber, E.; Braun, R.

2003-01-01

24

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

SciTech Connect

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

Zinder, S.

1991-12-31

25

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

SciTech Connect

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

Zinder, S.

1991-01-01

26

Kinetics of acetic acid oxidation in supercritical water  

SciTech Connect

Acetic acid was oxidized in supercritical water in batch microreactors at temperatures between 380 and 440[degrees]C. The acetic acid concentrations ranged from 1.0 [times] 10[sup [minus]4] to 5.2 [times] 10[sup [minus]3] M, the oxygen concentrations ranged from 5.7 [times] 10[sup [minus]3] to 7.1 [times] 10[sup [minus]2] M, and the water density ranged from 6.7 to 25 M. Oxygen was always present in at least 3.5 times the stoichiometric amount required for complete oxidation. Analysis of the kinetics data showed that the global oxidation rate law was first order in acetic acid, 0.6 order in oxygen, and second order in water. The global rate constant has a pre-exponential factor of 10[sup 19.8] M[sup [minus]26] S[sup [minus]1] and an activation energy of 73.6 kcal/mol. This rate law also satisfactorily describes other sets of experimental data in the literature for the oxidation of acetic acid in supercritical water. 19 refs., 5 figs., 3 tabs.

Savage, P.E.; Smith, M.A. (Univ. of Michigan, Ann Arbor, MI (United States))

1995-01-01

27

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 ...

28

[Conversion of acetic acid to methane by thermophiles  

SciTech Connect

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

Zinder, S.H.

1993-01-01

29

Gas-phase properties and reactivity of the acetate radical anion. Determination of the CH bond strengths in acetic acid and acetate ion  

Microsoft Academic Search

The acetate radical anion, CH[sub 2]CO[sub 2] [sup [center dot]-], has been generated in the gas phase at room temperature and its thermochemical properties and reactivity have been examined with use of a flowing afterglow-triple quadrupole instrument. This ion is formed in high yield from the reaction between F[sub 2] and the enolate ions of either acetic acid or trimethylsilyl

Paul G. Wenthold; Robert R. Squires

1994-01-01

30

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

31

Catabolism of indole-3-acetic acid and 4- and 5-chloroindole-3-acetic acid in Bradyrhizobium japonicum.  

PubMed Central

Some strains of Bradyrhizobium japonicum have the ability to catabolize indole-3-acetic acid. Indoleacetic acid (IAA), 4-chloro-IAA (4-Cl-IAA), and 5-Cl-IAA were metabolized to different extents by strains 61A24 and 110. Metabolites were isolated and analyzed by high-performance liquid chromatography and conventional mass spectrometry (MS) methods, including MS-mass spectroscopy, UV spectroscopy, and high-performance liquid chromatography-MS. The identified products indicate a novel metabolic pathway in which IAA is metabolized via dioxindole-3-acetic acid, dioxindole, isatin, and 2-aminophenyl glyoxylic acid (isatinic acid) to anthranilic acid, which is further metabolized. Degradation of 4-Cl-IAA apparently stops at the 4-Cl-dioxindole step in contrast to 5-Cl-IAA which is metabolized to 5-Cl-anthranilic acid. PMID:7592320

Jensen, J B; Egsgaard, H; Van Onckelen, H; Jochimsen, B U

1995-01-01

32

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

33

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

34

Behavior of atmospheric formic and acetic acid in the presence of hydrometeors  

Microsoft Academic Search

The partitioning of formic and acetic acid between the atmospheric liquid and gaseous phase is modelled for a range of liquid water contents. At low liquid water content, formic acid is dissolved preferentially over acetic acid. Applying these results to the analysis of processes taking place in clouds, one can explain the frequently found enrichment of formic over acetic acid

G. Helas; M. O. Andreae; W. R. Hartmann

1992-01-01

35

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

Code of Federal Regulations, 2010 CFR

...DEVICES Clinical Chemistry Test Systems § 862.1390 5-Hydroxyindole...acetic acid/serotonin test system. (a) Identification...acetic acid/serotonin test system is a device intended to...treatment of carcinoid tumors of endocrine tissue. (b)...

2010-04-01

36

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

Code of Federal Regulations, 2012 CFR

...DEVICES Clinical Chemistry Test Systems § 862.1390 5-Hydroxyindole...acetic acid/serotonin test system. (a) Identification...acetic acid/serotonin test system is a device intended to...treatment of carcinoid tumors of endocrine tissue. (b)...

2012-04-01

37

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

Code of Federal Regulations, 2013 CFR

...DEVICES Clinical Chemistry Test Systems § 862.1390 5-Hydroxyindole...acetic acid/serotonin test system. (a) Identification...acetic acid/serotonin test system is a device intended to...treatment of carcinoid tumors of endocrine tissue. (b)...

2013-04-01

38

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

Code of Federal Regulations, 2014 CFR

...DEVICES Clinical Chemistry Test Systems § 862.1390 5-Hydroxyindole...acetic acid/serotonin test system. (a) Identification...acetic acid/serotonin test system is a device intended to...treatment of carcinoid tumors of endocrine tissue. (b)...

2014-04-01

39

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

Code of Federal Regulations, 2011 CFR

...DEVICES Clinical Chemistry Test Systems § 862.1390 5-Hydroxyindole...acetic acid/serotonin test system. (a) Identification...acetic acid/serotonin test system is a device intended to...treatment of carcinoid tumors of endocrine tissue. (b)...

2011-04-01

40

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...

41

21 CFR 184.1005 - Acetic acid.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

42

21 CFR 184.1005 - Acetic acid.  

Code of Federal Regulations, 2012 CFR

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

2012-04-01

43

21 CFR 184.1005 - Acetic acid.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

44

21 CFR 184.1005 - Acetic acid.  

Code of Federal Regulations, 2014 CFR

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

2014-04-01

45

21 CFR 184.1005 - Acetic acid.  

Code of Federal Regulations, 2011 CFR

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

2011-04-01

46

Catabolism of Indole3Acetic Acid and 4- and 5-Chloroindole- 3Acetic Acid inBradyrhizobium japonicum  

Microsoft Academic Search

Some strains of Bradyrhizobium japonicum have the ability to catabolize indole-3-acetic acid. Indoleacetic acid (IAA), 4-chloro-IAA (4-Cl-IAA), and 5-Cl-IAA were metabolized to different extents by strains 61A24 and 110. Metabolites were isolated and analyzed by high-performance liquid chromatography and conventional mass spectrometry (MS) methods, including MS-mass spectroscopy, UV spectroscopy, and high-performance liquid chromatography-MS. The identified products indicate a novel metabolic

JOHN BECK JENSEN; HELGE EGSGAARD; HARRY VAN ONCKELEN; ANDBJARNE U. JOCHIMSEN

1995-01-01

47

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

Federal Register 2010, 2011, 2012, 2013, 2014

...EPA-HQ-OPP-2010-0429; FRL-8841-2] Acetic Acid Ethenyl Ester, Polymer With Oxirane...requirement of a tolerance for residues of acetic acid ethenyl ester, polymer with oxirane...permissible level for residues of acetic acid ethenyl ester, polymer with oxirane...

2010-08-25

48

75 FR 40736 - Acetic Acid; Exemption from the Requirement of a Tolerance  

Federal Register 2010, 2011, 2012, 2013, 2014

...EPA-HQ-OPP-2010-0561;FRL-8833-8] Acetic Acid; Exemption from the Requirement of a Tolerance...existing tolerance exemption for acetic acid by establishing an exemption from the requirement of a tolerance for residues of acetic acid, also known as vinegar in or on all...

2010-07-14

49

The occurrence, control and esoteric effect of acetic acid bacteria in winemaking  

Microsoft Academic Search

This review focuses on acetic acid bacteria in the winemaking process. The enumeration, isolation and identification of acetic acid bacteria from grapes and wines are discussed. This is followed by an outline of the conditions and measures that can assist the wine producer to inhibit the unwanted growth of acetic acid bacteria in wine, which include the ethanol concentration, low

W. J. DU TOIT; I. S. PRETORIUS

50

Evaporation kinetics of acetic acid-water solutions  

NASA Astrophysics Data System (ADS)

The transport of water molecules across vapor-liquid interfaces in the atmosphere is a crucial step in the formation and evolution of cloud droplets. Despite decades of study, the effects of solutes on the mechanism and rate of evaporation and condensation remain poorly characterized. The present work aims to determine the effect of atmospherically-relevant solutes on the evaporation rate of water. In our experiments, we create a train of micron-sized droplets and measure their temperature via Raman thermometry as they undergo evaporation without condensation. Analysis of the cooling rate yields the evaporation coefficient (?). Previous work has shown that inorganic salts have little effect on ?, with surface-adsorbing anions causing a slight reduction in the coefficient from that measured for pure water. Organic acids are ubiquitous in aqueous aerosol and have been shown to disrupt the surface structure of water. Here we describe measurements of the evaporation rate of acetic acid solutions, showing that acetic acid reduces ? to a larger extent than inorganic ions, and that ? decreases with increasing acetic acid concentration.

Duffey, K.; Wong, N.; Saykally, R.; Cohen, R. C.

2012-12-01

51

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

52

Acetic acid accumulation in aerobic growth of recombinant Escherichia coli  

Microsoft Academic Search

A correlation between ?HAc (specific acetic acid accumulation rate) and ? (specific growth rate) for a recombinant Escherichia coli BL21 strain was defined under typical conditions to achieve high cell densities (fed-batch process, dissolved oxygen concentration higher than 30% saturation, semi-synthetic medium). The feeding rate of glucose was continuously adjusted in order to support constant values of ? (0.4, 0.3,

D. C. Suárez; B. V. Kilikian

2000-01-01

53

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

E-print Network

(12) from h1gh-moisture grain rations. The addition of 2't acet1c acid through reconstitution d1d not affect milk production. Average acetic acid intake per day 1n this study was 237. 2 g (33. 32 g/100 kg body weight). Jones (13) obtained the same... acid. Ruminal pH was not s1gnificantly altered by treatments. Ruminal acet1c:prop1onic acid ratio of the dry grain ration was higher than the water, 0. 5 and 1. 0/ acetic acid recon- st1tuted gra1n rations, and lower than the 1. 5 and 2. 5? acet1c...

Bade, David Heinie

1972-01-01

54

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

55

Preparation of vinyl acetate  

DOEpatents

This invention pertains to the preparation of vinyl acetate by contacting a mixture of hydrogen and ketene with a heterogeneous catalyst containing a transition metal to produce acetaldehyde, which is then reacted with ketene in the presence of an acid catalyst to produce vinyl acetate.

Tustin, Gerald Charles (Kingsport, TN); Zoeller, Joseph Robert (Kingsport, TN); Depew, Leslie Sharon (Kingsport, TN)

1998-01-01

56

Preparation of vinyl acetate  

DOEpatents

This invention pertains to the preparation of vinyl acetate by contacting a mixture of hydrogen and ketene with a heterogeneous catalyst containing a transition metal to produce acetaldehyde, which is then reacted with ketene in the presence of an acid catalyst to produce vinyl acetate.

Tustin, G.C.; Zoeller, J.R.; Depew, L.S.

1998-03-24

57

Selective extraction of acetic acid from the fermentation broth produced by Mannheimia succiniciproducens.  

PubMed

Acetic acid is by-product from fermentation processes for producing succinic acid using Mannheimia succiniciproducens . To obtain pure succinic acid from the final fermentation broth, acetic acid was selectively removed based on the different extractability of succinic acid and acetic acid with pH using tri-n-octylamine (TOA) as extractant. When successive batch extractions were performed using 0.25 mol TOA kg(-1) dissolved in 1-octanol at pH 5, the mol ratio of succinic acid to acetic acid before extraction was 4.9 and the final ratio after the fourth batch was 9.4. PMID:15604800

Huh, Yun Suk; Hong, Yeon Ki; Hong, Won Hi; Chang, Ho Nam

2004-10-01

58

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

59

Radioiron utilization and gossypol acetic acid in male rats  

SciTech Connect

The 24-h incorporation of VZFe into circulating red blood cells, bone marrow, urine, liver, spleen, and skeletal muscle was measured in splenectomized and sham-splenectomized rats which had received a daily, oral dose of gossypol acetic acid (20 mg GAA/kg body wt) for 91 days. A significant decrease in total body weight gain was observed in all GAA treated animals. Splenectomized rats dosed with GAA exhibited a significant decrease in hemoglobin concentration, hematocrit and erythrocyte count. A significant increase in VZFe incorporation by red blood cells and a decrease in hepatic incorporation of VZFe indicate a preferential utilization of iron in erythropoiesis among GAA treated animals.

Tone, J.N.; Jensen, D.R.

1985-01-01

60

Adaptation to alcoholic fermentation in Drosophila: a parallel selection imposed by environmental ethanol and acetic acid.  

PubMed Central

Besides ethanol, acetic acid is produced in naturally fermenting sweet resources and is a significant environmental stress for fruit-breeding Drosophila populations and species. Although not related to the presence of an active alcohol dehydrogenase, adult acetic acid tolerance was found to correlate with ethanol tolerance when sensitive (Afrotropical) and resistant (European) natural populations of Drosophila melanogaster were compared. The same correlation was found when comparing various Drosophila species. Tolerance to acetic acid also correlated with the tolerance to longer aliphatic acids of three, four, or five carbons but did not correlate with the tolerance to inorganic acids (i.e., hydrochloric and sulfuric acids). These observations suggest that acetic acid is detoxified by the conversion of acetate into acetyl-CoA, a metabolic step also involved in ethanol detoxification. Future investigations on the adaptation of Drosophila to fermenting resources should consider selective effects of both ethanol and acetic acid. PMID:8475110

Chakir, M; Peridy, O; Capy, P; Pla, E; David, J R

1993-01-01

61

The Key to Acetate: Metabolic Fluxes of Acetic Acid Bacteria under Cocoa Pulp Fermentation-Simulating Conditions  

PubMed Central

Acetic acid bacteria (AAB) play an important role during cocoa fermentation, as their main product, acetate, is a major driver for the development of the desired cocoa flavors. Here, we investigated the specialized metabolism of these bacteria under cocoa pulp fermentation-simulating conditions. A carefully designed combination of parallel 13C isotope labeling experiments allowed the elucidation of intracellular fluxes in the complex environment of cocoa pulp, when lactate and ethanol were included as primary substrates among undefined ingredients. We demonstrate that AAB exhibit a functionally separated metabolism during coconsumption of two-carbon and three-carbon substrates. Acetate is almost exclusively derived from ethanol, while lactate serves for the formation of acetoin and biomass building blocks. Although this is suboptimal for cellular energetics, this allows maximized growth and conversion rates. The functional separation results from a lack of phosphoenolpyruvate carboxykinase and malic enzymes, typically present in bacteria to interconnect metabolism. In fact, gluconeogenesis is driven by pyruvate phosphate dikinase. Consequently, a balanced ratio of lactate and ethanol is important for the optimum performance of AAB. As lactate and ethanol are individually supplied by lactic acid bacteria and yeasts during the initial phase of cocoa fermentation, respectively, this underlines the importance of a well-balanced microbial consortium for a successful fermentation process. Indeed, AAB performed the best and produced the largest amounts of acetate in mixed culture experiments when lactic acid bacteria and yeasts were both present. PMID:24837393

Adler, Philipp; Frey, Lasse Jannis; Berger, Antje; Bolten, Christoph Josef; Hansen, Carl Erik

2014-01-01

62

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

63

Clostridium lentocellum SG6--a potential organism for fermentation of cellulose to acetic acid.  

PubMed

A cellulolytic, acetic acid producing anaerobic bacterial isolate, Gram negative, rod-shaped, motile, terminal oval shaped endospore forming bacterium identified as Clostridium lentocellum SG6 based on physiological and biochemical characteristics. It produced acetic acid as a major end product from cellulose fermentation at 37 degrees C and pH 7.2. Acetic acid production was 0.67 g/g cellulose substrate utilized in cellulose mineral salt (CMS) medium. Yeast extract (0.4%) was the best nitrogen source among the various nitrogenous nutrients tested in production medium containing 0.8% cellulose as substrate. No additional vitamins or trace elemental solution were required for acetic acid fermentation. This is the highest acetic acid fermentation yield in monoculture fermentation for direct conversion of cellulose to acetic acid. PMID:11601540

Ravinder, T; Swamy, M V; Seenayya, G; Reddy, G

2001-12-01

64

Acetate treatment increases fatty acid content in LPS-stimulated BV2 microglia.  

PubMed

Acetate supplementation increases plasma acetate, brain acetyl-CoA, histone acetylation, phosphocreatine levels, and is anti-inflammatory in models of neuroinflammation and neuroborreliosis. Although radiolabeled acetate is incorporated into the cellular lipid pools, the effect that acetate supplementation has on lipid deposition has not been quantified. To determine the impact acetate-treatment has on cellular lipid content, we investigated the effect of acetate in the presence of bacterial lipopolysaccharide (LPS) on fatty acid, phospholipid, and cholesterol content in BV2 microglia. We found that 1, 5, and 10 mM of acetate in the presence of LPS increased the total fatty acid content in BV2 cells by 23, 34, and 14 % at 2 h, respectively. Significant increases in individual fatty acids were also observed with all acetate concentrations tested with the greatest increases occurring with 5 mM acetate in the presence of LPS. Treatment with 5 mM acetate in the absence of LPS increased total cholesterol levels by 11 %. However, neither treatment in the absence of LPS significantly altered the content of individual phospholipids or total phospholipid content. To determine the minimum effective concentration of acetate we measured the time- and concentration-dependent changes in histone acetylation using western blot analysis. These studies showed that 5 mM acetate was necessary to induce histone acetylation and at 10 mM acetate, the histone acetylation-state increased as early as 0.5 h following the start of treatment. These data suggest that acetate increases fatty acid content in LPS-stimulated BV2 microglia that is reflected by an increase in fatty acids esterified into membrane phospholipids. PMID:24852320

Bhatt, Dhaval P; Rosenberger, Thad A

2014-07-01

65

Degradation of acetic acid with sulfate radical generated by persulfate ions photolysis  

Microsoft Academic Search

The photolysis of S2O82- was studied for the removal of acetic acid in aqueous solution and compared with the H2O2\\/UV system. The SO4- radicals generated from the UV irradiation of S2O82- ions yield a greater mineralization of acetic acid than the OH radicals. Acetic acid is oxidized by SO4- radicals without significant formation of intermediate by-products. Increasing system pH results

Justine Criquet; Nathalie Karpel Vel Leitner

2009-01-01

66

Bactericidal effect of ADP and acetic acid on Bacillus subtilis.  

PubMed

Bacillus subtilis is a ubiquitous soil bacterium used for measuring the beta-lysin activity and in other bioassays. We observed a complete bactericidal effect of ADP on B. subtilis at concentrations of 50-100 microM at pH values <5.5, which disappeared at pH values above 6. The effect was also found for acetic acid at concentrations >17.4 microM and similar pH values. ATP, adenosine, and HCl were not bactericidal. We used BCECF-AM, a pH-sensitive probe, and found that the killing of B. subtilis was due to a change in the intracellular pH caused by the passage across the cell membrane of these weak organic acids when incubated with B. subtilis at pH values near the pK. More experiments are needed to determine the biological meaning of these in vitro findings. PMID:8939804

Asensi, V; Parra, F; Fierer, J; Valle, E; Bordallo, C; Rendueles, P; Gascón, S; Carton, J A; Maradona, J A; Arribas, J M

1997-01-01

67

Relation between mass transfer and operation parameters in the electrodialysis recovery of acetic acid  

Microsoft Academic Search

The recovery of acetic acid from dilute wastewater by means of bipolar membrane electrodialysis is studied in more detail. The current efficiency of the electrodialysis recovery of acetic acid from dilute wastewater is related to the current density and other operation parameters. There exists a highest value of current efficiency at optimal current density. The highest concentration of recovered acid

Lixin Yu; Tao Lin; Qingfeng Guo; Jihua Hao

2003-01-01

68

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

69

Diaterebic acid acetate and diaterpenylic acid acetate: atmospheric tracers for secondary organic aerosol formation from 1,8-cineole oxidation.  

PubMed

Detailed organic speciation of summer time PM10 collected in Melbourne, Australia, indicated the presence of numerous monoterpene oxidation products that have previously been reported in the literature. In addition, two highly oxygenated compounds with molecular formulas C9H14O6 (MW 218) and C10H16O6 (MW 232), previously unreported, were detected during a period associated with high temperatures and bushfire smoke. These two compounds were also present in laboratory-produced secondary organic aerosol (SOA) through the reaction of OH radicals with 1,8-cineole (eucalyptol), which is emitted by Eucalyptus trees. The retention times and mass spectral behavior of the highly oxygenated compounds in high-performance liquid chromatography (LC) coupled to electrospray ionization-time-of-flight mass spectrometry (MS) in parallel to ion trap MS of agree perfectly between the ambient samples and the laboratory-produced SOA samples, suggesting that 1,8-cineole is the precursor of the highly oxygenated compounds. The proposed structure of the compound with molecular formula C10H16O6 was confirmed by synthesis of a reference compound. The two novel compounds were identified as diaterebic acid acetate (2-[1-(acetyloxy)-1-methylethyl]succinic acid, C9H14O6) and diaterpenylic acid acetate (3-[1-(acetyloxy)-1-methylethyl]glutaric acid, C10H16O6) based on the consideration of reaction mechanisms, the structure of a reference compound, and the interpretation of mass spectral data. Depending on the experimental conditions, the SOA yields determined in chamber experiments ranged between 16 and 20% for approximately 25 ppb of hydrocarbon consumed. The concentrations of these compounds were as high as 50 ng m(-3) during the summertime in Melbourne. This study demonstrates the importance and influence of local vegetation patterns on SOA chemical composition. PMID:19238952

Iinuma, Yoshiteru; Böge, Olaf; Keywood, Melita; Gnauk, Thomas; Herrmann, Hartmut

2009-01-15

70

Nanofiltration of model acetate solutions  

Microsoft Academic Search

Several nanofiltration and reverse osmosis membranes were screened for separating acetic acid from model solutions. Flux increased with pressure and temperature and decreased with pH and concentration of acetate. Rejection increased with pH, probably depending on the degree of dissociation of the acetate. At higher pH, acetate rejection could be correlated with NaCl rejection. Of all the membranes screened, the

I. S. Han; M. Cheryan

1995-01-01

71

[Advances in functional genomics studies underlying acetic acid tolerance of Saccharomyces cerevisiae].  

PubMed

Industrial microorganisms are subject to various stress conditions, including products and substrates inhibitions. Therefore, improvement of stress tolerance is of great importance for industrial microbial production. Acetic acid is one of the major inhibitors in the cellulosic hydrolysates, which affects seriously on cell growth and metabolism of Saccharomyces cerevisiae. Studies on the molecular mechanisms underlying adaptive response and tolerance of acetic acid of S. cerevisiae benefit breeding of robust strains of industrial yeast for more efficient production. In recent years, more insights into the molecular mechanisms underlying acetic acid tolerance have been revealed through analysis of global gene expression and metabolomics analysis, as well as phenomics analysis by single gene deletion libraries. Novel genes related to response to acetic acid and improvement of acetic acid tolerance have been identified, and novel strains with improved acetic acid tolerance were constructed by modifying key genes. Metal ions including potassium and zinc play important roles in acetic acid tolerance in S. cerevisiae, and the effect of zinc was first discovered in our previous studies on flocculating yeast. Genes involved in cell wall remodeling, membrane transport, energy metabolism, amino acid biosynthesis and transport, as well as global transcription regulation were discussed. Exploration and modification of the molecular mechanisms of yeast acetic acid tolerance will be done further on levels such as post-translational modifications and synthetic biology and engineering; and the knowledge obtained will pave the way for breeding robust strains for more efficient bioconversion of cellulosic materials to produce biofuels and bio-based chemicals. PMID:25007573

Zhao, Xinqing; Zhang, Mingming; Xu, Guihong; Xu, Jianren; Bai, Fengwu

2014-03-01

72

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

PubMed

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

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

2014-10-01

73

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

74

Acetic Acid from the Carbonylation of Chloride Methane Over Rhodium Based Catalysts  

E-print Network

Acetic Acid from the Carbonylation of Chloride Methane Over Rhodium Based Catalysts Yafang Fan Æ Chloride methane Á Carbonylation Á Rhodium catalysts 1 Introduction The conversion of natural gas has be carbonylated by carbon monoxide over rhodium-based catalyst to produce acetic acid [14]. The possibility

Bao, Xinhe

75

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...

76

Vinegar as a burn-down herbicide: Acetic acid concentrations, application volumes, and adjuvants  

Technology Transfer Automated Retrieval System (TEKTRAN)

Acetic acid acts as a contact herbicide, injuring and killing plants by first destroying the cell membranes, which causes the rapid desiccation of the plant tissues. Vinegars with acetic acid concentrations of 11% or greater can burn the skin and cause serious to severe eye injury, including blindn...

77

Improved isolation of zein from corn gluten meal using acetic acid as solvent  

Technology Transfer Automated Retrieval System (TEKTRAN)

To develop new uses for corn zein, an improved means of isolating zein is needed. We have evaluated the ability of acetic acid to remove zein from corn gluten meal, distillers dried grains and ground corn. Acetic acid removed zein more quickly, at lower temperatures and in higher yields when compa...

78

Electrochemical reduction of uranyl nitrate in acetic acid solutions  

SciTech Connect

Electrochemical reduction of UO{sub 2}(NO{sub 3}){sub 2} has been studied by polarography on a mercury cathodes in CH{sub 3}COOH solutions. It has been found that UO{sub 2}(NO{sub 3}) is reduced to U(IV) by a mechanism similar to reduction in nitric acid solutions at pH>2. The polarograms have been recorded with various solid cathodes. The cathodes having current density of uranyl reduction close to that on mercury cathode have been further investigated. The most suitable cathode materials for reducing 1-2 M UO{sub 2}(NO{sub 3}){sub 2} solutions have been found to be Hg, Ti, and stainless steel. The use of a stainless steel cathode is complicated by minor corrosion; as a result, iron ions appear in the solution, which catalyze the oxidation of U(IV) with air oxygen and nitrate ions. On a titanium cathode at a potential of -0.24 V 1.6 M UO{sub 2}(NO{sub 3}){sub 2} solution in 5 m CH{sub 3}COOH is reduced in the presence of 0.5 g 1{sup -1} of N{sub 2}H{sub 4} with 90% current efficiency and 99.3% extent of reduction. In the case of a mercury cathode 1.9 M UO{sub 2}(NO{sub 3}){sub 2} solution in 4-6 M CH{sub 3}COOH is reduced to U(IV) in the presence of 0.5 g 1{sup -1} of N{sub 2}H{sub 4} with 97{plus_minus}2% current efficiency and 99.7% extent of reduction. The formal potential of the U(VI)/U(IV) couple is equal to 0.32{plus_minus}0.01 V and only slightly depends on temperature T and concentration of acetic acid [CH{sub 3}COOH] over 20-0{degrees}C and 0.5-4 M ranges respectively. The acetic acid solutions of U(IV) thus obtained from UO{sub 2}(NO{sub 3}){sub 2} are considerably more stable than nitric acid solutions of U(IV), even in the presence of much smaller amounts of N{sub 2}H{sub 4} or other stabilizers.

Fedoseev, A.M.; Shilov, V.P. [Institute of Physical Chemistry, Moscow (Russian Federation)

1995-07-01

79

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. PMID:20973990

2010-01-01

80

Formation of biologically relevant carboxylic acids during the gamma irradiation of acetic acid  

NASA Technical Reports Server (NTRS)

Irradiation of aqueous solutions of acetic acid with gamma rays produced several carboxylic acids in small yield. Their identification was based on the technique of gas chromatography combined with mass spectrometry. Some of these acids are Krebs Cycle intermediates. Their simultaneous formation in experiments simulating the primitive conditions on the earth suggests that metabolic pathways may have had their origin in prebiotic chemical processes.

Negron-Mendoza, A.; Ponnamperuma, C.

1976-01-01

81

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

PubMed

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

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

2014-02-01

82

Putative ABC Transporter Responsible for Acetic Acid Resistance in Acetobacter aceti  

PubMed Central

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

Nakano, Shigeru; Fukaya, Masahiro; Horinouchi, Sueharu

2006-01-01

83

Enhancement of Acetic Acid Tolerance in Saccharomyces cerevisiae by Overexpression of the HAA1 Gene, Encoding a Transcriptional Activator  

PubMed Central

Haa1 is a transcriptional activator required for Saccharomyces cerevisiae adaptation to weak acids. Here we show that the constitutive HAA1-overexpressing strain acquired a higher level of acetic acid tolerance. Under conditions of acetic acid stress, the intracellular level of acetic acid was significantly lower in HAA1-overexpressing cells than in the wild-type cells. PMID:22961896

Tanaka, Koichi; Ishii, Yukari; Ogawa, Jun

2012-01-01

84

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

PubMed

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

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

2014-12-01

85

Distinct Effects of Sorbic Acid and Acetic Acid on the Electrophysiology and Metabolism of Bacillus subtilis  

PubMed Central

Sorbic acid and acetic acid are among the weak organic acid preservatives most commonly used to improve the microbiological stability of foods. They have similar pKa values, but sorbic acid is a far more potent preservative. Weak organic acids are most effective at low pH. Under these circumstances, they are assumed to diffuse across the membrane as neutral undissociated acids. We show here that the level of initial intracellular acidification depends on the concentration of undissociated acid and less on the nature of the acid. Recovery of the internal pH depends on the presence of an energy source, but acidification of the cytosol causes a decrease in glucose flux. Furthermore, sorbic acid is a more potent uncoupler of the membrane potential than acetic acid. Together these effects may also slow the rate of ATP synthesis significantly and may thus (partially) explain sorbic acid's effectiveness. PMID:25038097

van Beilen, J. W. A.; Teixeira de Mattos, M. J.; Hellingwerf, K. J.

2014-01-01

86

Acetic Acid Production by Clostridium thermoaceticum in pH-Controlled Batch Fermentations at Acidic pH  

PubMed Central

Four strains of the homofermentative, obligately anaerobic thermophile Clostridium thermoaceticum were compared in pH-controlled batch fermentation for their tolerance to acetic acid, efficiency of converting glucose to acetic acid and cell mass, and growth rate. At pH 6 (and pH 7) and initial acetic acid concentrations of less than 10 g/liter, the four strains had mass doubling times of 5 to 7 h and conversion efficiencies to acetic acid and cell mass of about 90% (70 to 110%) and 10%, respectively. At pH 6 and initial acetic acid concentrations of greater than 10 g/liter, only two of the strains grew, the mass doubling time increased to 18 h, and the conversion efficiencies to acetic acid and cell mass remained unchanged. Both of these strains had been selected for their ability to grow in the presence of acetate at neutral pH. The highest acetic acid concentrations reached were about 15 and 20 g/liter at pH 6 and 7, respectively. C. thermoaceticum is apparently more sensitive to free acetic acid than to either acetate ion or pH. It was also shown that, at pH 6 and 7, the redox potential must be at least as low as ?300 and ?360 mV, respectively, for growth to occur. Images PMID:16346034

Schwartz, Robert D.; Keller, Frederick A.

1982-01-01

87

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

SciTech Connect

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

Snyder, S. W.; Energy Systems

2010-02-08

88

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. Solvent mixtures formed of such a modified solvent with a desired co-solvent, preferably a low boiling hydrocarbon, 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.; Clausen, Edgar C.; Ko, Ching-Whan; Wade, Leslie E.; Wikstrom, Carl V.

2004-06-22

89

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. Solvent mixtures formed of such a modified solvent with a desired co-solvent, preferably a low boiling hydrocarbon, 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.; Clausen, Edgar C.; Ko, Ching-Whan; Wade, Leslie E.; Wikstrom, Carl V.

2007-03-27

90

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

91

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

Code of Federal Regulations, 2012 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...

2012-07-01

92

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

Code of Federal Regulations, 2014 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...

2014-07-01

93

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

Code of Federal Regulations, 2011 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...

2011-07-01

94

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

95

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

PubMed Central

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

Chapman, B.; Ross, T.

2009-01-01

96

Beneficial Effect of Acetic Acid on the Xylose Utilization and Bacterial Cellulose Production by Gluconacetobacter xylinus.  

PubMed

In this work, acetic acid was found as one promising substrate to improve xylose utilization by Gluconacetobacter xylinus CH001. Also, with the help of adding acetic acid into medium, the bacterial cellulose (BC) production by G. xylinus was increased significantly. In the medium containing 3 g l(-1) acetic acid, the optimal xylose concentration for BC production was 20 g l(-1). In the medium containing 20 g l(-1) xylose, the xylose utilization and BC production by G. xylinus were stimulated by acetic acid within certain concentration. The highest BC yield (1.35 ± 0.06 g l(-1)) was obtained in the medium containing 20 g l(-1) xylose and 3 g l(-1) acetic acid after 14 days. This value was 6.17-fold higher than the yield (0.21 ± 0.01 g l(-1)) in the medium only containing 20 g l(-1) xylose. The results analyzed by FE-SEM, FTIR, and XRD showed that acetic acid affected little on the microscopic morphology and physicochemical characteristics of BC. Base on the phenomenon observed, lignocellulosic acid hydrolysates (xylose and acetic acid are main carbon sources present in it) could be considered as one potential substrate for BC production. PMID:24891733

Yang, Xiao-Yan; Huang, Chao; Guo, Hai-Jun; Xiong, Lian; Luo, Jun; Wang, Bo; Chen, Xue-Fang; Lin, Xiao-Qing; Chen, Xin-De

2014-09-01

97

Acetic Acid Induces pH-Independent Cellular Energy Depletion in Salmonella enterica.  

PubMed

Weak organic acids are widely used as preservatives and disinfectants in the food industry. Despite their widespread use, the antimicrobial mode of action of organic acids is still not fully understood. This study investigated the effect of acetic acid on the cell membranes and cellular energy generation of four Salmonella strains. Using a nucleic acid/protein assay, it was established that acetic acid did not cause leakage of intracellular components from the strains. A scanning electron microscopy study further confirmed that membrane disruption was not the antimicrobial mode of action of acetic acid. Some elongated Salmonella cells observed in the micrographs indicated a possibility that acetic acid may inhibit DNA synthesis in the bacterial cells. Using an ATP assay, it was found that at a neutral pH, acetic acid caused cellular energy depletion with an ADP/ATP ratio in the range between 0.48 and 2.63 (p<0.05) that was apparent for the four Salmonella strains. We suggest that this effect was probably due solely to the action of undissociated acid molecules. The antimicrobial effect of acetic acid was better under acidic conditions (ADP/ATP ratio of 5.56±1.27; p<0.05), where the role of both pH and undissociated acid molecules can act together. We concluded that the inhibitory effect of acetic acid is not solely attributable to acidic pH but also to undissociated acid molecules. This finding has implication for the use of acetic acid as an antimicrobial against Salmonella on food products, such as chicken meat, which can buffer its pH. PMID:25562466

Tan, Sin Mei; Lee, Sui Mae; Dykes, Gary A

2015-03-01

98

Effect of acetic acid on lipid accumulation by glucose-fed activated sludge cultures  

SciTech Connect

The effect of acetic acid, a lignocellulose hydrolysis by-product, on lipid accumulation by activated sludge cultures grown on glucose was investigated. This was done to assess the possible application of lignocellulose as low-cost and renewable fermentation substrates for biofuel feedstock production. Results: Biomass yield was reduced by around 54% at a 2 g L -1 acetic acid dosage but was increased by around 18% at 10 g L -1 acetic acid dosage relative to the control run. The final gravimetric lipid contents at 2 and 10 g L -1 acetic acid levels were 12.5 ���± 0.7% and 8.8 ���± 3.2% w/w, respectively, which were lower than the control (17.8 ���± 2.8% w/w). However, biodiesel yields from activated sludge grown with acetic acid (5.6 ���± 0.6% w/w for 2 g L -1 acetic acid and 4.2 ���± 3.0% w/w for 10 g L -1 acetic acid) were higher than in raw activated sludge (1-2% w/w). The fatty acid profiles of the accumulated lipids were similar with conventional plant oil biodiesel feedstocks. Conclusions: Acetic acid enhanced biomass production by activated sludge at high levels but reduced lipid production. Further studies are needed to enhance acetic acid utilization by activated sludge microorganisms for lipid biosynthesis.

Mondala, Andro; Hernandez, Rafael; French, Todd; McFarland, Linda; Sparks, Darrell; Holmes, William; Haque, Monica

2012-01-01

99

Acetic Acid Bacteria, Newly Emerging Symbionts of Insects?  

PubMed Central

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

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

2010-01-01

100

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

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

101

Tolerance to acetic acid is improved by mutations of the TATA-binding protein gene.  

PubMed

Screening a library of overexpressing mutant alleles of the TATA-binding gene SPT15 yielded two Saccharomyces cerevisiae strains (MRRC 3252 and 3253) with enhanced tolerance to acetic acid. They were also tolerant to propionic acid and hydrogen peroxide. Transcriptome profile analysis identified 58 upregulated genes and 106 downregulated genes in MRRC 3252. Stress- and protein synthesis-related transcription factors were predominantly enriched in the upregulated and downregulated genes respectively. Eight deletion mutants for some of the highly downregulated genes were acetic acid-tolerant. The level of intracellular reactive oxygen species was considerably lessened in MRRC 3252 and 3253 upon exposure to acetic acid. Metabolome profile analysis revealed that intracellular concentrations of 5 and 102 metabolites were increased and decreased, respectively, in MRRC 3252, featuring a large increase of urea and a significant decrease of amino acids. The dur1/2?mutant, in which the urea degradation gene DUR1/2 is deleted, displayed enhanced tolerance to acetic acid. Enhanced tolerance to acetic acid was also observed on the medium containing a low concentration of amino acids. Taken together, this study identified two SPT15 alleles, nine gene deletions and low concentration of amino acids in the medium that confer enhanced tolerance to acetic acid. PMID:24761971

An, Jieun; Kwon, Hyeji; Kim, Eunjung; Lee, Young Mi; Ko, Hyeok Jin; Park, Hongjae; Choi, In-Geol; Kim, Sooah; Kim, Kyoung Heon; Kim, Wankee; Choi, Wonja

2015-03-01

102

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

PubMed Central

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

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

1998-01-01

103

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

PubMed Central

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

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

2012-01-01

104

Effect of exogenous indole-3-acetic acid and naphthalene acetic acid on regeneration of damask rose cuttings in three growing media.  

