WorldWideScience
1

Development of Acetic Acid Removal Technology for the UREX+Process  

Energy Technology Data Exchange (ETDEWEB)

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

2

Development of Acetic Acid Removal Technology for the UREX+Process  

International Nuclear Information System (INIS)

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 downstream steps can be avoided. 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

3

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

Science.gov (United States)

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

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AN EXPLORATORY STUDY ON THE REMOVAL OF ACETIC AND FORMIC ACIDS FROM BIO-OIL  

Directory of Open Access Journals (Sweden)

Full Text Available Bio-oil produced from fast pyrolysis of biomass contains various levels of acetic and formic acids derived from breakdown of cellulose and hemi-cellulose components. Removal of these organic acids from bio-oil was investigated for use as industrial chemicals as well as to improve the quality of recovered bio-oil as fuel in various applications. Calcium oxide and a quaternary ammonium anion-exchange resin were used to form acid salts of the organic acids, which were then separated, and the organic acids were generated by reacting with sulfuric acid. Both methods were found to be effective in limited ways and various difficulties encountered in this approach are discussed.

Badmakhand Sukhbaatar

5

Removal of Zn(II) from Aqueous Acetate Solution Using Di (2-Ethylhexyl) Phosphoric Acid & Tributylphosphate  

OpenAIRE

The extraction of Zinc (II) in acetate medium with di (2-ethylhexyl) phosphoric acid (D2EHPA) in chloroform diluent was investigated under different experimental conditions, in order to have a better understanding of the extraction mechanism. The extraction yield was found to depend on the concentrations of Zinc (II) and D2EHPA, and the equilibrium pH. The effects of acetic acid and the salting-out agent were also studied. The nature of the extracted species was inv...

Brahim Guezzen; Mohamed Amine Didi

2012-01-01

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

Science.gov (United States)

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

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Effects of pod removal on the transport and accumulation of abscisic Acid and indole-3-acetic Acid in soybean leaves.  

Science.gov (United States)

Concentrations of abscisic acid (ABA) and indole-3-acetic acid (IAA) in the second most recently expanded trifoliolate leaf were determined during reproductive development of soybean (Glycine max [L.] Merr cv ;Chippewa 64'). The concentration of ABA in leaves was constant during most of the seed filling period until the seeds began to dry. The concentration of IAA in the leaves decreased throughout development. Removal of pods 36 hours prior to sampling resulted in increased concentrations of ABA in leaves during the period of rapid pod filling but had little effect on the concentration of IAA in leaves. ABA appears to accumulate in leaves after fruit removal only when fruits represent the major sink for photosynthate.ABA and IAA moving acropetally and basipetally in petioles of soybean were estimated using a phloem exudation technique. ABA was found to move mostly in the basipetal direction in petioles (away from laminae). IAA, primarily in the form of ester conjugate(s), was found to be moving acropetally (toward laminae) in petioles. The highest amount of IAA ester(s) was found in petiole exudate during the mid and late stages of seed filling. Removal of fruits 36 hours prior to exudation reduced the amount of IAA ester recovered in exudate, suggesting that fruits were a source of the IAA conjugate in petiole exudate. PMID:16663979

Hein, M B; Brenner, M L; Brun, W A

1984-12-01

8

Antibiofilm Properties of Acetic Acid  

DEFF Research Database (Denmark)

Bacterial biofilms are known to be extremely tolerant toward antibiotics and other antimicrobial agents. These biofilms cause the persistence of chronic infections. Since antibiotics rarely resolve these infections, the only effective treatment of chronic infections is surgical removal of the infected implant, tissue, or organ and thereby the biofilm. Acetic acid is known for its antimicrobial effect on bacteria in general, but has never been thoroughly tested for its efficacy against bacterial biofilms. In this article, we describe complete eradication of both Gram-positive and Gram-negative biofilms using acetic acid both as a liquid and as a dry salt. In addition, we present our clinical experience of acetic acid treatment of chronic wounds. In conclusion, we here present the first comprehensive in vitro and in vivo testing of acetic acid against bacterial biofilms.

Bjarnsholt, Thomas; Alhede, Morten

2014-01-01

9

Removal of aqueous Hg(II) and Cr(VI) using phytic acid doped polyaniline/cellulose acetate composite membrane.  

Science.gov (United States)

Conductive composite membrane-phytic acid (PA) doped polyaniline (PANI)/cellulose acetate (CA) (PANI-PA/CA) was prepared in a simple and environmental-friendly method, in which aniline was blended with CA/PA solution and polymerized before the phase conversion. The resultant composite membranes were characterized by SEM, EDX, FTIR-ATR, BET and electrical resistance measurements. When used as adsorbent for Hg(II) and Cr(VI) ions, the prepared composite membrane exhibits excellent adsorption capability. The adsorption of Hg(II) and Cr(VI) follows a pseudo-second-order kinetic model and best fits the Langmuir isotherm model, with the maximum adsorption capacity reaching 280.11 and 94.34 mg g(-1), respectively. The heavy metal loaded composite membrane can be regenerated and reused after treatment with acid or alkali solution, making it a promising and practical adsorbent for Hg(II) and Cr(VI) removal. Tests with river water were also carried out, indicating good performance and application. PMID:25127386

Li, Renjie; Liu, Lifen; Yang, Fenglin

2014-09-15

10

A novel fermentation strategy for removing the key inhibitor acetic acid and efficiently utilizing the mixed sugars from lignocellulosic hydrolysates  

Energy Technology Data Exchange (ETDEWEB)