PubMed

An experiment was conducted to evaluate the performance of various levels of indole-3-acetic acid (IAA) and naphthalene acetic acid (NAA) treatments i.e., 0, 25, 50, 75, 100 mg L(-1) on the regeneration of damask rose (Rosa damascena Mill.) cuttings in different growing media at the research farm of Arid Zone Research Institute D.I. Khan during 2004. The data revealed significant effect of different levels of growth regulators and growing media on the rose establishment parameters viz., plant height, plant spread, number of primary shoots, secondary shoots and survival percentage. Maximum plant height (134.2 cm), plant spread (46.3 cm), primary shoots (6.3), secondary shoots (25) and survival percentage (94.72%) were recorded when the rose cuttings were applied with NAA at the rate of 50 mg L(-1). Among the plant growth regulators, Naphthalene Acetic Acid (NAA) was found to be superior to indole-3-acetic acid (IAA) for its stronger effect regarding all parameters. The optimum level of Naphthalene Acetic Acid (NAA) was found in the range of 50 and 75 mg L(-1), while no such conclusion could be drawn for indole-3-acetic acid (IAA) as all growth parameters were linearly increased up to the highest concentrations of IAA i.e., 100 mg L(-1). Regarding growing media, the leaf mould appeared the best in terms of its positive effect on establishment of rose cuttings by giving the maximum plant height (125.1 cm), plant spread (37 cm), primary shoots (5.2), secondary shoots (19.48) and survival percentage (85.67%), followed by soil + leaf mould, while soil media was least effective. PMID:19093472

Khan, Rahmat Ullah; Khan, Muhammad Sohail; Rashid, Abdur; Farooq, Arshad

2007-10-15

105

Age-specific titer and antennal perception of acetic acid, a component of male Pseudaletia unipuncta (Haw.) hairpencil secretion  

Microsoft Academic Search

Hairpencil secretion ofPseudaletia unipuncta (Haw.) contains acetic acid as well as previously identified benzaldehyde and benzyl alcohol. Age-specific titers of acetic acid were significantly greater than those of benzaldehyde and, at 25 °C, accumulation of both compounds in the hairpencils peaked on the second day after emergence. Excised antennae of males and females perceived both compounds. Antennal response to acetic

Sheila M. Fitzpatrick; Jeremy N. Mcneil; David Miller

1989-01-01

106

Production and optimization of indole acetic acid by indigenous micro flora using agro waste as substrate.  

PubMed

Indole Acetic Acid (IAA) producing bacterium was isolated from the Rhizosphere soil and identified as Rhizobium sp. and Bacillus sp., Optimization of Indole acetic acid production was carried out at different cultural conditions, such as pH, temperature and substrate with Rhizobium sp., Bacillus sp. and Rhizobium sp., produced higher amount of Indole acetic acid (6.1 mg mL(-1)) than the Bacillus sp., (4.4 mg mL(-1)) at pH 7 and 37 degrees C in the Bengal gram substrate. Partial purification of Indole acetic acid was done by Thin Layer Chromatography (TLC). In conclusion Rhizobium sp., appear to be a suitable soil microorganism for high level of IAA production. PMID:22530441

Sudha, M; Gowri, R Shyamala; Prabhavathi, P; Astapriya, P; Devi, S Yamuna; Saranya, A

2012-01-01

107

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

108

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

E-print Network

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

Clement, Jenny D.

2011-08-08

109

The comparison of fluorescent spectra on acetic acid and ethanol solutions  

NASA Astrophysics Data System (ADS)

Acetic acid and ethanol solutions can emit fluorescence when induced by 253.7nm UV-light. In this paper, fluorescence spectral characteristics of acetic acid and ethanol solutions are analyzed and studied in theory and in experiment. The results indicate that both acetic acid and ethanol can emit two fluorescence spectral bands, one is from 330nm to 493nm and the other is from 534nm to 665nm. The emitting fluorescence intensity is very sensitive to the solutions concentrations, and fluorescence quenching occurs in some solutions of the two samples. Furthermore, the physical mechanism of fluorescence emission of acetic acid and ethanol molecules is analyzed based on the theory of molecule orbital structure, and the quenching mechanism are studied by the dynamic process. Investigation on the native fluorescence spectrum of the two solvent and their characteristics will contribute to the study of the fluorescence spectra when they serve as solute, hydrolysis catalyst and food additive.

Liu, Ying; Lan, Xiufeng; Gao, Shumei; Shen, Zhonghua; Lu, Jian; Ni, Xiao-Wu

2003-12-01

110

Effect of chlorhexidine and acetic acid on phagocytosis by polymorphonuclear leucocytes.  

PubMed

The effect of two disinfectants, chlorhexidine and acetic acid, on host leucocytes and bacteria was studied. At a concentration of 50 mg/l, chlorhexidine was found to be bactericidal without interfering with leucocyte function. A concentration of 500 mg/l of acetic acid was neither leucotoxic nor bactericidal. Effects equivalent to the aforementioned were achieved in serum by increasing the chlorhexidine concentration by a factor of 20 and the acetic acid concentration by a factor of 5. Acetic acid reduced leucocyte function more rapidly than it killed bacteria. On the basis of these findings, chlorhexidine is to be preferred for local application in burn wounds to prevent colonisation and infection. PMID:4065136

van Saene, J J; Veringa, S I; van Saene, H K; Verhoef, J; Lerk, C F

1985-10-01

111

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

112

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

PubMed Central

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

Ylitervo, Päivi; Franzén, Carl Johan; Taherzadeh, Mohammad J.

2014-01-01

113

Malabsorption of zinc in rats with acetic acid-induced enteritis and colitis.  

PubMed

Acute intestinal inflammation was established in rats by intraluminal administration of acetic acid into loops of distal ileum, proximal jejunum or ascending colon. The study included two control groups of intact (untreated) rats and sham-operated (saline-treated) rats for each intestinal segment. A third group of rats received acetic acid. Histological evaluation demonstrated that acetic acid treatment induced a mild inflammatory response. Two days after treatment, zinc absorption was measured using ligated 10-cm loops of each segment in which 65Zn was injected intraluminally. 65Zn absorption by the ileum, jejunum and colon was markedly reduced in those rats in which inflammation was induced by acetic acid. The liver showed the highest uptake of radioisotope, but the relative tissue distribution generally followed the amount of absorption. The surgical procedure itself seemed to reduce zinc absorption. No changes in [3H]leucine absorption were observed between sham-operated and acetic acid-treated controls. There was no significant serosal-->luminal secretion of intramuscularly injected 65Zn in any of the studied segments. Therefore, based upon the data obtained, we conclude that acetic acid-induced intestinal inflammation reduces absorption of zinc by the small and large intestine, and that a surgical procedure (laparotomy) also reduces zinc absorption. The mechanism of this inflammation is such that malabsorption shows some specificity. PMID:8336209

Naveh, Y; Lee-Ambrose, L M; Samuelson, D A; Cousins, R J

1993-08-01

114

Global Analysis of Escherichia coli Gene Expression during the Acetate-Induced Acid Tolerance Response  

PubMed Central

The ability of Escherichia coli to survive at low pH is strongly affected by environmental factors, such as composition of the growth medium and growth phase. Exposure to short-chain fatty acids, such as acetate, proprionate, and butyrate, at neutral or nearly neutral pH has also been shown to increase acid survival of E. coli and Salmonella enterica serovar Typhimurium. To investigate the basis for acetate-induced acid tolerance in E. coli O157:H7, genes whose expression was altered by exposure to acetate were identified using gene arrays. The expression of 60 genes was reduced by at least twofold; of these, 48 encode components of the transcription-translation machinery. Expression of 26 genes increased twofold or greater following treatment with acetate. This included six genes whose products are known to be important for survival at low pH. Five of these genes, as well as six other acetate-induced genes, are members of the E. coli RpoS regulon. RpoS, the stress sigma factor, is known to be required for acid tolerance induced by growth at nonlethal low pH or by entry into stationary phase. Disruption of the rpoS gene by a transposon insertion mutation also prevented acetate-induced acid tolerance. However, induction of RpoS expression did not appear to be sufficient to activate the acid tolerance response. Treatment with either NaCl or sodium acetate (pH 7.0) increased expression of an rpoS::lacZ fusion protein, but only treatment with acetate increased acid survival. PMID:11244055

Arnold, Carrie N.; McElhanon, Justin; Lee, Aaron; Leonhart, Ryan; Siegele, Deborah A.

2001-01-01

115

Studies on bipolar membranes. Part II — Conversion of sodium acetate to acetic acid and sodium hydroxide  

Microsoft Academic Search

The electrodialytic water-splitting technology using bipolar membrane is an attractive cost-effective process for the production of acids and alkalies from the corresponding salts occurring in waste waters. Earlier report by us described the preparation of bipolar membranes and its application in converting sodium sulfate into sulfuric acid and sodium hydroxide. In this paper, as an extension of our earlier published

G. S. Trivedi; B. G. Shah; S. K. Adhikary; V. K. Indusekhar; R. Rangarajan

1997-01-01

116

Chromoendoscopy of gastric adenoma using an acetic acid indigocarmine mixture  

PubMed Central

AIM: To investigate the usefulness of chromoendoscopy, using an acetic acid indigocarmine mixture (AIM), for gastric adenoma diagnosed by forceps biopsy. METHODS: A total of 54 lesions in 45 patients diagnosed as gastric adenoma by forceps biopsy were prospectively enrolled in this study and treated by endoscopic submucosal dissection (ESD) between January 2011 and January 2012. AIM-chromoendoscopy (AIM-CE) was performed followed by ESD. AIM solution was sprinkled and images were recorded every 30 s for 3 min. Clinical characteristics such as tumor size (< 2 cm, ? 2 cm), surface color in white light endoscopy (WLE) (whitish, normochromic or reddish), macroscopic appearance (flat or elevated, depressed), and reddish change in AIM-CE were selected as valuables. RESULTS: En bloc resection was achieved in all 54 cases, with curative resection of fifty two lesions (96.3%). Twenty three lesions (42.6%) were diagnosed as well-differentiated adenocarcinoma and the remaining 31 lesions (57.4%) were gastric adenoma. All adenocarcinoma lesions were well-differentiated tubular adenocarcinomas and were restricted within the mucosal layer. The sensitivity of reddish color change in AIM-CE is significantly higher than that in WLE (vs tumor size ? 2 cm, P = 0.016, vs normochromic or reddish surface color, P = 0.046, vs depressed macroscopic type, P = 0.0030). On the other hand, no significant differences were found in the specificity and accuracy. In univariate analysis, normochromic or reddish surface color in WLE (OR = 3.7, 95%CI: 1.2-12, P = 0.022) and reddish change in AIM-CE (OR = 14, 95%CI: 3.8-70, P < 0.001) were significantly related to diagnosis of early gastric cancer (EGC). In multivariate analysis, only reddish change in AIM-CE (OR = 11, 95%CI: 2.3-66, P = 0.0022) was a significant factor associated with diagnosis of EGC. CONCLUSION: AIM-CE may have potential for screening EGC in patients initially diagnosed as gastric adenoma by forceps biopsy. PMID:24803824

Kono, Yoshiyasu; Takenaka, Ryuta; Kawahara, Yoshiro; Okada, Hiroyuki; Hori, Keisuke; Kawano, Seiji; Yamasaki, Yasushi; Takemoto, Koji; Miyake, Takayoshi; Fujiki, Shigeatsu; Yamamoto, Kazuhide

2014-01-01

117

Thermal decarboxylation of acetic acid: Implications for origin of natural gas  

USGS Publications Warehouse

Laboratory experiments on the thermal decarboxylation of solutions of acetic acid at 200??C and 300??C were carried out in hydrothermal equipment allowing for on-line sampling of both the gas and liquid phases for chemical and stable-carbon-isotope analyses. The solutions had ambient pH values between 2.5 and 7.1; pH values and the concentrations of the various acetate species at the conditions of the experiments were computed using a chemical model. Results show that the concentrations of acetic acid, and not total acetate in solution, control the reaction rates which follow a first order equation based on decreasing concentrations of acetic acid with time. The decarboxylation rates at 200??C (1.81 ?? 10-8 per second) and 300??C (8.17 ?? 10-8 per second) and the extrapolated rates at lower temperatures are relatively high. The activation energy of decarboxylation is only 8.1 kcal/mole. These high decarboxylation rates, together with the distribution of short-chained aliphatic acid anions in formation waters, support the hypothesis that acid anions are precursors for an important portion of natural gas. Results of the ??13C values of CO2, CH4, and total acetate show a reasonably constant fractionation factor of about 20 permil between CO2 and CH4 at 300??C. The ??13C values of CO2 and CH4 are initially low and become higher as decarboxylation increases. ?? 1983.

Kharaka, Y.K.; Carothers, W.W.; Rosenbauer, R.J.

1983-01-01

118

Formic acid and acetic acid induce a programmed cell death in pathogenic Candida species.  

PubMed

Cutaneous fungal infections are common and widespread. Antifungal agents used for the treatment of these infections often have undesirable side effects. Furthermore, increased resistance of the microorganisms to the antifungal drugs becomes the growing problem. Accordingly, the search for natural antifungal compounds continues to receive attention. Apoptosis is highly regulated programmed cell death. During yeast cell apoptosis, amino acids and peptides are released and can stimulate regeneration of human epithelium cells. Thus, detection of chemical compounds inducing apoptosis in yeast and nontoxic for humans is of great medical relevance. The aim of this study was to detect chemical compound inducing apoptosis in pathogenic Candida species with the lowest toxicity to the mammalian cells. Five chemical compounds--acetic acid, sodium bicarbonate, potassium carbonate, lithium acetate, and formic acid--were tested for evaluation of antifungal activity on C. albicans, C. guilliermondii, and C. lusitaniae. The results showed that acetic acid and formic acid at the lowest concentrations induced yeast cells death. Apoptosis analysis revealed that cells death was accompanied by activation of caspase. Minimal inhibitory concentrations of potassium carbonate and sodium bicarbonate induced Candida cells necrosis. Toxicity test with mammalian cell cultures showed that formic acid has the lowest effect on the growth of Jurkat and NIH 3T3 cells. In conclusion, our results show that a low concentration of formic acid induces apoptosis-like programmed cell death in the Candida yeast and has a minimal effect on the survivability of mammalian cells, suggesting potential applications in the treatment of these infections. PMID:24752490

Lastauskien?, Egl?; Zinkevi?ien?, Auks?; Girkontait?, Irut?; Kaunietis, Arnoldas; Kvedarien?, Violeta

2014-09-01

119

Pallidol hexa­acetate 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. PMID:24046702

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

2013-01-01

120

Acetic acid modulates spike rate and spike latency to salt in peripheral gustatory neurons of rats.  

PubMed

Sour and salt taste interactions are not well understood in the peripheral gustatory system. Therefore, we investigated the interaction of acetic acid and NaCl on taste processing by rat chorda tympani neurons. We recorded multi-unit responses from the severed chorda tympani nerve (CT) and single-cell responses from intact narrowly tuned and broadly tuned salt-sensitive neurons in the geniculate ganglion simultaneously with stimulus-evoked summated potentials to signal when the stimulus contacted the lingual epithelium. Artificial saliva served as the rinse and solvent for all stimuli [0.3 M NH(4)Cl, 0.5 M sucrose, 0.1 M NaCl, 0.01 M citric acid, 0.02 M quinine hydrochloride (QHCl), 0.1 M KCl, 0.003-0.1 M acetic acid, and 0.003-0.1 M acetic acid mixed with 0.1 M NaCl]. We used benzamil to assess NaCl responses mediated by the epithelial sodium channel (ENaC). The CT nerve responses to acetic acid/NaCl mixtures were less than those predicted by summing the component responses. Single-unit analyses revealed that acetic acid activated acid-generalist neurons exclusively in a concentration-dependent manner: increasing acid concentration increased response frequency and decreased response latency in a parallel fashion. Acetic acid suppressed NaCl responses in ENaC-dependent NaCl-specialist neurons, whereas acetic acid-NaCl mixtures were additive in acid-generalist neurons. These data suggest that acetic acid attenuates sodium responses in ENaC-expressing-taste cells in contact with NaCl-specialist neurons, whereas acetic acid-NaCl mixtures activate distinct receptor/cellular mechanisms on taste cells in contact with acid-generalist neurons. We speculate that NaCl-specialist neurons are in contact with type I cells, whereas acid-generalist neurons are in contact with type III cells in fungiform taste buds. PMID:22896718

Breza, Joseph M; Contreras, Robert J

2012-11-01

121

Acetic acid modulates spike rate and spike latency to salt in peripheral gustatory neurons of rats  

PubMed Central

Sour and salt taste interactions are not well understood in the peripheral gustatory system. Therefore, we investigated the interaction of acetic acid and NaCl on taste processing by rat chorda tympani neurons. We recorded multi-unit responses from the severed chorda tympani nerve (CT) and single-cell responses from intact narrowly tuned and broadly tuned salt-sensitive neurons in the geniculate ganglion simultaneously with stimulus-evoked summated potentials to signal when the stimulus contacted the lingual epithelium. Artificial saliva served as the rinse and solvent for all stimuli [0.3 M NH4Cl, 0.5 M sucrose, 0.1 M NaCl, 0.01 M citric acid, 0.02 M quinine hydrochloride (QHCl), 0.1 M KCl, 0.003–0.1 M acetic acid, and 0.003–0.1 M acetic acid mixed with 0.1 M NaCl]. We used benzamil to assess NaCl responses mediated by the epithelial sodium channel (ENaC). The CT nerve responses to acetic acid/NaCl mixtures were less than those predicted by summing the component responses. Single-unit analyses revealed that acetic acid activated acid-generalist neurons exclusively in a concentration-dependent manner: increasing acid concentration increased response frequency and decreased response latency in a parallel fashion. Acetic acid suppressed NaCl responses in ENaC-dependent NaCl-specialist neurons, whereas acetic acid-NaCl mixtures were additive in acid-generalist neurons. These data suggest that acetic acid attenuates sodium responses in ENaC-expressing-taste cells in contact with NaCl-specialist neurons, whereas acetic acid-NaCl mixtures activate distinct receptor/cellular mechanisms on taste cells in contact with acid-generalist neurons. We speculate that NaCl-specialist neurons are in contact with type I cells, whereas acid-generalist neurons are in contact with type III cells in fungiform taste buds. PMID:22896718

Breza, Joseph M.

2012-01-01

122

Direct catalytic formation of acetic acid from CO 2 and methane  

Microsoft Academic Search

The direct synthesis of acetic acid from methane and carbon dioxide was investigated. Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) experiments showed the formation of an adsorbed acetate on both a 5% Pd\\/carbon and a 5% Pt\\/alumina catalyst when the catalyst was exposed to a mixture of methane and carbon dioxide at a temperature of about 400°C. Temperature programmed reaction

Esther M Wilcox; George W Roberts; James J Spivey

2003-01-01

123

Molecular Structure of Phenylmercuric acetate  

NSDL National Science Digital Library

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

2004-11-10

124

Microbiological preservation of cucumbers for bulk storage using acetic acid and food preservatives.  

PubMed

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 ensure preservation were low enough so that stored cucumbers could be converted to the finished product without the need to wash out and discard excess acid or preservative. Since no thermal process was required, this method of preservation would be applicable for storing cucumbers in bulk containers. Acid tolerant pathogens died off in less than 24 h with the pH, acetic acid, and sodium benzoate concentrations required to assure the microbial stability of cucumbers stored at 30 degrees C. Potassium sorbate as a preservative in this application was not effective. Yeast growth was observed when sulfite was used as a preservative. PMID:19241560

Pérez-Díaz, I M; McFeeters, R F

2008-08-01

125

Dissolution enthalpy of phosphoric and acetic acids in water-dimethylformamide mixtures  

Microsoft Academic Search

Dissolution enthalpies of phosphoric and acetic acids were experimentally determined (concentration of acid, up to 3 mol\\/kg) in water---dimethylformamide (DMF) mixtures (molar part of DMF, from 0 to 1) at 298.15 K. Standard dissolution enthalpies of acids in the mixed water-DMF solvent were estimated on the basis of the obtained data.

L. P. Safonova; A. A. Pryakhin; N. G. Manin

2011-01-01

126

Effect of formic, acetic and propionic acid on preservation and aerobic deterioration of grass silage  

E-print Network

not retard lactic acid fermentation in the early ensilage phase. #12; exposed to air for 10 days. Ensilage phase. Growth of LAB and lactic acid production were retarded in HDMEffect of formic, acetic and propionic acid on preservation and aerobic deterioration of grass

Paris-Sud XI, Université de

127

Formic and Acetic Acids in the Boundary Layer Over the North Atlantic Ocean  

Microsoft Academic Search

Gaseous formic acid (HCOOH) and acetic acid (CH _3COOH), abbreviated as HFo _{rm g} and HAc_ {rm g}, respectively, are significant contributors to the acidity of precipitation on a global scale. They are reactive in the atmosphere in both liquid and gas phases, and are important in the trace-gas chemistry of the remote marine atmosphere. This work describes the first

Joseph John Schultz Tokos

1989-01-01

128

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. PMID:23262483

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

2013-01-01

129

Anodic acyloxylation based on the acid–base reactions between acetic acid or trifluoroacetic acid and solid-supported bases  

Microsoft Academic Search

We have developed a novel electrolytic system for anodic acyloxylation based on the acid–base reactions between acetic acid or trifluoroacetic acid and solid-supported bases. On the basis of the electrolytic system, anodic acyloxylation of organic compounds, which even have considerably high oxidation potentials, was successfully carried out to provide the corresponding acyloxylated products in moderate to excellent yields. Furthermore, it

Toshiki Tajima; Yuichiro Kishi; Atsushi Nakajima

2009-01-01

130

Acetic acid—friend or foe in anaerobic batch conversion of glucose to ethanol by Saccharomyces cerevisiae?  

Microsoft Academic Search

The permissible region of growth of Saccharomyces cerevisiae on glucose under anaerobic conditions was determined as a function of both pH and the concentration of added acetic acid to the medium. In the absence of acetic acid, growth was possible at a pH as low as 2.5, whereas a total acetic acid addition of 10 gl?1 increased the minimum allowable

Mohammad J. Taherzadeh; Claes Niklasson; Gunnar Lidén

1997-01-01

131

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

132

Regulation of Auxin Homeostasis and Gradients in Arabidopsis Roots through the Formation of the Indole-3-Acetic Acid Catabolite 2-Oxindole-3-Acetic Acid[C][W][OPEN  

PubMed Central

The native auxin, indole-3-acetic acid (IAA), is a major regulator of plant growth and development. Its nonuniform distribution between cells and tissues underlies the spatiotemporal coordination of many developmental events and responses to environmental stimuli. The regulation of auxin gradients and the formation of auxin maxima/minima most likely involve the regulation of both metabolic and transport processes. In this article, we have demonstrated that 2-oxindole-3-acetic acid (oxIAA) is a major primary IAA catabolite formed in Arabidopsis thaliana root tissues. OxIAA had little biological activity and was formed rapidly and irreversibly in response to increases in auxin levels. We further showed that there is cell type–specific regulation of oxIAA levels in the Arabidopsis root apex. We propose that oxIAA is an important element in the regulation of output from auxin gradients and, therefore, in the regulation of auxin homeostasis and response mechanisms. PMID:24163311

P?n?ík, Aleš; Simonovik, Biljana; Petersson, Sara V.; Henyková, Eva; Simon, Sibu; Greenham, Kathleen; Zhang, Yi; Kowalczyk, Mariusz; Estelle, Mark; Zažímalová, Eva; Novák, Ond?ej; Sandberg, Göran; Ljung, Karin

2013-01-01

133

Nuclear magnetic resonance study of acetic acid permeation of large unilamellar vesicle membranes.  

PubMed Central

The permeation of acetic acid through large unilamellar phospholipid vesicle membranes has been investigated using the unique capability of nuclear magnetic resonance to characterize flow under pseudo-equilibrium conditions. Two types of experiments have been employed: total line shape analysis and selective population transfer. These techniques are sensitive to permeation on time scales ranging form 0.001 to 10.0 s. The permeation rate dependence on pH and acetic acid concentration indicates that the neutral acetic acid monomer is the dominant permeant species with a permeation coefficient of 5 +/- 2 x 10-4 cm/s. Mechanisms of permeation and the applicability of nuclear magnetic resonance methodology are discussed. PMID:262441

Alger, J R; Prestegard, J H

1979-01-01

134

Acetic acid induced ulceration in rats is not affected by infection with Hymenolepis diminuta.  

PubMed

Analysis of rodent models of inflammatory bowel disease, airways hyper-reactivity, diabetes, and multiple sclerosis has shown that infection with helminth parasites can significantly reduce the severity of the disease. Here, we assessed whether rats infected with the tapeworm Hymenolepis diminuta were protected from gastric ulceration induced by the serosal application of acetic acid. All rats gavaged with infective cysticercoids harbored adult worms when assessed 6 wk later, and acetic acid evoked the expected gastric ulceration. However, infection with H. diminuta did not affect the degree of gastric ulceration at either 3 or 7 days post-acetic acid application, as gauged by ulcer area or histopathology. While the data do not dismiss the possibility that infection with other helminths could be anti-ulcerogenic, they illustrate that 'helminth therapy' for inflammatory disease is likely to be both disease- and helminth-specific. PMID:18767911

McKay, Derek M; Wallace, John L

2009-04-01

135

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

136

Synthesis of Hydrophobic Molecular Sieves by Hydrothermal Treatment with Acetic Acid  

Microsoft Academic Search

A series of calcined borosilicate molecular sieves are treated hydrothermally with aqueous acetic acid and subsequently characterized in detail. The acid treatments are shown to expel boron from the molecular sieves, and the defects created by the boron removal are subsequently healed with silicon dissolved from other parts of the crystal. By use of this procedure, highly crystalline, hydrophobic all-silica

Christopher W. Jones; Son-Jong Hwang; Tatsuya Okubo; Mark E. Davis

2001-01-01

137

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

PubMed

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

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

2014-11-01

138

Concentrations of Abscisic Acid and Indole-3-Acetic Acid in Soybean Seeds during Development 1  

PubMed Central

Concentrations of abscisic acid (ABA) and indole-3-acetic acid (IAA) in seed parts were determined during reproductive development of soybean plants (Glycine max [L.] Merr. cv `Chippewa 64'). The concentration of ABA and IAA changed independently in individual seed parts with time. Measurement of the level of ABA and IAA in whole seeds masked the changes which occurred in individual seed tissues. The concentration of ABA was generally highest and that of IAA was generally lowest in the embryonic axis of soybean seeds. In the testa, the IAA concentration was generally highest while the ABA concentration was generally the lowest compared to other parts of the seed. PMID:16663978

Hein, Mich B.; Brenner, Mark L.; Brun, William A.

1984-01-01

139

Adiabatic ionization potential of acetic acid and torsional dynamics of its cation.  

PubMed

Pulsed-field-ionization zero-kinetic-energy photoelectron spectroscopy and supersonic cooling are used to investigate the CH(3) torsional dynamics of the acetic acid cation and to determine an accurate value for the first adiabatic ionization potential of acetic acid (IP=85 912+/-5 cm(-1)), which has been the subject of debates for more than 40 yr. A doubling of the torsional barrier upon ionization is due to a significant shortening of the C-C bond and reduces the tunneling efficiency by an order of magnitude. PMID:19508049

Zielke, Philipp; Forysinski, Piotr W; Luckhaus, David; Signorell, Ruth

2009-06-01

140

Acetic Acid Bacteria and the Production and Quality of Wine Vinegar  

PubMed Central

The production of vinegar depends on an oxidation process that is mainly performed by acetic acid bacteria. Despite the different methods of vinegar production (more or less designated as either “fast” or “traditional”), the use of pure starter cultures remains far from being a reality. Uncontrolled mixed cultures are normally used, but this review proposes the use of controlled mixed cultures. The acetic acid bacteria species determine the quality of vinegar, although the final quality is a combined result of technological process, wood contact, and aging. This discussion centers on wine vinegar and evaluates the effects of these different processes on its chemical and sensory properties. PMID:24574887

Torija, María Jesús; García-Parrilla, María del Carmen; Troncoso, Ana María

2014-01-01

141

Acetic acid bacteria and the production and quality of wine vinegar.  

PubMed

The production of vinegar depends on an oxidation process that is mainly performed by acetic acid bacteria. Despite the different methods of vinegar production (more or less designated as either "fast" or "traditional"), the use of pure starter cultures remains far from being a reality. Uncontrolled mixed cultures are normally used, but this review proposes the use of controlled mixed cultures. The acetic acid bacteria species determine the quality of vinegar, although the final quality is a combined result of technological process, wood contact, and aging. This discussion centers on wine vinegar and evaluates the effects of these different processes on its chemical and sensory properties. PMID:24574887

Mas, Albert; Torija, María Jesús; García-Parrilla, María del Carmen; Troncoso, Ana María

2014-01-01

142

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

143

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

NASA Astrophysics Data System (ADS)

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

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

2012-01-01

144

Acetic Acid, the Active Component of Vinegar, Is an Effective Tuberculocidal Disinfectant  

PubMed Central

ABSTRACT Effective and economical mycobactericidal disinfectants are needed to kill both Mycobacterium tuberculosis and non-M. tuberculosis mycobacteria. We found that acetic acid (vinegar) efficiently kills M. tuberculosis after 30 min of exposure to a 6% acetic acid solution. The activity is not due to pH alone, and propionic acid also appears to be bactericidal. M. bolletii and M. massiliense nontuberculous mycobacteria were more resistant, although a 30-min exposure to 10% acetic acid resulted in at least a 6-log10 reduction of viable bacteria. Acetic acid (vinegar) is an effective mycobactericidal disinfectant that should also be active against most other bacteria. These findings are consistent with and extend the results of studies performed in the early and mid-20th century on the disinfectant capacity of organic acids. IMPORTANCE  Mycobacteria are best known for causing tuberculosis and leprosy, but infections with nontuberculous mycobacteria are an increasing problem after surgical or cosmetic procedures or in the lungs of cystic fibrosis and immunosuppressed patients. Killing mycobacteria is important because Mycobacterium tuberculosis strains can be multidrug resistant and therefore potentially fatal biohazards, and environmental mycobacteria must be thoroughly eliminated from surgical implements and respiratory equipment. Currently used mycobactericidal disinfectants can be toxic, unstable, and expensive. We fortuitously found that acetic acid kills mycobacteria and then showed that it is an effective mycobactericidal agent, even against the very resistant, clinically important Mycobacterium abscessus complex. Vinegar has been used for thousands of years as a common disinfectant, and if it can kill mycobacteria, the most disinfectant-resistant bacteria, it may prove to be a broadly effective, economical biocide with potential usefulness in health care settings and laboratories, especially in resource-poor countries. PMID:24570366

Cortesia, Claudia; Vilchèze, Catherine; Bernut, Audrey; Contreras, Whendy; Gómez, Keyla; de Waard, Jacobus; Jacobs, William R.; Kremer, Laurent; Takiff, Howard

2014-01-01

145

Acetic Acid, the active component of vinegar, is an effective tuberculocidal disinfectant.  

PubMed

Effective and economical mycobactericidal disinfectants are needed to kill both Mycobacterium tuberculosis and non-M. tuberculosis mycobacteria. We found that acetic acid (vinegar) efficiently kills M. tuberculosis after 30 min of exposure to a 6% acetic acid solution. The activity is not due to pH alone, and propionic acid also appears to be bactericidal. M. bolletii and M. massiliense nontuberculous mycobacteria were more resistant, although a 30-min exposure to 10% acetic acid resulted in at least a 6-log10 reduction of viable bacteria. Acetic acid (vinegar) is an effective mycobactericidal disinfectant that should also be active against most other bacteria. These findings are consistent with and extend the results of studies performed in the early and mid-20th century on the disinfectant capacity of organic acids. IMPORTANCE Mycobacteria are best known for causing tuberculosis and leprosy, but infections with nontuberculous mycobacteria are an increasing problem after surgical or cosmetic procedures or in the lungs of cystic fibrosis and immunosuppressed patients. Killing mycobacteria is important because Mycobacterium tuberculosis strains can be multidrug resistant and therefore potentially fatal biohazards, and environmental mycobacteria must be thoroughly eliminated from surgical implements and respiratory equipment. Currently used mycobactericidal disinfectants can be toxic, unstable, and expensive. We fortuitously found that acetic acid kills mycobacteria and then showed that it is an effective mycobactericidal agent, even against the very resistant, clinically important Mycobacterium abscessus complex. Vinegar has been used for thousands of years as a common disinfectant, and if it can kill mycobacteria, the most disinfectant-resistant bacteria, it may prove to be a broadly effective, economical biocide with potential usefulness in health care settings and laboratories, especially in resource-poor countries. PMID:24570366

Cortesia, Claudia; Vilchèze, Catherine; Bernut, Audrey; Contreras, Whendy; Gómez, Keyla; de Waard, Jacobus; Jacobs, William R; Kremer, Laurent; Takiff, Howard

2014-01-01

146

Indole3Acetic Acid Controls Cambial Growth in Scots Pine by Positional Signaling1  

Microsoft Academic Search

The vascular cambium produces secondary xylem and phloem in plants and is responsible for wood formation in forest trees. In this study we used a microscale mass-spectrometry technique coupled with cryosectioning to visualize the radial concentration gradient of endogenous indole-3-acetic acid (IAA) across the cambial meristem and the differentiating derivatives in Scots pine (Pinus sylvestris L.) trees that had different

Claes Uggla; Ewa J Mellerowicz; Bjorn Sundberg

1998-01-01

147

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...

148

Interaction of acetic acid and phenylacetaldehyde as attractants for trapping pest species of moths (Lepidoptera: Noctuidae)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Phenylacetaldehyde is a flower volatile and attractant for many nectar-seeking moths. Acetic acid is a microbial fermentation product that is present in insect sweet baits. It is weakly attractive to some moths and other insects, but can be additive or synergistic with other compounds to make more p...

149

EXTRACTION AND ELECTROSPINNING OF ZEIN EXTRACTED FROM CORN GLUTEN MEAL USING ACETIC ACID  

Technology Transfer Automated Retrieval System (TEKTRAN)

It has been demonstrated that zein fibers can be produced using the electrospinning technique. Fibers electrospun from acetic acid solution under suitable conditions provide fibers with a more consistent morphology (round 0.5-2.0 micro fibers) compared to fibers produced from aqueous ethanol soluti...

150

Molecular Cloning and Biochemical Characterization of Indole-3-acetic Acid Methyltransferase from Poplar (Populus trichocarpa)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Indole-3-acetic acid (IAA) is the most active endogenous auxin involved in various physiological processes in higher plants. Concentrations of IAA in plant tissues are regulated at multiple levels including de novo biosynthesis, degradation, and conjugation/deconjugation. In this paper, we report id...

151

Role of neutrophils in acetic acid-induced colitis in rats  

Microsoft Academic Search

Intrarectal administration of 4% acetic acid produces diffuse inflammation that ultimately results in erosions and ulcerations of the rat colon. Although this model of colitis has been used extensively over the past several years, there are no quantitative data available regarding the relationship between neutrophil infiltration and mucosal injury during times of active inflammation. Therefore, the objective of this study

Tamaki Yamada; Barbara J. Zimmerman; Robert D. Specian; Matthew B. Grisham

1991-01-01

152

Poly(vinyl chloride) polyacrylonitrile composite membranes for the dehydration of acetic acid  

Microsoft Academic Search

Composite membranes have been prepared consisting of a poly(vinyl chloride) (PVC) top layer on either a dense polyacrylonitrile (PAN) layer (bi-layer membrane) or a porous PAN support layer (normal composite membrane) and studied with respect to the dehydration of acetic acid. Especially, the influence of the surface porosity of the porous support layer on the selectivity and flux was studied

G. H. Koops; J. A. M. Nolten-Oude Hendrikman; M. H. V. Mulder; C. A. Smolders

1993-01-01

153

Sources and sinks of formic, acetic, and pyruvic acids over central Amazonia. 2. Wet season  

Microsoft Academic Search

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

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

1990-01-01

154

INTRODUCTION The plant hormone auxin (indole-3-acetic acid) has been  

E-print Network

INTRODUCTION The plant hormone auxin (indole-3-acetic acid) has been shown to regulate a wide, auxin affects elongation, division and differentiation, but the mechanisms by which it produces these cellular effects remain poorly understood. The auxin-binding protein ABP1 appears to function as an auxin

Estelle, Mark

155

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

156

Utilization of Vinegar for Isolation of Cellulose Producing Acetic Acid Bacteria  

Microsoft Academic Search

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

Y. Andelib Aydin; Nuran Deveci Aksoy

2010-01-01

157

Clostridium acetireducens sp. nov., a Novel Amino Acid Oxidizing, Acetate-Reducing Anaerobic Bacterium  

Microsoft Academic Search

Strain 30AT (T = type strain), which was isolated from an anaerobic bioreactor fed on waste from a potato starch factory in De Krim, The Netherlands, is a nonmotile, gram-positive, anaerobic, rod-shaped organism that is able to degrade various amino acids, including alanine, leucine, isoleucine, valine, serine, and threonine. Acetate is required as an electron acceptor for the utilization of

JANNEKE KROONEMAN; MATTHEW D. COLLINS; CHRISTINA PASCUAL; JAN C. GOTTSCHAL

158

Acetic Acid Mediated Synthesis of Phosphonate-Substituted Titanium Oxo Clusters  

PubMed Central

New phosphonate/acetate-substituted titanium oxo/alkoxo clusters were prepared from Ti(OiPr)4 and bis(trimethylsilyl) phosphonates in the presence of acetic acid, which served to generate water in situ through ester formation. The process led to clusters with a higher degree of condensation than in previously known phosphonate-substituted titanium oxo clusters. The clusters [Ti6O4(OiPr)10(OAc)2(O3PR)2] (OAc = acetate) were obtained for a large variety of functional and non-functional groups R under a range of reaction conditions. This cluster type, which is also retained in solution, therefore appears to be very robust. Two other clusters, [Ti5O(OiPr)11(OAc)(O3PCH2CH2CH2Br)3] and [Ti5O3(OiPr)6(OAc)4(O3P-xylyl)2], were only isolated in special cases.

Czakler, Matthias; Artner, Christine; Schubert, Ulrich

2014-01-01

159

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

SciTech Connect

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

Zinder, S.H.

1993-06-01

160

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

161

Chemometric and Molecular Modeling Study of 1H-Indole-3-acetic Acid Derivatives with Auxin Activity*  

E-print Network

Chemometric and Molecular Modeling Study of 1H-Indole-3-acetic Acid Derivatives with Auxin Activity) study on 22 1H-indole-3-acetic acid de- rivatives with auxin activity was performed by means (PLS) and Multiple Li- near Regression (MLR). Molecular geometry of the auxins was optimized at MMFF94

Ferreira, Márcia M. C.

162

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.; Clausen, Edgar C.; Ko, Ching-Whan; Wade, Leslie E.; Wikstrom, Carl V.

2006-07-11

163

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

164

TRAP RESPONSE OF MICHIGAN SOCIAL WASPS (HYMENOPTERA: VESPIDAE) TO THE FEEDING ATTRACTANTS ACETIC ACID, ISOBUTANOL, AND HEPTYL BUTYRATE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Nine Species of social wasps were captured in traps baited with acetic acid, isobutanol, heptyl butyrate and combinations of acetic acid and either isobutanol or heptyl butrate. Three yellowjacket species in the Vespula rufa species group were captured in traps (Vespula acadica (Sladen), Vespula co...

165

Deterministic modeling of the corrosion of a low-carbon steel by carbon dioxide and the effect of acetic acid  

Microsoft Academic Search

The current work is carried out with the aim of developing a deterministic model of the corrosion of low-carbon steel by carbon dioxide including the effect of acetic acid. The interaction of acetic acid with the corrosion-products layer is studied and the system is modelled by considering reactions and the transport processes within the boundary layer along with protective film

Omar Rosas-Camacho

2010-01-01

166

Dissolution enthalpy of phosphoric and acetic acids in water-dimethylformamide mixtures  

Microsoft Academic Search

Dissolution enthalpies of phosphoric and acetic acids were experimentally determined (concentration of acid, up to 3 mol\\/kg)\\u000a in water—dimethylformamide (DMF) mixtures (molar part of DMF, from 0 to 1) at 298.15 K. Standard dissolution enthalpies of\\u000a acids in the mixed water-DMF solvent were estimated on the basis of the obtained data.

L. P. Safonova; A. A. Pryakhin; N. G. Manin

2011-01-01

167

Electrophoretic Determination of Vanilmandelic Acid (VMA) in Urine by Direct Application to Cellulose Acetate  

Microsoft Academic Search

The VMA in urine was quantitated electrophoretically by application of urine to cellulose acetate. Separation of several hydrophenolic acids is distinct. VMA is detected at 0.1-i.g. levels. Normal valueson 400 specimenswas 4.0 ± 2.0 mg.\\/24 hr. 'THE VALUE of vanilmandelic acid (3-methoxy-4-hydroxymandelic acid, 1\\/MA) in urine for the diagnosis of pheochromocytoma is well recog- nized. The comprehensive review of VMA

Thorne J. Butler

168

Proposed Model for the Peroxidase-Catalyzed Oxidation of Indole-3-acetic Acid in the Presence of the Inhibitor Ferulic Acid 1  

PubMed Central

Linear increments in ferulic acid concentration produce logarithmic increases in the ferulic acid-induced lag periods prior to the peroxidase-catalyzed oxidation of indole-3-acetic acid in a system containing 2,4-dichlorophenol and MnCl2 in acetate buffer at pH 5.6. Maintaining the ratio of indole-3-acetic acid to ferulic acid constant at 100 while linearly raising the ferulic acid concentration results in linear increases in the lag period. Both indole-3-acetic acid and ferulic acid are substrates of horseradish peroxidase in the presence of H2O2, and indole-3-acetic acid competitively inhibits the oxidation of ferulic acid. A model for the enzymatic oxidation of indole-3-acetic acid catalyzed by peroxidase is proposed. PMID:16658447

Gelinas, D. A.

1973-01-01

169

Anaerobic Conversion of Lactic Acid to Acetic Acid and 1,2-Propanediol by Lactobacillus buchneri  

PubMed Central

The degradation of lactic acid under anoxic conditions was studied in several strains of Lactobacillus buchneri and in close relatives such as Lactobacillus parabuchneri, Lactobacillus kefir, and Lactobacillus hilgardii. Of these lactobacilli, L. buchneri and L. parabuchneri were able to degrade lactic acid under anoxic conditions, without requiring an external electron acceptor. Each mole of lactic acid was converted into approximately 0.5 mol of acetic acid, 0.5 mol of 1,2-propanediol, and traces of ethanol. Based on stoichiometry studies and the high levels of NAD-linked 1,2-propanediol-dependent oxidoreductase (530 to 790 nmol min?1 mg of protein?1), a novel pathway for anaerobic lactic acid degradation is proposed. The anaerobic degradation of lactic acid by L. buchneri does not support cell growth and is pH dependent. Acidic conditions are needed to induce the lactic-acid-degrading capacity of the cells and to maintain the lactic-acid-degrading activity. At a pH above 5.8 hardly any lactic acid degradation was observed. The exact function of anaerobic lactic acid degradation by L. buchneri is not certain, but some results indicate that it plays a role in maintaining cell viability. PMID:11133436

Oude Elferink, Stefanie J. W. H.; Krooneman, Janneke; Gottschal, Jan C.; Spoelstra, Sierk F.; Faber, Folkert; Driehuis, Frank

2001-01-01

170

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

171

Dichromate dosimetry. The effect of acetic acid on the radiolytic reduction yield  

NASA Astrophysics Data System (ADS)

The radiation chemical yield for the reduction of dichromate, Cr(VI) ? Cr 3+, in an acidic aqueous perchloric acid solution of potassium dichromate, may be increased from 0.04 to >0.2 ? mol J -1 by adding acetic acid. The increased yield, G[-(Cr 2O 7) 2-] is about the same in N 2- and O 2-saturated solutions. The molar linear absorption coefficient at 350 nm also is the same in both solutions ( ?m = 2800 M-1cm-1) at pH 0.4. The proposed mechanism to explain the enhanced response in N 2-saturated solutions involves the efficient reaction of acetic acid with hydroxyl radicals by the abstraction of H from the methyl group; the resulting acid radicals react with relatively high yield to reduce Cr(VI). In O 2-saturated solution, the acetic acid radical apparently goes through an acetic acid peroxyl radical by a bimolecular reaction to the tetroxide intermediate of acetic acid, which releases H 2O 2 with relatively high yield by a Bennett-type reaction. This additional H 2O 2, as a reducing agent, reacts slowly with dichromate and boosts the value of G[-(Cr 2O 7) 2-]. The negative slope of the response (? A vs dose) continues to increase during the period immediately after irradiation of oxygenated solution, due to slow reaction of radiolytically-produced H 2O 2 with dichromate. There is also in both O 2- and N 2-saturated solution a long-term slow reaction involving oxidation of the organic substrate (in this case, acetic acid). Because of these instabilities, the solutions cannot readily be used for dosimetry without the presence of silver ions, which in the oxidized state, Ag 2+, act to stabilize the solution after irradiation. The addition of silver dichromate at a concentration of 0.1 mM decreases the yield to G[-(Cr 2O 7) 2-] = 0.17 ?molJ-1, but greatly improves the stability of the solution after irradiation. The absorbed dose range for the modified dichromate dosimeter when analyzed spectrophotometrically at 350 nm wavelength is approx. 2 × 10 2-2 × 10 3 Gy.

Al-Sheikhly, M.; Hussmann, M. H.; McLaughlin, W. L.

172

Removal of dicyclohexyl acetic acid from aqueous solution using ultrasound, ozone and their combination.  

PubMed

Naphthenic acids are a complex mixture of organic components, some of which include saturated alkyl-substituted cycloaliphatic carboxylic acids and acyclic aliphatic acids. They are naturally found in hydrocarbon deposits like oil sand, petroleum, bitumen and crude oil. In this study, the oxidation of a relatively high molecular weight naphthenic acid (Dicyclohexyl acetic acid) was investigated using ozonation, ultrasonication and hydrogen peroxide alone and their combinations. Effects on oxidation of dicyclohexyl acetic acid (DAA) were measured for different concentrations of ozone ranging between 0.7 to 3.3 mg L(-1) and pH in the range 6 to 10. Ultrasonication and hydrogen peroxide alone were not effective to oxidize dicyclohexyl acetic acid, but combining ultrasonication with H2O2 had a significant effect on oxidation of dicyclohexyl acetic acid with maximum removal reaching to 84 ± 2.2% with 81 ± 2.1% reduction in chemical oxygen demand (COD). Synergistic effects were observed for combining ultrasonication with ozonation and resulted in 100% DAA removal with 98 ± 0.8% reduction in COD within 15 min at 3.3 mg L(-1) ozone concentration and 130 Watts ultrasonication power. The reaction conditions obtained for the maximum oxidation of DAA and COD removal were used for the degradation of naphthenic acids mixture extracted from oil sands process water (OSPW). The percentage oxidation of NAs mixture extracted from OSPW was 89.3 ± 1.1% in ozonation and combined ozonation and ultrasonication, but COD removal observed was 65 ± 1.2% and 78 ± 1.4% for ozonation and combined ozonation and ultrasonication treatments, respectively. PMID:25137539

Kumar, Pardeep; Headley, John; Peru, Kerry; Bailey, Jon; Dalai, Ajay

2014-01-01

173

Radiolysis of aqueous solutions of acetic acid in the presence of Na-montmorillonite  

NASA Technical Reports Server (NTRS)

The gamma-irradiation of 0.8 mol dm-3 aqueous, oxygen-free acetic acid solutions was investigated in the presence or absence of Na-montmorillonite. H2, CH4, CO, CO2, and several polycarboxylic acids were formed in all systems. The primary characteristics observed in the latter system were: (1) Higher yield of the decomposition of acetic acid; (2) Lower yield of the formation of polycarboxylic acids; (3) No effect on the formation of methane; (4) Higher yield of the formation of carbon dioxide; and (5) The reduction of Fe3+ in the octahedral sites of Na-montmorillonite. A possible reaction scheme was proposed to account for the observed changes. The results are important in understanding heterogeneous processes in radiation catalysis and might be significant to prebiotic chemistry.

Navarro-Gonzalez, R.; Negron-Mendoza, A.; Ramos, S.; Ponnamperuma, C.

1990-01-01

174

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

PubMed

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

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

2014-11-26

175

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

PubMed Central

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

Puri, Pranav; Goel, Anisha; Bochynska, Agnieszka

2014-01-01

176

Characterization of spoilage yeasts isolated from fermented vegetables and Inhibition by lactic, acetic and propionic acids  

Microsoft Academic Search

Two Saccharomyces sp. yeasts isolated from spoiled fermented vegetables were identified, and the effects of pH, temperature, initial yeast count and organic acids (lactic, acetic or propionic) on their growth in a vegetable juice medium (VJM) was examined. The VJM was fermented by a mixed lactic acid culture to a pH of 3·74, which represented the fermented VJM (VJM-F). A

Tony Savard; Carole Beaulieu; Nancy J. Gardner; Claude P. Champagne

2002-01-01

177

The gamma-irradiation of aqueous acetic acid-clay suspensions  

Microsoft Academic Search

gamma-radiolysis of 0.8 mol dm-3 aqueous, oxygen-free acetic acid solutions was investigated in the presence or absence of Na-montmorillonite (1 3 g per 10 cm-3). The systems were irradiated at their natural pH (3.5), and 25 °C in a dose range from 0.01 to 500 kGy. H2, CH4, CO, CO2, and a variety of polycarboxylic acids were formed in all

Alicia Negrón-Mendoza; Rafael Navarro-González

1990-01-01

178

Rates of Oxidation of Isomeric Dihydroxy- and Tetrahydroxy-stearic Acids by Lead Tetra-acetate  

Microsoft Academic Search

MEASUREMENTS of the rate of consumption of lead tetra-acetate, when used in strictly comparable conditions to oxidize various isomeric polyhydroxystearic acids, have revealed marked differences between the speed of oxidation of isomeric forms. We have observed these differences both in the two isomeric 9, 10-dihydroxystearic acids (m.p. 95° and 132°) and in the four known forms of 9, 10, 12,

T. P. Hilditch; H. Jasperson

1941-01-01

179

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. PMID:20955010

Becker, Jorg D.; Sá-Correia, Isabel

2010-01-01

180

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

2013-05-15

181

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

EPA Science Inventory

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

182

A Simple and Efficient Method for Direct Acylation of Acetals with Long Alkyl-Chain Carboxylic Acid Anhydrides  

Microsoft Academic Search

We have developed an efficient and simple method for direct transformation of acetals to carboxylic acid esters. The method consists of treatment of acetals with carboxylic anhydrides in the presence of boron trifluoride etherate as a catalyst and affords the corresponding ester derivatives in high yields with retention of configuration in the alcohol moiety. Some mechanistic aspects of this synthetically

Stephan D. Stamatov; Jacek Stawinski

2000-01-01

183

Ulcer healing activity of Mumijo aqueous extract against acetic acid induced gastric ulcer in rats  

PubMed Central

Objective: Gastric ulcer is an important clinical problem, chiefly due to extensive use of some drugs. The aim was to assess the activity of Mumijo extract (which is used in traditional medicine) against acetic acid induced gastric ulcer in rats. Materials and Methods: The aqueous extract of Mumijo was prepared. Animals were randomly (n = 10) divided into four groups: Control, sham-operated group (received 0.2 ml of acetic acid to induce gastric ulcer), Mumijo (100 mg/kg/daily) were given for 4 days postacetic acid administration, and ranitidine group (20 mg/kg). The assessed parameters were pH and pepsin levels (by Anson method) of gastric contents and gastric histopathology. Ranitidine was used as reference anti-ulcer drug. Results: The extract (100 mg/kg/daily, p.o.) inhibited acid acetic-induced gastric ulceration by elevating its pH versus sham group (P < 0.01) and decreasing the pepsin levels compared to standard drug, ranitidine (P < 0.05). The histopathology data showed that the treatment with Mumijo extract had a significant protection against all mucosal damages. Conclusion: Mumijo extract has potent antiulcer activity. Its anti-ulcer property probably acts via a reduction in gastric acid secretion and pepsin levels. The obtained results support the use of this herbal material in folk medicine. PMID:25709338

Shahrokhi, Nader; Keshavarzi, Zakieh; Khaksari, Mohammad

2015-01-01

184

The Use of an Enzyme Electrode in the Analysis of Indole-3-acetic Acid Oxidase Activity in Avena  

PubMed Central

A flexible analytical system which allows for the continuous potentiometric monitoring of the disappearance of an electrochemical species, ferrocyanide, by the peroxidase enzyme is described. The ability of peroxidase to mediate the oxidation of indole-3-acetic acid is followed by observing the competition of indole-3-acetic acid with ferrocyanide for the peroxidase enzyme. This is accomplished by examining potentiometrically the decrease in the rate of ferrocyanide oxidation with increasing indole-3-acetic acid concentration. Homogenates of Avena sativa coleoptiles are investigates for both peroxidase and indole-3-acetic acid oxidase activity. Observations are made with respect to H2O2 and ferrocyanide in the presence and absence of indole-3-acetic acid and naphthalene acetic acid and several interpretations of the reaction kinetics are postulated. Solutions previously assayed for indole-3-acetic acid oxidase activity, when dialyzed and reassayed for peroxidase activity, demonstrated an unimpaired ability to oxidize ferrocyanide peroxidatively, suggesting interpretations of the bisubstrate situation which differ slightly from interpretations given in the literature. PMID:16658775

McCreight, William H.; Perley, James E.

1974-01-01

185

Electrochemical reduction of uranyl nitrate in acetic acid solutions  

Microsoft Academic Search

Electrochemical reduction of UOâ(NOâ)â has been studied by polarography on a mercury cathodes in CHâCOOH solutions. It has been found that UOâ(NOâ) is reduced to U(IV) by a mechanism similar to reduction in nitric acid solutions at pH>2. The polarograms have been recorded with various solid cathodes. The cathodes having current density of uranyl reduction close to that on mercury

A. M. Fedoseev; V. P. Shilov

1995-01-01

186

Negative Pressure Wound Therapy of Chronically Infected Wounds Using 1% Acetic Acid Irrigation  

PubMed Central

Background Negative-pressure wound therapy (NPWT) induces angiogenesis and collagen synthesis to promote tissue healing. Although acetic acid soaks normalize alkali wound conditions to raise tissue oxygen saturation and deconstruct the biofilms of chronic wounds, frequent dressing changes are required. Methods Combined use of NPWT and acetic acid irrigation was assessed in the treatment of chronic wounds, instilling acetic acid solution (1%) beneath polyurethane membranes twice daily for three weeks under continuous pressure (125 mm Hg). Clinical photographs, pH levels, cultures, and debrided fragments of wounds were obtained pre- and posttreatment. Tissue immunostaining (CD31, Ki-67, and CD45) and reverse transcription-polymerase chain reaction (vascular endothelial growth factor [VEGF], vascular endothelial growth factor receptor [VEGFR]; procollagen; hypoxia-inducible factor 1 alpha [HIF-1-alpha]; matrix metalloproteinase [MMP]-1,-3,-9; and tissue inhibitor of metalloproteinase [TIMP]) were also performed. Results Wound sizes tended to diminish with the combined therapy, accompanied by drops in wound pH (weakly acidic or neutral) and less evidence of infection. CD31 and Ki-67 immunostaining increased (P<0.05) post-treatment, as did the levels of VEGFR, procollagen, and MMP-1 (P<0.05), whereas the VEGF, HIF-1-alpha, and MMP-9/TIMP levels declined (P<0.05). Conclusions By combining acetic acid irrigation with negative-pressure dressings, both the pH and the size of chronic wounds can be reduced and infections be controlled. This approach may enhance angiogenesis and collagen synthesis in wounds, restoring the extracellular matrix. PMID:25606491

Lee, Byeong Ho; Lee, Hye Kyung; Kim, Hyoung Suk; Moon, Min Seon; Suh, In Suck

2015-01-01

187

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

PubMed Central

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

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

2014-01-01

188

2-(Acet­oxy­meth­yl)benzoic acid  

PubMed Central

The title compound, C10H10O4, crystallizes with the well-known carb­oxy­lic acid dimer-forming R 2 2(8) hydrogen-bond motif. Chains approximately parallel to (-1-12) are then built through C(methyl­ene,phen­yl)–H?O(carbon­yl) inter­actions [C(6) and C(8) motifs] with one (meth­yl)C—H?? inter­action providing inter­planar binding. The weakness of the latter inter­action is consistent with the difficulty experienced in obtaining suitable single crystals. PMID:23424536

Gainsford, Graeme J.; Schwörer, Ralf

2013-01-01

189

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

190

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

2013-05-01

191

Clostridium stain which produces acetic acid from waste gases  

DOEpatents

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

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

1997-01-01

192

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

193

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

194

Indole Acetic Acid Distribution Coincides with Vascular Differentiation Pattern during Arabidopsis Leaf Ontogeny  

Microsoft Academic Search

We used an anti-indole acetic acid (IAA or auxin) monoclonal antibody-based immunocytochemical procedure to monitor IAA level in Arabidopsis tissues. Using immunocytochemistry and the IAA-driven -glucuronidase (GUS) activity of Aux\\/IAA promoter::GUS constructs to detect IAA distribution, we investigated the role of polar auxin transport in vascular differentiation during leaf development in Arabidopsis. We found that shoot apical cells contain high

Orna Avsian-Kretchmer; Jin-Chen Cheng; Lingjing Chen; Edgar Moctezuma; Z. Renee Sung

2002-01-01

195

Developmental Regulation of Indole3Acetic Acid Turnover in Scots Pine Seedlings  

Microsoft Academic Search

Indole-3-acetic acid (IAA) homeostasis was investigated during seed germination and early seedling growth in Scots pine (Pinus sylvestris). IAA-ester conjugates were initially hydrolyzed in the seed to yield a peak of free IAA prior to initiation of root elongation. Developmental regulation of IAA synthesis was observed, with tryptophan-dependent synthesis being initiated around 4 d and tryptophan-independent synthesis occurring around 7

Karin Ljung; Anders Ostin; Laetitia Lioussanne; Goran Sandberg

2001-01-01

196

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

Microsoft Academic Search

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

Yoshiyuki Inouye; Manjiro Noda; Osamu Hirayama

1955-01-01

197

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

PubMed Central

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

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

1985-01-01

198

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

Microsoft Academic Search

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

T. T. Lee; T. Dumas

1985-01-01

199

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

Microsoft Academic Search

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

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

1998-01-01

200

Aminomethyl coumarin acetic acid: A new fluorescent labelling agent for proteins  

Microsoft Academic Search

Summary  A new fluorescent protein labelling agent, 7-amino-4-methyl coumarin-3-acetic acid (AMCA), emits in the blue region (440–460 nm) on activation with UV light (350 nm). The active reagent is theN-hydroxysuccinimide ester which reacts with lysine residues under mild conditions to form photostable amide links.The Stokes shift of 100 nm compared to 30 nm for Fluorescein isothiocyanate (FITC) allows easy filter discrimination

H. Khalfan; R. Abuknesha; M. Rand-Weaver; R. G. Price; D. Robinson

1986-01-01

201

Differential responses of pea seedlings to indole acetic acid under manganese toxicity  

Microsoft Academic Search

Present study showed the responses of pea seedlings to exogenous indole acetic acid (IAA; 10 and 100 ?M) application under\\u000a manganese (Mn; 50, 100 and 250 ?M) toxicity. Manganese and 100 ?M IAA alone as well as in combination decreased growth of\\u000a pea seedlings compared to control. Moreover, some parameters of oxidative stress—hydrogen peroxide (H2O2) and malondialdehyde (MDA) were also increased by single

Savita Gangwar; Vijay Pratap Singh; Sheo Mohan Prasad; Jagat Narayan Maurya

2011-01-01

202

Palladium-catalyzed ?-arylation of aryl acetic acid derivatives via dienolate intermediates with aryl chlorides and bromides.  

PubMed

To date, examples of ?-arylation of carboxylic acids remain scarce. Using a deprotonative cross-coupling process (DCCP), a method for palladium-catalyzed ?-arylation of aryl acetic acids with aryl halides has been developed. This protocol is applicable to a wide range of aryl bromides and chlorides. A procedure for the palladium-catalyzed ?-arylation of styryl acetic acids is also described. PMID:25582024

Sha, Sheng-Chun; Zhang, Jiadi; Walsh, Patrick J

2015-02-01

203

Effects of ethanol and acetic acid on the transport of malic acid and glucose in the yeast Schizosaccharomyces pombe: implications in wine deacidification  

Microsoft Academic Search

Ethanol and acetic acid, at concentrations which may occur during wine-making, inhibited the transport of l-malic acid in Schizosaccharomyces pombe. The inhibition was non-competitive, the decrease of the maximum initial velocity following exponential kinetics. Glucose transport was not significantly affected either by ethanol (up to 13%, w\\/v) or by acetic acid (up to 1.5%, w\\/v). The uptake of labelled acetic

Maria João Sousa; Manuel Mota; Cecilia Leão

1995-01-01

204

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

2011-11-15

205

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

PubMed Central

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

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

2013-01-01

206

Biodegradation of cellulose acetate by Neisseria sicca.  

PubMed

Bacteria capable of assimilating cellulose acetate, strains SB and SC, were isolated from soil on a medium containing cellulose acetate as a carbon source, and identified as Neisseria sicca. Both strains degraded cellulose acetate membrane filters (degree of substitution, DS, mixture of 2.8 and 2.0) and textiles (DS, 2.34) in a medium containing cellulose acetate (DS, 2.34) or its oligomer, but were not able to degrade these materials in a medium containing cellobiose octaacetate. Biodegradation of cellulose acetate (DS, 1.81 and 2.34) on the basis of biochemical oxygen demand reached 51 and 40% in the culture of N. sicca SB and 60 and 45% in the culture of N. sicca SC within 20 days. A decrease in the acetyl content of degraded cellulose acetate films and powder was confirmed by infrared and nuclear magnetic resonance analyses. After 10-day cultivation of N. sicca SB and SC, the number-average molecular weight of residual cellulose acetate decreased by 9 and 5%, respectively. Activities of enzymes that released acetic acid and produced reducing sugars from cellulose acetate were mainly present in the culture supernatant. Reactivity of enzymes for cellulose acetate (DS, 1.81) was higher than that for cellulose acetate (DS, 2.34). PMID:8987659

Sakai, K; Yamauchi, T; Nakasu, F; Ohe, T

1996-10-01

207

Leuconostoc gelidum and Leuconostoc gasicomitatum strains dominated the lactic acid bacterium population associated with strong slime formation in an acetic-acid herring preserve  

Microsoft Academic Search

Spoilage characterised by strong slime and gas formation affected some manufacture lots of an acetic-acid Baltic herring (Culpea haerengus membras) preserve after few weeks of storage at 0–6 °C. The product consisted of herring filets in acetic acid marinade containing sugar, salt, allspice and carrot slices. Microbiological analyses of the spoiled product showed high lactic acid bacterium (LAB) levels ranging

Ulrike Lyhs; Joanna M. K. Koort; Hanna-Saara Lundström; K. Johanna Björkroth

2004-01-01

208

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

NASA Astrophysics Data System (ADS)

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

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

2011-06-01

209

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

PubMed

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

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

2014-09-11

210

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

Microsoft Academic Search

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

Yuliya A. Fadeeva; Lyubov P. Safonova

2011-01-01

211

Desmopressin Acetate in Intracranial Haemorrhage  

PubMed Central

Introduction. The secondary increase in the size of intracranial haematomas as a result of spontaneous haemorrhage or trauma is of particular relevance in the event of prior intake of platelet aggregation inhibitors. We describe the effect of desmopressin acetate as a means of temporarily stabilising the platelet function. Patients and Methods. The platelet function was analysed in 10 patients who had received single (N = 4) or multiple (N = 6) doses of acetylsalicylic acid and 3 patients (control group) who had not taken acetylsalicylic acid. All subjects had suffered intracranial haemorrhage. Analysis was performed before, half an hour and three hours after administration of desmopressin acetate. Statistical analysis was performed by applying a level of significance of P ? 0.05. Results. (1) Platelet function returned to normal 30 minutes after administration of desmopressin acetate. (2) The platelet function worsened again after three hours. (3) There were no complications related to electrolytes or fluid balance. Conclusion. Desmopressin acetate can stabilise the platelet function in neurosurgical patients who have received acetylsalicylic acid prior to surgery without causing transfusion-related side effects or a loss of time. The effect is, however, limited and influenced by the frequency of drug intake. Further controls are needed in neurosurgical patients. PMID:25610644

Kapapa, Thomas; Röhrer, Stefan; Struve, Sabine; Petscher, Matthias; König, Ralph; Wirtz, Christian Rainer; Woischneck, Dieter

2014-01-01

212

Effective trapping of fruit flies with cultures of metabolically modified acetic Acid bacteria.  

PubMed

Acetoin in vinegar is an attractant to fruit flies when combined with acetic acid. To make vinegar more effective in attracting fruit flies with increased acetoin production, Komagataeibacter europaeus KGMA0119 was modified by specific gene disruption of the acetohydroxyacid isomeroreductase gene (ilvC). A previously constructed mutant lacking the putative ligand-sensing region in the leucine-responsive regulatory protein (KeLrp, encoded by Kelrp) was also used. The ilvC and Kelrp disruptants (KGMA5511 and KGMA7203, respectively) produced greater amounts of acetoin (KGMA5511, 0.11%; KGMA7203, 0.13%) than the wild-type strain KGMA0119 (0.069%). KGMA7203 produced a trace amount of isobutyric acid (0.007%), but the other strains did not. These strains produced approximately equal amounts of acetic acid (0.7%). The efficiency of fruit fly attraction was investigated with cultured Drosophila melanogaster. D. melanogaster flies (approximately 1,500) were released inside a cage (2.5 m by 2.5 m by 1.5 m) and were trapped with a device containing vinegar and a sticky sheet. The flies trapped on the sticky sheet were counted. The cell-free supernatant from KGMA7203 culture captured significantly more flies (19.36 to 36.96% of released flies) than did KGMA0119 (3.25 to 11.40%) and KGMA5511 (6.87 to 21.50%) cultures. Contrastingly, a 0.7% acetic acid solution containing acetoin (0.13%) and isobutyric acid (0.007%), which mimicked the KGMA7203 supernatant, captured significantly fewer flies (0.88 to 4.57%). Furthermore, the KGMA0119 supernatant with additional acetoin (0.13%) and isobutyric acid (0.007%) captured slightly more flies than the original KGMA0119 supernatant but fewer than the KGMA7203 supernatant, suggesting that the synergistic effects of acetic acid, acetoin, isobutyric acid, and unidentified metabolites achieved the efficient fly trapping of the KGMA7203 supernatant. PMID:25595769

Ishii, Yuri; Akasaka, Naoki; Goda, Itsuko; Sakoda, Hisao; Fujiwara, Shinsuke

2015-04-01

213

Ulipristal acetate: in uterine fibroids.  

PubMed

Ulipristal acetate, a selective progesterone-receptor modulator, inhibits the proliferation and induces apoptosis of leiomyoma cells in vitro. It also modulates the expression of vascular endothelial growth factors and hormone receptors and modulates extracellular matrix breakdown in leiomyoma cells but not in myometrial cells. In two randomized, double-blind, multinational phase III trials of 13 weeks' duration in women aged 18-50 years with uterine fibroids, a once-daily regimen of oral ulipristal acetate 5 mg/day controlled excessive uterine bleeding (primary endpoint) in ?90% of patients. Ulipristal acetate 5 mg/day was more effective than placebo and was shown to be noninferior to intramuscular leuprolide acetate 3.75 mg once monthly in controlling uterine bleeding. Uterine bleeding was rapidly controlled by ulipristal acetate. Approximately half of recipients of ulipristal acetate 5 mg/day became amenorrhoeic within the first 10 days of treatment. Furthermore, uterine bleeding was controlled significantly more rapidly for recipients of ulipristal acetate than recipients of leuprolide acetate. A significantly greater median reduction from baseline in total fibroid volume was observed for recipients of ulipristal acetate 5 mg once daily than recipients of placebo following 13 weeks' treatment (coprimary endpoint). For patients who did not undergo surgery, the volume reduction was maintained for at least 6 months after discontinuing treatment. Ulipristal acetate was generally well tolerated in women with uterine fibroids. The incidence of hot flush occurred with a significantly lower frequency for recipients of ulipristal acetate than for recipients of leuprolide acetate. PMID:22568731

Croxtall, Jamie D

2012-05-28

214

Acetate dependence of tumors.  

PubMed

Acetyl-CoA represents a central node of carbon metabolism that plays a key role in bioenergetics, cell proliferation, and the regulation of gene expression. Highly glycolytic or hypoxic tumors must produce sufficient quantities of this metabolite to support cell growth and survival under nutrient-limiting conditions. Here, we show that the nucleocytosolic acetyl-CoA synthetase enzyme, ACSS2, supplies a key source of acetyl-CoA for tumors by capturing acetate as a carbon source. Despite exhibiting no gross deficits in growth or development, adult mice lacking ACSS2 exhibit a significant reduction in tumor burden in two different models of hepatocellular carcinoma. ACSS2 is expressed in a large proportion of human tumors, and its activity is responsible for the majority of cellular acetate uptake into both lipids and histones. These observations may qualify ACSS2 as a targetable metabolic vulnerability of a wide spectrum of tumors. PMID:25525877

Comerford, Sarah A; Huang, Zhiguang; Du, Xinlin; Wang, Yun; Cai, Ling; Witkiewicz, Agnes K; Walters, Holly; Tantawy, Mohammed N; Fu, Allie; Manning, H Charles; Horton, Jay D; Hammer, Robert E; McKnight, Steven L; Tu, Benjamin P

2014-12-18

215

The short-chain fatty acid acetate reduces appetite via a central homeostatic mechanism  

PubMed Central

Increased intake of dietary carbohydrate that is fermented in the colon by the microbiota has been reported to decrease body weight, although the mechanism remains unclear. Here we use in vivo11C-acetate and PET-CT scanning to show that colonic acetate crosses the blood–brain barrier and is taken up by the brain. Intraperitoneal acetate results in appetite suppression and hypothalamic neuronal activation patterning. We also show that acetate administration is associated with activation of acetyl-CoA carboxylase and changes in the expression profiles of regulatory neuropeptides that favour appetite suppression. Furthermore, we demonstrate through 13C high-resolution magic-angle-spinning that 13C acetate from fermentation of 13C-labelled carbohydrate in the colon increases hypothalamic 13C acetate above baseline levels. Hypothalamic 13C acetate regionally increases the 13C labelling of the glutamate–glutamine and GABA neuroglial cycles, with hypothalamic 13C lactate reaching higher levels than the ‘remaining brain’. These observations suggest that acetate has a direct role in central appetite regulation. PMID:24781306

Frost, Gary; Sleeth, Michelle L.; Sahuri-Arisoylu, Meliz; Lizarbe, Blanca; Cerdan, Sebastian; Brody, Leigh; Anastasovska, Jelena; Ghourab, Samar; Hankir, Mohammed; Zhang, Shuai; Carling, David; Swann, Jonathan R.; Gibson, Glenn; Viardot, Alexander; Morrison, Douglas; Louise Thomas, E; Bell, Jimmy D.

2014-01-01

216

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

217

Substituent Effects on the Reactions of Diarylgermylenes and Tetraaryldigermenes with Acetic Acid and Other Lewis Bases in  

E-print Network

Substituent Effects on the Reactions of Diarylgermylenes and Tetraaryldigermenes with Acetic Acid that involve initial nucleophilic attack at germanium in all cases. The Lewis acid-base complexation facile insertion into the O-H bonds of alcohols and carboxylic acids, form Lewis acid-base complexes

Leigh, William J.

218

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

E-print Network

to acetic acid in concentrated sulfuric acid using a combination of Pd2+ and Cu2+ in the presence of oxygen from methane without the addition of COx.3 The reaction is carried out in concentrated sulfuric acid be regenerated by sulfuric acid oxidation of Pd(0); however, this process is slow. We recently showed

Bell, Alexis T.

219

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

2012-07-01

220

Glycolaldehyde, methyl formate and acetic acid adsorption and thermal desorption from interstellar ices  

NASA Astrophysics Data System (ADS)

We have undertaken a detailed investigation of the adsorption, desorption and thermal processing of the astrobiologically significant isomers glycolaldehyde, acetic acid and methyl formate. Here, we present the results of laboratory infrared and temperature programmed desorption (TPD) studies of the three isomers from model interstellar ices adsorbed on a carbonaceous dust grain analogue surface. Laboratory infrared data show that the isomers can be clearly distinguished on the basis of their infrared spectra, which has implications for observations of interstellar ice spectra. Laboratory TPD data also show that the three isomers can be distinguished on the basis of their thermal desorption behaviour. In particular, TPD data show that the isomers cannot be treated the same way in astrophysical models of desorption. The desorption of glycolaldehyde and acetic acid from water-dominated ices is very similar, with desorption being mainly dictated by water ice. However, methyl formate also desorbs from the surface of the ice, as a pure desorption feature, and therefore desorbs at a lower temperature than the other two isomers. This is more clearly indicated by models of the desorption on astrophysical time-scales corresponding to the heating rate of 25 and 5 M? stars. For a 25 M? star, our model shows that a proportion of the methyl formate can be found in the gas phase at earlier times compared to glycolaldehyde and acetic acid. This has implications for the observation and detection of these molecules, and potentially explains why methyl formate has been observed in a wider range of astrophysical environments than the other two isomers.

Burke, Daren J.; Puletti, Fabrizio; Brown, Wendy A.; Woods, Paul M.; Viti, Serena; Slater, Ben

2015-02-01

221

Protective effect of sanguinarine against acetic acid-induced ulcerative colitis in mice.  

PubMed

The quaternary ammonium salt, sanguinarine (SANG), is of great practical and research interest because of its pronounced, widespread physiological effects, which promote anti-microbial and anti-inflammatory responses in experimental animals. Although SANG is originally shown to possess anti-inflammatory properties and it has been used to treat various inflammatory diseases, its effects on ulcerative colitis have not been previously explored. The aim of the present study is to evaluate the effect of SANG on acetic acid-induced ulcerative colitis in mice. Experimental animals received SANG (1, 5 and 10 mg/kg, p.o.) and sulfasalazine (500 mg/kg, p.o.) for seven consecutive days after induction of colitis by intra-rectal acetic acid (5% v/v) administration. The colonic mucosal injury was assessed by clinical, macroscopic, biochemical and histopathological examinations. SANG treatment significantly decreased mortality rate, body weight loss, disease activity index (DAI), wet colon weight, macroscopic and histological score when compared to acetic acid-induced controls. In addition, administration of SANG effectively inhibited p65 NF-?B protein expression and MPO activity accumulation. The levels of TNF-? and IL-6 in the serum and colon tissue of mice with experimental colitis were decreased by SANG in a concentration-dependent manner in response to p65 NF-?B. The possible mechanism of protection on experimental colitis was that SANG could be through attenuating early steps of inflammation as well as decreasing the expression of NF-?B and subsequent pro-inflammatory cytokines production. PMID:23352506

Niu, Xiaofeng; Fan, Ting; Li, Weifeng; Huang, Huimin; Zhang, Yanmin; Xing, Wei

2013-03-15

222

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

SciTech Connect

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

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

2005-12-15

223

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

Microsoft Academic Search

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

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

2010-01-01

224

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

225

Functionalized alkylidenecyclopentenes by acid-catalyzed electrocyclic ring closure of (2Z)-(di)vinylallene acetals  

Microsoft Academic Search

Acid-induced electrocyclic ring-closure of (2Z)-4-tert-butyl-3-methyl-2,4,5,7-tetraene acetals 3 afforded a mixture of alkylidenecyclopentene dioxanes Z-4 and E-4. The lack of torquoselective effects on the electrocyclization suggested the transition state structures for the two alternative conrotatory modes to have similar energies. The results of an ab initio study of a model system at the DFT B3LYP\\/6-31G? level were consistent with this hypothesis.