As part of preliminary research efforts, we have completed several experiments which demonstrate 'proof of concept.' These experiments addressed the following three questions: (1) Can a synthetic mixed sugar solution of glucose and xylose be efficiently consumed using the multi-organism approach? (2) Can this approach be used to accumulate a model product? (3) Can this approach be applied to the removal of an inhibitor, acetate, selectively from mixtures of xylose and glucose? To answer the question of whether this multi-organism approach can effectively consume synthetic mixed sugar solutions, we first tested substrate-selective uptake using two strains, one unable to consume glucose and one unable to consume xylose. The xylose-selective strain ALS998 has mutations in the three genes involved in glucose uptake, rendering it unable to consume glucose: ptsG codes for the Enzyme IICB{sup Glc} of the phosphotransferase system (PTS) for carbohydrate transport (Postma et al., 1993), manZ codes for the IID{sup Man} domain of the mannose PTS permease (Huber, 1996), glk codes for glucokinase (Curtis and Epstein 1975) We also constructed strain ALS1008 which has a knockout in the xylA gene encoding for xylose isomerase, rendering ALS1008 unable to consume xylose. Two batch experiments and one continuous bioprocess were completed. In the first experiment, each strain was grown separately in a defined medium of 8 g/L xylose and 15 g/L glucose which represented xylose and glucose concentrations that can be generated by actual biomass. In the second experiment, the two strains were grown together in batch in the same defined, mixed-sugar medium. In a third experiment, we grew the strains continuously in a 'chemostat', except that we shifted the concentrations of glucose and xylose periodically to observe how the system would respond. (For example, we shifted the glucose concentration suddenly from 15 g/L to 30 g/L in the feed).

Mark A. Eiteman PHD; Elliot Altman Phd

2009-02-11

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Maleopimaric acid acetic acid solvate  

Directory of Open Access Journals (Sweden)

Full Text Available The title compound, C24H32O5·C2H4O2, is a derivative of abietic acid. The two fused and unbridged cyclohexane rings have chair conformations and the anhydride ring is planar. Of the other three six-membered rings, two have boat conformations and one has a twist-boat conformation. The crystal structure is stabilized by intermolecular O—H...O and C—H...O hydrogen bonds.

Meng Zhang

2009-07-01

12

Maleopimaric acid acetic acid solvate.  

Science.gov (United States)

The title compound, C(24)H(32)O(5)·C(2)H(4)O(2), is a derivative of abietic acid. The two fused and unbridged cyclo-hexane rings have chair conformations and the anhydride ring is planar. Of the other three six-membered rings, two have boat conformations and one has a twist-boat conformation. The crystal structure is stabilized by inter-molecular O-H?O and C-H?O hydrogen bonds. PMID:21582965

Zhang, Meng; Zhou, Yong-Hong; Guo, Xiao-Xin; Hu, Li-Hong

2009-01-01

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Asymmetric Brønsted Acid Catalysis: Acetals & Confined Catalysts  

OpenAIRE

The developments of Brønsted acid catalyzed asymmetric syntheses of acetals and a novel class of confined Brønsted acid catalysts are described. The first highly enantioselective intramolecular transacetalization reaction catalyzed by the chiral BINOL-derived phosphoric acid TRIP was developed to access chiral acetals with the acetal carbon as the only stereogenic center. The practical utility of the catalytic asymmetric transacetalization reaction was demonstrated in a kinetic resoluti...

C?oric?, Ilija

2012-01-01

14

Recovery of acetic acid from dilute acetate solution  

Energy Technology Data Exchange (ETDEWEB)

Petroleum-based feedstocks have reached such high prices that interest is increasing in possibly producing oxychemical feedstocks, such as acetic acid, from renewable materials like corn or lignocellulosic biomass. The organism Clostridium thermoaceticum converts glucose or xylose to acetic acid in nearly quantitative yields. However, at neutral pH, the product is in acetate form. This study explores using carbon dioxide at 75 atm and 55/sup 0/C to acidify the fermenter effluent to release free acid for extraction by conventional solvents. The acid is subsequently recovered by azeotropic distillation. The steam required to drive this still is by far the cost-controlling element of the recovery process. Process economics would be greatly improved if the organism could be adapted to higher product concentrations at lower pH. 8 figures, 4 tables.

Busche, R.M.; Shimshick, E.J.; Yates, R.A.

1982-01-01

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Acetic Acid Production by an Electrodialysis Fermentation Method with a Computerized Control System  

OpenAIRE

In acetic acid fermentation by Acetobacter aceti, the acetic acid produced inhibits the production of acetic acid by this microorganism. To alleviate this inhibitory effect, we developed an electrodialysis fermentation method such that acetic acid is continuously removed from the broth. The fermentation unit has a computerized system for the control of the pH and the concentration of ethanol in the fermentation broth. The electrodialysis fermentation system resulted in improved cell growth an...

Nomura, Yoshiyuki; Iwahara, Masayoshi; Hongo, Motoyoshi

1988-01-01

16

Microbial removal of acetate selectively from sugar mixtures.  

Science.gov (United States)

Acetic acid is an unavoidable constituent of the biomass hydrolysates generated from acetylated hemicellulose and lignin, and acetate affects the performance of microbes used to convert these hydrolysates into biofuels or other biochemicals. In this study, acetate was selectively removed from synthetic mixtures of glucose and xylose using metabolically engineered Escherichia coli strains having mutations in the glucose phosphotransferase system (PTS) genes (ptsG, manZ, crr), glucokinase (glk), and xylose (xylA). In batch culture, ALS1060 (ptsG manZ glk xylA) consumed exclusively acetate to depletion, and then consumed the two sugars only at a very slow rate (a growth rate of about 0.01 h(-1)). We also examined the effects of an additional knockout of either malX, fruA, fruB, bglF, or crr, genes that are involved in other PTSs, and a batch process using KD840 (ptsG manZ glk crr xylA) demonstrated a further reduction in glucose or xylose consumption by E. coli. These results demonstrate the feasibility of using a substrate-selective approach for the pre-treatment of biomass hydrolysate for microbial processes. PMID:21225311

Lakshmanaswamy, Arun; Rajaraman, Eashwar; Eiteman, Mark A; Altman, Elliot

2011-09-01

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Isolation of acetic acid bacteria from honey  

OpenAIRE

Four thermotolerant acetic acid bacteria designated as CMU1, CMU2, CMU3 and CMU4 were isolated from six honey samples produced by three native bee species in northern Thailand, namely the dwarf honey bee (Apis florea), Asian honey bee (A. cerena) and giant honey bee (A. dorsata). All isolates were tested for their tolerance to acetic acid and ethanol at 30?C and 37?C. It was found that they grew only in a medium containing 1% (v/v) acetic acid at 30?C. However, isolate CMU4 showe...