Angel R. de Lera; José García Rey; David Hrovat; Beatriz Iglesias; Susana López

1997-01-01

226

In Planta Production of Indole-3-Acetic Acid by Colletotrichum gloeosporioides f. sp. aeschynomene  

PubMed Central

The plant pathogenic fungus Colletotrichum gloeosporioides f. sp. aeschynomene utilizes external tryptophan to produce indole-3-acetic acid (IAA) through the intermediate indole-3-acetamide (IAM). We studied the effects of tryptophan, IAA, and IAM on IAA biosynthesis in fungal axenic cultures and on in planta IAA production by the fungus. IAA biosynthesis was strictly dependent on external tryptophan and was enhanced by tryptophan and IAM. The fungus produced IAM and IAA in planta during the biotrophic and necrotrophic phases of infection. The amounts of IAA produced per fungal biomass were highest during the biotrophic phase. IAA production by this plant pathogen might be important during early stages of plant colonization. PMID:15006816

Maor, Rudy; Haskin, Sefi; Levi-Kedmi, Hagit; Sharon, Amir

2004-01-01

227

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

228

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

NASA Technical Reports Server (NTRS)

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

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

1990-01-01

229

Acetate Kinase Isozymes Confer Robustness in Acetate Metabolism  

PubMed Central

Acetate kinase (ACK) (EC no: 2.7.2.1) interconverts acetyl-phosphate and acetate to either catabolize or synthesize acetyl-CoA dependent on the metabolic requirement. Among all ACK entries available in UniProt, we found that around 45% are multiple ACKs in some organisms including more than 300 species but surprisingly, little work has been done to clarify whether this has any significance. In an attempt to gain further insight we have studied the two ACKs (AckA1, AckA2) encoded by two neighboring genes conserved in Lactococcus lactis (L. lactis) by analyzing protein sequences, characterizing transcription structure, determining enzyme characteristics and effect on growth physiology. The results show that the two ACKs are most likely individually transcribed. AckA1 has a much higher turnover number and AckA2 has a much higher affinity for acetate in vitro. Consistently, growth experiments of mutant strains reveal that AckA1 has a higher capacity for acetate production which allows faster growth in an environment with high acetate concentration. Meanwhile, AckA2 is important for fast acetate-dependent growth at low concentration of acetate. The results demonstrate that the two ACKs have complementary physiological roles in L. lactis to maintain a robust acetate metabolism for fast growth at different extracellular acetate concentrations. The existence of ACK isozymes may reflect a common evolutionary strategy in bacteria in an environment with varying concentrations of acetate. PMID:24638105

Chan, Siu Hung Joshua; Nørregaard, Lasse; Solem, Christian; Jensen, Peter Ruhdal

2014-01-01

230

The kinetics of process dependent ammonia inhibition of methanogenesis from acetic acid.  

PubMed

Advanced anaerobic digestion processes aimed at improving the methanization of sewage sludge may be potentially impaired by the production of inhibitory compounds (e.g. free ammonia). The result of methanogenic inhibition is relatively high effluent concentrations of acetic acid and other soluble organics, as well as reduced methane yields. An extreme example of such an advanced process is the thermal hydrolytic pretreatment of sludge prior to high solids digestion (THD). Compared to a conventional mesophilic anaerobic digestion process (MAD), THD operates in a state of constant inhibition driven by high free ammonia concentrations, and elevated pH values. As such, previous investigations of the kinetics of methanogenesis from acetic acid under uninhibited conditions do not necessarily apply well to the modeling of extreme processes such as THD. By conducting batch ammonia toxicity assays using biomass from THD and MAD reactors, we compared the response of these communities over a broad range of ammonia inhibition. For both processes, increased inhibitor concentrations resulted in a reduction of biomass growth rate (r(max) = ?(max)?X) and a resulting decrease in the substrate half saturation coefficient (K(S)). These two parameters exhibited a high degree of correlation, suggesting that for a constant transport limited system, the K(S) was mostly a linear function of the growth rate. After correcting for reactor pH and temperature, we found that the THD and MAD biomass were both able to perform methanogenesis from acetate at high free ammonia concentrations (equivalent to 3-5 g/L total ammonia nitrogen), albeit at less than 30% of their respective maximum rates. The reduction in methane production was slightly less pronounced for the THD biomass than for MAD, suggesting that the long term exposure to ammonia had selected for a methanogenic pathway less dependent on those organisms most sensitive to ammonia inhibition (i.e. aceticlastic methanogens). PMID:23062786

Wilson, Christopher Allen; Novak, John; Takacs, Imre; Wett, Bernhard; Murthy, Sudhir

2012-12-01

231

Intravenous Acetate Elicits a Greater Free Fatty Acid Rebound in Normal than Hyperinsulinaemic Humans  

PubMed Central

Background/Objectives Colonic fermentation of dietary fiber may improve insulin sensitivity via the metabolic effects of short chain fatty acids (SCFA) in reducing free fatty acids (FFA). The main objectives of this study were to compare peripheral uptake of acetate (AC) in participants with normal (< 40pmol/L, NI) and high (? 40pmol/L, HI) plasma-insulin and the ability of AC to reduce FFA in both groups. Subject/Methods Overnight fasted NI (n = 9) and HI (n = 9) participants were given an intravenous (IV) infusion of 140 mmol/L sodium acetate at 3 different rates over 90 minutes. The total amount of AC infused was 51.85 mmols. Results Acetate clearance in NI participants was not significantly different than that in HI participants (2.11 ± 0.23 vs 2.09 ± 0.24 ml/min). FFA fell in both groups, but rebounded to a greater extent in NI than HI participants (time × group interaction, P = 0.001). Significant correlations between insulin resistance (IR) indices (HOMA-IR, Matsuda and Insulinogenic Index) vs FFA rebound during IV AC infusion were also observed. Conclusions These findings suggest that AC uptake is similar in both groups. Participants with lower plasma insulin and lower IR indices had a greater FFA rebound. These results support the hypothesis that increasing AC concentrations in the systemic circulation may reduce lipolysis and plasma FFA concentrations and thus improve insulin sensitivity. More in-depth studies are needed to look at the effects of SCFA on FFA metabolism in insulin resistant participants. PMID:22828730

Fernandes, Judlyn; Vogt, Janet; Wolever, Thomas MS

2014-01-01

232

Manufacturing Ethyl Acetate From Fermentation Ethanol  

NASA Technical Reports Server (NTRS)

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

Rohatgi, Naresh K.; Ingham, John D.

1991-01-01

233

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

SciTech Connect

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 2{sup 3}-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` yeast, whereas no significant difference in tolerance towards the compounds was detected between the S. cerevisiae strains. Furfural and the lignin derived compound p-hydroxybenzoic acid did not affect any of the yeasts at the cell mass concentration used. The results indicated that the linear model was not adequate to describe the experimental data. Based on the results from the 2{sup 3}-full factorial experiment, an extended experiment was designed based on a central composite design to investigate the influence of the factors on the specific growth rate ({mu}), biomass yield (Y{sub x}), volumetric ethanol productivity (Q{sub EtOH}), and Y{sub EtOH}. Bakers` yeast was chosen in the extended experiment due to its better tolerance towards acetic acid, which makes it a more interesting organism for use in industrial fermentations of lignocellulosic hydrolysates.

Palmqvist, E.; Grage, H.; Meinander, N.Q.; Hahn-Haegerdal, B. [Univ. of Lund (Sweden)

1999-04-05

234

A lytic enzyme cocktail from Streptomyces sp. B578 for the control of lactic and acetic acid bacteria in wine  

Microsoft Academic Search

Beside yeasts, lactic acid bacteria (LAB) are the most abundant microbes in must during vinification. Whereas Oenococcos oeni is commercially used as a starter culture for the biological acid reduction in wines, other species are responsible for different\\u000a types of wine spoilage. Members of the genera Pediococcus, Weissella, Leuconostoc, and Lactobacillus are producers of exopolysaccharide slimes, biogenic amines, acetic acid,

V. Blättel; K. Wirth; H. Claus; B. Schlott; P. Pfeiffer; H. König

2009-01-01

235

The effect of water content on the electropolishing behavior of Inconel 718 alloy in perchloric–acetic acid mixtures  

Microsoft Academic Search

The electropolishing behavior of Inconel 718 alloy was studied in perchloric–acetic acid mixtures using a rotating disc electrode. The electropolishing behavior of an Inconel 718 weld, which was prepared with electron beam welding, was also investigated. A leveled but not brightened surface can be achieved when Inconel 718 alloy is potentiostatically polished in the acid mixture with 20vol.% perchloric acid.

Ching An Huang; Yu Chen Chen

2009-01-01

236

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

237

Isolation of novel indole-3-acetic acid conjugates by immunoaffinity extraction.  

PubMed

An analytical protocol for the isolation and quantification of indole-3-acetic acid (IAA) and its amino acid conjugates was developed. IAA is an important phytohormone and formation of its conjugates plays a crucial role in regulating IAA levels in plants. The developed protocol combines a highly specific immunoaffinity extraction with a sensitive and selective LC-MS/MS analysis. By using internal standards for each of the studied compounds, IAA and seven amino acid conjugates were analyzed in quantities of fresh plant material as low as 30 mg. In seeds of Helleborus niger, physiological levels of these compounds were found to range from 7.5 nmol g(-1) fresh weight (IAA) to 0.44 pmol g(-1) fresh weight (conjugate with Ala). To our knowledge, the identification of IAA conjugates with Gly, Phe and Val from higher plants is reported here for the first time. PMID:19836533

Pencík, Ales; Rolcík, Jakub; Novák, Ondrej; Magnus, Volker; Barták, Petr; Buchtík, Roman; Salopek-Sondi, Branka; Strnad, Miroslav

2009-12-15

238

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

PubMed

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

Mirhosseini, Mahboubeh; Arjmand, Vahid

2014-09-01

239

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

240

Characterization of DNA Damage in Yeast Apoptosis Induced by Hydrogen Peroxide, Acetic Acid, and Hyperosmotic Shock  

PubMed Central

Saccharomyces cerevisiae has been reported to die, under certain conditions, from programmed cell death with apoptotic markers. One of the most important markers is chromosomal DNA fragmentation as indicated by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining. We found TUNEL staining in S. cerevisiae to be a consequence of both single- and double-strand DNA breaks, whereas in situ ligation specifically stained double-strand DNA breaks. Cells treated with hydrogen peroxide or acetic acid staining positively for TUNEL assay stained negatively for in situ ligation, indicating that DNA damage in both cases mainly consists of single-strand DNA breaks. Pulsed field gel electrophoresis of chromosomal DNA from cells dying from hydrogen peroxide, acetic acid, or hyperosmotic shock revealed DNA breakdown into fragments of several hundred kilobases, consistent with the higher order chromatin degradation preceding DNA laddering in apoptotic mammalian cells. DNA fragmentation was associated with death by treatment with 10 mM hydrogen peroxide but not 150 mM and was absent if cells were fixed with formaldehyde to eliminate enzyme activity before hydrogen peroxide treatment. These observations are consistent with a process that, like mammalian apoptosis, is enzyme dependent, degrades chromosomal DNA, and is activated only at low intensity of death stimuli. PMID:16899507

Ribeiro, Gabriela F.; Côrte-Real, Manuela

2006-01-01

241

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

2013-02-01

242

Enantioselective Synthesis of 1,2-Dihydronaphthalene-1-carbaldehydes by Addition of Boronates to Isochromene Acetals Catalyzed by Tartaric Acid.  

PubMed

Tartaric acid is an ideal asymmetric catalyst as it is abundant, cheap, and environmentally friendly. (+)-Tartaric acid was found to catalyze a novel enantioselective [4 + 2] cycloaddition of isochromene acetals and vinylboronates. A variety of substituted isochromene acetals were tolerated, furnishing the desired dihydronaphthalenes and dihydrobenzofluorene products in good yields. High enantiomeric ratios (up to 98.5:1.5) and excellent diastereoselectivities (all >99:1) were observed employing 10 mol % of (+)-tartaric acid as the catalyst, in combination with 5 mol % of Ho(OTf)3. PMID:25715172

Luan, Yi; Barbato, Keith S; Moquist, Philip N; Kodama, Tomohiro; Schaus, Scott E

2015-03-11

243

Regulation of acetic acid production by homo- and heterofermentative lactobacilli in whole-wheat sour-doughs.  

PubMed

The efficiency of sour-dough as a possible preservative agent of microbial spoilage of bread depends on its acetic acid content. As a secondary metabolite of sugar fermentation by lactic acid bacteria, acetic acid may be promoted in the presence of O2 or H+ acceptors. This paper studies the influence of O2 and high fructose content products (pure sugar, invert sugar, fructose syrup) addition on acetic acid production by hetero- (Lactobacillus brevis 25a, B-21, L-62; L. sanfrancisco L-99) and homofermentative (L. plantarum B-39) lactobacilli in whole-wheat sour-doughs [280 and 250 dough yield (DY)]. The pH and total titratable acidity (TTA) of sour-doughs after 44 h fermentation varied with DY and strain. As expected, the addition of O2 promoted greater increases in TTA with heterofermentative lactobacilli (15-42%) than with L. plantarum (15%). Fructose addition was only effective for heterofermentative strains, but the overall effects were smaller than those observed for oxygenation. The ability of lactobacilli to produce acetic acid in sour-doughs without treatment varied from 0.16 g/100 g flour at 44 h (B-39, 280, 350 DY) to 0.47-0.65% (L-62, 280, 350 DY). The production of acetic acid was positively promoted by all treatments. Oxygenation was again the most effective way of inducing acetic acid production; increases ranged from 54% (B-21) to 269% (L-99, 350 DY). The addition of H+ acceptors had variable effects.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7975904

Martínez-Anaya, M A; Llin, M L; Pilar Macías, M; Collar, C

1994-09-01

244

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

245

Liquid-liquid equilibria of the ternary system water + acetic acid + 1-hexanol  

SciTech Connect

The recovery of organic acids from dilute solutions resulting from fermentation processes is important and many solvents have been tried to improve such recovery. Liquid-liquid equilibria for the ternary system water + acetic acid + 1-hexanol were measured over a temperature range of (288 to 323) K. The results were used to estimate the interaction parameters between each of the three compounds for the NRTL and UNIQUAC models and between each of the main groups of H{sub 2}O, CH{sub 2} (paraffinic CH{sub 2}), OH, and COOH for the UNIFAC model as a function of temperature. The estimated interaction parameters were successfully used to predict the equilibrium compositions by the three models. The NRTL equation was the most accurate model in correlating the overall equilibrium compositions of the studied system. The UNIQUAC and UNIFAC models satisfactorily predicted the equilibrium compositions.

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

1997-01-01

246

Biorefining of wheat straw using an acetic and formic acid based organosolv fractionation process.  

PubMed

To assess the potential of acetic and formic acid organosolv fractionation of wheat straw as basis of an integral biorefinery concept, detailed knowledge on yield, composition and purity of the obtained streams is needed. Therefore, the process was performed, all fractions extensively characterized and the mass balance studied. Cellulose pulp yield was 48% of straw dry matter, while it was 21% and 27% for the lignin and hemicellulose-rich fractions. Composition analysis showed that 67% of wheat straw xylan and 96% of lignin were solubilized during the process, resulting in cellulose pulp of 63% purity, containing 93% of wheat straw cellulose. The isolated lignin fraction contained 84% of initial lignin and had a purity of 78%. A good part of wheat straw xylan (58%) ended up in the hemicellulose-rich fraction, half of it as monomeric xylose, together with proteins (44%), minerals (69%) and noticeable amounts of acids used during processing. PMID:24508905

Snelders, Jeroen; Dornez, Emmie; Benjelloun-Mlayah, Bouchra; Huijgen, Wouter J J; de Wild, Paul J; Gosselink, Richard J A; Gerritsma, Jort; Courtin, Christophe M

2014-03-01

247

Thermal Chemistry of Trimethyl Acetic Acid on TiO?(110)  

SciTech Connect

Based on temperature programmed desorption and isothermal reaction mass spectrometry, the thermal surface chemistry of trimethyl acetic acid, (CH)CCOOH, dosed onto a well characterized single crystal TiO(110) surface is described. Deprotonation occurs at or below 300 K to form trimethyl acetate, (CH)CCOO-, and hydroxide, OH-. (CH)CCOO- is bound to exposed Ti cations and OH- involves a bridging oxygen atom of the substrate. Based on temperature programmed desorption and isothermal reaction mass spectrometry, the desorbing products include (CH)CCOOH, isobutene (i-CH), carbon monoxide and water accompanied by smaller amounts of other products including methyl isopropenyl ketone (CH=C(CH)C(=O)CH), isobutane (i-C4H10), and di-t-butyl ketone, (CH)CC(=O)C(CH). Much of the (CH)CCOO- is relatively stable and decomposes to release mainly carbon monoxide and isobutene above 550 K with a maximum rate at 660 K. Thermal desorption to 750 K leaves a carbon-free surface that is indistinguishable from the initially clean surface. During dosing at 550 K, a steady-state reaction condition is realized with about half the adsorption sites being occupied at any instant.

White, J M.; Szanyi, Janos; Henderson, Michael A.

2004-03-18

248

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

2013-09-17

249

Biomonitoring of 2-(2-alkoxyethoxy)ethanols by analysing urinary 2-(2-alkoxyethoxy)acetic acids.  

PubMed

2-Methoxyacetic and 2-ethoxyacetic acids are well known toxic metabolites of 2-alkoxyethanols. The use of 2-alkoxyethanols is now restricted, and the regulations have forced manufacturers to find substitutive solvents, 2-(2-alkoxyethoxy)ethanols. 2-(2-Alkoxyethoxy)ethanols resemble 2-alkoxyethanols, and their most hazardous similarity is their ability to metabolize to the 2-(2-alkoxyethoxy)acetic acids. In the present study, floor lacquerers' (n = 22) inhalation and total exposure to 2-(2-alkoxy)ethoxyethanols was measured. The measurements of inhalation exposure were done with charcoal tubes, and total exposure was biomonitored by urinalysis of 2-(2-alkoxyethoxy)acetic acids. The 8h inhalation exposures of floor lacquerers to 2-(2-methoxyethoxy)ethanol (DEGME), 2-(2-ethoxyethoxy)ethanol (DEGEE) and 2-(2-butoxyethoxy)ethanol (DEGBE) were in average 0.23 +/- 0.07 ppm (average+/-S.D., n = 3), 0.08 +/- 0.07 ppm (n = 16), and 0.05 +/- 0.03 ppm (n = 16), respectively. The excretions of 2-(2-methoxyethoxy)acetic acid (MEAA), 2-(2-ethoxyethoxy)acetic acid (EEAA) and 2-(2-butoxyethoxy)acetic acid (BEAA) were in average 4.9 +/- 4.3 mmol/mol creatinine, 9.3 +/- 8.0 mmol/mol creatinine and 9.2 +/- 7.4 mmol/mol creatinine, respectively. A linear relationship was found between the urinary 2-(2-alkoxyethoxy)acetic acid concentrations and the preceding 8-h occupational exposure to 2-(2-alkoxyethoxy)ethanol. PMID:15705492

Laitinen, J; Pulkkinen, J

2005-03-28

250

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

2012-06-01

251

Engineering efficient xylose metabolism into an acetic acid-tolerant Zymomonas mobilis strain by introducing adaptation-induced mutations.  

PubMed

The impact of the two adaptation-induced mutations in an improved xylose-fermenting Zymomonas mobilis strain was investigated. The chromosomal mutation at the xylose reductase gene was critical to xylose metabolism by reducing xylitol formation. Together with the plasmid-borne mutation impacting xylose isomerase activity, these two mutations accounted for 80 % of the improvement achieved by adaptation. To generate a strain fermenting xylose in the presence of high acetic acid concentrations, we transferred the two mutations to an acetic acid-tolerant strain. The resulting strain fermented glucose + xylose (each at 5 % w/v) with 1 % (w/v) acetic acid at pH 5.8 to completion with an ethanol yield of 93.4 %, outperforming other reported strains. This work demonstrated the power of applying molecular understanding in strain improvement. PMID:22669340

Agrawal, Manoj; Wang, Yun; Chen, Rachel Ruizhen

2012-10-01

252

Association and liquid structure of pyridine-acetic acid mixtures determined from neutron scattering using a 'free proton' EPSR simulation model.  

PubMed

The liquid structure of pyridine-acetic acid mixtures have been investigated using neutron scattering at various mole fractions of acetic acid, ?HOAc = 0.33, 0.50, and 0.67 and compared to the structures of neat pyridine and acetic acid. Data has been modelled using empirical potential structure refinement (EPSR) with a 'free proton' reference model, which has no prejudicial weighting towards either the existence of molecular or ionised species. Analysis of the neutron scattering results shows the existence of hydrogen-bonded acetic acid chains with pyridine inclusions, rather than the formation of an ionic liquid by proton transfer. PMID:25670622

McCune, Jade A; Turner, Adam H; Coleman, Fergal; White, Caithlin M; Callear, Samantha K; Youngs, Tristan G A; Swad?ba-Kwa?ny, Ma?gorzata; Holbrey, John D

2015-02-25

253

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

EPA Science Inventory

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

254

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

PubMed

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

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

2014-12-21

255

Inactivity of Oxidation Products of Indole-3-acetic Acid on Ethylene Production in Mung Bean Hypocotyls 1  

PubMed Central

The suggestion that indole-3-acetic acid (IAA)-stimulated ethylene production is associated with oxidative degradation of IAA and is mediated by 3-methyleneoxindole (MOI) has been tested in mung bean (Phaseolus aureus Roxb.) hypocotyl segments. While IAA actively stimulated ethylene production, MOI and indole-3-aldehyde, the major products of IAA oxidation, were inactive. Tissues treated with a mixture of intermediates of IAA oxidation, obtained from a 1-hour incubation of IAA with peroxidase, failed to stimulate ethylene production. Furthermore, chlorogenic acid and p-coumaric acid, which are known to interfere with the enzymic oxidation of IAA to MOI, had no effect on IAA-stimulated ethylene production. Other oxidation products of IAA, including oxindole-3-acetic acid, indole-3-carboxylic acid, (2-sulfoindole)-3-acetic acid, and dioxindole-3-acetic acid, were all inactive. 1-Naphthaleneacetic acid was as active as IAA in stimulating ethylene production but was decarboxylated at a much lower rate than IAA, suggesting that oxidative decarboxylation of auxins is not linked to ethylene production. These results demonstrate that IAA-stimulated ethylene production in mung bean hypocotyl tissue is not mediated by MOI or other associated oxidative products of IAA. PMID:16660239

Lau, Oi-lim; John, William W.; Yang, S. F.

1978-01-01

256

Isotopic composition of Murchison organic compounds: Intramolecular carbon isotope fractionation of acetic acid. Simulation studies of cosmochemical organic syntheses  

NASA Technical Reports Server (NTRS)

Recently, in our laboratories, samples of Murchison acetic acid were decarboxylated successfully and the carbon isotopic composition was measured for the methane released by this procedure. These analyses showed significant differences in C-13/C-12 ratios for the methyl and carboxyl carbons of the acetic acid molecule, strongly suggesting that more than one carbon source may be involved in the synthesis of the Murchison organic compounds. On the basis of this finding, laboratory model systems simulating cosmochemical synthesis are being studied, especially those processes capable of involving two or more starting carbon sources.

Yuen, G. U.; Cronin, J. R.; Blair, N. E.; Desmarais, D. J.; Chang, S.

1991-01-01

257

Acetic acid recovery from a hybrid biological-hydrothermal treatment process of sewage sludge - a pilot plant study.  

PubMed

A two-stage process consisting of anaerobic fermentation followed by sub-critical wet oxidation was used to generate acetic acid from sewage sludge at pilot scale. Volatile fatty acids, dominated by propionic acid, were produced over 4-6 days in the 2,000 L fermentation reactor, which also achieved 31% solids reduction. Approximately 96% of the carbon was retained in solution over the fermentation stage. Using a 200 L wet oxidation reactor operating in batch mode, the second stage achieved 98% volatile suspended solids (VSS) destruction and 67% total chemical oxygen demand (tCOD) destruction. Acetic acid produced in this stage was recalcitrant to further degradation and was retained in solution. The gross yield from VSS was 16% for acetic acid and 21% for volatile fatty acids across the process, higher than reported yields for wet oxidation alone. The pilot plant results showed that 72% of the incoming phosphorus was retained in the solids, 94% of the nitrogen became concentrated in solution and 41% of the carbon was converted to a soluble state, in a more degradable form. Acetic acid produced from the process has the potential to be used to offset ethanol requirements in biological nutrient removal plants. PMID:25768220

Andrews, J; Dare, P; Estcourt, G; Gapes, D; Lei, R; McDonald, B; Wijaya, N

2015-03-01

258

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

2011-09-01

259

[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

260

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: (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; (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 18n- alkyl chains as well as the C 15 and C 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

261

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

262

Treatment of Myositis Ossificans with acetic acid phonophoresis: a case series  

PubMed Central

Objective To create awareness of myositis ossificans (MO) as a potential complication of muscle contusion by presenting its clinical presentation and diagnostic features. An effective method of treatment is offered for those patients who develop traumatic MO. Management: Patients in this case series developed traumatic MO, confirmed on diagnostic ultrasound. Patients participated in a treatment regimen consisting of phonophoresis of acetic acid with ultrasound. Outcome: In all cases, a trial of phonophoresis therapy significantly decreased patient signs, symptoms and the size of the calcification on diagnostic ultrasound in most at a 4-week post diagnosis mark. Discussion: Due to the potential damage to the muscle and its function, that surgical excision carries; safe effective methods of conservative treatment for MO are crucial. MO deserves more attention in the literature due to its common presentation in athletes. PMID:25550659

Bagnulo, Angela; Gringmuth, Robert

2014-01-01

263

Indole acetic acid and its metabolism in root nodules of a monocotyledonous tree Roystonea regia.  

PubMed

A monocotyledonous tree, Roystonea regia, was found to bear root nodules. The root nodules contained a high amount (16.9 microg/g fresh mass) of indole acetic acid (IAA). A big tryptophan pool (1555.1 microg/g fresh mass) was found in the root nodules, which might serve as a source of IAA production. The presence of IAA-metabolizing enzymes IAA oxidase and peroxidase indicated metabolism of IAA in the root nodules. The symbiont isolated from the root nodules of R. regia, a Rhizobium sp., produced high amount of IAA in culture when supplemented with tryptophan. The possible role of this IAA production in the monocotyledonous tree-Rhizobium symbiosis is discussed. PMID:9662615

Basu, P S; Ghosh, A C

1998-08-01

264

Vapor phase ketonization of acetic acid on ceria based metal oxides  

SciTech Connect

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

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

2013-12-01

265

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

NASA Astrophysics Data System (ADS)

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

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

2014-12-01

266

Systematic profiling of indole-3-acetic acid biosynthesis in bacteria using LC-MS/MS.  

PubMed

Indole-3-acetic acid (IAA) is produced from tryptophan through five synthesis pathways. A comprehensive method for the quantification of IAA and biosynthesis-related intermediates in a culture medium was developed. Sample preparation was simple with protein precipitation. The analytes were separated on a superficially porous C18 silica column and detected by electrospray ionization-tandem mass spectrometry in the positive ion multiple reaction monitoring mode. The limit of detection was 0.05?M, and the lower limits of quantification ranged from 0.05 to 2?M. The intra-day and inter-day precision and accuracy were less than 13.96%. Ion suppression was observed, and the deuterated internal standards were used to compensate for the matrix effect. The method was applied to analyze changes in tryptophan catabolism in a culture medium of Pseudomonas putida. The proposed method is robust and suitable for the systematic profiling of IAA biosynthesis in culture supernatant. PMID:25746752

Lin, Guang-Huey; Chang, Chung-Yu; Lin, Huei-Ru

2015-04-15

267

Sensitizers containing donor cascade and rhodanine-3-acetic acid moieties for dye-sensitized solar cells  

SciTech Connect

Three organic dyes with D-{pi}-D-{pi}-A structure based on triarylamine, dimethylarylamine, and rhodanine-3-acetic acid moieties are designed and synthesized. Incorporating thiophene moieties into the system affords sensitizers with high molar extinction coefficients. These dyes were applied into nanocrystalline TiO{sub 2} dye-sensitized solar cells through standard operations. For a typical device the maximal monochromatic incident photon-to-current conversion efficiency (IPCE) can reach 73%, with a short-circuit photocurrent density (J{sub sc}) of 7.3 mA/cm{sup 2}, an open-circuit voltage (V{sub oc}) of 636 mV, and a fill factor (ff) of 0.61, corresponding to an overall conversion efficiency ({eta}) of 2.86%. (author)

Wu, Quan-Ping [Department of Thermal and Power Engineering, Tianjin University of Technology, Tianjin 300384 (China); Zhang, Lu; Liang, Mao; Sun, Zhe; Xue, Song [Department of Applied Chemistry, Tianjin University of Technology, Tianjin 300384 (China)

2011-01-15

268

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. PMID:21188166

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

2011-01-01

269

One-component thioxanthone acetic acid derivative photoinitiator for free radical polymerization.  

PubMed

Acetic acid-based thioxanthone (TXCH2 COOH) was synthesized and characterized and used as a photoinitiator for free radical photopolymerization of methyl methacrylate (MMA) in the absence and presence of a tertiary amine (MDEA) in different solvents. Different absorption properties were observed depending on the solvent. Fluorescence and phosphorescence experiments were also carried out successfully. The fluorescence quantum yield was found to be 0.09 and the phosphorescence lifetime was calculated as 138 ms at 77 K. The photoinitiator undergoes efficient intersystem crossing into the triplet state and the lowest triplet state possesses ?-?* configuration. Laser flash photolysis experiments show that transient absorption of TXCH2 COOH is similar to the parent thioxanthone and the triplet lifetime was calculated as 2.3 ?s at 630 nm. PMID:24372104

Esen, Duygu S; Temel, Gokhan; Balta, Demet K; Allonas, Xavier; Arsu, Nergis

2014-01-01

270

Characterization of three endophytic, indole-3-acetic acid-producing yeasts occurring in Populus trees.  

PubMed

Three endophytic yeast, one isolated from stems of wild cottonwood (Populus trichocarpa), two from stems of hybrid poplar (P. trichocarpaxPopulus deltoides), were characterized by analyzing three ribosomal genes, the small subunit (18S), internal transcribed spacer (ITS), and D1/D2 region of the large subunit (26S). Phenotypic characteristics of the yeast isolates were also obtained using a commercial yeast identification kit and used for assisting the species identification. The isolate from wild cottonwood was identified to be closest to species Rhodotorula graminis. The two isolates from hybrid poplar were identified to be species Rhodotorula mucilaginosa. In addition, the three yeast isolates were observed to be able to produce indole-3-acetic acid (IAA), a phytohormone which can promote plant growth, when incubated with l-tryptophan. To our knowledge, the yeast strains presented in this study were the first endophytic yeast strains isolated from species of Populus. PMID:19539760

Xin, Gang; Glawe, Dean; Doty, Sharon L

2009-09-01

271

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

272

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

2011-07-11

273

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

PubMed Central

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

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

2014-01-01

274

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

275

Acetic acid bacteria genomes reveal functional traits for adaptation to life in insect guts.  

PubMed

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

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

2014-04-01

276

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

PubMed Central

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

Ebaugh, David

2010-01-01

277

Pickled egg production: effect of brine acetic acid concentration and packing conditions on acidification rate.  

PubMed

U.S. federal regulations require that acidified foods must reach a pH of 4.6 or lower within 24 h of packaging or be kept refrigerated until then. Processes and formulations should be designed to satisfy this requirement, unless proper studies demonstrate the safety of other conditions. Our objective was to determine the effect of brine acetic acid concentration and packing conditions on the acidification rate of hard-boiled eggs. Eggs were acidified (60/40 egg-to-brine ratio) at various conditions of brine temperature, heat treatment to filled jars, and postpacking temperature: (i) 25 °C/none/25 °C (cold fill), (ii) 25 °C/none/2 °C (cold fill/refrigerated), (iii) 85 °C/none/25 °C (hot fill), and (iv) 25 °C/100 °C for 16 min/25 °C (water bath). Three brine concentrations were evaluated (7.5, 4.9, and 2.5% acetic acid) and egg pH values (whole, yolk, four points within egg) were measured from 4 to 144 h, with eggs equilibrating at pH 3.8, 4.0, and 4.3, respectively. Experiments were conducted in triplicate, and effects were considered significant when P < 0.05. Multiple linear regression analysis was conducted to evaluate the effect on pH values at the center of the yolk. Regression analysis showed that brine concentration of 2.5% decreased the acidification rate, while packing conditions of the hot fill trial increased it. Inverse prediction was used to determine the time for the center of the yolk and the total yolk to reach a pH value of 4.6. These results demonstrate the importance of conducting acidification studies with proper pH measurements to determine safe conditions to manufacture commercially stable pickled eggs. PMID:24780334

Acosta, Oscar; Gao, Xiaofan; Sullivan, Elizabeth K; Padilla-Zakour, Olga I

2014-05-01

278

The use of SEP-PAK C18 Cartridges in the Preparation of Bile Acid Methyl Ester Acetates  

Microsoft Academic Search

A method is described for the rapid and Quantitative extraction of bile acid derivates by Sep-Pak C18 cartridge. The method is used for the preparation of bile acid methyl ester acetates. The method was validated by determining the efficiency and the recovery of radiolabelled taurine-conjugated and free bile acids and of bile acid containing biological samples, by thin-layer chromatography with

Yvo Ghoos; Paul Rutgeerts; Gaston Vantrappen

1982-01-01

279

Effects of intramuscular injection of alpha-tocopheryl acetate on fatty acid profile in lamb liver.  

PubMed

The effects of intramuscularly administrated vitamin E on total lipids, fatty acid profile, and lipid stability to oxidation was investigated in lamb liver. Twenty-four 5-day-old lambs were allotted to 4 groups of 6 each and given respectively 0 (control), 125, 200, 300 mg dl-alpha-tocopheryl acetate weekly from day 5 to 33. alpha-Tocopherol stored in lamb liver at the end of experiment showed linear correlation with the level of injected vitamin E. No effect on total lipids was found. A decrease in the level of liver thiobarbituric-acid reactive substances (TBARS), significantly correlated with liver alpha-tocopherol content, was found in vitamin E groups. The amount of linoleic and linolenic acids significantly increased in the vitamin E groups as compared to control group, and were correlated with the liver alpha-tocopherol content. TBARS were negatively correlated with the concentration of unsaturated fatty acids. Finally, in the liver of the treated groups, vitamin E concentrations in the range 30-50 micrograms/g showed adequate for an efficient protection from peroxidation of membrane lipids, and determined an increase in the unsaturated to saturated fatty acid ratio. PMID:10642895

Oriani, G; Salvatori, G; Maiorano, G; Manchisi, A; Brienza, A; Pantaleo, L; Di Caterina, R; Rotunno, T

1999-11-01

280

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

PubMed

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 fermentation or as a product of the metabolism of acetic and lactic acid bacteria, which can metabolize residual sugars to increase volatile acidity. Acetic acid has a negative impact on yeast fermentative performance and affects the quality of certain types of wine when present above a given concentration. In this mini-review, we present an overview of fermentation conditions and grape-must composition favoring acetic acid formation, as well the metabolic pathways leading to its formation and degradation by yeast. The negative effect of acetic acid on the fermentative performance of Saccharomyces cerevisiae will also be covered, including its role as a physiological inducer of apoptosis. Finally, currently available wine deacidification processes and new proposed solutions based on zymological deacidification by select S. cerevisiae strains will be discussed. PMID:20931186

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

2011-01-01

281

Evaluation of the tolerance of acetic acid and 2-furaldehyde on the growth of Pichia stipitis and its respiratory deficient.  

PubMed

The use of lignocellulosic residues for ethanol production is limited by toxic compounds in fermenting yeasts present in diluted acid hydrolysates like acetic acid and 2-furaldehyde. The respiratory deficient phenotype gives the cell the ability to resist several toxic compounds. So the aim of this work was to evaluate the tolerance to toxic compounds present in lignocellulosic hydrolysates like acetic acid and 2-furaldehyde in Pichia stipitis and its respiratory deficient strains. The respiratory deficient phenotype was induced by exposure to chemical agents such as acriflavine, acrylamide and rhodamine; 23 strains were obtained. The selection criterion was based on increasing specific ethanol yield (g ethanol g(-1) biomass) with acetic acid and furaldehyde tolerance. The screening showed that P. stipitis NRRL Y-7124 ACL 2-1RD (lacking cytochrome c), obtained using acrylamide, presented the highest specific ethanol production rate (1.82 g g(-1 )h(-1)). Meanwhile, the ACF8-3RD strain showed the highest acetic acid tolerance (7.80 g L(-1)) and the RHO2-3RD strain was able to tolerate up to 1.5 g L(-1) 2-furaldehyde with a growth and ethanol production inhibition of 23 and 22 %, respectively. The use of respiratory deficient yeast phenotype is a strategy for ethanol production improvement in a medium with toxic compounds such as hydrolysed sugarcane bagasse amongst others. PMID:24700134

Ortiz-Muñiz, B; Rasgado-Mellado, J; Solis-Pacheco, J; Nolasco-Hipólito, C; Domínguez-González, J M; Aguilar-Uscanga, M G

2014-10-01

282

Bombella intestini gen. nov., sp. nov., an acetic acid bacterium isolated from bumble bee crop.  

PubMed

In the frame of a bumble bee gut microbiota study, acetic acid bacteria (AAB) were isolated using a combination of direct isolation methods and enrichment procedures. MALDI-TOF MS profiling of the isolates and a comparison of these profiles with profiles of established AAB species identified most isolates as Asaia astilbis or as 'Commensalibacter intestini', except for two isolates (R-52486 and LMG 28161(T)) that showed an identical profile. A nearly complete 16S rRNA gene sequence of strain LMG 28161(T) was determined and showed the highest pairwise similarity to Saccharibacter floricola S-877(T) (96.5%), which corresponded with genus level divergence in the family Acetobacteraceae. Isolate LMG 28161(T) was subjected to whole-genome shotgun sequencing; a 16S-23S rRNA internal transcribed spacer (ITS) sequence as well as partial sequences of the housekeeping genes dnaK, groEL and rpoB were extracted for phylogenetic analyses. The obtained data confirmed that this isolate is best classified into a new genus in the family Acetobacteraceae. The DNA G+C content of strain LMG 28161(T) was 54.9 mol%. The fatty acid compositions of isolates R-52486 and LMG 28161(T) were similar to those of established AAB species [with C18:1?7c (43.1%) as the major component], but the amounts of fatty acids such as C19:0 cyclo ?8c, C14:0 and C14:0 2-OH enabled to differentiate them. The major ubiquinone was Q-10. Both isolates could also be differentiated from the known genera of AAB by means of biochemical characteristics, such as their inability to oxidize ethanol to acetic acid, negligible acid production from melibiose, and notable acid production from d-fructose, sucrose and d-mannitol. In addition, they produced 2-keto-d-gluconate, but not 5-keto-d-gluconate from d-glucose. Therefore, the name Bombella intestini gen nov., sp. nov. is proposed for this new taxon, with LMG 28161(T) (?=DSM 28636(T)?=R-52487(T)) as the type strain of the type species. PMID:25336723

Li, Leilei; Praet, Jessy; Borremans, Wim; Nunes, Olga C; Manaia, Célia M; Cleenwerck, Ilse; Meeus, Ivan; Smagghe, Guy; De Vuyst, Luc; Vandamme, Peter

2015-01-01

283

A Radial Concentration Gradient of Indole3Acetic Acid 1s Related to Secondary Xylem Development in Hybrid Aspen  

Microsoft Academic Search

lhe radial distribution pattern of indole-3-acetic acid (IAA) was determined across the developing tissues of the cambial region in the stem of hybrid aspen (Populus tremula L. x Populus tremuloides Michx). IAA content was measured in consecutive tangential cryo- sections using a microscale mas spectrometry technique. Analysis was performed with wild-type and transgenic trees with an ectopic expression of Agrobacterium

Hannele Tuominen; Laurence Puech; Siegfried Fink; Bjorn Sundberg

284

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...

285

Accelerating Effect of Umbelliferone on Peroxidase-Catalyzed Oxidation of Indole-3-acetic Acid at Neutral pH  

E-print Network

Accelerating Effect of Umbelliferone on Peroxidase-Catalyzed Oxidation of Indole-3-acetic Acid The acceleration by the phenol umbelliferone (7-hydroxycoumarin) of the horseradish peroxidase (HRP) catalyzed no further effect. The rate constants for the peroxidase compounds I and II (HRP-I and HRP-II) reductions

Krylov, Sergey

286

Resolving the electrospinnability zones and diameter prediction for the electrospinning of the gelatin/water/acetic acid system.  

PubMed

The development of suitable biomimetic scaffolds is a fundamental requirement of tissue engineering. Although electrospinning has emerged as an effective method for producing such scaffolds of nanometer-sized fibers, the influence of solution characteristics on the morphology of the resulting nanofibers depends on each polymer solution system. In this study, gelatin nanofibers and microfibers were prepared via electrospinning using mixtures of water and acetic acid at different ratios as solvents. The viscosities of gelatin solutions before electrospinning were analyzed and two different behaviors were found as a function of the solvent composition, taking into account classic models of polymer science. A power law relationship between viscosity and gelatin concentration was found for each solvent system, and an empirical model including the influence of acetic acid was obtained for aqueous systems. Moreover, a ternary diagram considering gelatin, water, and acetic acid mass fractions was constructed as a tool to establish the electrospinnability domains in terms of fiber occurrence and morphology. Also, the isodiametric curves were defined in the fibers region. Finally, in order to correlate the diameter of electrospun nanofibers and the electrospinnability zones, the Berry number was used. However, as its only allows the range of electrospinnability to be established for a fixed solvent composition, a new dimensionless parameter (Bemod) was suggested to take into account all the acetic acid aqueous solutions as a single solvent. PMID:24870557

Erencia, Marisa; Cano, Francisco; Tornero, Jose A; Macanás, Jorge; Carrillo, Fernando

2014-06-24

287

Mechanistic aspects of benzylic bromide formation and oxidation during the cobalt acetate bromide catalyzed oxidation of alkylbenzenes in carboxylic acids  

Microsoft Academic Search

The formation and fate of benzylic bromides during the cobalt acetate bromide catalyzed oxidation of toluene and 4-chlorotoluene were investigated in carboxylic acid solvents. The rate of formation of benzylic bromides depends on the substrate and catalyst concentrations while the conversion of ionic bromide to benzylic bromides is strongly influenced by the type of solvent and the presence of nucleophilic

Gary M. Dugmore; Gregory J. Powels; Ben Zeelie

1995-01-01

288

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...

289

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

290

INFLUENCE OF DILUTE ACETIC ACID TREATMENTS ON SURVIVAL OF AMERICAN PONDWEED WINTER BUDS IN THE NEVADA IRRIGATION DISTRICT, CALIFORNIA  

Technology Transfer Automated Retrieval System (TEKTRAN)

American pondweed (Potamogeton nodosus Poir.) is commonly found in northern California irrigation canals. The purpose of this study was to test the hypothesis that exposure of American pondweed winter buds to dilute acetic acid under field conditions would result in reduced survivorship and subsequ...

291

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

EPA Science Inventory

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

292

Acetic Acid Sclerotherapy for Treatment of a Bile Leak from an Isolated Bile Duct After Laparoscopic Cholecystectomy  

SciTech Connect

Bile leak after laparoscopic cholecystectomy is not uncommon, and it mainly occurs from the cystic duct stump and can be easily treated by endoscopic techniques. However, treatment for leakage from an isolated bile duct can be troublesome. We report a successful case of acetic acid sclerotherapy for bile leak from an isolated bile duct after laparoscopic cholecystectomy.

Choi, Gibok, E-mail: choigibok@yahoo.co.kr; Eun, Choong Ki, E-mail: ilovegod@chollian.net [Inje University, Department of Radiology, Haeundae Paik Hospital, College of Medicine (Korea, Republic of); Choi, HyunWook, E-mail: gdkid92@daum.net [Maryknoll Medical Center, Department of Radiology (Korea, Republic of)

2011-02-15

293

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...

294

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

Microsoft Academic Search

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

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

2008-01-01

295

Sequential injection redox or acid–base titration for determination of ascorbic acid or acetic acid  

Microsoft Academic Search

Two sequential injection titration systems with spectrophotometric detection have been developed. The first system for determination of ascorbic acid was based on redox reaction between ascorbic acid and permanganate in an acidic medium and lead to a decrease in color intensity of permanganate, monitored at 525 nm. A linear dependence of peak area obtained with ascorbic acid concentration up to

Narong Lenghor; Jaroon Jakmunee; Michael Vilen; Rolf Sara; Gary D Christian; Kate Grudpan

2002-01-01

296

Detailed Model of the Peroxidase-Catalyzed Oxidation of Indole-3-Acetic Acid at Neutral Sergey N. Krylov* and H. Brian Dunford*  

E-print Network

Detailed Model of the Peroxidase-Catalyzed Oxidation of Indole-3-Acetic Acid at Neutral pH Sergey N of peroxidase-catalyzed oxidation of indole-3-acetic acid (IAA) at neutral pH has been developed, characterized in the presence of HRP by two pathways: (i) the standard peroxidase cycle, which is accompanied by (ii

Krylov, Sergey

297

Analysis of picogram quantities of indole-3-acetic acid by gas chromatography with fused silica column and flameless nitrogen selective detector  

Microsoft Academic Search

Use of a gas chromatograph equipped with a fused silica capillary column and a nitrogen-phosphorus detector permits selective detection of indole-3-acetic acid and other indoles at the low picogram level. The applicability of the method is demonstrated by the analysis of endogenous indole-3-acetic acid from shoots of Salix pentandra L.

Einar Jensen; Arild Ernstsen; Göran Sandberg

1986-01-01

298

Gluconacetobacter medellinensis sp. nov., cellulose- and non-cellulose-producing acetic acid bacteria isolated from vinegar.  

PubMed

The phylogenetic position of a cellulose-producing acetic acid bacterium, strain ID13488, isolated from commercially available Colombian homemade fruit vinegar, was investigated. Analyses using nearly complete 16S rRNA gene sequences, nearly complete 16S-23S rRNA gene internal transcribed spacer (ITS) sequences, as well as concatenated partial sequences of the housekeeping genes dnaK, groEL and rpoB, allocated the micro-organism to the genus Gluconacetobacter, and more precisely to the Gluconacetobacter xylinus group. Moreover, the data suggested that the micro-organism belongs to a novel species in this genus, together with LMG 1693(T), a non-cellulose-producing strain isolated from vinegar by Kondo and previously classified as a strain of Gluconacetobacter xylinus. DNA-DNA hybridizations confirmed this finding, revealing a DNA-DNA relatedness value of 81?% between strains ID13488 and LMG 1693(T), and values <70?% between strain LMG 1693(T) and the type strains of the closest phylogenetic neighbours. Additionally, the classification of strains ID13488 and LMG 1693(T) into a single novel species was supported by amplified fragment length polymorphism (AFLP) and (GTG)5-PCR DNA fingerprinting data, as well as by phenotypic data. Strains ID13488 and LMG 1693(T) could be differentiated from closely related species of the genus Gluconacetobacter by their ability to produce 2- and 5-keto-d-gluconic acid from d-glucose, their ability to produce acid from sucrose, but not from 1-propanol, and their ability to grow on 3?% ethanol in the absence of acetic acid and on ethanol, d-ribose, d-xylose, sucrose, sorbitol, d-mannitol and d-gluconate as carbon sources. The DNA G+C content of strains ID13488 and LMG 1693(T) was 58.0 and 60.7 mol%, respectively. The major ubiquinone of LMG 1693(T) was Q-10. Taken together these data indicate that strains ID13488 and LMG 1693(T) represent a novel species of the genus Gluconacetobacter for which the name Gluconacetobacter medellinensis sp. nov. is proposed. The type strain is LMG 1693(T) (?=?NBRC 3288(T)?=?Kondo 51(T)). PMID:22729025

Castro, Cristina; Cleenwerck, Ilse; Trcek, Janja; Zuluaga, Robin; De Vos, Paul; Caro, Gloria; Aguirre, Ricardo; Putaux, Jean-Luc; Gañán, Piedad

2013-03-01

299

Identification of indole-3-acetic acid producing freshwater wetland rhizosphere bacteria associated with Juncus effusus L.  

PubMed

Production of indole-3-acetic acid (IAA), a key physiological feature of culturable, O2-tolerant bacteria associated with the freshwater macrophyte Juncus effusus L., was examined over a period of 2 years. Up to 74% of rhizobacteria identified and tested produced IAA. The number of indoleacetic acid producers decreased in winter. IAA was produced even when L-tryptophan, a precursor of IAA, was not added to the medium. Most of the IAA-producing strains were dominated by strains that were not identifiable to species level on the basis of API testing. Based on 16S rRNA gene sequencing and fatty acid analysis, it was found that IAA-producing rhizosphere bacteria associated with the freshwater wetland plant Juncus effusus L. are representatives of several families, including the Enterobacteriaceae, Pseudomonadaceae, Aeromonadaceae, Burkholderiaceae, and Bacillaceae. This study identifies numerous potentially important bacterial physiological groups of freshwater wetlands. Additionally, the study provides a baseline for monitoring and assessing the mutualistic relationships of wetland plants with rhizosphere bacteria in freshwater wetlands. PMID:15162203

Halda-Alija, Lidija

2003-12-01

300

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

2012-09-01

301

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

302

Effects of acetic acid, ethanol, and SO(2) on the removal of volatile acidity from acidic wines by two Saccharomyces cerevisiae commercial strains.  

PubMed

Herein, we report the influence of different combinations of initial concentration of acetic acid and ethanol on the removal of acetic acid from acidic wines by two commercial Saccharomyces cerevisiae strains S26 and S29. Both strains reduced the volatile acidity of an acidic wine (1.0 gl(-1) acetic acid and 11% (v/v) ethanol) by 78% and 48%, respectively. Acetic acid removal by strains S26 and S29 was associated with a decrease in ethanol concentration of 0.7 and 1.2% (v/v), respectively. Strain S26 revealed better removal efficiency due to its higher tolerance to stress factors imposed by acidic wines. Sulfur dioxide (SO(2)) in the concentration range 95-170 mg l(-1)inhibits the ability of both strains to reduce the volatile acidity of the acidic wine used under our experimental conditions. Therefore, deacidification should be carried out either in wines stabilized by filtration or in wines with SO(2)concentrations up to 70 mg l(-1). Deacidification of wines with the better performing strain S26 was associated with changes in the concentration of volatile compounds. The most pronounced increase was observed for isoamyl acetate (banana) and ethyl hexanoate (apple, pineapple), with an 18- and 25-fold increment, respectively, to values above the detection threshold. The acetaldehyde concentration of the deacidified wine was 2.3 times higher, and may have a detrimental effect on the wine aroma. Moreover, deacidification led to increased fatty acids concentration, but still within the range of values described for spontaneous fermentations, and with apparently no negative impact on the organoleptical properties. PMID:20390413

Vilela-Moura, Alice; Schuller, Dorit; Mendes-Faia, Arlete; Côrte-Real, Manuela

2010-07-01

303

Ulipristal acetate for emergency contraception.  

PubMed

Ulipristal acetate is a progesterone receptor modulator. As an emergency contraceptive, a 30-mg micronized formulation is effective for use up to 120 h from unprotected sexual intercourse. Ulipristal acetate acts as an antagonist of the progesterone receptor at the transcriptional level and a competitive antagonist of glucocorticoid receptor function. In contrast to other contraceptives, it has little effect on sex hormone-binding globulin. Although a single small study demonstrated some potential endometrial effects after ulipristal acetate administration, the clinical relevance of these findings is unclear. The incidence of adverse events in clinical trials for emergency contraception has typically been minimal, with one study showing a higher than expected incidence of nausea upon ulipristal acetate use. Ulipristal acetate, like other emergency contraceptive products, can lengthen the time to the next expected menstruation. Ulipristal acetate may have several advantages over currently approved emergency contraceptives. When compared to levonorgestrel, ulipristal acetate maintains its efficacy for a full 120 h, whereas levonorgestrel formulations have declining efficacy over that time frame. Moreover, although the copper intrauterine device (IUD) is highly effective as an emergency contraceptive, accessibility is an issue since the IUD requires a skilled provider for insertion. PMID:20967297

Russo, J A; Creinin, M D

2010-09-01

304

Efficacy of washing meat surfaces with 2% levulinic, acetic, or lactic acid for pathogen decontamination and residual growth inhibition.  

PubMed

We compared spray washing at 55.4 °C with 2% levulinic acid to that with lactic or acetic acid for decontamination of pathogenic bacteria inoculated onto meat surfaces, and their residual protection against later growth of pathogenic bacteria. The model systems included Escherichia coli O157:H7 on beef plate, Salmonella on chicken skin and pork belly, and Listeria monocytogenes on turkey roll. In the decontamination studies, acid washes lowered recoverable numbers of pathogens by 0.6 to 1 log/cm(2) as compared to no-wash controls, and only lactic acid lowered the number of pathogens recovered as compared to the water wash. Washing with levulinic acid at 68.3 or 76.7 °C did not result in additional decontamination of E. coli. Acetic acid prevented residual growth of E. coli and L. monocytogenes, and it reduced numbers of Salmonella on chicken skin to below recoverable levels. Overall, levulinic acid did not provide as effective decontamination as lactic acid nor residual protection as acetic acid. PMID:21251765

Carpenter, C E; Smith, J V; Broadbent, J R

2011-06-01

305

Cartilage and bone malformations in the head of zebrafish (Danio rerio) embryos following exposure to disulfiram and acetic acid hydrazide  

SciTech Connect

In order to investigate teratogenic effects, especially on cartilage and bone formation, zebrafish embryos were exposed for 144 h to the dithiocarbamate pesticide disulfiram (20–320 ?g/L) and acetic acid hydrazide (0.375–12 g/L), a degradation product of isoniazid. After fixation and full-mount staining, disulfiram could be shown to induce strong cartilage malformations after exposure to ? 80 ?g/L, whereas acetic acid hydrazide caused cartilage alterations only from 1.5 g/L. Undulating notochords occurred after exposure to disulfiram even at the lowest test concentration of 20 ?g/L, whereas at the two lowest concentrations of acetic acid hydrazide (0.375 and 0.75 g/L) mainly fractures of the notochord were observed. Concentrations of acetic acid hydrazide ? 1.5 g/L resulted in undulated notochords similar to disulfiram. Cartilages and ossifications of the cranium, including the cleithrum, were individually analyzed assessing the severity of malformation and the degree of ossification in a semi-quantitative approach. Cartilages of the neurocranium such as the ethmoid plate proved to be more stable than cartilages of the pharyngeal skeleton such as Meckel's cartilage. Hence, ossification proved significantly more susceptible than cartilage. The alterations induced in the notochord as well as in the cranium might well be of ecological relevance, since notochord malformation is likely to result in impaired swimming and cranial malformation might compromise regular food uptake. - Highlights: ? Disulfiram and acetic acid hydrazide as notochord, cartilage and bone teratogens ? Zebrafish embryos to model effects on single cartilages and bones in the head ? LC50 calculation and head length measurements after six days post-fertilization ? Lethality, head length and teratogenic effects are dose-dependent. ? Cartilages of the neurocranium are the most stable elements in the head.

Strecker, Ruben, E-mail: Ruben.Strecker@cos.uni-heidelberg.de [Aquatic Ecology and Toxicology Section, Center for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 230, D-69120 Heidelberg (Germany); Weigt, Stefan, E-mail: stefan.weigt@merckgroup.com [Institute of Toxicology, Merck KGaA, 64293 Darmstadt (Germany); Braunbeck, Thomas, E-mail: braunbeck@uni-hd.de [Aquatic Ecology and Toxicology Section, Center for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 230, D-69120 Heidelberg (Germany)

2013-04-15

306

Molecular Structure of Sodium acetate  

NSDL National Science Digital Library

Sodium acetate is known for its ability to supercool. It freezes at 130 degrees, but can exist as a liquid at a much lower temperature. In order to melt solidified sodium acetate, however, every single crystal must liquify, otherwise the material will recrystallize. Sodium acetate has been used as a deicer for roads and runways. It is also used a component of buffer systems and in the manufacture of pharmaceuticals and heat pads. The compound is quite stable. It may act as an irritant and be harmful if inhaled or absorbed through the skin.

2002-08-26

307

Ulipristal acetate: contraceptive or contragestive?  

PubMed

Ulipristal acetate is the first selective progesterone receptor modulator approved for postcoital contraception in the US. It appears to be significantly more effective in inhibition of ovulation than other forms of emergency contraception. However, ulipristal acetate is structurally similar to mifepristone, and several lines of evidence suggest that a postfertilization mechanism of action is also operative. This mechanism of action is considered to be contragestive versus contraceptive. Ulipristal acetate administration is contraindicated in a known or suspected pregnancy; however, it could quite possibly be used as an effective abortifacient. Health-care providers should inform patients of the possibility of both mechanisms of action with use of this drug. PMID:21666088

Keenan, Jeffrey A

2011-06-01

308

Lewis acid-catalyzed intramolecular condensation of ynol ether-acetals. Synthesis of alkoxycycloalkene carboxylates  

PubMed Central

Treatment of ynol ether-tethered dialkyl acetals with catalytic quantities of scandium triflate in CH3CN gives rise to five-, six-, and seven-membered alkoxycycloalkene carboxylates in good to excellent yields. Trisubstituted and tetrasubsituted 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

2012-01-01

309

Photochemistry and Photobiology. 1996. 63(5): Optically Pumped Chemiluminescence of Indole-3-Acetic Acid  

E-print Network

Photochemistry and Photobiology. 1996. 63(5): Optically Pumped Chemiluminescence of Indole-3-Acetic January 1996 ABSTRACT the main ~ource of al. (4) have ~hown Optically pumped chemiluminescence of indole-3-sen- sitized photooxidation of luminal is a prospective technique for the creation of a new chemiluminescent

Krylov, Sergey

310

Impact of gluconic fermentation of strawberry using acetic acid bacteria on amino acids and biogenic amines profile.  

PubMed

This paper studies the amino acid profile of beverages obtained through the fermentation of strawberry purée by a surface culture using three strains belonging to different acetic acid bacteria species (one of Gluconobacter japonicus, one of Gluconobacter oxydans and one of Acetobacter malorum). An HPLC-UV method involving diethyl ethoxymethylenemalonate (DEEMM) was adapted and validated. From the entire set of 21 amino acids, multiple linear regressions showed that glutamine, alanine, arginine, tryptophan, GABA and proline were significantly related to the fermentation process. Furthermore, linear discriminant analysis classified 100% of the samples correctly in accordance with the microorganism involved. G. japonicus consumed glucose most quickly and achieved the greatest decrease in amino acid concentration. None of the 8 biogenic amines were detected in the final products, which could serve as a safety guarantee for these strawberry gluconic fermentation beverages, in this regard. PMID:25704705

Ordóñez, J L; Sainz, F; Callejón, R M; Troncoso, A M; Torija, M J; García-Parrilla, M C

2015-07-01

311

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. PMID:5500209

Ockerse, Ralph; Waber, Jack

1970-01-01

312

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. PMID:24098533

Donati, Andrew J.; Lee, Hae-In; Leveau, Johan H. J.; Chang, Woo-Suk

2013-01-01

313

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

PubMed

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

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

2005-01-01

314

The toxicity of substituted phenolic compounds to a detoxifying and an acetic acid bacterium.  

PubMed

In the detoxifying bacterium Acinetobacter calcoaceticus 69-V and in the acetic acid bacterium Acetobacter methanolicus MB 58, glucose and xylose are oxidized, respectively, via PQQ-dependent membrane-bound dehydrogenases, which are linked to the respiratory chain in a manner enabling energy conservation via electron transport phosphorylation (ETP) in the cytoplasmic membrane. Neither the glucose and gluconic acid nor the xylose and xylonic acid are metabolized. Therefore, measurements of sugar oxidation-driven ATP syntheses ought not to be disturbed by ATP drainage caused by anabolic processes. Studying the effect of substituted phenolic compounds on these energization processes reveals that their toxicity increases with an increasing degree of chlorination and that A. calcoaceticus 69-V is more stable than A. methanolicus MB 58 against chlorinated phenols. On the other hand, A. methanolicus MB 58 is more stable against 2,4-dinitrophenol (2,4-DNP) and 2,4-dichlorophenoxyacetic acid (2,4-D), especially in the acidic pH range, in which the sensitivity of ATP synthesis to the uncouplers is higher than that of respiration. The toxicity caused by protonophoric activities ought to be barely detectable by respiratory and dehydrogenase tests. The luminescence system of Photobacterium phosphoreum tested in the luminescent bacteria test was much more sensitive. This test system should be used as a screening tool and the effects measured must be confirmed by toxicity tests evaluating the stability of bacteria themselves involved in processes of detoxification as well as the production of toxic metabolites, monitored with respect to their velocity and efficiency. PMID:9143455

Loffhagen, N; Härtig, C; Babel, W

1997-04-01

315

Nuclear magnetic resonance studies of acetic acid inhibition of rec Zymomonas mobilis ZM4(pZB5).  

PubMed

The fermentation characteristics and effects of lignocellulosic toxic compounds on recombinant Zymomonas mobilis ZM4(pZB5), which is capable of converting both glucose and xylose to ethanol, and its parental strain, ZM4, were characterized using 13C and 31P nuclear magnetic resonance (NMR) in vivo. From the 31P NMR data, the levels of nucleoside triphosphates (NTP) of ZM(pZB5) using xylose were lower than those of glucose. This can be related to the intrinsically slower assimilation and/or metabolism of xylose compared to glucose and is evidence of a less energized state of ZM4(pZB5) cells during xylose fermentation. Acetic acid was shown to be strongly inhibitory to ZM4(pZB5) on xylose medium, with xylose utilization being completely inhibited at pH 5.0 or lower in the presence of 10.9 g/L of sodium acetate. From the 31P NMR results, the addition of sodium acetate caused decreased NTP and sugar phosphates, together with acidification of the cytoplasm. Intracellular deenergization and acidification appear to be the major mechanisms by which acetic acid exerts its toxic effects on this recombinant strain. PMID:10849802

Kim, I S; Barrow, K D; Rogers, P L

2000-01-01

316

Combined effect of acetic acid, pH and ethanol on intracellular pH of fermenting yeast  

Microsoft Academic Search

The internal pH of Saccharomyces cerevisiae IGC 3507 III (a respiratory-deficient mutant) was measured by the distribution of [14C]propionic acid, when the yeast was fermenting glucose at pH 3.5, 4.5 and 5.5 in the presence of several concentrations of acetic acid and ethanol. Good correlation was obtained between fermentation rates and internal pH. For all external pH values tested, the

M. E. Pampulha; M. C. Loureiro-Dias

1989-01-01

317

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

318

Binding of ring-substituted indole-3-acetic acids to human serum albumin.  

PubMed

The plant hormone, indole-3-acetic acid (IAA), and its ring-substituted derivatives have recently attracted attention as promising pro-drugs in cancer therapy. Here we present relative binding constants to human serum albumin for IAA and 34 of its derivatives, as obtained using the immobilized protein bound to a support suitable for high-performance liquid chromatography. We also report their octanol-water partition coefficients (logK(ow)) computed from retention data on a C(18) coated silica gel column. A four-parameter QSPR (quantitative structure-property relationships) model, based on physico-chemical properties, is put forward, which accounts for more than 96% of the variations in the binding affinities of these compounds. The model confirms the importance of lipophilicity as a global parameter governing interaction with serum albumin, but also assigns significant roles to parameters specifically related to the molecular topology of ring-substituted IAAs. Bulky substituents at ring-position 6 increase affinity, those at position 2 obstruct binding, while no steric effects were noted at other ring-positions. Electron-withdrawing substituents at position 5 enhance binding, but have no obvious effect at other ring positions. PMID:17481907

Soski?, Milan; Magnus, Volker

2007-07-01

319

A computational NQR study on the hydrogen-bonded lattice of cytosine-5-acetic acid.  

PubMed

A computational study at the level of density functional theory (DFT) employing 6-311++G** standard basis set was carried out to evaluate nuclear quadrupole resonance (NQR) spectroscopy parameters in cytosine-5-acetic acid (C5AA). Since the electric field gradient (EFG) tensors are very sensitive to the electrostatic environment at the sites of quadruple nuclei, the most possible interacting molecules with the target one were considered in a five-molecule model system of C5AA using X-ray coordinates transforming. The hydrogen atoms positions were optimized and two model systems of original and H-optimized C5AA were considered in NQR calculations. The calculated EFG tensors at the sites of (17)O, (14)N, and (2)H nuclei were converted to their experimentally measurable parameters, quadrupole coupling constants and asymmetry parameters. The evaluated NQR parameters reveal that the nuclei in original and H-optimized systems contribute to different hydrogen bonding (HB) interaction. The comparison of calculated parameters between optimized isolated gas-phase and crystalline monomer also shows the relationship between the structural deformation and NQR parameters in C5AA. The basis set superposition error (BSSE) calculations yielded no significant errors for employed basis set in the evaluation of NQR parameters. All the calculations were performed by Gaussian 98 package of program. PMID:17926341

Mirzaei, Mahmoud; Hadipour, Nasser L

2008-04-15

320

Protein acetylation affects acetate metabolism, motility and acid stress response in Escherichia coli  

PubMed Central

Although protein acetylation is widely observed, it has been associated with few specific regulatory functions making it poorly understood. To interrogate its functionality, we analyzed the acetylome in Escherichia coli knockout mutants of cobB, the only known sirtuin-like deacetylase, and patZ, the best-known protein acetyltransferase. For four growth conditions, more than 2,000 unique acetylated peptides, belonging to 809 proteins, were identified and differentially quantified. Nearly 65% of these proteins are related to metabolism. The global activity of CobB contributes to the deacetylation of a large number of substrates and has a major impact on physiology. Apart from the regulation of acetyl-CoA synthetase, we found that CobB-controlled acetylation of isocitrate lyase contributes to the fine-tuning of the glyoxylate shunt. Acetylation of the transcription factor RcsB prevents DNA binding, activating flagella biosynthesis and motility, and increases acid stress susceptibility. Surprisingly, deletion of patZ increased acetylation in acetate cultures, which suggests that it regulates the levels of acetylating agents. The results presented offer new insights into functional roles of protein acetylation in metabolic fitness and global cell regulation. PMID:25518064

Castaño-Cerezo, Sara; Bernal, Vicente; Post, Harm; Fuhrer, Tobias; Cappadona, Salvatore; Sánchez-Díaz, Nerea C; Sauer, Uwe; Heck, Albert JR; Altelaar, AF Maarten; Cánovas, Manuel

2014-01-01

321

Cellulose production and cellulose synthase gene detection in acetic acid bacteria.  

PubMed

The ability of acetic acid bacteria (AAB) to produce cellulose has gained much industrial interest due to the physical and chemical characteristics of bacterial cellulose. The production of cellulose occurs in the presence of oxygen and in a glucose-containing medium, but it can also occur during vinegar elaboration by the traditional method. The vinegar biofilm produced by AAB on the air-liquid interface is primarily composed of cellulose and maintains the cells in close contact with oxygen. In this study, we screened for the ability of AAB to produce cellulose using different carbon sources in the presence or absence of ethanol. The presence of cellulose in biofilms was confirmed using the fluorochrome Calcofluor by microscopy. Moreover, the process of biofilm formation was monitored under epifluorescence microscopy using the Live/Dead BacLight Kit. A total of 77 AAB strains belonging to 35 species of Acetobacter, Komagataeibacter, Gluconacetobacter, and Gluconobacter were analysed, and 30 strains were able to produce a cellulose biofilm in at least one condition. This cellulose production was correlated with the PCR amplification of the bcsA gene that encodes cellulose synthase. A total of eight degenerated primers were designed, resulting in one primer pair that was able to detect the presence of this gene in 27 AAB strains, 26 of which formed cellulose. PMID:25381910

Valera, Maria José; Torija, Maria Jesús; Mas, Albert; Mateo, Estibaliz

2015-02-01

322

Large-scale gaseous acetic acid treatment to disinfect alfalfa seeds inoculated with Escherichia coli.  

PubMed

Most outbreaks of foodborne illness related to sprout consumption are ascribed to bacterial contamination of its seeds, and they need disinfection before sprouting. Recently, gaseous acetic acid (GAA) treatment received great attention as a method for seed disinfection. In this study, the effect of GAA treatment on alfalfa seed disinfection was evaluated in a large-scale device to simulate practical applications. Alfalfa seeds (3?kg) inoculated with Escherichia coli were treated with 8.7% (vol/vol) GAA at 55°C for 1-3?h. The population of E. coli was significantly reduced (p<0.05), and the reduction was larger with longer exposure times. After 3-h treatment, a maximum decrease by more than 5 log colony-forming units/g was observed. The germination ratio of alfalfa seeds was not affected by the treatments under all the conditions. The results indicated that the GAA treatment has a potential for practical application to reduce the risk of foodborne illness caused by consumption of sprouts. PMID:24400985

Nei, Daisuke; Enomoto, Katsuyoshi; Yamamoto, Kazutaka

2014-04-01

323

Production of the phytohormone indole-3-acetic acid by estuarine species of the genus Vibrio.  

PubMed

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

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

2009-04-01

324

Indole-3-acetic acid production by endophytic Streptomyces sp. En-1 isolated from medicinal plants.  

PubMed

Plant-associated actinobacteria are rich sources of bioactive compounds including indole-derived molecules such as phytohormone indole-3-acetic acid (IAA). In view of few investigations concerning the biosynthesis of IAA by endophytic actinobacteria, this study evaluated the potential of IAA production in endophytic streptomycete isolates sourced from medicinal plant species Taxus chinensis and Artemisia annua. By HPLC analysis of IAA combined with molecular screening approach of iaaM, a genetic determinant of streptomycete IAA synthesis via indole-3-acetamide (IAM), our data showed the putative operation of IAM-mediated IAA biosynthesis in Streptomyces sp. En-1 endophytic to Taxus chinensis. Furthermore, using the co-cultivation system of model plant Arabidopsis thaliana and streptomycete, En-1 was found to be colonized intercellularly in the tissues of Arabidopsis, an alternative host, and the effects of endophytic En-1 inoculation on the model plant were also assayed. The phytostimulatory effects of En-1 inoculation suggest that IAA-producing Streptomyces sp. En-1 of endophytic origin could be a promising candidate for utilization in growth improvement of plants of economic and agricultural value. PMID:23512121

Lin, Lan; Xu, Xudong

2013-08-01

325

Diagnosis of early gastric cancer using narrow band imaging and acetic acid  

PubMed Central

AIM: To determine whether the endoscopic findings of depressed-type early gastric cancers (EGCs) could precisely predict the histological type. METHODS: Ninety depressed-type EGCs in 72 patients were macroscopically and histologically identified. We evaluated the microvascular (MV) and mucosal surface (MS) patterns of depressed-type EGCs using magnifying endoscopy (ME) with narrow-band imaging (NBI) (NBI-ME) and ME enhanced by 1.5% acetic acid, respectively. First, depressed-type EGCs were classified according to MV pattern by NBI-ME. Subsequently, EGCs unclassified by MV pattern were classified according to MS pattern by enhanced ME (EME) images obtained from the same angle. RESULTS: We classified the depressed-type EGCs into the following 2 MV patterns using NBI-ME: a fine-network pattern that indicated differentiated adenocarcinoma (25/25, 100%) and a corkscrew pattern that likely indicated undifferentiated adenocarcinoma (18/23, 78.3%). However, 42 of the 90 (46.7%) lesions could not be classified into MV patterns by NBI-ME. These unclassified lesions were then evaluated for MS patterns using EME, which classified 33 (81.0%) lesions as MS patterns, diagnosed as differentiated adenocarcinoma. As a result, 76 of the 90 (84.4%) lesions were matched with histological diagnoses using a combination of NBI-ME and EME. CONCLUSION: A combination of NBI-ME and EME was useful in predicting the histological type of depressed-type EGC. PMID:25632201

Matsuo, Ken; Takedatsu, Hidetoshi; Mukasa, Michita; Sumie, Hiroaki; Yoshida, Hikaru; Watanabe, Yasutomo; Akiba, Jun; Nakahara, Keita; Tsuruta, Osamu; Torimura, Takuji

2015-01-01

326

A diverse assemblage of indole-3-acetic acid producing bacteria associate with unicellular green algae.  

PubMed

Microalgae have tremendous potential as a renewable feedstock for the production of liquid transportation fuels. In natural waters, the importance of physical associations and biochemical interactions between microalgae and bacteria is generally well appreciated, but the significance of these interactions to algal biofuels production have not been investigated. Here, we provide a preliminary report on the frequency of co-occurrence between indole-3-acetic acid (IAA)-producing bacteria and green algae in natural and engineered ecosystems. Growth experiments with unicellular algae, Chlorella and Scenedesmus, revealed IAA concentration-dependent responses in chlorophyll content and dry weight. Importantly, discrete concentrations of IAA resulted in cell culture synchronization, suggesting that biochemical priming of cellular metabolism could vastly improve the reliability of high density cultivation. Bacterial interactions may have an important influence on algal growth and development; thus, the preservation or engineered construction of the algal-bacterial assembly could serve as a control point for achieving low input, reliable production of algal biofuels. PMID:24879600

Bagwell, Christopher E; Piskorska, Magdalena; Soule, Tanya; Petelos, Angela; Yeager, Chris M

2014-08-01

327

Intraperitoneal administration of butyrate prevents the severity of acetic acid colitis in rats.  

PubMed

Intrarectal infusion of butyrate improves colorectal disorders including ulcerative colitis (UC). However, it is not established whether systemically administered butyrate benefits such patients. The current study aimed at exploring and comparing the potential of intraperitoneally, intrarectally, and orally administered butyrate against acetic acid (AA)-induced UC in rats. Intrarectal administration of 2 ml of 50% AA was done after or without prior treatment of rats for 7 consecutive days with 100 mg/kg sodium butyrate (SB) intraperitoneally, intrarectally, or orally. Rats were sacrificed after 48 h of AA-treatment. Subsequently, colon sections were processed routinely for histopathological examination. We clinically observed diarrhea, loose stools, and hemoccult-positive stools, and histologically, epithelial loss and ulceration, crypt damage, goblet cell depletion, hemorrhage, and mucosal infiltration of inflammatory cells. The changes were significantly reduced by intraperitoneal, intrarectal, or oral butyrate, with intraperitoneal butyrate exhibiting the highest potency. It is concluded that intraperitoneal administration of butyrate abrogates the lesions of AA-induced UC and its potency surpasses that of intrarectal or oral butyrate. PMID:25743124

Malago, Joshua J; Sangu, Catherine L

2015-03-01

328

Branching Mutant rms-2 in Pisum sativum (Grafting Studies and Endogenous Indole-3-Acetic Acid Levels).  

PubMed Central

Isogenic lines of pea (Pisum sativum L.) were used to determine the physiological site of action of the Rms-2 gene, which maintains apical dominance, and its effect on endogenous free indole-3-acetic acid (IAA) levels. In mutant rms-2 scions, which normally produce lateral branches below node 3 and above node 7, apical dominance was almost fully restored by grafting to Rms-2 (wild-type) stocks. In the reciprocal grafts, rms-2 stocks did not promote branching in wild-type shoots. Together, these results suggest that the Rms-2 gene inhibits branching in the shoot of pea by controlling the synthesis of a translocatable (hormone-like) substance that is produced in the roots and/or cotyledons and in the shoot. At all stages, including the stage at which aerial lateral buds commence outgrowth, the level of IAA in rms-2 shoots was elevated (up to 5-fold) in comparison with that in wild-type shoots. The internode length of rms-2 plants was 40% less than in wild-type plants, and the mutant plants allocated significantly more dry weight to the shoot than to the root in comparison with wild-type plants. Grafting to wild-type stocks did not normalize IAA levels or internode length in rms-2 scions, even though it inhibited branching, suggesting that the involvement of Rms-2 in the control of IAA level and internode length may be confined to processes in the shoot. PMID:12232140

Beveridge, C. A.; Ross, J. J.; Murfet, I. C.

1994-01-01

329

VUV absorption spectrum of acetic acid between 6 and 20 eV  

NASA Astrophysics Data System (ADS)

Absorption spectra of acetic acid were measured between 6 and 20 eV at a resolution of 8 meV. Previous measurements had a spectral limit of 11.7 eV. Analysis and band assignment were aided by data from theoretical calculations on valence states and from photoelectron spectroscopy. Valence transitions and nsa' ? 13a', npa' ? 13a' and nda' ? 13a' Rydberg transitions converging to the ground state of CH 3COOH +, as well as transitions converging to the first excited state of the ion are discussed and assigned in the spectral region below 12 eV. Our assignments of valence transitions differ in many aspects from those of previous studies. Most of the Rydberg bands have never previously been assigned. Observation, analysis and possible assignments of absorption features between 12 and 20 eV were carried out for the first time. Rydberg bands converging to the higher ionization limits merge to form broad absorption features. Some absorption features in the 14-17 eV region are assigned to two types of valence ?*(C-H) ? ? transitions.