Wasu Pathom-aree

2009-01-01

18

Improvement of productivity in acetic acid fermentation with Clostridium thermoaceticum  

Energy Technology Data Exchange (ETDEWEB)

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

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Acetic acid mediated interactions between alumina surfaces  

International Nuclear Information System (INIS)

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

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Acetic acid mediated interactions between alumina surfaces  

Energy Technology Data Exchange (ETDEWEB)

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

Sato, Kimiyasu, E-mail: sato.kimiyasu@aist.go.jp [National Institute of Advanced Industrial Science and Technology (AIST), Anagahora 2266-98, Shimoshidami, Moriyama-ku, Nagoya 463-8560 (Japan); Y Latin-Small-Letter-Dotless-I lmaz, Hueseyin [National Institute of Advanced Industrial Science and Technology (AIST), Anagahora 2266-98, Shimoshidami, Moriyama-ku, Nagoya 463-8560 (Japan); Gebze Institute of Technology, Materials Science and Engineering Department, 41400, Gebze-Kocaeli (Turkey); Ijuin, Atsuko; Hotta, Yuji; Watari, Koji [National Institute of Advanced Industrial Science and Technology (AIST), Anagahora 2266-98, Shimoshidami, Moriyama-ku, Nagoya 463-8560 (Japan)

2012-02-01

21

Isolation of acetic acid bacteria from honey  

Directory of Open Access Journals (Sweden)

Full Text Available Four thermotolerant acetic acid bacteria designated as CMU1, CMU2, CMU3 and CMU4 were isolated from six honey samples produced by three native bee species in northern Thailand, namely the dwarf honey bee (Apis florea, Asian honey bee (A. cerena and giant honey bee (A. dorsata. All isolates were tested for their tolerance to acetic acid and ethanol at 30?C and 37?C. It was found that they grew only in a medium containing 1% (v/v acetic acid at 30?C. However, isolate CMU4 showed the highest toleration to ethanol, viz. 10% (v/v and 9% (v/v at 30?C and 37?C respectively. Morphological and biochemical examination indicated that all isolates were members of the genus Gluconobacter.

Wasu Pathom-aree

2009-02-01

22

Polypyrrole based strong acid catalyst for acetalization  

Science.gov (United States)

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

Liang, Xuezheng; Cheng, Yuxiao; Qi, Chenze

2011-09-01

23

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

International Nuclear Information System (INIS)

Tungsten electrodes have advantageously been used for potentiometric end-point detection in perchloric acid titration of bases in a mixture of acetic acid and acetic anhydride. They have also given good results in biamperometric detection of the equivalence point in continuous coulometric titration of small quantities of bases and acids in the same solvent. Tungsten electrodes in the presence of quinhydrone behave like platinum electrodes, but in biamperometric end-point determination in the absence of quinhydrone it is better to remove the oxide layer from their surface. Some other factors affecting their behaviour have also been studied. Errors in determination do not exceed +-2% even in titration of very small quantities of substances. (author)

24

4,4?-Bipyridine acetic acid disolvate  

OpenAIRE

The crystal structure of the title compound, C10H8N2·2C2H4O2, is built up from 4,4?-bipyridine and acetic acid molecules linked by strong O—H...N hydrogen bonds. The 4,4?-bipyridine and the two acetic acid molecules are further connected through weak C—H...O hydrogen bonds to form a supramolecular two-dimensional network parallel to the (001) plane. The two pyridine rings make a dihedral angle of 31.8?(1)°.

Ling Ye

2008-01-01

25

Potentiometric titrations in anhydrous acetic acid  

International Nuclear Information System (INIS)

The method used for studying anhydrous acetic acid is potentiometry with a glass electrode. We have in this way studied the titration of common inorganic acids (HClO4 - HBr - H2SO4 - HCl - HNO3 - H3PO4) and of some metallic salts. Furthermore we have shown that complex acids are formed between HCl and some metallic chlorides. An analysis of the titration curves for the inorganic acids against pyridinium chloride has made it possible to calculate a certain number of values for the dissociation pK of these acids and of the corresponding pyridinium salts. The titration of metallic perchlorates constitutes a method of studying the stability of acetates; we have thus been able to draw up a classification for some of these acetates. The metallic chlorides studied fall into two groups according to their behaviour in weak or strong acids. The differences have been explained on the basis of the role played by solvolysis. In the third part we have studied the acidic properties of mixtures of HCl with certain metallic chlorides. This work has demonstrated the existence, in certain cases, of acid complexes of the type (HCl)m MCln. (author)

26

2-(Benzenesulfonamido)acetic acid  

OpenAIRE

The title compound, C8H9NO4S, is of interest as a precursor to biologically active sulfur-containing heterocyclic cmpounds. The crystal structure displays the classical O—H...O intermolecular hydrogen bonding typical for carboxylic acids forming dimers. Symmetry-related dimers are, in turn, linked through head-to-tail pairs of intermolecular N—H...O interactions, giving rise to a zigzag chain along the c axis.

Muhammad Zia-ur-Rehman; Islam Ullah Khan; Muhammad Nadeem Arshad

2008-01-01

27

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

Science.gov (United States)

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

28

Kinetics of Ethyl Acetate Synthesis Catalyzed by Acidic Resins  

Science.gov (United States)

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

29

Rapid Economic, Acetic Acid, Papanicolaou Stain (REAP) -  

OpenAIRE

The universal stain for cervical cytological screening is Papanicolaou stain which has been used in different laboratories with many modifications. Aims: The study is designed to search for a superior and improved qualitative staining technique which is cheaper but rapid in cancer screening by cytology. The modified technique is referred as Rapid, economic, acetic acid Papanicolaou stain (REAP).Material & methods: 220 PAP smears from 110 patients ( 2 per subject) were collected . One set of s...