Leach, Sydney; Schwell, Martin; Un, Sun; Jochims, Hans-Werner; Baumgärtel, Helmut

2006-01-01

330

Intraperitoneal administration of butyrate prevents the severity of acetic acid colitis in rats  

PubMed Central

Intrarectal infusion of butyrate improves colorectal disorders including ulcerative colitis (UC). However, it is not established whether systemically administered butyrate benefits such patients. The current study aimed at exploring and comparing the potential of intraperitoneally, intrarectally, and orally administered butyrate against acetic acid (AA)-induced UC in rats. Intrarectal administration of 2 ml of 50% AA was done after or without prior treatment of rats for 7 consecutive days with 100 mg/kg sodium butyrate (SB) intraperitoneally, intrarectally, or orally. Rats were sacrificed after 48 h of AA-treatment. Subsequently, colon sections were processed routinely for histopathological examination. We clinically observed diarrhea, loose stools, and hemoccult-positive stools, and histologically, epithelial loss and ulceration, crypt damage, goblet cell depletion, hemorrhage, and mucosal infiltration of inflammatory cells. The changes were significantly reduced by intraperitoneal, intrarectal, or oral butyrate, with intraperitoneal butyrate exhibiting the highest potency. It is concluded that intraperitoneal administration of butyrate abrogates the lesions of AA-induced UC and its potency surpasses that of intrarectal or oral butyrate. PMID:25743124

Malago, Joshua J.; Sangu, Catherine L.

2015-01-01

331

Modulation of Endogenous Indole-3-Acetic Acid Biosynthesis in Bacteroids within Medicago sativa Nodules  

PubMed Central

To evaluate the dose-response effects of endogenous indole-3-acetic acid (IAA) on Medicago plant growth and dry weight production, we increased the synthesis of IAA in both free-living and symbiosis-stage rhizobial bacteroids during Rhizobium-legume symbiosis. For this purpose, site-directed mutagenesis was applied to modify an 85-bp promoter sequence, driving the expression of iaaM and tms2 genes for IAA biosynthesis. A positive correlation was found between the higher expression of IAA biosynthetic genes in free-living bacteria and the increased production of IAA under both free-living and symbiotic conditions. Plants nodulated by RD65 and RD66 strains, synthetizing the highest IAA concentration, showed a significant (up to 73%) increase in the shoot fresh weight and upregulation of nitrogenase gene, nifH, compared to plants nodulated by the wild-type strain. When these plants were analyzed by confocal microscopy, using an anti-IAA antibody, the strongest signal was observed in bacteroids of Medicago sativa RD66 (Ms-RD66) plants, even when they were located in the senescent nodule zone. We show here a simple system to modulate endogenous IAA biosynthesis in bacteria nodulating legumes suitable to investigate which is the maximum level of IAA biosynthesis, resulting in the maximal increase of plant growth. PMID:24814784

Bianco, C.; Senatore, B.; Arbucci, S.; Pieraccini, G.

2014-01-01

332

Maize Root Growth and Localized Indol-3yl-Acetic Acid Treatment  

PubMed Central

Resin beads loaded with indol-3yl-acetic acid (IAA) were used as asymmetrical donors along the elongation zone of intact primary Zea mays L. roots. A strong curvature, towards and above the bead, occurred when IAA was applied at a mean distance of 2.20 mm from the tip. No curvature was detected after applications at 3.89 and 5.71 mm from the tip. Correspondence analysis, a new methodological approach in plant hormone studies, permitted the evaluation of the relative influence of several factors on the curvature observed for each root. The parameters considered were the initial growth rate, the exact location of the bead (1.64-2.73 millimeters from tip) and the quantity of IAA absorbed. Roots which grew rapidly bent earlier than slowly growing ones and the more basal the treatment was, the less curvature occurred. Surprisingly, the amount of IAA taken up (between 1.2 and 2.2 times the endogenous IAA content) was found to have no influence on either the time-course or the magnitude of this growth inhibition (curvature). The usefulness of this multivariate analysis is also discussed. PMID:16665595

Meuwly, Philippe; Pilet, Paul-Emile

1987-01-01

333

Synthesis and structural elucidation of novel uranyl-crown ether compounds isolated from nitric, hydrochloric, sulfuric, and acetic acids  

Microsoft Academic Search

The reactions of UOâSOâÃ3HâO with 12-crown-4, 15-crown-5, benzo-15-crown-5, 18-crown-6, and dibenzo-18-crown-6 were investigated in nitric, acetic, hydrochloric, and sulfuric acids. Impurities in the nitric acid resulted in the isolation of the complexes ((HâOâ)((NOâ)â benzo-15-crown-5)â)â((UOâ(NOâ)â)âCâOâ) (benzo-15-crown-5 was nitrated during the reaction) and ((HâO)(18-crown-6))â(UOâ(NOââ)âCâOâ), which were crystallographically characterized. (Mg(OHâ)â)((HâO)(15-crown-5))â((UOâ(SOâ))âCâOâ)â was also isolated from nitric acid and partially characterized crystallographically. Reactions in acetic

Robin D. Rogers; Andrew H. Bond; William G. Hipple; Andrew N. Rollins; Rodger F. Henry

1991-01-01

334

Effects of ethanol and acetic acid on the transport of malic acid and glucose in the yeast Schizosaccharomyces pombe: implications in wine deacidification.  

PubMed

Ethanol and acetic acid, at concentrations which may occur during wine-making, inhibited the transport of L-malic acid in Schizosaccharomyces pombe. The inhibition was non-competitive, the decrease of the maximum initial velocity following exponential kinetics. Glucose transport was not significantly affected either by ethanol (up to 13%, w/v) or by acetic acid (up to 1.5%, w/v). The uptake of labelled acetic acid followed simple diffusion kinetics, indicating that a carrier was not involved in its transport. Therefore, the undissociated acid appears to be the only form that enters the cells and is probably responsible for the toxic effects. Accordingly, deacidification by Ss. pombe during wine fermentation should take place before, rather than after, the main alcoholic fermentation by Saccharomyces cerevisiae. PMID:7705612

Sousa, M J; Mota, M; Leão, C

1995-02-15

335

Inhibitory Effect of Curcumin, Chlorogenic Acid, Caffeic Acid, and Ferulic Acid on Tumor Promotion in Mouse Skin by 12-O-Tetradecanoylphorbol-13-acetate  

Microsoft Academic Search

The effects of topically applied curcumin, chlorogenic acid, caffeic acid, and ferulic acid on 12-O-tetradecanoylphorbol-13-acetate (TPA)- induced epidermal ornithine decarboxylase activity, epidermal DNA syn thesis, and the promotion of skin tumors were evaluated in female CD-I mice. Topical application of 0.5, 1, 3, or 10 iano\\\\ of curcumin inhibited by 31, 46, 84, or 98%, respectively, the induction of epidermal

Mou-Tuan Huang; Robert C. Smart; Ching-Quo Wong; Allan H. Conney

336

Biosynthesis of indole-3-acetic acid in tomato shoots: Measurement, mass-spectral identification and incorporation of ?2 H from ?2 H 2 O into indole-3-acetic acid, d- and l-tryptophan, indole-3-pyruvate and tryptamine  

Microsoft Academic Search

Indole-3-acetic acid (IAA) and its putative precursors, l- and d-tryptophan, indole-3-pyruvate, and tryptamine were isolated from tomato (Lycopersicon esculentum (L.) Mill.) shoots, identified by mass spectrometry, and measured using capillary gas chromatography with an electron capture detector and radioactive internal standards. Average amounts present were 7.9ng · (g FW)--1 IAA, 5.7ng · (g FW)--1 indole-3-pyruvate, 132 ng · (g FW)--1

Terrence P. Cooney; Heather M. Nonhebel

1991-01-01

337

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

SciTech Connect

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

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

2008-09-24

338

Comparison of acetate- and pyruvate-dependent fatty-acid synthesis by spinach chloroplasts  

Microsoft Academic Search

In recent studies using intact chloroplasts of spinach (Spinacia oleracea L.) to investigate the accumulation of acetyl-CoA produced by the activity of either acetyl-CoA synthetase (EC 6.2.1.1) or the pyruvate-dehydrogenase complex, this product was not detectable. These results in combination with new information on the physiological levels of acetate and pyruvate in spinach chloroplasts (H.-J. Treede et al. 1986, Z.

Jutta Springer; Klaus-Peter Heise

1989-01-01

339

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

PubMed

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

Chatveera, B; Lertwattanaruk, P

2014-01-15

340

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

PubMed

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

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

2014-08-28

341

Gluconobacter thailandicus sp. nov., an acetic acid bacterium in the alpha-Proteobacteria.  

PubMed

Four strains of acetic acid bacteria were isolated from flowers collected in Thailand. In phylogenetic trees based on 16S rRNA gene sequences and 16S-23S rDNA internal transcribed spacer (ITS) region sequences, the four isolates were located in the lineage of the genus Gluconobacter and constituted a separate cluster from the known Gluconobacter species, Gluconobacter oxydans, Gluconobacter cerinus, and Gluconobacter frateurii. In addition, the isolates were distinguished from the known species by restriction analysis of 16S-23S rDNA ITS region PCR products using three restriction endonucleases Bsp1286I, MboII, and AvaII. The DNA base composition of the isolates ranged from 55.3-56.3 mol% G+C. The four isolates constituted a taxon separate from G. oxydans, G. cerinus, and G. frateurii on the basis of DNA-DNA similarities. Morphologically, physiologically, and biochemically, the four isolates were very similar to the type strains of G. oxydans, G. cerinus, and G. frateurii; however, the isolates were discriminated in their growth at 37 degrees C from the type strains of G. cerinus and G. frateurii, and in their growth on L-arabitol and meso-ribitol from the type strain of G. oxydans. The isolates showed no acid production from myo-inositol or melibiose, which differed from the type strains of the three known species. The major ubiquinone homologue was Q-10. On the basis of the results obtained, Gluconobacter thailandicus sp. nov. was proposed for the four isolates. The type strain is isolate F149-1(T) (=BCC 14116(T)=NBRC 100600(T)=JCM 12310(T)=TISTR 1533(T)=PCU 225(T)), which had 55.8 mol% G+C, isolated from a flower of the Indian cork tree (Millingtonia hortensis) collected in Bangkok, Thailand. PMID:15486825

Tanasupawat, Somboon; Thawai, Chitti; Yukphan, Pattaraporn; Moonmangmee, Duangtip; Itoh, Takashi; Adachi, Osao; Yamada, Yuzo

2004-06-01

342

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

PubMed Central

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

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

2009-01-01

343

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

PubMed

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

Wu, Wenbiao; Yang, Yixing

2011-01-01

344

Born Oppenheimer Molecular Dynamics calculation of the ?O-H IR spectra for acetic acid cyclic dimers  

NASA Astrophysics Data System (ADS)

Both ab initio molecular dynamics simulations based on the Born-Oppenheimer approach calculations and a quantum theoretical model are used in order to study the IR spectrum of the acetic acid dimer in the gas phase. The theoretical model is taking into account the strong anharmonic coupling, Davydov coupling, multiple Fermi resonances between the first harmonics of some bending modes and the first excited state of the symmetric combination of the two vO-H modes and the quantum direct and indirect relaxation. The IR spectra obtained from DFT-based molecular dynamics is compared with our theoretical lineshape and with experiment. Note that in a previous work we have shown that our approach reproduces satisfactorily the main futures of the IR experimental lineshapes of the acetic acid dimer [Mohamed el Amine Benmalti, Paul Blaise, H. T. Flakus, Olivier Henri-Rousseau, Chem Phys, 320(2006) 267-274.].

El Amine Benmalti, Mohamed; Krallafa, Abdelghani; Gaigeot, Marie-Pierre

2015-01-01

345

Myo-inositol esters of indole-3-acetic acid are endogenous components of Zea mays L. shoot tissue  

NASA Technical Reports Server (NTRS)

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

Chisnell, J. R.

1984-01-01

346

Ab initio Hartree-Fock investigation of 1- H-pyrrolo[3,2- b]pyridine-3-yl acetic acid  

NASA Astrophysics Data System (ADS)

The potential energy surface of 1- H-pyrrolo[3,2- b]pyridine-3-yl acetic acid has been investigated via RIIF/6-31G* calculations. The stationary points and reaction paths for syn orientation of the COOH group were determined and are compared with those of the derivatives of 3-indole acetic acid, which act as plant growth hormones. 1- H-pyrrolo[3,2- b]pyridine-3-yl acetic acid forms a kinetically stable conformer with a strong intramolecular hydrogen bond, in which the COOH group is in anti orientation. The influence of this hydrogen bond on bond lengths and vibration frequencies is described.

Ramek, Michael; Tomi?, Sanja

2001-09-01

347

Flavone8Acetic Acid (Flavonoid) Profoundly Reduces Platelet-Dependent Thrombosis and Vasoconstriction After Deep Arterial Injury In Vivo  

Microsoft Academic Search

Background—Flavone-8-acetic acid (FAA; (Flavonoid)), an adjuvant antitumor drug, inhibits ristocetin-induced aggre- gation of human platelets. The effect of FAA on platelet-dependent thrombosis was studied in vivo in the porcine carotid artery after deep arterial injury by balloon angioplasty. Methods and Results— 111In-labeled autologous platelet and 125I-labeled porcine fibrin(ogen) deposition, and the incidence of macroscopic mural thrombosis onto deeply injured artery

Jozef S. Mruk; Mark W. I. Webster; Magda Heras; Joel M. Reid; Diane E. Grill; James H. Chesebro

348

Action of red light on indole-3-acetic-acid status and growth in coleoptiles of etiolated maize seedlings  

Microsoft Academic Search

Brief irradiation of intact etiolated seedlings of maize (Zea mays L.) with red light (R; 30 µW cm-2, 10 min) reduces the amounts of diffusible and free (solvent-extractable) indole-3-acetic acid (IAA) obtainable from excised coleoptile tips. The effect is transient, the lowest level (30% of the dark control) occurring at about 3 h after irradiation. The free-IAA content of the

Moritoshi Iino

1982-01-01

349

Design, synthesis and SAR studies of GABA uptake inhibitors derived from 2-substituted pyrrolidine-2-yl-acetic acids.  

PubMed

In this paper, we disclose the design and synthesis of a series of 2-substituted pyrrolidine-2-yl-acetic acid as core structures and the N-arylalkyl derivatives thereof as potential GABA transport inhibitors. The 2-position in the side chain of pyrrolidine-2-yl-acetic acid derivatives was substituted with alkyl, hydroxy and amino groups to modulate the activity and selectivity to mGAT1 and mGAT4 proteins. SAR studies of the compounds performed for the four mouse GABA transporter proteins (mGAT1-mGAT4) implied significant potencies and subtype selectivities for 2-hydroxy-2-pyrrolidine-2-yl-acetic acid derivatives. The racemate rac-(u)-13c exhibited the highest potency (pIC50 5.67) at and selectivity for mGAT1 in GABA uptake assays. In fact, the potency of rac-(u)-13c at hGAT-1 (pIC50 6.14) was even higher than its potency at mGAT1. These uptake results for rac-(u)-13c are in line with the binding affinities to the aforesaid proteins mGAT1 (pKi 6.99) and hGAT-1 (pKi 7.18) determined by MS Binding Assay based on NO711 as marker quantified by LC-ESI-MS-MS analysis. Interestingly, the 2-hydroxy-2-pyrrolidine-2-yl-acetic acid rac-(u)-13d containing 2-{[tris(4-methoxyphenyl)]methoxy} ethyl group at the nitrogen atom of the pyrrolidine ring showed high potency at mGAT4 and a comparatively better selectivity for this protein (>15 against mGAT3) than the well known mGAT4 uptake inhibitor (S)-SNAP-5114. PMID:25698617

Steffan, Tobias; Renukappa-Gutke, Thejavathi; Höfner, Georg; Wanner, Klaus T

2015-03-15

350

Antidepressants enhance the antinociceptive effects of carbamazepine in the acetic acid-induced writhing test in mice  

Microsoft Academic Search

Some antidepressants, as well as antiepileptics, are effective for treating pain of varying etiology. The present study was designed to characterize the antinociceptive effects of imipramine, a tricyclic antidepressant, fluvoxamine, a selective serotonin reuptake inhibitor, milnacipran, a serotonin noradrenaline reuptake inhibitor, and carbamazepine, an antiepileptic drug, using the acetic acid-induced writhing test in mice. Imipramine (1.25–10 mg\\/kg, i.p.), fluvoxamine (5–40 mg\\/kg, i.p.)

Mieko Aoki; Minoru Tsuji; Hiroshi Takeda; Yoichiro Harada; Jun Nohara; Teruhiko Matsumiya; Hiroshige Chiba

2006-01-01

351

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

PubMed Central

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

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

2013-01-01

352

EFFECT OF ACETIC ACID ON CO2 CORROSION OF CARBON STEEL IN VAPOR-WATER TWO-PHASE HORIZONTAL FLOW  

Microsoft Academic Search

The effect of acetic acid on the corrosion behavior of X 65 and C 1018 carbon steel in vapor-water two-phase stratified flow (Vsg: 2 m\\/s; Vsl: 0.1 m\\/s) at 2 bars total pressure, 1.54 bars CO2 partial pressure, pH 5.5, and 80°C was studied in a low pressure-high temperature multiphase flow horizontal loop using electrochemical and mass loss techniques. The liquid phase

P. C. Okafor; S. Nesic

2007-01-01

353

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

Microsoft Academic Search

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

Anil Kumar

2005-01-01

354

Clinical aspects of a phase I trial of 5,6-dimethylxanthenone-4-acetic acid (DMXAA), a novel antivascular agent  

Microsoft Academic Search

The antitumour action of 5,6-dimethylxanthenone-4-acetic acid (DMXAA) is mediated through tumour-selective antivascular effects and cytokine induction. This clinical phase I trial was conducted to examine its toxicity, maximum tolerated dose, pharmacokinetics (PK) and pharmacodynamics (PD). A secondary objective was to assess its antitumour efficacy. DMXAA was administered every 3 weeks as a 20-min i.v. infusion. Dose escalation initially followed a

M B Jameson; P I Thompson; B C Baguley; B D Evans; V J Harvey; D J Porter; M R McCrystal; M Small; K Bellenger; L Gumbrell; G W Halbert; P Kestell

2003-01-01

355

Ethylene Formation in Pea Seedlings; Its Relation to the Inhibition of Bud Growth Caused by Indole-3-Acetic Acid 1  

PubMed Central

Indole-3-acetic acid stimulates ethylene production in the nodal region of pea stems, and the gas inhibits bud growth. At all concentrations of IAA there is a close correlation between the intensity and duration of ethylene production and the bud inhibition which results. Kinetin reverses the inhibitory actions of ethylene and IAA on bud growth. It is concluded that auxins suppress bud development by stimulating ethylene formation. The possibility that auxin induced ethylene formation controls apical dominance is considered. PMID:16656884

Burg, Stanley P.; Burg, Ellen A.

1968-01-01

356

Estrogen treatment of acetic acid burns to the vagina, cervix, and perineum: a case report and review of the literature.  

PubMed

In colposcopic evaluation of the cervix, acetic acid of 3 to 5% is commonly used for identification of preneoplastic and neoplastic cells. Acetic acid is a known caustic substance and has the potential to cause irritation and chemical burns when there is sufficient concentration or duration of contact. The authors present a unique case of a woman who inadvertently received undiluted acetic acid during a routine colposcopy, resulting in significant chemical burns of the vagina, cervix, and perineum. Her burns were treated with topical estrogen cream of 1 g twice daily applied directly to the wounds. The burn wounds were fully healed within 8 weeks without complication or additional treatment. At 6 months after the injury, the patient was allowed to engage in sexual activity, and vaginal dilation and pelvic floor therapy were initiated. At 12 months postinjury, her only symptomatic scarring at the left vaginal wall continues to improve. Thus, topical estrogen treatment of 1 g applied twice daily should be continued until burn scar maturation is complete and treatment improvement plateaus in cases of burns to the vagina, cervix, and perineum. This case is further clinical evidence of estrogen's positive effect on wound healing and its potential role in burn treatment. PMID:25144814

Ching, Jessica A; Kuykendall, Lauren V; Troy, Jared S; Smith, David J

2014-01-01

357

Selective liquid chromatographic separation of yttrium from heavier rare earth elements using acetic acid as a novel eluent.  

PubMed

One of the major difficulties in the rare earth elements separation is purification of yttrium from heavy rare earth elements. Thus, an HPLC method using acetic acid as novel eluent was explored for selective separation of yttrium form the heavy rare earth elements. When acetic acid is used as a mobile phase yttrium eluted with the lighter lanthanides. This is contrary to its relative position amongst heavier lanthanides when eluents commonly used for separation of rare earth elements were employed. The shift in elution position of yttrium with acetic acid as eluent may reflect a relatively lower stability constant of the yttrium-AcOH complex (in the same order as for the lighter lanthanides) compared to the corresponding AcOH complexes with heavy lanthanides, enabling selective separation of yttrium from the latter. The method was successfully used for selective separation of yttrium in mixed rare earth sample containing about 80% of yttrium and about 20% of heavy rare earth oxides. Thus, the use of AcOH as eluent is an effective approach for separating and determining the trace amounts of heavy rare earth elements in large amounts of yttrium matrix. Separation was performed on C18 column by running appropriate elution programs. The effluent from the column was monitored with diode array detector at absorbance wavelength of 658nm after post column derivatization with Arsenazo III. PMID:23932372

Kifle, Dejene; Wibetoe, Grethe

2013-09-13

358

Density Functional Investigation of the Adsorption of Isooctane, Ethanol, and Acetic Acid on a Water-Covered Fe(100) Surface  

PubMed Central

The presence of water in biofuels poses the question of how it affects the frictional performance of additives in fuels containing organic substances. To investigate the effect of water on the adsorption of molecules present in fuel and its additives we simulated within the framework of density functional theory the adsorption of ethanol, isooctane (2,2,4-trimethylpentane), and acetic acid on a bare and a water-covered Fe(100) surface. Van der Waals interactions are taken into account in our computations. In those molecules, where dispersion forces contribute significantly to the binding mechanism, the water layer has a stronger screening effect. Additionally, this effect can be enhanced by the presence of polar functional groups in the molecule. Thus, with the introduction of a water layer, the adsorption energy of isooctane and ethanol is reduced but it is increased in the case of the acetic acid. The adsorption configuration of ethanol is changed, while the one of acetic acid is moderately, and for isooctane only very slightly altered. Therefore, the effect of a water layer in the adsorption of organic molecules on an Fe(100) surface strongly depends on the type of bond and consequently, so do the tribological properties. PMID:25243045

2014-01-01

359

Protective effect of comaruman, a pectin of cinquefoil Comarum palustre L., on acetic acid-induced colitis in mice.  

PubMed

The efficacy of comaruman CP, a pectin of marsh cinquefoil Comarum palustre L., was investigated using a model of acetic acid-induced colitis in mice. Mice were administered comaruman CP orally 2 days prior to rectal injection of 5% acetic acid and examined for colonic damage 24 hr later. Colonic inflammation was characterized by macroscopical injury, higher levels of myeloperoxidase activity, enhanced vascular permeability, and diminution of colonic mucus. Oral administration of comaruman CP was found to prevent progression of colitis. Colonic macroscopic scores and the total square of damage were significantly reduced in mice treated with CP compared with the vehicle-treated colitis group. Peroral pretreatment of mice with comaruman CP was shown to decrease tissue myeloperoxidase activity in colons compared with the colitis group. Comaruman CP was found to stimulate production of mucus by colons of normal and colitis mice. Comaruman CP decreased the inflammatory status of normal mice as elicited by reduction of vascular permeability and adhesion of peritoneal neutrophils and macrophages. Thus, a preventive effect of comaruman on acetic acid-induced colitis in mice was detected. Reduction of neutrophil infiltration and enhancement of colon-bound mucus may be implicated in the protective effect of comaruman. PMID:16927150

Popov, Sergey V; Ovodova, Raisa G; Markov, Pavel A; Nikitina, Ida R; Ovodov, Yury S

2006-09-01

360

Exchange of atmospheric formic and acetic acids with trees and crop plants under controlled chamber and purified air conditions  

NASA Astrophysics Data System (ADS)

We investigated the exchange of formic and acetic acids between the atmosphere and various tree species such as beech ( Fagus sylvatica L.), ash ( Fraxinus excelsior L.), spruce ( Picea abies L.) Karst, holm oak ( Quercus ilex L.), and birch ( Betula pendula L.). and some crop-plant species such as corn ( Zea mays, var. Banjo), pea ( Pisum sativum, var. Solara), barley ( Hordeum vulgare, var. Igri) and oat (Avena sativa, var. Wiesel). All experiments were done with dynamic enclosures flushed with purified oxidant-free air, containing only low or controlled amounts of the two acids. Significant and light-triggered emission of both acids from all tree species was observed. For one tree species (ash) a seasonal large increase in fall due to early leaf decomposition was found. The standard emission factors (30°C and PAR=1000 ?mol m 2 s -1) given as (nmol m -2 min -1) for acetic and formic acids, respectively, were 8.1 and 29.7 (ash, autumn), 1.0 and 3.3 (ash, summer), 0.9 and 1.4 (beech), 0.7 and 1.45 (spruce), 1.9 and 2.4 (Holm oak) and 1.7 and 6.7 (birch). Rough estimation of global annual emissions range between 20 and 130 Gmol formic acid and 10 and 33 Gmol acetic acid. These numbers reflect a 15-30% contribution by forest emissions to the continental organic acid budget. As compared to the global total NMHC emissions low molecular weight organic acids are of minor importance. In contrast to the trees, none of the crop-plant species investigated showed an emission, but always a clear deposition of both acids. Both emission from trees as well as uptake by the agricultural plants could be related to transpiration rates and leaf conductances.

Kesselmeier, J.; Bode, K.; Gerlach, C.; Jork, E.-M.

361

Contribution of Indole-3-Acetic Acid Production to the Epiphytic Fitness of Erwinia herbicola  

PubMed Central

Erwinia herbicola 299R produces large quantities of indole-3-acetic acid (IAA) in culture media supplemented with l-tryptophan. To assess the contribution of IAA production to epiphytic fitness, the population dynamics of the wild-type strain and an IAA-deficient mutant of this strain on leaves were studied. Strain 299XYLE, an isogenic IAA-deficient mutant of strain 299R, was constructed by insertional interruption of the indolepyruvate decarboxylase gene of strain 299R with the xylE gene, which encodes a 2,3-catechol dioxygenase from Pseudomonas putida mt-2. The xylE gene provided a useful marker for monitoring populations of the IAA-deficient mutant strain in mixed populations with the parental strain in ecological studies. A root bioassay for IAA, in which strain 299XYLE inhibited significantly less root elongation than strain 299R, provided evidence that E. herbicola produces IAA on plant surfaces in amounts sufficient to affect the physiology of its host and that IAA production in strain 299R is not solely an in vitro phenomenon. The epiphytic fitness of strains 299R and 299XYLE was evaluated in greenhouse and field studies by analysis of changes in the ratio of the population sizes of these two strains after inoculation as mixtures onto plants. Populations of the parental strain increased to approximately twice those of the IAA-deficient mutant strain after coinoculation in a proportion of 1:1 onto bean plants in the greenhouse and onto pear flowers in field studies. In all experiments, the ratio of the population sizes of strain 299R and 299XYLE increased during periods of active growth on plant tissue but not when population sizes were not increasing with time. PMID:9726868

Brandl, M. T.; Lindow, S. E.

1998-01-01

362

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

NASA Astrophysics Data System (ADS)

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 observed for CH3OH and NH3. However, a halocarbon wax coated inlet (normally used on the system) had excellent transmission (comparable to room temperature Teflon) for both CH3OH and NH3, even at temperatures as low as 5°C. Thus the wax is valuable for coating sampling system components that cannot be fashioned from Teflon. The instrument had a delayed response (˜10-40 s) for NH3 only, which was attributed to passivation of the Pyrex multipass cell. To determine sampling artifacts that could arise from the complex sample matrix presented by smoke, the closed-cell FTIR system was intercompared with an open-path FTIR system (which is immune to sampling artifacts) in well-mixed smoke. A similar cell passivation delay for NH3 was the only artifact found in this test. Overall, the results suggest that ˜10 s is sufficient to detect >80% of an NH3/CO ratio sampled by our fast-flow, closed-cell system. Longer sampling times or consecutive samples return better results. In field campaigns the closed-cell system sampling times were normally 10 to >100 s so NH3 was probably underestimated by 5-15%.

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

2003-10-01

363

Global Effect of Indole-3-Acetic Acid Biosynthesis on Multiple Virulence Factors of Erwinia chrysanthemi 3937?  

PubMed Central

Production of the plant hormone indole-3-acetic acid (IAA) is widespread among plant-associated microorganisms. The non-gall-forming phytopathogen Erwinia chrysanthemi 3937 (strain Ech3937) possesses iaaM (ASAP16562) and iaaH (ASAP16563) gene homologues. In this work, the null knockout iaaM mutant strain Ech138 was constructed. The IAA production by Ech138 was reduced in M9 minimal medium supplemented with l-tryptophan. Compared with wild-type Ech3937, Ech138 exhibited reduced ability to produce local maceration, but its multiplication in Saintpaulia ionantha was unaffected. The pectate lyase production of Ech138 was diminished. Compared with wild-type Ech3937, the expression levels of an oligogalacturonate lyase gene, ogl, and three endopectate lyase genes, pelD, pelI, and pelL, were reduced in Ech138 as determined by a green fluorescent protein-based fluorescence-activated cell sorting promoter activity assay. In addition, the transcription of type III secretion system (T3SS) genes, dspE (a putative T3SS effector) and hrpN (T3SS harpin), was found to be diminished in the iaaM mutant Ech138. Compared with Ech3937, reduced expression of hrpL (a T3SS alternative sigma factor) and gacA but increased expression of rsmA in Ech138 was also observed, suggesting that the regulation of T3SS and pectate lyase genes by IAA biosynthesis might be partially due to the posttranscriptional regulation of the Gac-Rsm regulatory pathway. PMID:17189441

Yang, Shihui; Zhang, Qiu; Guo, Jianhua; Charkowski, Amy O.; Glick, Bernard R.; Ibekwe, A. Mark; Cooksey, Donald A.; Yang, Ching-Hong

2007-01-01

364

Global effect of indole-3-acetic acid biosynthesis on multiple virulence factors of Erwinia chrysanthemi 3937.  

PubMed

Production of the plant hormone indole-3-acetic acid (IAA) is widespread among plant-associated microorganisms. The non-gall-forming phytopathogen Erwinia chrysanthemi 3937 (strain Ech3937) possesses iaaM (ASAP16562) and iaaH (ASAP16563) gene homologues. In this work, the null knockout iaaM mutant strain Ech138 was constructed. The IAA production by Ech138 was reduced in M9 minimal medium supplemented with l-tryptophan. Compared with wild-type Ech3937, Ech138 exhibited reduced ability to produce local maceration, but its multiplication in Saintpaulia ionantha was unaffected. The pectate lyase production of Ech138 was diminished. Compared with wild-type Ech3937, the expression levels of an oligogalacturonate lyase gene, ogl, and three endopectate lyase genes, pelD, pelI, and pelL, were reduced in Ech138 as determined by a green fluorescent protein-based fluorescence-activated cell sorting promoter activity assay. In addition, the transcription of type III secretion system (T3SS) genes, dspE (a putative T3SS effector) and hrpN (T3SS harpin), was found to be diminished in the iaaM mutant Ech138. Compared with Ech3937, reduced expression of hrpL (a T3SS alternative sigma factor) and gacA but increased expression of rsmA in Ech138 was also observed, suggesting that the regulation of T3SS and pectate lyase genes by IAA biosynthesis might be partially due to the posttranscriptional regulation of the Gac-Rsm regulatory pathway. PMID:17189441

Yang, Shihui; Zhang, Qiu; Guo, Jianhua; Charkowski, Amy O; Glick, Bernard R; Ibekwe, A Mark; Cooksey, Donald A; Yang, Ching-Hong

2007-02-01

365

Repeat dose study of the novel proapoptotic chemotherapeutic agent alpha-tocopheryloxy acetic acid in mice.  

PubMed

Alpha-tocopheryloxy acetic acid (?-TEA) is an ether derivative of vitamin E and has been shown to suppress tumor growth in various murine and human xenograft tumor models, including melanoma, breast, lung, prostate, and ovarian cancers. The purpose of this study was to assess its safety and pharmacokinetics after repeat dosing in a preclinical murine model. Male and female mice received ?-TEA doses of 100, 300, or 1500 mg/kg/day by daily oral gavage for 28 days. ?-TEA serum levels were determined weekly by high-performance liquid chromatography with mass spectrometric detection. After 28 days of dosing, complete blood counts were taken, blood chemistry was analyzed, and histology was performed. Pharmacokinetic parameters were determined after single dosing. There was no mortality, and we found no clinical signs of toxicity in any of the ?-TEA doses tested. Histopathological evaluation of major organs (heart, lung, kidney, liver, spleen, jejunum, ileum, and cecum) revealed no significant ?-TEA treatment-related lesions. Blood counts revealed low-grade anemia but no other significant differences between treatment and control groups. Blood chemistry revealed moderate liver toxicity that was dose dependent and was absent in the lowest dose group. There were no significant sex-specific differences in the toxicity profile. The half-life of orally administered ?-TEA was determined to be 52 h. This is the first report comprehensively evaluating the toxicity profile of this novel anticancer drug and will facilitate the design of clinical trials to evaluate the safety and antitumor efficacy of ?-TEA in patients with cancer. PMID:22185820

Hahn, Tobias; Akporiaye, Emmanuel T

2012-04-01

366

Conversion of the refractory ammonia and acetic acid in catalytic wet air oxidation of animal byproducts.  

PubMed

Wet air oxidation (WAO) and catalytic wet air oxidation (CWAO) of slaughtered animal byproducts (ABPs) were investigated. Two step experiment was carried out consisting of a non-catalysed WAO run followed by a CWAO run at 170-275 degrees C, 20 MPa, and reaction time 180 min. The WAO (1st step) of sample (5 g/L total organic carbon (TOC)) yielded (82.0 +/- 4)% TOC removal and (78.4 +/- 13.2)% conversion of the initial organic-N into NH4(+)-N. Four metal catalysts (Pd, Pt, Rh, Ru) supported over alumina have been tested in catalytic WAO (2nd step) at elevated pH to enhance ammonia conversion and organic matter removal, particularly acetic acid. It was found that the catalysts Ru, Pt, and Rh had significant effects on the TOC removal (95.1%, 99.5% and 96.7%, respectively) and on the abatement of ammonia (93.4%, 96.7% and 96.3%, respectively) with high nitrogen selectivity. The catalyst Pd was found to have the less activity while Pt had the best performance. The X-Ray diffraction analysis showed that the support of catalyst was not stable under the experimental conditions since it reacted with phosphate present in solution. Nitrite and nitrate ions were monitored during the oxidation reaction and it was concluded that CWAO of ammonia in real waste treatment framework was in good agreement with the results obtained from the literature for ideal solutions of ammonia. PMID:21520823

Fontanier, Virginie; Zalouk, Sofiane; Barbati, Stéphane

2011-01-01

367

Preparation of cellouronic acids and partially acetylated cellouronic acids by TEMPO/NaClO oxidation of water-soluble cellulose acetate.  

PubMed

Water-soluble cellulose acetates with a degree of substitution (DS) of 0.5, prepared by partial deacetylation of cellulose acetate of DS=2.5, were oxidized with catalytic amount of 2,2,6,6,-tetramethyl-1-piperidinyloxy radical (TEMPO), sodium hypochlorite, and sodium bromide to provide useful cellouronic acids. The oxidation was conducted at a constant pH of 10 and at 2 degrees C to avoid the occurrence of side products. Whereas only the primary hydroxyl groups of cellulose acetate were oxidized, a variable degree of oxidation (DO) resulted in a range of 0.33 to 1.0, depending on the concentration in sodium hypochlorite. Thus, polyglucuronic acid as well as partially acetylated cellouronic acid, having a range of DO were obtained. PMID:15003022

Gomez-Bujedo, Silvia; Fleury, Etienne; Vignon, Michel R

2004-01-01

368

The Conjugated Auxin Indole-3-Acetic Acid–Aspartic Acid Promotes Plant Disease Development[C][W  

PubMed Central

Auxin is a pivotal plant hormone that regulates many aspects of plant growth and development. Auxin signaling is also known to promote plant disease caused by plant pathogens. However, the mechanism by which this hormone confers susceptibility to pathogens is not well understood. Here, we present evidence that fungal and bacterial plant pathogens hijack the host auxin metabolism in Arabidopsis thaliana, leading to the accumulation of a conjugated form of the hormone, indole-3-acetic acid (IAA)-Asp, to promote disease development. We also show that IAA-Asp increases pathogen progression in the plant by regulating the transcription of virulence genes. These data highlight a novel mechanism to promote plant susceptibility to pathogens through auxin conjugation. PMID:22374398

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

2012-01-01

369

Spontaneous organic cocoa bean box fermentations in Brazil are characterized by a restricted species diversity of lactic acid bacteria and acetic acid bacteria  

Microsoft Academic Search

Spontaneous organic cocoa bean box fermentations were carried out on two different farms in Brazil. Physical parameters, microbial growth, bacterial species diversity [mainly lactic acid bacteria (LAB) and acetic acid bacteria (AAB)], and metabolite kinetics were monitored, and chocolates were produced from the fermented dry cocoa beans. The main end-products of the catabolism of the pulp substrates (glucose, fructose, and

Zoi Papalexandratou; Gino Vrancken; Katrien De Bruyne; Peter Vandamme; Luc De Vuyst

2011-01-01

370

ANTIFUNGAL AND SPROUT REGULATORY BIOACTIVITIES OF PHENYLACETIC ACID, INDOLE-3-ACETIC ACID, AND TYROSOL ISOLATED FROM THE POTATO DRY ROT SUPPRESSIVE BACTERIUM ENTEROBACTER CLOACAE S11:T:07  

Technology Transfer Automated Retrieval System (TEKTRAN)

Enterobacter cloacae S11:T:07 (NRRL B-21050) is a promising biological control agent which has significantly reduced both fungal dry rot disease and sprouting in lab and pilot potato storages. The metabolites phenylacetic acid (PAA), indole-3-acetic acid (IAA), and tyrosol (TSL) were isolated from ...