Ranu RoyBiswas

2008-01-01

30

Rapid Economic, Acetic Acid, Papanicolaou Stain (REAP -  

Directory of Open Access Journals (Sweden)

Full Text Available The universal stain for cervical cytological screening is Papanicolaou stain which has been used in different laboratories with many modifications. Aims: The study is designed to search for a superior and improved qualitative staining technique which is cheaper but rapid in cancer screening by cytology. The modified technique is referred as Rapid, economic, acetic acid Papanicolaou stain (REAP.Material & methods: 220 PAP smears from 110 patients ( 2 per subject were collected . One set of smears was stained by conventional Papanicolaou stain & the other set by REAP stain. Pre- Orange G 6 & post- Orange G 6 and post- EA50 ethanol baths in REAP stain were replaced by 1% acetic acid. Tap water was used instead of Scott’s tap water to reduce cost. Hematoxylin was preheated in waterbath to 60? C before staining for rapid penetration. Methanol was used for final dehydration. Results: The two methods were compared in respect of optimal cytoplasmic & nuclear staining, stain preservation, cost & total time for the procedure. In REAP technique, cytoplasmic & nuclear staining was optimal in 100 & 105 cases respectively. The cost was reduced to 25% due to limited alcohol use. The staining-time was minimised to 3 minutes. Conclusion: REAP stain, in comparison to conventional Papanicolaou, provides a suitable, excellent & rapid alternative for cytological screening with minimum cost. The stain preservation is also good in REAP method.

Ranu RoyBiswas

2008-12-01

31

Submillimeter wave spectrum of acetic acid  

Science.gov (United States)

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

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

2013-08-01

32

Removal of nitrate by electrodialysis in the presence of acetate  

International Nuclear Information System (INIS)

In order to remove nitrate selectively from different salt-loaded water, we have studied the electrodialysis of a solution containing nitrate and acetate ions through an original ion exchange membrane. We have showed that NO3- was removed more effectively than CH3COO-. We realized electrodialysis of synthetic solutions containing first of all a single kind of anion, the ion nitrate or the ion acetate, and in the second place the mixture of both kinds of ions and at the same concentration. The ion-exchange membrane (MEA) was obtained from the company ERAS Labo [1], designed initially for use in alkaline fuel cells. We wanted to test its behavior for electrodialysis. The results show that this MEA behaves practically in the same way towards both kinds of ions when the solution contains only a single kind of anion, the migration rate being linked to the value of the current. But once the anions are mixed, we noticed that the migration of the ion nitrate of the central compartment into the anodic compartment was much faster than that of the ion acetate. NO3-migrating easily while the CH3COO- stops practically migrating during 10 min approximately of time of electrodialysis. This demonstrates a selectivity of this kind of membrane towards the anion nitrate. The ion mobility, the hydrated ionic radii as well as the conductivity of the ionic solution may influence the transfer through theion may influence the transfer through the utilized membrane.

33

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

Science.gov (United States)

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

Gerhardt, Valeska; Tutughamiarso, Maya; Bolte, Michael

2012-02-01

34

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

Science.gov (United States)

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

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

2013-04-15

35

Ion exchange behaviour of actinide elements in acetic acid solutions  

International Nuclear Information System (INIS)

Distribution coefficients of Th, Pa, U, Np, Pu, Am, Cm, Cf, Eu between cationite (Dowex-50x8) and anionite (Dowex-1x8)and acetic acid solutions are determined as a function of CH3COOH concentration. It is shown that cationites can be used for concentration of actinide elements from acetic acid solutions in a wide CH3COOH concentration range (0.1-10 mol/l), whereas anionites - only from CH3COOH solutions with concentration more than 17 mol/l. Cation exchange method of actinide concentrating from acetic acid solutions with following selective elution by inorganic acid solutions are developed

36

Enrichment of amino acid-oxidizing, acetate-reducing bacteria.  

Science.gov (United States)

In anaerobic condition, amino acids are oxidatively deaminated, and decarboxylated, resulting in the production of volatile fatty acids. In this process, excess electrons are produced and their consumption is necessary for the accomplishment of amino acid degradation. In this study, we anaerobically constructed leucine-degrading enrichment cultures from three different environmental samples (compost, excess sludge, and rice field soil) in order to investigate the diversity of electron-consuming reaction coupled to amino acid oxidation. Constructed enrichment cultures oxidized leucine to isovalerate and their activities were strongly dependent on acetate. Analysis of volatile fatty acids (VFAs) profiles and community structure analysis during batch culture of each enrichment indicated that Clostridium cluster I coupled leucine oxidation to acetate reduction in the enrichment from the compost and the rice field soil. In these cases, acetate was reduced to butyrate. On the other hand, Clostridium cluster XIVb coupled leucine oxidation to acetate reduction in the enrichment from the excess sludge. In this case, acetate was reduced to propionate. To our surprise, the enrichment from rice field soil oxidized leucine even in the absence of acetate and produced butyrate. The enrichment would couple leucine oxidation to reductive butyrate synthesis from CO2. The coupling reaction would be achieved based on trophic link between hydrogenotrophic acetogenic bacteria and acetate-reducing bacteria by sequential reduction of CO2 and acetate. Our study suggests anaerobic degradation of amino acids is achieved yet-to-be described reactions. PMID:24630616

Ato, Makoto; Ishii, Masaharu; Igarashi, Yasuo

2014-08-01

37

Thermal decomposition of sodium perborate in acetic and trifluoroacetic acids  

International Nuclear Information System (INIS)

Study of sodium perborate thermal decomposition kinetics in acetic and trifluoroacetic acids permitted ascertaining the decomposition rate constants for two groups of compounds with different types of peroxide bonds. It has been revealed that sodium perborate decomposition in trifluoroacetic acid occurs according to the first order. Sodium perborate decomposition in acetic acid is complicated by formation of two types of compounds featuring different mechanisms of decomposition

38

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

Science.gov (United States)

...2010-04-01 false 5-Hydroxyindole acetic acid/serotonin test system...Systems § 862.1390 5-Hydroxyindole acetic acid/serotonin test system...Identification. A 5-hydroxyindole acetic acid/serotonin test...

2010-04-01

39

Biosynthetic origin of acetic acid using SNIF-NMR  

International Nuclear Information System (INIS)

The main purpose of this work is to describe the use of the technique Site-Specific Natural Isotopic Fractionation of hydrogen (SNIF-NMR), using 2H and 1H NMR spectroscopy, to investigate the biosynthetic origin of acetic acid in commercial samples of Brazilian vinegar. This method is based on the deuterium to hydrogen ratio at a specific position (methyl group) of acetic acid obtained by fermentation, through different biosynthetic mechanisms, which result in different isotopic ratios. We measured the isotopic ratio of vinegars obtained through C3, C4, and CAM biosynthetic mechanisms, blends of C3 and C4 (agrins) and synthetic acetic acid. (author)

40

Acetic acid production from marine algae. Progress report No. 2, September 30--December 31, 1977  

Energy Technology Data Exchange (ETDEWEB)

Preliminary results on the production of acetic acid from marine algae by anaerobic fermentation indicate that the rate is quite fast. First order rate constants of 0.77 day/sup -1/ were observed. This rate constant gives a half-life of less than one day. In other words, with a properly designed product removal system a five day retention time would yield 98% of theoretical conversion. Determination of the theoretical conversion of marine algae to acetic acid is the subject of much experimentation. The production of one acetic acid molecule (or equivalent in higher organic acids) for each three carbon atoms in the substrate has been achieved; but it is possible that with a mixed culture more than one acetic acid molecule may be produced for each three carbons in the substrate. Work is continuing to improve the yield of acetic acid from marine algae. Marine algae have been found to be rather low in carbon, but the carbon appears to be readily available for fermentation. It, therefore, lends itself to the production of higher value chemicals in relatively expensive equipment, where the rapid conversion rate is particularly cost effective. Fixed packed bed fermenters appear to be desirable for the production of liquid products which are inhibitory to the fermentation from coarse substrates. The inhibitory products may be removed from the fermentation by extraction during recirculation. This technique lends itself to either conventional processing or low capital processing of substrates which require long retention times.

1977-01-01

41

Biosynthesis of the halogenated auxin, 4-chloroindole-3-acetic acid.  

Science.gov (United States)

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

2012-07-01

42

Study of alkaline-earth element complexes in anhydrous acetic acid  

International Nuclear Information System (INIS)

We have studied the complexes of alkaline-earth elements in anhydrous acetic acid. Using glass-electrode potentiometry we have studied the titration of alkaline earth acetates with perchloric acid which is the strongest acid in anhydrous acetic acid. These titrations have shown that the basic strength of these acetates increases as follows: Mg 4); the mixed acetate-acid sulfate complex of barium: Ba (OAc)(HSO4); the mixed acetate-chloride of barium: Ba (OAc)(Cl). (author)

43

Recovery of Acetic Acid From Effluent via Freeze Crystallization  

Directory of Open Access Journals (Sweden)

Full Text Available Freeze crystallization is an efficient separation process that can potentially be used in any application. Freeze crystallization is a high energy efficiency separation process that can be applied to a wide variety of industrial requirements. Although the vapor-liquid equilibrium is generally employed to separate the components of a solution, use of solid-liquid equilibrium should be considered – it may be cheaper. This paper describes a case study of recovery of acetic acid from effluent via freeze crystallization. Complete recovery of acetic acid from acetic acid-water solution by ordinary distillation is nearly impossible, because relative volatility of this mixture in the range of 1-30% of acetic acid in water is very close to one. But the same separation is possible by freeze separation technique and it is found experimentally that large amount of acetic acid (about 71.5% can be recovered via freeze separation technique. Also it is found that the energy required for recovery of acetic acid is much lower (about 24 times than that of distillation.

Tarak C. Padhiyar

2013-04-01

44

Ternary Phase Equilibrium Data for Acetic Acid-Water-Solvent Systems and Separation of Acetic Acid from Aqueous Solution  

Directory of Open Access Journals (Sweden)

Full Text Available Ternary phase equilibrium data for acetic acid with water and solvent (n-butyl alcohol, isobutyl alcohol and amyl alcohol are presented and used to evaluate the possibility of employing distribution of acetic acid between water and these alcohols as a means of separation of acetic acid from its aqueous solution. Mutual solubility curves, tie-line data, distribution coefficient, selectivity diagrams and separation factor data were determined for these systems. From these data it has been concluded that of these solvents amyl alcohol offers the best hope of achieving separation of acetic acid by distribution between amyl alcohol and water as it has the highest separation factor value than those of other two alcohols.

Bhupesh C. Roy

2005-01-01

45

Proteome analysis of Acetobacter pasteurianus during acetic acid fermentation.  

Science.gov (United States)

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

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

2012-03-16

46

Synthesis of imidazol-1-yl-acetic acid hydrochloride: A key intermediate for zoledronic acid  

Directory of Open Access Journals (Sweden)

Full Text Available A convenient and practical synthesis of imidazol-1-yl-acetic acid hydrochloride was achieved via N-alkylation of imidazole using tert-butyl chloroacetate followed by a non-aqueous ester cleavage of the resulting imidazol-1-yl-acetic acid tert-butyl ester in the presence of titanium tetrachloride. The synthesized imidazol-1-yl-acetic acid hydrochloride was then utilized to prepare zoledronic acid.