371

Pretreatment of Gymnema sylvestre revealed the protection against acetic acid-induced ulcerative colitis in rats  

PubMed Central

Background Overproduction of free radicals and decreased antioxidant capacity are well-known risk factors for inflammatory bowel diseases. Gymnema sylvestre (GS) leaves extract is distinguished for its anti-diabetic, antioxidant and anti-inflammatory properties. Present study is designed to evaluate the preventative activities of GS against acetic acid (AA)-induced ulcerative colitis in Wistar rats. Methods Experimentally ulcerative colitis (UC) was induced by AA in animals pretreated with three different doses of GS leaves extract (50, 100, 200 mg/kg/day) and a single dose of mesalazine (MES, 300 mg/kg/day) for seven days. Twenty four hours later, animals were sacrificed and the colonic tissues were collected. Colonic mucus content was determined using Alcian blue dye binding technique. Levels of thiobarbituric acid reactive substances (TBARS), total glutathione sulfhydryl group (T-GSH) and non-protein sulfhydryl group (NPSH) as well as the activity of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) were estimated in colon tissues. Colonic nucleic acids (DNA and RNA) and total protein (TP) concentrations were also determined. Levels of pro-inflammatory cytokines including interleukin-1 beta (IL-1?), tumor necrosis factor-alpha (TNF-?) and interleukin-6 (IL-6) as well as prostaglandin E2 (PGE2) and nitric oxide (NO) were estimated in colonic tissues. The histopathological changes of the colonic tissues were also observed. Results In AA administered group TBARS levels were increased, while colonic mucus content, T-GSH and NP-SH, SOD and CAT were reduced in colon. Pretreatment with GS inhibited TBARS elevation as well as mucus content, T-GSH and NP-SH reduction. Enzymatic activities of SOD and CAT were brought back to their normal levels in GS pretreated group. A significant reduction in DNA, RNA and TP levels was seen following AA administration and this inhibition was significantly eliminated by GS treatment. GS pretreatment also inhibited AA-induced elevation of pro-inflammatory cytokines, PGE2 and NO levels in colon. The apparent UC protection was further confirmed by the histopathological screening. Conclusion The GS leaves extract showed significant amelioration of experimentally induced colitis, which may be attributed to its anti-inflammatory and antioxidant property. PMID:24507431

2014-01-01

372

Effects of indole-3-acetic acid on Botrytis cinerea isolates obtained from potted plants.  

PubMed

We study the growth of different isolates of Botrytis cinerea collected from potted plants which were affected by Botrytis blight in southern Spain during recent years. These isolates, which show widely phenotypic differences when grown in vitro, are differentially affected by growth temperature, gibberellic acid applications and paclobutrazol, an efficient plant growth retardant and fungicide at the same time. In this work, we have evaluated the effect of the auxin indole-3-acetic acid (IAA) dose (0, 1, 10, and 100 mg/plate) on the growth of the collection of B. cinerea isolates obtained from the following potted plants: Cyclamen persicum, Hydrangea macrophylla, Lantona camara, and Lonicera japonica. B. cinerea produces indolacetic acid, but so far the precise biosynthetic pathway and some effects on this fungal species are still unclear, although recent studies have revealed an antifungal activity of IAA on several fungi, including B. cinerea isolated from harvested fruits. Mycelial growth curves and growth rates assessed from difference in colony areas during the both linear and deceleration phase, conidiation (measured as time of appearance), conidia length (microm), and sclerotia production (number/plate) were evaluated in the isolates, which were grown at 26 degrees C on Petri dishes containing potato dextrose agar for up to 35 days. Mycelial growth curves fitted a typical kinetic equation of fungi grown on solid media. B. cinerea isolates showed a high degree of variability in their growth kinetics, depending on the isolate and auxin dose. This plant growth substance delayed mycelial growth during the linear phase in an isolate-dependent manner, thus isolates from C. persicum, H. macrophylla and L. camara were more affected by IAA than L. japonica. On the other hand, 100 mg of IAA was the critical dose to significantly reduce the growth rate in all isolates and to promote brown-striped hyphae development, especially in isolate from C. persicum. 10 and 100 mg IAA delayed conidiation in isolates from H. macrophylla but scarcely effects were found in the conidia length. The sclerotia production process was blocked at IAA doses of 100 mg in isolates from L. camara and L. japonica, and was reduced in isolate from H. macrophylla. However, dose of 100 mg IAA had no effect on sclerotia production in isolate from C. persicum. It was concluded that the effect of IAA on B. cinerea growth depends on the isolate, thus isolates from H. macrophylla and L. camara were the most affected by IAA. B. cinerea reduced its development under IAA applications, depending on the isolate and dose. These results confirm those recently published on the inhibitory effect of IAA on Botrytris species growth. PMID:22702183

Martínez, J A; Valdés, R; Gómez-Bellot, M J; Bañón, S

2011-01-01

373

The Aerobic Oxidation of Bromide to Dibromine Catalyzed by Homogeneous Oxidation Catalysts and Initiated by Nitrate in Acetic Acid  

SciTech Connect

A small amount of nitrate, ~0.002 molal, initiates the Co/Mn catalyzed aerobic oxidation of bromide compounds (HBr,NaBr,LiBr) to dibromine in acetic acid at room temperature. At temperatures 40oC or less , the reaction is autocatalytic. Co(II) and Mn(II) themselves and mixed with ionic bromide are known homogeneous oxidation catalysts. The reaction was discovered serendipitously when a Co/Br and Co/Mn/Br catalyst solution was prepared for the aerobic oxidation of methyaromatic compounds and the Co acetate contained a small amount of impurity i.e. nitrate. The reaction was characterized by IR, UV-VIS, MALDI and EXAFS spectroscopies and the coordination chemistry is described. The reaction is inhibited by water and its rate changed by pH. The change in these variables, as well as others, are identical to those observed during homogeneous, aerobic oxidation of akylaromatics. A mechanism is proposed. Accidental addition of a small amount of nitrate compound into a Co/Mn/Br/acetic acid mixture in a large, commercial feedtank is potentially dangerous.

Partenheimer, Walt; Fulton, John L.; Sorensen, Christina M.; Pham, Van Thai; Chen, Yongsheng

2014-06-01

374

Recovering/concentrating of hemicellulosic sugars and acetic acid by nanofiltration and reverse osmosis from prehydrolysis liquor of kraft based hardwood dissolving pulp process.  

PubMed

This work investigated the feasibility of recovering and concentrating sugars and acetic acid (HAc) from prehydrolysis liquor (PHL) of the kraft-based dissolving pulp process prior to fermentation of hemicellulosic sugars, by the combination of activated carbon adsorption, nanofiltration (NF) and reverse osmosis (RO) processes. To reduce the fouling PHL was subjected to adsorption on activated carbon, then the treated PHL (TPHL) passed through a nanofiltration (NF DK) membrane to retain the sugars, and the permeate of acetic acid rich solution was passed through a reverse osmosis membrane (RO SG). It was found that for NF process sugars were concentrated from 48 to 227g/L at a volume reduction factor (VRF) of 5 while 80 to 90% of acetic acid was permeated. For the reverse osmosis process, 68% of acetic acid retention was achieved at pH 4.3 and 500 psi pressure and the HAc concentration increased from 10 to 50g/L. PMID:24434701

Ahsan, Laboni; Jahan, M Sarwar; Ni, Yonghao

2014-03-01

375

Acetic Acid Can Catalyze Succinimide Formation from Aspartic Acid Residues by a Concerted Bond Reorganization Mechanism: A Computational Study  

PubMed Central

Succinimide formation from aspartic acid (Asp) residues is a concern in the formulation of protein drugs. Based on density functional theory calculations using Ace-Asp-Nme (Ace = acetyl, Nme = NHMe) as a model compound, we propose the possibility that acetic acid (AA), which is often used in protein drug formulation for mildly acidic buffer solutions, catalyzes the succinimide formation from Asp residues by acting as a proton-transfer mediator. The proposed mechanism comprises two steps: cyclization (intramolecular addition) to form a gem-diol tetrahedral intermediate and dehydration of the intermediate. Both steps are catalyzed by an AA molecule, and the first step was predicted to be rate-determining. The cyclization results from a bond formation between the amide nitrogen on the C-terminal side and the side-chain carboxyl carbon, which is part of an extensive bond reorganization (formation and breaking of single bonds and the interchange of single and double bonds) occurring concertedly in a cyclic structure formed by the amide NH bond, the AA molecule and the side-chain C=O group and involving a double proton transfer. The second step also involves an AA-mediated bond reorganization. Carboxylic acids other than AA are also expected to catalyze the succinimide formation by a similar mechanism. PMID:25588215

Takahashi, Ohgi; Kirikoshi, Ryota; Manabe, Noriyoshi

2015-01-01

376

Concentrating aqueous acetate solutions with tertiary amines  

E-print Network

= I'7o(w/wk) 11 Liquid-liquid equilibrium data for the calcium acetate/water/amuie system with various extractants. (T= TEA, D= DEMA. Initial aqueous-phase calcium acetate concentration= 2%(w/w). ) 27 28 31 34 via FIGURE Page 12 Liquid.... (Calcium acetate/water /amine, TEA:DEMA= I mL:2 mL, initial aqueous calcium acetate= 1% (w/w). ) Equilibrium calcium acetate concentrations in the aqueous phase determined by FTIR and AA measurements. (Calcium acetate/water /amine, TEA:DEMA= I mL;2 m...

Lee, Champion

1993-01-01

377

Process for the preparation of vinyl acetate  

DOEpatents

This invention pertains to the preparation of vinyl acetate by contacting within a contact zone a mixture of ketene and acetaldehyde with an acid catalyst at about one bar pressure and between about 85.degree. and 200.degree. C. and removing the reaction products from the contact zone.

Tustin, Gerald Charles (Kingsport, TN); Zoeller, Joseph Robert (Kingsport, TN); Depew, Leslie Sharon (Kingsport, TN)

1998-01-01

378

Process for the preparation of vinyl acetate  

DOEpatents

This invention pertains to the preparation of vinyl acetate by contacting within a contact zone a mixture of ketene and acetaldehyde with an acid catalyst at about one bar pressure and between about 85 and 200 C and removing the reaction products from the contact zone.

Tustin, G.C.; Zoeller, J.R.; Depew, L.S.

1998-02-17

379

Methane to Acetic Acid over Cu-Exchanged Zeolites: Mechanistic Insights from a Site-Specific Carbonylation Reaction.  

PubMed

The selective low temperature oxidation of methane is an attractive yet challenging pathway to convert abundant natural gas into value added chemicals. Copper-exchanged ZSM-5 and mordenite (MOR) zeolites have received attention due to their ability to oxidize methane into methanol using molecular oxygen. In this work, the conversion of methane into acetic acid is demonstrated using Cu-MOR by coupling oxidation with carbonylation reactions. The carbonylation reaction, known to occur predominantly in the 8-membered ring (8MR) pockets of MOR, is used as a site-specific probe to gain insight into important mechanistic differences existing between Cu-MOR and Cu-ZSM-5 during methane oxidation. For the tandem reaction sequence, Cu-MOR generated drastically higher amounts of acetic acid when compared to Cu-ZSM-5 (22 vs 4 ?mol/g). Preferential titration with sodium showed a direct correlation between the number of acid sites in the 8MR pockets in MOR and acetic acid yield, indicating that methoxy species present in the MOR side pockets undergo carbonylation. Coupled spectroscopic and reactivity measurements were used to identify the genesis of the oxidation sites and to validate the migration of methoxy species from the oxidation site to the carbonylation site. Our results indicate that the Cu(II)-O-Cu(II) sites previously associated with methane oxidation in both Cu-MOR and Cu-ZSM-5 are oxidation active but carbonylation inactive. In turn, combined UV-vis and EPR spectroscopic studies showed that a novel Cu(2+) site is formed at Cu/Al <0.2 in MOR. These sites oxidize methane and promote the migration of the product to a Brønsted acid site in the 8MR to undergo carbonylation. PMID:25562431

Narsimhan, Karthik; Michaelis, Vladimir K; Mathies, Guinevere; Gunther, William R; Griffin, Robert G; Román-Leshkov, Yuriy

2015-02-11

380

Visual Inspection after Acetic Acid (VIA) Is Highly Heterogeneous in Primary Cervical Screening in Amazonian Peru  

PubMed Central

Background Conventional cytology (Pap) and visual inspection after the application of acetic acid (VIA) are currently used in primary screening in Peru. Studies suggest that the quality of VIA is highly variable. Over 36 000 women were screened with Pap and VIA in the TATI (Tamizaje y Tratamiento Inmediato de Lesiones Cervico-uterinas) project conducted in Amazonian Peru. Within a nested study to compare several screening techniques (C-TATI), a total of 5435 women were additionally screened with liquid-based cytology (LBC) and high-risk human papillomavirus testing (HR-HPV). We investigate the variation of positivity rates of VIA, Pap, LBC and HR-HPV in C-TATI and of VIA in the full TATI intervention. Methods At the screening visit, midwives collected three cervical samples for Pap, LBC and HC2 before performing VIA. The dispersion factor “D” (D = Pearson chi-square value/degrees-of-freedom) was used to measure the variability of tests results. Within C-TATI, the variability of positivity rates of VIA, Pap, LBC and HR-HPV was also graphically assessed with box- and scatter plots by midwife and month of screening. Funnel plots and smoothed scatter plots were used to correlate the variation of VIA by the number of examinations performed by each midwife over the full TATI intervention. Results Consistently over TATI, VIA results were highly variable, independently of the examiner, the time when the test was performed and the number of tests the examiner performed (D>6, p-values<0.001). In C-TATI, VIA results varied the most while those of HR-HPV varied the least (Ds>25, p-values<0.001 for VIA, Ds<1.6, p-values>0.05 for HR-HPV). No evidence for correlation between the number of VIAs done per midwife and the variability of VIA results was observed. Conclusion The lack of over-dispersion for HR-HPV detection suggests that the variable VIA results do not reflect true variation in underlying disease, but a lack of consistency in human judgement. PMID:25635965

Almonte, Maribel; Ferreccio, Catterina; Luciani, Silvana; Gonzales, Miguel; Delgado, Jose M.; Santos, Carlos; Alvarez, Manuel; Cuzick, Jack; Sasieni, Peter

2015-01-01

381

Isomers of the acetic Acid-water complex trapped in an argon matrix.  

PubMed

The complexes of acetic acid (AcOH) with water have been studied using FTIR matrix isolation spectroscopy and DFT/B3LYP, DFT/B3LYP-D, and MP2 calculations with the aug-cc-pVTZ basis set. The AcOH/H2O/Ar matrices were prepared in two different ways. In one set of experiments, the vapor above a solid AcOH sample, cooled to 203 K, was diluted with H2O/Ar mixture in the vacuum chamber of the cryostat, and the mixture was solidified on the target. In the second set of experiments, the matrix was prepared by simultaneous deposition of AcOH/Ar and H2O/Ar mixtures at room temperature. The first method of matrix preparation strongly favors the formation of the "acyclic" higher energy AcOH-H2O complex I(B) compared to the second one. Warming of matrices containing the higher energy complex, I(B), from 11 to 39 K, results in the decrease of I(B) concentration and formation of the lowest energy cyclic complex I(A). The calculations indicate that I(B) is formed by an O-H···O hydrogen bond between the carbonyl oxygen and a water O-H group and, additionally, by a weak interaction between one of the methyl group hydrogen atoms and the water oxygen atom. The cyclic complex I(A) has a six-membered ring involving two O-H···O bonds. An activation energy of 0.94, 1.71, and 1.38 kcal mol(-1) was calculated for the I(B) ? I(A) rearrangement at the B3LYP, B3LYP-D, and MP2 levels of theory, respectively. Van't Hoff plots for the association of H2O and AcOH leading to formation of the complexes I(A) and I(B) are presented and discussed. Evidence is also given for the formation of the AcOH-(H2O)2 and (AcOH)2-H2O complexes in the matrices. A potential atmospheric impact of the enhanced formation of the higher energy I(B) complex at low temperatures is discussed. PMID:25424198

Haupa, Karolina; Bil, Andrzej; Barnes, Austin; Mielke, Zofia

2015-03-19

382

Oleanolic acid acetate inhibits atopic dermatitis and allergic contact dermatitis in a murine model  

SciTech Connect

Atopic dermatitis (AD) and allergic contact dermatitis (ACD) are common allergic and inflammatory skin diseases caused by a combination of eczema, scratching, pruritus, and cutaneous sensitization with allergens. This paper examines whether oleanolic acid acetate (OAA) modulates AD and ACD symptoms by using an existing AD model based on the repeated local exposure of mite extract (Dermatophagoides farinae extract, DFE) and 2,4-dinitrochlorobenzene to the ears of BALB/c mice. In addition, the paper uses a 2,4-dinitrofluorobenzene-sensitized local lymph node assay (LLNA) for the ACD model. The oral administration of OAA over a four-week period attenuated AD symptoms in terms of decreased skin lesions, epidermal thickness, the infiltration of immune cells (CD4{sup +} cells, eosinophils, and mast cells), and serum IgE, IgG2a, and histamine levels. The gene expression of Th1, Th2, Th17, and Th22 cytokines was reduced by OAA in the lymph node and ear tissue, and the LLNA verified that OAA suppressed ACD. The oral administration of OAA over a three-day period attenuated ACD symptoms in terms of ear thickness, lymphocyte proliferation, and serum IgG2a levels. The gene expression of Th1, Th2, and Th17 cytokines was reduced by OAA in the thymus and ear tissue. Finally, to define the underlying mechanism, this paper uses a TNF-?/IFN-?-activated human keratinocyte (HaCaT) model. OAA inhibited the expression of cytokines and chemokines through the downregulation of NF-?B and MAPKs in HaCaT cells. Taken together, the results indicate that OAA inhibited AD and ACD symptoms, suggesting that OAA may be effective in treating allergic skin disorders. - Highlights: • OAA reduced both acute and chronic AD symptoms. • OAA had a controlling effect on the immune reaction for ACD. • The effect of OAA on allergic skin disorders was comparable to the cyclosporine A. • OAA might be a candidate for the treatment of allergic skin disorders.

Choi, Jin Kyeong [CMRI, Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of); Oh, Hyun-Mee [Bio-Materials Research Institute, Korea Research Institute of Bioscience and Biotechnology, Jeongeup 580-185 (Korea, Republic of); Lee, Soyoung [CMRI, Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of); Park, Jin-Woo [Department of Periodontology, School of Dentistry, Kyungpook National University, Daegu 700-412 (Korea, Republic of); Khang, Dongwoo [School of Nano and Advanced Materials Science and Engineering, Gyeongsang National University, Jinju 660-701 (Korea, Republic of); Lee, Seung Woong; Lee, Woo Song [Bio-Materials Research Institute, Korea Research Institute of Bioscience and Biotechnology, Jeongeup 580-185 (Korea, Republic of); Rho, Mun-Chual, E-mail: rho-m@kribb.re.kr [Bio-Materials Research Institute, Korea Research Institute of Bioscience and Biotechnology, Jeongeup 580-185 (Korea, Republic of); Kim, Sang-Hyun, E-mail: shkim72@knu.ac.kr [CMRI, Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of)

2013-05-15

383

Protective effects of N-acetylcysteine on acetic acid-induced colitis in a porcine model  

PubMed Central

Background Ulcerative colitis is a chronic inflammatory disease and involves multiple etiological factors. Acetic acid (AA)-induced colitis is a reproducible and simple model, sharing many characteristics with human colitis. N-acetylcysteine (NAC) has been widely used as an antioxidant in vivo and in vitro. NAC can affect several signaling pathways involving in apoptosis, angiogenesis, cell growth and arrest, redox-regulated gene expression, and inflammatory response. Therefore, NAC may not only protect against the direct injurious effects of oxidants, but also beneficially alter inflammatory events in colitis. This study was conducted to investigate whether NAC could alleviate the AA-induced colitis in a porcine model. Methods Weaned piglets were used to investigate the effects of NAC on AA-induced colitis. Severity of colitis was evaluated by colon histomorphology measurements, histopathology scores, tissue myeloperoxidase activity, as well as concentrations of malondialdehyde and pro-inflammatory mediators in the plasma and colon. The protective role of NAC was assessed by measurements of antioxidant status, growth modulator, cell apoptosis, and tight junction proteins. Abundances of caspase-3 and claudin-1 proteins in colonic mucosae were determined by the Western blot method. Epidermal growth factor receptor, amphiregulin, tumor necrosis factor-alpha (TNF-?), and toll-like receptor 4 (TLR4) mRNA levels in colonic mucosae were quantified using the real-time fluorescent quantitative PCR. Results Compared with the control group, AA treatment increased (P?

2013-01-01

384

Magnifying narrow-band imaging with acetic acid to diagnose early colorectal cancer  

PubMed Central

AIM: To evaluate the diagnostic characteristics of magnifying endoscopy with acetic acid spray and narrow-band imaging (MA-NBI) for early colorectal cancer. METHODS: We conducted a prospective study to evaluate the diagnostic characteristics of MA-NBI in differentiating early colorectal adenocarcinomas from adenomas. To compare the results, we used magnifying endoscopy with NBI (M-NBI) and magnifying endoscopy with crystal violet staining (M-CV). The study was performed in 2 phases. In phase 1, 10 colonoscopists at our institution were shown still photographs of 35 colorectal polyps (24 adenocarcinomas and 11 adenomas) in M-NBI, MA-NBI, and M-CV. They made diagnostic predictions using a five-grade scoring evaluation. We plotted receiver operating characteristic curves and compared the areas under the curves (AUCs). In phase 2, colorectal polyps measuring ? 8 mm were prospectively enrolled. During real-time colonoscopy, one of the 7 colonoscopists scored the lesion as an adenocarcinoma or an adenoma and assigned a level of confidence to the prediction (high or low). We calculated the accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for each method and compared the proportions of high-confidence predictions. RESULTS: In phase 1, the mean ± SD AUCs were 0.64 ± 0.031 in M-NBI, 0.71 ± 0.066 in MA-NBI, and 0.76 ± 0.059 in M-CV (P < 0.05 for M-NBI vs MA-NBI, P < 0.001 for M-NBI vs M-CV, and not significant for MA-NBI vs M-CV). In phase 2, 84 patients with 91 lesions (46 adenocarcinomas and 45 adenomas) were enrolled. The diagnostic characteristics were as follows: 73% accuracy, 85% sensitivity, 60% specificity, 68% PPV, and 79% NPV in M-NBI; 73% accuracy, 80% sensitivity, 64% specificity, 70% PPV, and 76% NPV in MA-NBI; and 73% accuracy, 83% sensitivity, 62% specificity, 69% PPV, and 78% NPV in M-CV. The proportions of high-confidence predictions were 57% in M-NBI, 75% in MA-NBI, and 76% in M-CV (P < 0.005 for M-NBI vs MA-NBI, P < 0.0005 for M-NBI vs M-CV, and P = 1.0 for MA-NBI vs M-CV). CONCLUSION: MA-NBI is useful for differentiating early colorectal adenocarcinomas from adenomas. PMID:25473188

Goto, Norihiro; Kusaka, Toshihiro; Tomita, Yumi; Tanaka, Hideyuki; Itokawa, Yoshio; Koshikawa, Yorimitsu; Yamaguchi, Daisuke; Nakai, Yoshitaka; Fujii, Shigehiko; Kokuryu, Hiroyuki

2014-01-01

385

Influence of phenolic acids on indole acetic acid production and on the type III secretion system gene transcription in food-associated Pseudomonas fluorescens KM05.  

PubMed

The purpose of these investigations was to evaluate the reduction capability of phenolic acids (ferulic, chlorogenic, gallic, and p-coumaric acids) on indole acetic acid synthesis by food-associated Pseudomonas fluorescens KM05. Specific genetic primer for the type III secretion system (TTSS) in P. fluorescens KM05 was designed and the influence of phenolic acids on its expression was investigated. In the work the ferulic and chlorogenic acids at the concentration of 0.02 and 0.04 ?g/ml affected on bacterial growth pattern and the signal molecules production. The phenolic acids, that were appreciable effective against P. fluorescens KM05 indole acetic acid production, significantly suppressed TTSS gene. PMID:24994472

Myszka, Kamila; Schmidt, Marcin T; Olejnik-Schmidt, Agnieszka K; Leja, Katarzyna; Czaczyk, Katarzyna

2014-12-01

386

Corrosion of Stainless Steel During Acetate Production  

Microsoft Academic Search

Corrosion of types 304, 304L, 316, and 316L stainless steel (SS) during the esterification of acetic acid and alcohol or glycol ether was investigated. The catalyst for this reaction, sulfuric acid or para-toluene sulfonic acid (PTSA), was shown to cause more corrosion on reactor equipment than CHâCOOH under the process conditions commonly practiced in industry. The corrosive action of the

J. S. Qi; G. C. Lester

1996-01-01

387

Biodiversity of yeasts, lactic acid bacteria and acetic acid bacteria in the fermentation of "Shanxi aged vinegar", a traditional Chinese vinegar.  

PubMed

Shanxi aged vinegar is a famous traditional Chinese vinegar made from several kinds of cereal by spontaneous solid-state fermentation techniques. In order to get a comprehensive understanding of culturable microorganism's diversity present in its fermentation, the indigenous microorganisms including 47 yeast isolates, 28 lactic acid bacteria isolates and 58 acetic acid bacteria isolates were recovered in different fermenting time and characterized based on a combination of phenotypic and genotypic approaches including inter-delta/PCR, PCR-RFLP, ERIC/PCR analysis, as well as 16S rRNA and 26S rRNA partial gene sequencing. In the alcoholic fermentation, the dominant yeast species Saccharomyces (S.) cerevisiae (96%) exhibited low phenotypic and genotypic diversity among the isolates, while Lactobacillus (Lb.) fermentum together with Lb. plantarum, Lb. buchneri, Lb. casei, Pediococcus (P.) acidilactici, P. pentosaceus and Weissella confusa were predominated in the bacterial population at the same stage. Acetobacter (A.) pasteurianus showing great variety both in genotypic and phenotypic tests was the dominant species (76%) in the acetic acid fermentation stage, while the other acetic acid bacteria species including A. senegalensis, A. indonesiensis, A. malorum and A. orientalis, as well as Gluconobacter (G.) oxydans were detected at initial point of alcoholic and acetic acid fermentation stage respectively. PMID:22265314

Wu, Jia Jia; Ma, Ying Kun; Zhang, Fen Fen; Chen, Fu Sheng

2012-05-01

388

Protective Role of Omega-3 Polyunsaturated Fatty Acid against Lead Acetate-Induced Toxicity in Liver and Kidney of Female Rats  

PubMed Central

The present study was conducted to investigate the protective role of Omega-3 polyunsaturated fatty acids against lead acetate-induced toxicity in liver and kidney of female rats. Animals were divided into four equal groups; group 1 served as control while groups 2 and 3 were treated orally with Omega-3 fatty acids at doses of 125 and 260?mg/kg body weight, respectively, for 10 days. These groups were also injected with lead acetate (25?mg/kg body weight) during the last 5 days. Group 4 was treated only with lead acetate for 5 days and served as positive control group. Lead acetate increased oxidative stress through an elevation in MDA associated with depletion in antioxidant enzymes activities in the tissues. Moreover, the elevation of serum enzymes activities (ALT, AST, ALP, and LDH) and the levels of urea and creatinine were estimated but total proteins were decreased. Also, lead acetate-treatment induced hyperlipidemia via increasing of lipid profiles associated with decline in HDL-c level. Significant changes of Hb, PCV, RBCs, PLT, and WBCs in group 4 were recorded. The biochemical alterations of lead acetate were confirmed by histopathological changes and DNA damage. The administration of Omega-3 provided significant protection against lead acetate toxicity. PMID:25045676

Abdou, Heba M.; Hassan, Mohamed A.

2014-01-01

389

trans-dominant mutations in the GPR1 gene cause high sensitivity to acetic acid and ethanol in the yeast Yarrowia lipolytica.  

PubMed

Acetate non-utilizing strains harbouring trans-dominant mutations in the GPR1 gene (GPR1(d)) of the dimorphic yeast Yarrowia lipolytica have been selected and characterized. These mutants are highly sensitive to low concentrations of acetic acid and ethanol, even in presence of glucose. The toxic effect of acetic acid is pH-dependent and has the strongest effect at low pH. In contrast, the action of ethanol is pH-independent. One GPR1(d) mutant has been detected that was highly sensitive to acetic acid but could still grow on ethanol, which indicates putative differences in the function of the GPR1 gene product in the sensitivity to acetic acid and ethanol. The GPR1(d) mutants exhibit a complex pleiotropic phenotype. The mutations cause changed colony morphology as well as dimorphism of cells, and induce early cell death during growth on glucose, even without the presence of dicarbon compounds. Composition of intracellular membranes, as well as morphology of vacuole and mitochondria, were strongly changed. Back-crosses with wild-type strains and analysis of recombinant strains have shown that the expression of the pleiotropic phenotype depends on the site of mutation in the GPR1 gene, as well as on the genetic background of the strain harbouring the responsive mutation. Our data suggest that Gpr1p is involved in a general response of cells to the toxic action of dicarbon compounds like acetic acid and ethanol. PMID:10572261

Tzschoppe, K; Augstein, A; Bauer, R; Kohlwein, S D; Barth, G

1999-11-01

390

Novel surface lipids of diapausing Manduca sexta pupae. Long chain oxoalcohol esters of acetoacetic, hydroxybutyric, and acetic acids.  

PubMed

Ester components in the surface wax from diapausing tobacco hornworm pupae, Manduca sexta L., were separated by thin layer chromatography and gas-liquid chromatography, and characterized by infrared spectroscopy and gas-liquid chromatography-mass spectrometry. Three groups of esters were identified as natural derivatives of acetic acid, acetoacetic acid, and 3-hydroxybutyric acid. The major ester fraction was identified as a mixture of C26 (10%), C27 (5%), and C28 (85%) oxoalcohol esters of acetoacetic acid. The major homolog consisted of equal amounts of 11-oxooctacosanyl 3-oxobutanoate and 12-oxooctacosanyl 3-oxobutanoate. Lesser amounts of 11- and 12-oxooctacosanyl and n-octacosanyl esters of acetic and 3-hydroxybutyric acids were also identified. The chain length distributions of these C26, C27, and C28 oxoalcohol and n-primary alcohol ester moieties, as well as the isomeric ratios for the 11- and 12-oxoalcohol isomers, were similar to the oxoaldehydes and unesterified oxoalcohols previously identified by Buckner et al (Buckner, J. S., Nelson, D. R., Haak, H., and Pomonis, J. G. (1984) J. Biol. Chem. 259, 8452-8470) as lipid components of the surface wax of M. sexta pupae. PMID:6736039

Buckner, J S; Nelson, D R; Fatland, C L; Hakk, H; Pomonis, J G

1984-07-10

391

Corrosion of stainless steel during acetate production  

SciTech Connect

Corrosion of types 304, 304L, 316, and 316L stainless steel (SS) during the esterification of acetic acid and alcohol or glycol ether was investigated. The catalyst for this reaction, sulfuric acid or para-toluene sulfonic acid (PTSA), was shown to cause more corrosion on reactor equipment than CH{sub 3}COOH under the process conditions commonly practiced in industry. The corrosive action of the catalyst occurred only in the presence of water. Thus, for the batch processes, corrosion occurred mostly during the initial stage of esterification, where water produced by the reaction created an aqueous environment. After water was distilled off, the corrosion rate declined to a negligible value. The corrosion inhibitor copper sulfate, often used in industrial acetate processes, was found to work well for a low-temperature process (< 95 C) such as in production of butyl acetate, but it accelerated corrosion in the glycol ether acetate processes where temperatures were > 108 C. Process conditions that imparted low corrosion rates were determined.

Qi, J.S.; Lester, G.C. [Occidental Chemical Corp. Technology Center, Grand Island, NY (United States)

1996-07-01

392

Ozone decomposition in aqueous acetate solutions  

SciTech Connect

The acetate radical ion reacts with ozone with a rate constant of k = (1.5 +/- 0.5) x 10Z dmT mol s . The products from this reaction are CO2, HCHO, and O2 . By subsequent reaction of the peroxy radical with ozone the acetate radical ion is regenerated through the OH radical. A chain decomposition of ozone takes place. It terminates when the acetate radical ion reacts with oxygen forming the unreactive peroxy acetate radical. The chain is rather short as oxygen is developed, as a result of the ozone consumption. The inhibiting effect of acetate on the ozone decay is rationalized by OH scavenging by acetate and successive reaction of the acetate radical ion with oxygen. Some products from the bimolecular disappearance of the peroxy acetate radicals, however, react further with ozone, reducing the effectiveness of the stabilization.

Sehested, K.; Holcman, J.; Bjergbakke, E.; Hart, E.J.

1987-01-01

393

Resistance of Streptococcus bovis to acetic acid at low pH: Relationship between intracellular pH and anion accumulation  

SciTech Connect

Streptococcus bovis JB1, an acid-tolerant ruminal bacterium, was able to grown at pHs from 6.7 to 4.5, and 100 mM acetate had little effect on growth rate or proton motive force across the cell membrane. When S. bovis was grown in glucose-limited chemostats at pH 5.2, the addition of sodium acetate (as much as 100 mM) had little effect on the production of bacterial protein. At higher concentrations of sodium acetate (100 to 360 mM), production of bacterial protein declined, but this decrease could largely be explained by a shift in fermentation products (acetate, formate, and ethanol production to lactate production) and a decline in ATP production (3 ATP per glucose versus 2 ATP per glucose). Y{sub ATP} (grams of cells per mole at ATP) was not decreased significantly even by high concentrations of acetate. Cultures supplemented with 100 mM sodium acetate took up ({sup 14}C)acetate and ({sup 14}C)benzoate in accordance with the Henderson-Hasselbalch equation and gave similar estimates of intracellular pH. As the extracellular pH declined, S. bovis allowed its intracellular pH to decrease and maintained a relatively constant pH gradient across the cell membrane (0.9 unit). The decrease in intracellular pH prevented S. bovis from accumulating large amounts of acetate anion. On the basis of these results it did not appear that acetate was acting as an uncoupler. The sensitivity of other bacteria to volatile fatty acids at low pH is explained most easily by a high transmembrane pH gradient and anion accumulation.

Russell, J.B. (Cornell Univ., Ithaca, NY (USA))

1991-01-01

394

Coaxial electrospinning with acetic acid for preparing ferulic acid/zein composite fibers with improved drug release profiles.  

PubMed

This study investigated drug/zein composite fibers prepared using a modified coaxial electrospinning process. With unspinnable acetic acid as sheath liquid and an electrospinnable co-dissolving solution of zein and ferulic acid (FA) as core fluid, the modified coaxial process could run smoothly and continuously without any clogging. Compared with those from the single-fluid electrospinning process, the FA-loaded zein fibers from the modified process were rounder and possessed higher quality in terms of diameter and distribution, as verified by scanning electron microscopic observations of their surface and cross-section. Differential scanning calorimetry and X-ray diffraction showed that fibers from both processes similarly formed a composite with the FA present in the zein matrix in an amorphous state. The driving force of encapsulation of FA into zein fibers was hydrogen bonding, as evidenced by the attenuated total reflectance Fourier transform infrared spectra. However, in vitro dissolution tests demonstrated that the fibers from the coaxial process exhibited better sustained-release profiles with a smaller initial burst effect and less tailing-off release compared with those from the single process. The modified coaxial electrospinning process is a useful tool for generating nanofibers with higher quality and improved functional performance. PMID:23107952

Yang, Jian-Mao; Zha, Liu-sheng; Yu, Deng-Guang; Liu, Jianyun

2013-02-01

395

Transport of the two natural auxins, indole-3-butyric acid and indole-3-acetic acid, in Arabidopsis  

NASA Technical Reports Server (NTRS)

Polar transport of the natural auxin indole-3-acetic acid (IAA) is important in a number of plant developmental processes. However, few studies have investigated the polar transport of other endogenous auxins, such as indole-3-butyric acid (IBA), in Arabidopsis. This study details the similarities and differences between IBA and IAA transport in several tissues of Arabidopsis. In the inflorescence axis, no significant IBA movement was detected, whereas IAA is transported in a basipetal direction from the meristem tip. In young seedlings, both IBA and IAA were transported only in a basipetal direction in the hypocotyl. In roots, both auxins moved in two distinct polarities and in specific tissues. The kinetics of IBA and IAA transport appear similar, with transport rates of 8 to 10 mm per hour. In addition, IBA transport, like IAA transport, is saturable at high concentrations of auxin, suggesting that IBA transport is protein mediated. Interestingly, IAA efflux inhibitors and mutations in genes encoding putative IAA transport proteins reduce IAA transport but do not alter IBA movement, suggesting that different auxin transport protein complexes are likely to mediate IBA and IAA transport. Finally, the physiological effects of IBA and IAA on hypocotyl elongation under several light conditions were examined and analyzed in the context of the differences in IBA and IAA transport. Together, these results present a detailed picture of IBA transport and provide the basis for a better understanding of the transport of these two endogenous auxins.

Rashotte, Aaron M.; Poupart, Julie; Waddell, Candace S.; Muday, Gloria K.; Brown, C. S. (Principal Investigator)

2003-01-01

396

Studies on the growth and indole-3-acetic acid and abscisic acid content of Zea mays seedlings grown in microgravity  

NASA Technical Reports Server (NTRS)

Measurements were made of the fresh weight, dry weight, dry weight-fresh weight ratio, free and conjugated indole-3-acetic acid, and free and conjugated abscisic acid in seedlings of Zea mays grown in darkness in microgravity and on earth. Imbibition of the dry kernels was 17 h prior to launch. Growth was for 5 d at ambient orbiter temperature and at a chronic accelerational force of the order of 3 x 10(-5) times earth gravity. Weights and hormone content of the microgravity seedlings were, with minor exceptions, not statistically different from seedlings grown in normal gravity. The tissues of the shuttle-grown plants appeared normal and the seedlings differed only in the lack of orientation of roots and shoots. These findings, based upon 5 d of growth in microgravity, cannot be extrapolated to growth in microgravity for weeks, months, and years, as might occur on a space station. Nonetheless, it is encouraging, for prospects of bioregeneration of the atmosphere and food production in a space station, that no pronounced differences in the parameters measured were apparent during the 5 d of plant seedling growth in microgravity.

Schulze, A.; Jensen, P. J.; Desrosiers, M.; Buta, J. G.; Bandurski, R. S.

1992-01-01

397

40 CFR 721.2076 - D-Glucuronic acid, polymer with 6-deoxy-L-mannose and D-glucose, acetate, calcium magnesium...  

Code of Federal Regulations, 2012 CFR

...acetate, calcium magnesium potassium sodium salt. 721.2076 Section 721.2076 Protection...acetate, calcium magnesium potassium sodium salt. (a) Chemical substance and significant...acetate, calcium magnesium potassium sodium salt (PMN P-00-7; CAS...