2008-11-01

47

Tetrazole acetic acid: Tautomers, conformers, and isomerization  

International Nuclear Information System (INIS)

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

48

Tetrazole acetic acid: Tautomers, conformers, and isomerization  

Energy Technology Data Exchange (ETDEWEB)

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{sup ?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{sup ?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{sup ?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{sup ?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{sup ?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 N{sub 2} 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 CO{sub 2} and 5-methyl-tetrazole, is proposed.

Araujo-Andrade, C. [Unidad Académica de Física de la Universidad Autónoma de Zacatecas, Zacatecas (Mexico); Department of Chemistry, University of Coimbra, 3004-535 Coimbra (Portugal); Reva, I., E-mail: reva@qui.uc.pt; Fausto, R. [Department of Chemistry, University of Coimbra, 3004-535 Coimbra (Portugal)

2014-02-14

49

Liquid-chromatographic determination of indole-3-acetic acid and 5- hydroxyindole-3-acetic acid in human plasma  

OpenAIRE

We describe a "high-performance" reversed-phase liquid-chromatographic method for determination of indole-3-acetic acid (I) and 5- hydroxyindole-3-acetic acid (II) in human plasma. I is eluted at 1.0 mL/min with a mixture of 1-pentanesulfonic acid (pH 3.1), methanol, and water. It is detected by fluorometry. A mixture of citric acid/sodium phosphate solution (pH 4.8) and methanol, at 1.5 mL/min, is used to elute II, which is detected with an electrochemical cell. Platelet-poor plasma samples ...

Marti?nez, Emili; Artigas, Francesc; Sun?ol, Cristina; Tusell, Josep Maria; Gelpi?, Emili

1983-01-01

50

Origin and fate of acetate in an acidic fen.  

Science.gov (United States)

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

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

2012-08-01

51

Disinfection of mung bean seed with gaseous acetic acid.  

Science.gov (United States)

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

52

Acetic acid production from marine algae. Progress report No. 3, January 1, 1978--March 31, 1978  

Energy Technology Data Exchange (ETDEWEB)

The program for acetic acid production from marine algae has made significant progress in the current quarter. Some of the significant developments during this period are: (1) conversion of the available reducing equivalents in Chondrus crispus to organic acids has been carried to better than 80% completion; (2) thermophilic fermentations produce higher ratios of acetic acid to total acid than is the case for mesophilic fermentations (80% vs. 50%); (3) a membrane extraction process for removing organic acid products has been developed which has potential for commercial use; (4) a large scale fermentation was shown to convert over 50% of the available carbon in five days; (5) a reducing equivalents balance on the large scale fermentation was closed to with 96% of theoretical.

Sanderson, J.E.; Wise, D.L.

1978-06-01

53

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

DEFF Research Database (Denmark)

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. Udgivelsesdato: 1995-Oct

Jensen, J B; Egsgaard, H

1995-01-01

54

2-[4-(Carboxymethylphenoxy]acetic acid  

Directory of Open Access Journals (Sweden)

Full Text Available The title compound, C10H10O5, was obtained by the reaction of 4-hydroxyphenylacetic acid with chloroacetic acid. In the crystal, the molecules form a three-dimensional network by way of intermolecular O—H...O hydrogen bonding.

Yi-Hang Wen

2011-01-01

55

Electrochemistry of caffeic acid in acetate-ethanolic solutions  

OpenAIRE

The electrochemical behaviour of caffeic acid in acetate solutions with and without added ethanol was studied by cyclic voltammetry. Solutions of pH and ethanol content close to the wine values (3.5 and 12%, respectively) were studied as a first model approach, pursuing work previously done. Studies at pH 7.4 and different ionic strengths were also done. It was found that cyclic voltammograms of caffeic acid acetate ethanolic solutions had oxidation peak potential values (? 470 mV) at p...

Mordido, S. C.; Rebelo, M. J. F.

2006-01-01

56

Molecular Interactions in Binary Mixture of Polymethylmethacrylate with Acetic Acid  

Directory of Open Access Journals (Sweden)

Full Text Available Solution is prepared by mixing Polymethylmethacrylate in solid form with acetic acid, which at differentconcentration were used to measure density, viscosity & ultrasonic velocity in the temperature range 300C-650C,using ultrasonic interferometer at 1MHz. Using these measured values of density, viscosity & sound velocity,different parameters like, adiabatic compressibility, acoustic impedance and relaxation time have been measuredfor solution of polymethylmethacrylate with acetic acid under different conditions of temperature andconcentration. Variations of above parameters with respect to temperature and concentration have beendiscussed in terms of molecular interactions.

Richa Saxena

2010-07-01

57

A specialized citric acid cycle requiring succinyl-coenzyme A (CoA):acetate CoA-transferase (AarC) confers acetic acid resistance on the acidophile Acetobacter aceti.  

Science.gov (United States)

Microbes tailor macromolecules and metabolism to overcome specific environmental challenges. Acetic acid bacteria perform the aerobic oxidation of ethanol to acetic acid and are generally resistant to high levels of these two membrane-permeable poisons. The citric acid cycle (CAC) is linked to acetic acid resistance in Acetobacter aceti by several observations, among them the oxidation of acetate to CO2 by highly resistant acetic acid bacteria and the previously unexplained role of A. aceti citrate synthase (AarA) in acetic acid resistance at a low pH. Here we assign specific biochemical roles to the other components of the A. aceti strain 1023 aarABC region. AarC is succinyl-coenzyme A (CoA):acetate CoA-transferase, which replaces succinyl-CoA synthetase in a variant CAC. This new bypass appears to reduce metabolic demand for free CoA, reliance upon nucleotide pools, and the likely effect of variable cytoplasmic pH upon CAC flux. The putative aarB gene is reassigned to SixA, a known activator of CAC flux. Carbon overflow pathways are triggered in many bacteria during metabolic limitation, which typically leads to the production and diffusive loss of acetate. Since acetate overflow is not feasible for A. aceti, a CO(2) loss strategy that allows acetic acid removal without substrate-level (de)phosphorylation may instead be employed. All three aar genes, therefore, support flux through a complete but unorthodox CAC that is needed to lower cytoplasmic acetate levels. PMID:18502856

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

2008-07-01

58

Different protonation equilibria of 4-methylimidazole and acetic acid.  

Science.gov (United States)

Dynamic protonation equilibria in water of one 4-methylimidazole molecule as well as for pairs and groups consisting of 4-methylimidazole, acetic acid and bridging water molecules are studied using Q-HOP molecular dynamics simulation. We find a qualitatively different protonation behavior of 4-methylimidazole compared to that of acetic acid. On one hand, deprotonated, neutral 4-methylimidazole cannot as easily attract a freely diffusing extra proton from solution. Once the proton is bound, however, it remains tightly bound on a time scale of tens of nanoseconds. In a linear chain composed of acetic acid, a separating water molecule and 4-methylimidazole, an excess proton is equally shared between 4-methylimidazole and water. When a water molecule is linearly placed between two acetic acid molecules, the excess proton is always found on the central water. On the other hand, an excess proton in a 4-methylimidazole-water-4-methylimidazole chain is always localized on one of the two 4-methylimidazoles. These findings are of interest to the discussion of proton transfer along chains of amino acids and water molecules in biomolecules. PMID:17960747

Gu, Wei; Helms, Volkhard

2007-12-01

59

Stable-isotope labeled metabolites of the phytohormone, indole-3-acetic acid  

International Nuclear Information System (INIS)

1,3-Dicyclohexylcarbodimide-mediated condensation of [3a,4,5,6,7,7a-13C6]indole-3-acetic acid with the bis(tert-butyl) esters of L-aspartic or L-glutamic acids, followed by removal of the ester groups by dilute alkali, afforded N-([3a,4,5,6,7,7a-13C6] indol-3-ylacetyl)-L-aspartic and N-([3a,4,5,6,7,7a-13C6]indol-3-ylacetyl-L-glutamic) acids, labeled forms of compounds involved in the regulation of plant growth and development. The corresponding conjugates of (R,S)-2,3-dihydro-2-oxoindole-3-acetic acid, which are likewise of physiological significance, were labeled with 15N in the amino moieties and were synthesized via the N-hydroxysuccinimide ester. (author)

60

Stable-isotope labeled metabolites of the phytohormone, indole-3-acetic acid  

Energy Technology Data Exchange (ETDEWEB)

1,3-Dicyclohexylcarbodimide-mediated condensation of [3a,4,5,6,7,7a-{sup 13}C{sub 6}]indole-3-acetic acid with the bis(tert-butyl) esters of L-aspartic or L-glutamic acids, followed by removal of the ester groups by dilute alkali, afforded N-([3a,4,5,6,7,7a-{sup 13}C{sub 6}] indol-3-ylacetyl)-L-aspartic and N-([3a,4,5,6,7,7a-{sup 13}C{sub 6}]indol-3-ylacetyl-L-glutamic) acids, labeled forms of compounds involved in the regulation of plant growth and development. The corresponding conjugates of (R,S)-2,3-dihydro-2-oxoindole-3-acetic acid, which are likewise of physiological significance, were labeled with {sup 15}N in the amino moieties and were synthesized via the N-hydroxysuccinimide ester. (author).

Ilic, Nebojsa [Maryland Univ., Plant Biology Dept., College Park, MD (United States); Magnus, Volker [Ruder Boskovic Inst., Organic Chemistry and Biochemistry Dept., Zagreb (Croatia); Ostin, Anders; Sandberg, Goeran [Swedish Univ. of Agricultural Sciences, Forest Genetics and Plant Physiology Dept., Umeaa (Sweden)

1997-05-01

61

Liquid-liquid equilibria for ternary systems acetic acid + n-butyl acetate + hydrocarbons at 293.15 K  

OpenAIRE

Liquid-liquid equilibrium data for acetic acid + n-butyl acetate + hydrocarbons ternary systems at T = 293.15 K are reported in this work. The effect of hydrocarbon chain length on liquid-liquid equilibrium is determined and discussed. Aliphatic hydrocarbons such as hexadecane, dodecane and decane were particularly investigated. The organic chemicals (esters and hydrocarbons) were quantified by gas chromatography using a flame ionisation detector while acetic acid was quantified by titration ...

Richard, Romain; Ferrando, Nicolas; Jacquin, Marc

2013-01-01

62

Electrosynthesis of anisidines in aqueous sulfuric and acetic acids  

Science.gov (United States)

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

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

2009-03-01

63

Molecular Interactions in Binary Mixture of Polymethylmethacrylate with Acetic Acid  

OpenAIRE

Solution is prepared by mixing Polymethylmethacrylate in solid form with acetic acid, which at differentconcentration were used to measure density, viscosity & ultrasonic velocity in the temperature range 300C-650C,using ultrasonic interferometer at 1MHz. Using these measured values of density, viscosity & sound velocity,different parameters like, adiabatic compressibility, acoustic impedance and re...

Richa Saxena; Bhatt, S. C.

2010-01-01

64

KRAFT MILL BIOREFINERY TO PRODUCE ACETIC ACID AND ETHANOL: TECHNICAL ECONOMIC ANALYSIS  

Directory of Open Access Journals (Sweden)

Full Text Available The “near neutral hemicellulose extraction process” involves extraction of hemicellulose using green liquor prior to kraft pulping. Ancillary unit operations include hydrolysis of the extracted carbohydrates using sulfuric acid, removal of extracted lignin, liquid-liquid extraction of acetic acid, liming followed by separation of gypsum, fermentation of C5 and C6 sugars, and upgrading the acetic acid and ethanol products by distillation. The process described here is a variant of the “near neutral hemicellulose extraction process” that uses the minimal amount of green liquor to maximize sugar production while still maintaining the strength quality of the final kraft pulp. Production rates vary between 2.4 to 6.6 million gallons per year of acetic acid and 1.0 and 5.6 million gallons per year of ethanol, depending upon the pulp production rate. The discounted cash flow rate of return for the process is a strong function of plant size, and the capital investment depends on the complexity of the process. For a 1,000 ton per day pulp mill, the production cost for ethanol was estimated to vary between $1.63 and $2.07/gallon, and for acetic acid between $1.98 and $2.75 per gallon depending upon the capital equipment requirements for the new process. To make the process economically attractive, for smaller mill sizes the processing must be simplified to facilitate reductions in capital cost.