2012-07-01

398

40 CFR 721.2076 - D-Glucuronic acid, polymer with 6-deoxy-L-mannose and D-glucose, acetate, calcium magnesium...  

Code of Federal Regulations, 2010 CFR

...acetate, calcium magnesium potassium sodium salt. 721.2076 Section 721.2076 Protection...acetate, calcium magnesium potassium sodium salt. (a) Chemical substance and significant...acetate, calcium magnesium potassium sodium salt (PMN P-00-7; CAS...

2010-07-01

399

Acetate absorption and metabolism in the rabbit hindgut.  

PubMed Central

Acetate disappearance from the loops of the hindgut in the rabbit was evaluated by measuring variations in the concentration of acetate in caecocolonic loops and differences in the arterial and venous plasma. In vivo metabolism in gut and liver tissues was studied after introduction of (1-14C) acetate into caecocolonic loops. The rate of disappearance from the loops was quantitatively significant and showed little variation irrespective of the location in the hindgut. Hindgut tissue metabolised acetate and the intensity of the metabolism varied with the segment studied. The distal position of the gut showed by far the highest acetate uptake. Radioactivity was found in a certain number of free amino acids, organic acids, and sugars. Acetate was mainly converted into aspartate and glutamate. These can be considered as 'stock forms' which can be diverted either towards oxidative metabolism or towards protein synthesis. Images Fig. 1 PMID:4007603

Marty, J F; Vernay, M Y; Abravanel, G M

1985-01-01

400

A gaseous acetic acid treatment to disinfect fenugreek seeds and black pepper inoculated with pathogenic and spoilage bacteria.  

PubMed

Contamination of spices by pathogenic and/or spoilage bacteria can be deleterious to consumer's health and cause deterioration of foods, and inactivation of such bacteria is necessary for the food industry. The present study examined the effect of gaseous acetic acid treatment in reducing Escherichia coli O157:H7, Salmonella Enteritidis and Bacillus subtilis populations inoculated on fenugreek seeds and black pepper. Treatment with gaseous acetic acid at 0.3 mmol/L, 0.6 mmol/L and 4.7 mmol/L for 1-3 h significantly reduced the populations of E. coli O157:H7 and Salmonella Enteritidis on black pepper and fenugreek seeds at 55 °C (p < 0.05). The gas treatments at 4.7 mmol/L were more effective in inactivating the pathogens than the treatment at 0.3 mmol/L. An approximately 5.0 log reduction was obtained after 3 h of treatment with 4.7 mmol/L acetic acid. No significant reductions in the population of B. subtilis spores inoculated on fenugreek seeds and black pepper were obtained after the gas treatments at 0.3 mmol/L or 0.6 mmol/L (p > 0.05). However, the gas treatment at 4.7 mmol/L significantly reduced B. subtilis spores (p < 0.05), and 4.0 log CFU/g and 3.5 log CFU/g reductions on fenugreek seeds and black pepper, respectively, were obtained after 3 h of treatment. PMID:25846935

Nei, Daisuke; Enomoto, Katsuyoshi; Nakamura, Nobutaka

2015-08-01

401

Ethanol and Acetic Acid Production from Carbon Monoxide in a Clostridium Strain in Batch and Continuous Gas-Fed Bioreactors  

PubMed Central

The effect of different sources of nitrogen as well as their concentrations on the bioconversion of carbon monoxide to metabolic products such as acetic acid and ethanol by Clostridium autoethanogenum was studied. In a first set of assays, under batch conditions, either NH4Cl, trypticase soy broth or yeast extract (YE) were used as sources of nitrogen. The use of YE was found statistically significant (p < 0.05) on the product spectrum in such batch assays. In another set of experiments, three bioreactors were operated with continuous CO supply, in order to estimate the effect of running conditions on products and biomass formation. The bioreactors were operated under different conditions, i.e., EXP1 (pH = 5.75, YE 1g/L), EXP2 (pH = 4.75, YE 1 g/L) and EXP3 (pH = 5.75, YE 0.2 g/L). When compared to EXP2 and EXP3, it was found that EXP1 yielded the maximum biomass accumulation (302.4 mg/L) and products concentrations, i.e., acetic acid (2147.1 mg/L) and ethanol (352.6 mg/L). This can be attributed to the fact that the higher pH and higher YE concentration used in EXP1 stimulated cell growth and did, consequently, also enhance metabolite production. However, when ethanol is the desired end-product, as a biofuel, the lower pH used in EXP2 was more favourable for solventogenesis and yielded the highest ethanol/acetic acid ratio, reaching a value of 0.54. PMID:25608591

Nalakath Abubackar, Haris; Veiga, María C.; Kennes, Christian

2015-01-01

402

Selective response inversion to NO2 and acetic acid in ZnO and CdS nanocomposite gas sensor  

NASA Astrophysics Data System (ADS)

High sensitivity zinc oxide (ZnO) tetrapods (TPs) have been functionalized by nucleating cadmium sulphide (CdS) nanoparticles (NPs) directly on their surface with a spotted coverage thanks to an optimized synthesis in dimethylformamide (DMF). The obtained hybrid coupled material has been used to realize a gas sensing device with a highly porous nanostructured network, in which the proper alternation of ZnO-TPs and CdS-NPs gives rise to unconventional chemoresistive behaviours. Among the different tested gases and vapours, the sensor showed a unique fingerprint response-inversion between 300 °C and 400 °C only for nitrogen dioxide (NO2) and acetic acid (CH3COOH).

Calestani, D.; Villani, M.; Mosca, R.; Lazzarini, L.; Coppedè, N.; Dhanabalan, S. C.; Zappettini, A.

2014-09-01

403

Crystal growth, structure analysis and characterisation of 2 - (1, 3 - dioxoisoindolin - 2 - yl) acetic acid single crystal  

NASA Astrophysics Data System (ADS)

Single crystal of dielectric material 2 - (1, 3 - dioxoisoindolin - 2 - yl) acetic acid has been grown by slow evaporation solution growth method. The grown crystal was harvested in 25 days. The crystal structure was analyzed by Single crystal X - ray diffraction. UV-vis-NIR analysis was performed to examine the optical property of the grown crystal. The thermal property of the grown crystal was studied by thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The dielectric measurements were carried out and the dielectric constant was calculated and plotted at all frequencies.

Sankari, R. Siva; Perumal, Rajesh Narayana

2014-04-01

404

Fragrance material review on ?-methylbenzyl acetate.  

PubMed

A toxicologic and dermatologic review of ?-methylbenzyl acetate when used as a fragrance ingredient is presented. ?-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 ?-methylbenzyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, skin sensitization, elicitation, and repeated dose 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:22406576

McGinty, D; Letizia, C S; Api, A M

2012-09-01

405

Fragrance material review on piperonyl acetate.  

PubMed

A toxicologic and dermatologic review of piperonyl acetate when used as a fragrance ingredient is presented. Piperonyl 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 piperonyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, skin sensitization, toxicokinetics, and genotoxicity 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:22445840

McGinty, D; Letizia, C S; Api, A M

2012-09-01

406

Fragrance material review on benzyl acetate.  

PubMed

A toxicologic and dermatologic review of benzyl acetate when used as a fragrance ingredient is presented. Benzyl 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 benzyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, skin sensitization, elicitation, phototoxicity, toxicokinetics, repeated dose, reproductive toxicity, genotoxicity, or carcinogenicity data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Refer Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22387848

McGinty, D; Vitale, D; Letizia, C S; Api, A M

2012-09-01

407

Fragrance material review on 2-phenylpropyl acetate.  

PubMed

A toxicologic and dermatologic review of 2-phenylpropyl acetate when used as a fragrance ingredient is presented. 2-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 2-phenylpropyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, and skin sensitization 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:22421639

McGinty, D; Letizia, C S; Api, A M

2012-09-01

408

Linalyl Acetate Is Metabolized by Pseudomonas incognita with the Acetoxy Group Intact  

PubMed Central

Metabolism of linalyl acetate by Pseudomonas incognita isolated by enrichment culture on the acyclic monoterpene alcohol linalool was studied. Biodegradation of linalyl acetate by this strain resulted in the formation of linalool, linalool-8-carboxylic acid, oleuropeic acid, and ?5-4-acetoxy-4-methyl hexenoic acid. Cells adapted to linalyl acetate metabolized linalyl acetate-8-aldehyde to linalool-8-carboxylic acid, linalyl acetate-8-carboxylic acid, ?5-4-acetoxy-4-methyl hexenoic acid, and geraniol-8-carboxylic acid. Resting cell suspensions previously grown with linalyl acetate oxidized linalyl acetate-8-aldehyde to linalyl acetate-8-carboxylic acid, ?5-4-acetoxy-4-methyl hexenoic acid, and pyruvic acid. The crude cell-free extract (10,000 g of supernatant), obtained from the sonicate of linalyl acetate-grown cells, was shown to contain enzyme systems responsible for the formation of linalyl acetate-8-carboxylic acid and linalool-8-carboxylic acid from linalyl acetate. The same supernatant contained NAD-linked alcohol and aldehyde dehydrogenases involved in the formation of linalyl acetate-8-aldehyde and linalyl acetate-8-carboxylic acid, respectively. On the basis of various metabolites isolated from the culture medium, resting cell experiments, growth and manometric studies carried out with the isolated metabolites as well as related synthetic analogs, and the preliminary enzymatic studies performed with the cell-free extract, a probable pathway for the microbial degradation of linalyl acetate with the acetoxy group intact is suggested. PMID:16346182

Renganathan, V.; Madyastha, K. Madhava

1983-01-01

409

Mesophilic syntrophic acetate oxidation during methane formation in biogas reactors  

Microsoft Academic Search

The reaction pathway for the formation of methane from acetate was investigated in sludge from 13 different biogas reactors. By following the conversion of [2-14C]acetate and [14C]bicarbonate it was shown that methane formation by syntrophic acetate oxidation was the dominating mechanism for acetotrophic methanogenesis in sludge containing high levels of salts, mainly ammonium, and volatile fatty acids. In one biogas

Anna Schnürer; Gerhard Zellner; Bo H. Svensson

1999-01-01

410

In situ FTIR investigation of acetic acid electrooxidation on carbon supported Pt-Sn based trimetallic catalysts: Influence of the nature of the third metal  

NASA Astrophysics Data System (ADS)

The effect of adding a third metal (Ni, Co, Pd, Rh) to Pt-Sn/C catalyst has been investigated for the adsorption and oxidation of acetic acid in acidic medium using in situ Fourier transform infrared (FTIR) spectroscopy. The results showed that the decomposition of acetic acid on the surface leads to the formation of different intermediate species and products such as acetate, acetyl, carbonate, CO and CO2. The reaction pathway of CO2 production proceeds via the formation of acetyl or carbonate through surface acetate species. It has been found that the selectivity of the acetate was enhanced by the addition of any third metal. However, the presence of Pd or Co increases the relative intensity of IR band for CO2. This is probably due to success in facilitating of the Csbnd C bond cleavage of acetyl. On the other hand, the conversion of acetate to carbonate is strongly affected by the adsorbed water, as is evident from the pronounced changes in the OH stretching region with the presence of Pd or Ni.

Beyhan, Seden; Léger, Jean-Michel; Kad?rgan, Figen

2014-12-01

411

Conversion of glucose, acetate and lactate to CO2 and fatty acids in liver and adipose tissue of prairie voles (Microtus ochrogaster).  

PubMed

Production of CO2 and fatty acids from acetate, glucose and lactate was determined in slices of liver and adipose tissue from prairie voles fed either a high-starch or a high-cellulose diet. Acetate and lactate were oxidized to CO2 and converted to fatty acids at greater rates than was glucose in both liver and adipose tissue. Fatty acid synthesis occurred at greater rates in adipose tissue than in liver. Fatty acid synthesis per adipocyte increased with increased adipocyte diameter. Fiber content of diets had only minimal effect on metabolic activities of liver and adipose tissue. PMID:6430637

Baldner, G L; Beitz, D C; Hood, R L

1984-01-01

412

Origin of Epilachnapaenulata defensive alkaloids: incorporation of [1-13C]-sodium acetate and [methyl-2H3]-stearic acid.  

PubMed

Ladybird beetles produce a large number of defensive alkaloids. Previous studies suggest that the structural diversity of these endogenous alkaloids can be traced to a common biosynthetic route based on the condensation of several acetate units. In this study, adults of Epilachna paenulata, a phytophagous neotropical species, were fed on diet enriched with potential precursors (sodium acetate, fatty acids and the amino acids lysine and ornithine) labeled with stable isotopes ((13)C, (2)H and (15)N). Labeled acetate was incorporated into the structurally related homotropane and piperidine alkaloids. The later also showed incorporation of [methyl-(2)H3] stearic acid. Our results hence support a fatty acid pathway for the biosynthesis of E. paenulata alkaloids. To our knowledge, this is the first report on the incorporation of a labeled fatty acid into a defensive piperidine alkaloid in insects. PMID:22062684

Camarano, S; González, A; Rossini, C

2012-01-01

413

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

PubMed

Twenty-three acetic acid bacteria, isolated from traditional heap fermentations of Ghanaian cocoa beans, were subjected to a polyphasic taxonomic study. The isolates were catalase-positive, oxidase-negative, Gram-negative rods. They oxidized ethanol to acetic acid and were unable to produce 2-ketogluconic acid, 5-ketogluconic acid and 2,5-diketogluconic acid from glucose; therefore, they were tentatively identified as Acetobacter species. 16S rRNA gene sequencing and phylogenetic analysis confirmed their position in the genus Acetobacter, with Acetobacter syzygii and Acetobacter lovaniensis as their closest phylogenetic neighbours. (GTG)(5)-PCR fingerprinting grouped the strains in a cluster that did not contain any type strains of members of the genus Acetobacter. DNA-DNA hybridization with the type strains of all recognized Acetobacter species revealed DNA-DNA relatedness values below the species level. The DNA G+C contents of three selected strains were 56.9-57.3 mol%. The novel strains had phenotypic characteristics that enabled them to be differentiated from phylogenetically related Acetobacter species, i.e. they were motile, did not produce 2-ketogluconic acid or 5-ketogluconic acid from glucose, were catalase-positive and oxidase-negative, grew on yeast extract with 30 % glucose, grew on glycerol (although weakly) but not on maltose or methanol as carbon sources, and did not grow with ammonium as sole nitrogen source and ethanol as carbon source. Based on the genotypic and phenotypic data, the isolates represent a novel species of the genus Acetobacter for which the name Acetobacter ghanensis sp. nov. is proposed. The type strain is R-29337(T) (=430A(T)=LMG 23848(T)=DSM 18895(T)). PMID:17625210

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

2007-07-01

414

Protective effect of naringenin on acetic acid-induced ulcerative colitis in rats  

PubMed Central

AIM: To evaluate the ameliorative effect of naringenin (NG) during ulcerative colitis (UC) in rats. METHODS: Rats were treated with three different doses (25, 50 and 100 mg/kg per day) of NG and a single dose of mesalazine (MES, 300 mg/kg per day) for seven days prior to ulcerative colitis induction by 4% acetic acid (AA). Twenty four hours after AA rectal administration, animals were scarified and the colonic tissues were dissected. Colonic mucus content was estimated using Alcian blue dye binding technique. In colon tissues, levels of total glutathione sulphadryls (T-GSH), non-protein sulphadryls (NP-SH) and thiobarbituric acid reactive substances (TBARS) were evaluated. The activities of the antioxidant enzymes, catalase (CAT) and superoxide dismutase (SOD) were measured. Concentrations of nucleic acids (DNA and RNA) and total protein were also estimated in colon tissues. Colonic levels of tumor necrosis factor-? (TNF-?), interleukin-1? (IL-1?), interleukin-6 (IL-6), prostaglandin E2 (PGE2) and nitric oxide (NO) were estimated. In cross section of colitis tissue the histopathological changes were observed. RESULTS: Colonic mucus content was decreased in AA compared to controls (587.09 ± 65.59 mg/kg vs 941.78 ± 68.41 mg/kg, P < 0.001). AA administration markedly reduced T-GSH (5.25 ± 0.37 nmol/L vs 3.04 ± 0.24 nmol/L, P < 0.01), NP-SH (3.16 ± 0.04 nmol/L vs 2.16 ± 0.30 nmol/L, P < 0.01), CAT (6.77 ± 0.40 U/mg vs 3.04 ± 0.2 U/mg, P < 0.01) and SOD (3.10 ± 0.11 U/mg vs 1.77 ± 0.18 U/mg, P < 0.01) while TBARS, TNF-?, IL-1?, IL-6, PGE2 and NO levels (15.09 ± 3.84 nmol/L vs 59.90 ± 16.34 nmol/L, P < 0.01; 113.56 ± 1.91 pg/mg vs 134.24 ± 4.77 pg/mg, P < 0.01; 209.20 ± 36.38 pg/mg vs 422.19 ± 31.47 pg/mg, P < 0.01; 250.83 ± 25.09 pg/mg vs 638.58 ± 115.9 pg/mg, P < 0.01; 248.19 ± 36.98 pg/mg vs 541.74 ± 58.34 pg/mg, P < 0.01 and 81.26 ± 2.98 mmol/g vs 101.90 ± 10.73 mmol/g, P < 0.001) were increased in colon of rats with UC compared controls respectively.Naringenin supplementation, significantly and dose dependently increased the colonic mucus content. The elevated TBARS levels were significantly decreased (39.35 ± 5.86 nmol/L, P < 0.05; 26.74 ± 3.17 nmol/L, P < 0.01 nmol/L and 17.74 ± 2.69 nmol/L, P < 0.01) compared to AA (59.90 ± 16.34 nmol/L) group while the decreased levels of T-GSH and NP-SH and activities of CAT and SOD found increased by NG treatments in dose dependent manner. The decreased values of nucleic acids and total protein in AA group were also significantly (P < 0.01) increased in all three NG supplemented groups respectively. NG pretreatment inhibited the TNF-? levels (123.76 ± 3.76 pg/mg, 122.62 ± 3.41 pg/mg and 121.51 ± 2.61 pg/mg vs 134.24 ± 4.78 pg/mg, P < 0.05) compared to AA group, respectively. Interleukins, IL-1? and IL-6 levels were also decreased in NG50 + AA (314.37 ± 16.31 pg/mg and 292.58 ± 23.68 pg/mg, P < 0.05) and NG100 + AA (416.72 ± 49.62 pg/mg and 407.96 ± 43.87 pg/mg, P < 0.05) when compared to AA (352.46 ± 8.58 pg/mg and 638.58 ± 115.98 pg/mg) group. Similar decrease (P < 0.05) was seen in PGE2 and NO values when compared to AA group. The group pretreated with MES, as a reference drug, showed significant (P < 0.01) protection against the changes induced in colon tissue by AA administration respectively. CONCLUSION: In present study, NG produced antioxidant and anti-inflammatory effects demonstrating protective effect in inflammatory bowel disease. PMID:24039355

Al-Rejaie, Salim S; Abuohashish, Hatem M; Al-Enazi, Maher M; Al-Assaf, Abdullah H; Parmar, Mihir Y; Ahmed, Mohammed M

2013-01-01

415

The role of angiotensin II and of its receptor subtypes in the acetic acid-induced abdominal constriction test.  

PubMed

The effects of angiotensin II (AngII), the AngII analogues saralasin--[Sar1, Ala8]AngII, sarmesin--[Sar1Tyr(Me)4]AngII, the nonpeptide AngII receptor antagonists DuP753 (losartan) (for AT1 receptor subtype) and PD123319 (for AT2 receptor subtype), as well as combinations of AngII and each of its analogues and receptor antagonists, administered intracerebroventricularly (ICV), were studied on mice using the acetic acid-induced abdominal constrictions test (acetic acid 1% intraperitoneally, IP). The abdominal constrictions were counted at 5-min intervals for 30 min. AngII at doses of 0.05, 0.1, and 1 microg exerted a dose-dependent antinociceptive effect. Saralasin, sarmesin, losartan, and PD123319 exhibited a dose-dependent effect on nociception: they either increased or decreased it. PD123319 antagonized the antinociceptive effect of AnglI while losartan was ineffective. The importance of AT2 receptor subtype for the nociception reducing effect of AngII is considered. PMID:9972688

Georgieva, D; Georgiev, V

1999-02-01

416

The protective effect of Echinacea spp. (Echinacea angustifolia and Echinacea purpurea) in a rat colitis model induced by acetic acid.  

PubMed

Ulcerative colitis (UC) is a chronic disease that causes an inflammatory condition in the colon. Several cytokines, including tumor necrosis factor alpha (TNF-?), interleukin 1 beta (IL-1?) and transforming growth factor beta (TGF-?) are crucial components of these inflammatory pathways. New therapeutic strategies are needed for improved clinical outcomes in UC and with less adverse effects. That is why alternative therapies such as herbal remedies are increasingly being used with favorable effects in the treatment of UC. Hence, in the present study, we aimed to evaluate the protective effect of Echinacea spp in an experimental rat colitis model induced by acetic acid (AA). Acetic acid was given via a rectal route to induce acute colitis in rats. Rats were placed in four groups: control, Echinacea, Echinacea-colitis and colitis. Tumor necrosis factor alpha, IL-1? and TGF-? levels were measured. Histopathological comparison of the groups was also performed. The disease activity index (DAI) was significantly higher in the colitis group compared to the control, Echinacea and Echinacea-colitis groups (p<0.001). There was no significant difference between the DAI of control, Echinacea and Echinacea-colitis groups (p>0.07). The inflammatory mediators IL-1? and TNF-? were significantly elevated in the colitis group compared to the other groups (p<0.007, <0.001 respectively). Therefore, Echinacea spp. may likely have some therapeutic favorable effects in the management of UC. PMID:25362606

Dogan, Zeynal; Ergul, Bilal; Sarikaya, Murat; Filik, Levent; Gonulta?, Mehmet Alparslan; Hucumenoglu, Sema; Can, Murat

2014-11-01

417

Identification of acetic acid bacteria in traditionally produced vinegar and mother of vinegar by using different molecular techniques.  

PubMed

Culture-dependent and culture-independent methods were combined for the investigation of acetic acid bacteria (AAB) populations in traditionally produced vinegars and mother of vinegar samples obtained from apple and grape. The culture-independent denaturing gradient gel electrophoresis (DGGE) analysis, which targeted the V7-V8 regions of the 16S rRNA gene, showed that Komagataeibacter hansenii and Komagataeibacter europaeus/Komagataeibacter xylinus were the most dominant species in almost all of the samples analyzed directly. The culture-independent GTG5-rep PCR fingerprinting was used in the preliminary characterization of AAB isolates and species-level identification was carried out by sequencing of the 16S rRNA gene, 16S-23S rDNA internally transcribed to the spacer (ITS) region and tuf gene. Acetobacter okinawensis was frequently isolated from samples obtained from apple while K. europaeus was identified as the dominant species, followed by Acetobacter indonesiensis in the samples originating from grape. In addition to common molecular techniques, real-time PCR intercalating dye assays, including DNA melting temperature (Tm) and high resolution melting analysis (HRM), were applied to acetic acid bacterial isolates for the first time. The target sequence of ITS region generated species-specific HRM profiles and Tm values allowed discrimination at species level. PMID:25828705

Yetiman, Ahmet E; Kesmen, Zülal

2015-07-01

418

Uniaxially aligned electrospun cellulose acetate nanofibers for thin layer chromatographic screening of hydroquinone and retinoic acid adulterated in cosmetics.  

PubMed

Uniaxially aligned cellulose acetate (CA) nanofibers were successfully fabricated by electrospinning and applied to use as stationary phase for thin layer chromatography. The control of alignment was achieved by using a drum collector rotating at a high speed of 6000 rpm. Spin time of 6h was used to produce the fiber thickness of about 10 ?m which was adequate for good separation. Without any chemical modification after the electrospinning process, CA nanofibers could be readily devised for screening hydroquinone (HQ) and retinoic acid (RA) adulterated in cosmetics using the mobile phase consisting of 65:35:2.5 methanol/water/acetic acid. It was found that the separation run on the aligned nanofibers over a distance of 5 cm took less than 15 min which was two to three times faster than that on the non-aligned ones. On the aligned nanofibers, the masses of HQ and RA which could be visualized were 10 and 25 ng, respectively, which were two times lower than those on the non-aligned CA fibers and five times lower than those on conventional silica plates due to the appearance of darker and sharper of spots on the aligned nanofibers. Furthermore, the proposed method efficiently resolved HQ from RA and ingredients commonly found in cosmetic creams. Due to the satisfactory analytical performance, facile and inexpensive production process, uniaxially aligned electrospun CA nanofibers are promising alternative media for planar chromatography. PMID:25294296

Tidjarat, Siripran; Winotapun, Weerapath; Opanasopit, Praneet; Ngawhirunpat, Tanasait; Rojanarata, Theerasak

2014-11-01

419

Sulphydryl groups and iodo-(/sup 3/H)acetic acid labeling in proteolipids from Torpedo electroplax  

SciTech Connect

Several fractions of proteolipids from Torpedo electroplax were separated by DEAE-cellulose chromatography in organic solvents, and the sulphydryl groups were determined by a spectrophotometric method. On the same fractions the covalent labeling with iodo-(/sup 3/H)acetic acid to sulphydryl groups was studied. In total proteolipids there were 30.3 nmol/mg protein of sulphydryl groups of which 20.6 nmoles were in the form of disulfide bonds and 10.9 nmol as free--SH groups. The highest content of sulphydryl groups (36.7 nmol/mg protein) was found in fraction II; while fraction I, that binds the cholinergic ligands, has a lower content (23.7 nmol/mg protein). The 42 Kdaltons polypeptide, which is the major band in Fraction II, has the strongest labeling with iodo-(/sup 3/H)acetic acid, while the 39 Kdaltons cholinergic polypeptide shows a lower labeling. The importance of proteolipids as channel-forming macromolecules is discussed in connection with the possible significance of the 42 Kdaltons polypeptide.

Criado, M.; Aguilar, J.S.; De Robertis, E.

1983-05-01

420

Silver nanoparticles in combination with acetic acid and zinc oxide quantum dots for antibacterial activities improvement-A comparative study  

NASA Astrophysics Data System (ADS)

Due to their remarkable antibacterial/antivirus properties, silver nanoparticles (Ag NPs) and zinc oxide quantum dots (ZnO Qds) have been widely used in the antimicrobial field. The mechanism of action of Ag NPs on bacteria was recently studied and it has been proven that Ag NPs exerts their antibacterial activities mainly by the released Ag+. In this work, Ag NPs and ZnO Qds were synthesized using polyol and hydrothermal method, respectively. It was demonstrated that Ag NPs can be oxidized easily in aqueous solution and the addition of acetic acid can increase the Ag+ release which improves the antibacterial activity of Ag NPs. A comparative study between bactericidal effect of Ag NPs/acetic acid and Ag NPs/ZnO Qds on Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumonia and Staphylococcus aureus was undertaken using agar diffusion method. The obtained colloids were characterized using UV-vis spectroscopy, Raman spectrometry, X-ray diffraction (XRD), transmission electron microscopy (TEM) and atomic force microscopy (AFM).

Sedira, Sofiane; Ayachi, Ahmed Abdelhakim; Lakehal, Sihem; Fateh, Merouane; Achour, Slimane

2014-08-01

421

PREPARATION OF WATER-SOLUBLE AND WATER-SWELLABLE STARCH ACETATES USING MICROWAVE HEATING  

Technology Transfer Automated Retrieval System (TEKTRAN)

Starch acetates of degree of substitution 0.1-1.5 were prepared by heating corn starch, acetic acid and acetic anhydride in sealed, stirred, Teflon vessels in a microwave reactor. Reaction efficiencies were typically >90% at reaction temperatures of 150-160 deg C for 4-7 minutes. Starch acetates w...

422

GAS-PHASE SYNTHESIS OF PRECURSORS OF INTERSTELLAR GLYCINE: A COMPUTATIONAL STUDY OF THE REACTIONS OF ACETIC ACID WITH HYDROXYLAMINE AND ITS IONIZED AND PROTONATED DERIVATIVES  

SciTech Connect

A computational study of the reactions of hydroxylamine and its ionized and protonated derivatives with acetic acid is provided. The reaction of neutral hydroxylamine with acetic acid, despite being clearly exothermic, involves a very large energy barrier. The reaction of ionized hydroxylamine with acetic acid is also clearly exothermic, but again a significant energy barrier is found (around 24 kcal mol{sup -1} at the CCSD(T) level). The reaction of the most stable protonated isomer of hydroxylamine, NH{sub 3}OH{sup +}, with acetic acid also involves a high barrier (more than 27 kcal mol{sup -1} at the CCSD(T) level). Only the higher energy isomer, NH{sub 2}OH{sup +}{sub 2}, leads to a sensibly lower energy barrier (about 2.3 kcal mol{sup -1} at the CCSD(T) level). Nevertheless, an estimate of the reaction coefficient at low temperatures such as those reigning in the interstellar medium gives very low values. Therefore, it seems that precursors of interstellar glycine could not be efficiently produced from the reactions of hydroxylamine-derived ions with acetic acid.

Barrientos, Carmen; Redondo, Pilar; Largo, Laura; Rayon, Victor M.; Largo, Antonio, E-mail: alargo@qf.uva.es [Departamento de Quimica Fisica y Quimica Inorganica, Facultad de Ciencias, Universidad de Valladolid, 47005 Valladolid (Spain)

2012-04-01

423

Determination of indole-3-acetic acid and indole-3-butyric acid in mung bean sprouts using high performance liquid chromatography with immobilized Ru(bpy) 3 2+–KMnO 4 chemiluminescence detection  

Microsoft Academic Search

A novel method for determination of indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) in an extract from mung bean sprouts using high performance liquid chromatography (HPLC) with chemiluminescence (CL) detection is described. The method is based on the CL reaction of auxin (indole-3-acetic acid and indole-3-butyric acid) with acidic potassium permanganate (KMnO4) and tris(2,2?-bipyridyl)ruthenium(II), which was immobilized on the cationic

Zhijun Xi; Zhujun Zhang; Yonghua Sun; Zuolong Shi; Wei Tian

2009-01-01

424

Adsorption of acetic acid on ice studied by ambient-pressure XPS and partial-electron-yield NEXAFS spectroscopy at 230-240 K.  

PubMed

Ice plays a key role in the environment, and the ice-air interface influences heterogeneous chemical reactions between snowpack or cirrus clouds and the surrounding air. Soluble gases have been suspected to affect the topmost, disordered layer on ice (often referred to as a quasiliquid layer, QLL). Changes are especially expected in the hydrogen-bonding structure of water in the presence of solutes at the ice surface. Here, we used ambient-pressure X-ray photoelectron spectroscopy (XPS) to detect acetic acid at the ice surface at 230-240 K under atmospheric conditions for the first time. Electron-kinetic-energy-dependent C 1s spectra indicate that acetic acid remains confined to the topmost ice surface layers. Spectral analysis provides information about the protonation state of acetate at the ice surface. Surface-sensitive Auger-electron-yield C-edge near-edge X-ray absorption fine structure (NEXAFS) spectra were recorded to probe the molecular state of the adsorbed species. The O-edge NEXAFS spectra show only minor differences between clean ice and ice with adsorbed acetic acid and thus indicate that acetic acid does not lead to an extended disordered layer on the ice surface between 230 and 240 K. PMID:23252403

K?epelová, Adéla; Bartels-Rausch, Thorsten; Brown, Matthew A; Bluhm, Hendrik; Ammann, Markus

2013-01-17

425

Comparative Study of Berberis vulgaris Fruit Extract and Berberine Chloride Effects on Acetic Acid-Induced Colitis in Rats.  

PubMed

Antioxidant and immunomodulatory effects of anthocyanins are abundant in berberry fruits suggesting that they may have beneficial effects on inflammatory bowel diseases (IBD). The present study was carried out to investigate the anti-colitic effect of Berberis vulgaris fruit extract (BFE) compared to berberine chloride (BEC) and corticosteroids using an animal model of acetic acid induced experimental colitis. BFE with three different doses (375, 750, and 1500 mg/Kg) was administered orally or rectally prior to ulcer induction. BEC (10 mg/Kg), prednisolone (5 mg/Kg), hydrocortisone acetate enema (20 mg/Kg) and normal saline (5 mL/Kg) were considered as respective controls. The tissue was assessed macroscopically for damage scores, area, index and weight/length ratio. They were also examined histopathologically for inflammation extent and severity, crypt damage, invasion involvement and total colitis index. Results indicated that greater doses of oral BFE (750, 1500 mg/Kg) as well as BEC (10 mg/Kg) were effective to protect against colonic damage. By rectal pretreatment, the extract was only effective to diminish the ulcer index and the efficacy was not significant for mucosal inflammation parameters. In conclusion BFE, which is nearly devoid of berberine, was effective to protect against colitis and this might be attributed to its anthocyanin constituents. PMID:24363687

Minaiyan, Mohsen; Ghannadi, Alireza; Mahzouni, Parvin; Jaffari-Shirazi, Elham

2011-01-01

426

Comparative Study of Berberis vulgaris Fruit Extract and Berberine Chloride Effects on Acetic Acid-Induced Colitis in Rats  

PubMed Central

Antioxidant and immunomodulatory effects of anthocyanins are abundant in berberry fruits suggesting that they may have beneficial effects on inflammatory bowel diseases (IBD). The present study was carried out to investigate the anti-colitic effect of Berberis vulgaris fruit extract (BFE) compared to berberine chloride (BEC) and corticosteroids using an animal model of acetic acid induced experimental colitis. BFE with three different doses (375, 750, and 1500 mg/Kg) was administered orally or rectally prior to ulcer induction. BEC (10 mg/Kg), prednisolone (5 mg/Kg), hydrocortisone acetate enema (20 mg/Kg) and normal saline (5 mL/Kg) were considered as respective controls. The tissue was assessed macroscopically for damage scores, area, index and weight/length ratio. They were also examined histopathologically for inflammation extent and severity, crypt damage, invasion involvement and total colitis index. Results indicated that greater doses of oral BFE (750, 1500 mg/Kg) as well as BEC (10 mg/Kg) were effective to protect against colonic damage. By rectal pretreatment, the extract was only effective to diminish the ulcer index and the efficacy was not significant for mucosal inflammation parameters. In conclusion BFE, which is nearly devoid of berberine, was effective to protect against colitis and this might be attributed to its anthocyanin constituents. PMID:24363687

Minaiyan, Mohsen; Ghannadi, Alireza; Mahzouni, Parvin; Jaffari-Shirazi, Elham

2011-01-01

427

In situ reactive extraction of cottonseeds with methyl acetate for biodiesel production using magnetic solid acid catalysts.  

PubMed

A magnetic solid acid catalyst S2O8(2)(-)/ZrO2-TiO2-Fe3O4 was prepared by coprecipitation and impregnation methods and its catalytic activity was investigated for the reactive extraction of cottonseeds with methyl acetate to produce biodiesel. The physicochemical properties of the catalyst were characterized in detail. The influences of Zr/Ti molar ratio and calcination temperature on the catalytic performance were investigated. Moreover, optimization of the reactive extraction process was performed using response surface methodology coupled with central composite design. The catalyst with a Zr/Ti molar ratio of 3/1 calcined at 550°C showed the best activity. An optimum biodiesel yield of 98.5% was obtained under the reaction temperature of 50°C, catalyst amount of 21.3wt.%, methyl acetate/seed ratio of 13.8ml/g and 10.8h of reaction time. Reuse of this catalyst indicated that it had steady catalytic activity and high recovery rate which could be a promising catalyst for biodiesel production from oilseeds. PMID:25463798

Wu, Haitang; Liu, Yanping; Zhang, Junhua; Li, Guanglu

2014-12-01

428

Molecular Structure of Ethyl acetate  

NSDL National Science Digital Library

Ethyl acetate is a colorless, volatile liquid with a mild and fragrant odor. It is used as solvent in chemistry laboratories but can also be found in many household products such as paints, coatings, and adhesives. The compound is also used in some extraction processes such as decaffeination or purification of antibiotics. It is present in both nail polish and removers. Some synthetic fruit essences may contain this and other esters. Etymologists like to use this solvent for insect collecting as the vapor kill the insect quickly and keep it soft for mounting.

2006-03-08

429

[Antiovulatory action of chlormadinone acetate].  

PubMed

Antiovulatory action of chlormadinone acetate (5 mg twice daily from day 7 to day 25) has been assessed in 6 healthy volunteers by daily determination of plasma FSH, LH, estradiol and progesterone. Hormonal profiles during the second treated cycle show that preovulatory gonadotropin surge is blunted and that no significant progesterone secretion occurs. Estradiol production is variable up to the middle of the cycle, and then homogeneously low normal. Menstrual cyclicity is respected and ovarian function is restored during the first cycle after treatment disruption. PMID:7511024

Pelissier, C; Blacker, C; Feinstein, M C; Cournot, A; Denis, C

1994-01-01

430

Uptake measurements of acetic acid on ice and nitric acid-doped thin ice films over upper troposphere/lower stratosphere temperatures.  

PubMed

The adsorption of gaseous acetic acid (CH(3)C(O)OH) on thin ice films and on ice doped with nitric acid (1.96 and 7.69 wt %) was investigated over upper troposphere and lower stratosphere (UT/LS) temperatures (198-208 K), and at low gas concentrations. Experiments were performed in a Knudsen flow reactor coupled to a quadrupole mass spectrometer. The initial uptake coefficients, ?(0), on thin ice films or HNO(3)-doped ice films were measured at low surface coverage. In all cases, ?(0) showed an inverse temperature dependence, and for pure thin ice films, it was given by the expression ?(0)(T) = (4.73 ± 1.13) × 10(-17) exp[(6496 ± 1798)/T]; the quoted errors are the 2? precision of the linear fit, and the estimated systematic uncertainties are included in the pre-exponential factor. The inverse temperature dependence suggests that the adsorption process occurs via the formation of an intermediate precursor state. Uptakes were well represented by the Langmuir adsorption model, and the saturation surface coverage, N(max), on pure thin ice films was (2.11 ± 0.16) × 10(14) molecules cm(-2), independent of temperature in the range 198-206 K. Light nitration (1.96 and 7.69 wt %) of ice films resulted in more efficient CH(3)C(O)OH uptakes and larger N(max) values that may be attributed to in-bulk diffusion or change in nature of the gas-ice surface interaction. Finally, it was estimated that the rate of adsorption of acetic acid on high-density cirrus clouds in the UT/LS is fast, and this is reflected in the short atmospheric lifetimes (2-8 min) of acetic acid; however, the extent of this uptake is minor resulting in at most a 5% removal of acetic acid in UT/LS cirrus clouds. PMID:22313232

Romanias, Manolis N; Zogka, Antonia G; Papadimitriou, Vassileios C; Papagiannakopoulos, Panos

2012-03-01