Haibo Mao

2010-05-01

65

2-(Benzene­sulfonamido)acetic acid  

OpenAIRE

The title compound, C8H9NO4S, is of inter­est as a precursor to biologically active sulfur-containing heterocyclic cmpounds. The crystal structure displays the classical O—H?O inter­molecular hydrogen bonding typical for carboxylic acids forming dimers. Symmetry-related dimers are, in turn, linked through head-to-tail pairs of inter­molecular N—H?O inter­actions, giving rise to a zigzag chain along the c axis.

Arshad, Muhammad Nadeem; Khan, Islam Ullah; Zia-ur-rehman, Muhammad

2008-01-01

66

Effects of acetic acid on light scattering from cells.  

Science.gov (United States)

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

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

2012-08-01

67

Formic and acetic acid aggregation in the liquid state  

International Nuclear Information System (INIS)

The microscopic structure of neat formic and acetic acid have been measured by neutron diffraction with H/D substitution on SANDALS at the ISIS neutron spallation source. These data, together with complementary x-ray data, have been modeled via the empirical potential structure refinement (EPSR) method, which integrates information obtained from the diffraction data in a Monte Carlo simulation in order to provide a three-dimensional model of the system under study compatible with the measured structure factors. Two models have been generated for each acid, in order to test their consistency, with positive results. The final structure obtained is that of two liquids that are very similar to each other, with high connectivity although rather disordered. They present a hierarchy of probability for hydrogen bond formation, where weaker bonds involving the carbonyl hydrogen for formic acid or the methyl hydrogen for acetic acid are more abundant than the stronger bonds involving the hydroxyl hydrogen. Cooperative effects are found to be fundamental for the description of aggregation of formic and acetic acid, but the structure in the liquid presents a greater variety of bonds than in the solid state.

68

Liquid-Liquid equilibria of the water-acetic acid-butyl acetate system  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Experimental liquid-liquid equilibria of the water-acetic acid-butyl acetate system were studied at temperatures of 298.15± 0.20, 303.15± 0.20 and 308.15± 0.20 K. Complete phase diagrams were obtained by determining solubility and tie-line data. The reliability of the experimental tie-line data was [...] ascertained by using the Othmer and Tobias correlation. The UNIFAC group contribution method was used to predict the observed ternary liquid-liquid equilibrium (LLE) data. It was found that UNIFAC group interaction parameters used for LLE did not provide a good prediction. Distribution coefficients and separation factors were evaluated for the immiscibility region.

E., Ince; S. Ismail, Kirbaslar.

2002-04-01

69

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

OpenAIRE

Background and Objectives: Acetic acid bacteria (AAB) are useful in industrial production of vinegar. The present study aims at isolation and identification of acetic acid bacteria with characterization, optimization, and evaluation of their acetic acid productivity."nMaterials and Methods: Samples from various fruits were screened for presence of acetic acid bacteria on glucose, yeast extract, calcium carbonate (GYC) medium. Carr medium supplemented with bromocresol green was used for distin...

Beheshti-maal, K.; Rasooli, I.; Sm, Sharafi

2010-01-01

70

LIQUID-LIQUID EQUILIBRIA OF THE ACETIC ACID-WATER-MIXED SOLVENT (CYCLOHEXYL ACETATE-CYCLOHEXANOL) SYSTEM  

OpenAIRE

Mixtures of cyclohexyl acetate and cyclohexanol were used as a mixed solvent to study liquid-liquid equilibria (LLE) of the acetic acid-water-cyclohexanol-cyclohexyl acetate quaternary system. The solubility diagram and tie-line data were determined at 298±0.20 K and atmospheric pressure, using various compositions of mixed solvent. Reliability of the data was ascertained by making Othmer-Tobias and Hand plots.

C?ehreli, S.

2002-01-01

71

LIQUID-LIQUID EQUILIBRIA OF THE ACETIC ACID-WATER-MIXED SOLVENT (CYCLOHEXYL ACETATE-CYCLOHEXANOL) SYSTEM  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Mixtures of cyclohexyl acetate and cyclohexanol were used as a mixed solvent to study liquid-liquid equilibria (LLE) of the acetic acid-water-cyclohexanol-cyclohexyl acetate quaternary system. The solubility diagram and tie-line data were determined at 298±0.20 K and atmospheric pressure, using vari [...] ous compositions of mixed solvent. Reliability of the data was ascertained by making Othmer-Tobias and Hand plots.

S., Çehreli.

2002-03-01

72

LIQUID-LIQUID EQUILIBRIA OF THE ACETIC ACID-WATER-MIXED SOLVENT (CYCLOHEXYL ACETATE-CYCLOHEXANOL SYSTEM  

Directory of Open Access Journals (Sweden)

Full Text Available Mixtures of cyclohexyl acetate and cyclohexanol were used as a mixed solvent to study liquid-liquid equilibria (LLE of the acetic acid-water-cyclohexanol-cyclohexyl acetate quaternary system. The solubility diagram and tie-line data were determined at 298±0.20 K and atmospheric pressure, using various compositions of mixed solvent. Reliability of the data was ascertained by making Othmer-Tobias and Hand plots.

Çehreli S.

2002-01-01

73

Anaerobic wastewater treatment of acetic acid rich condensate  

OpenAIRE

In this Master’s Thesis the anaerobic treatment of Stora Enso Heinola Fluting mill condensates was examined and its benefits for the mill assessed. The anaerobic treatment of the condensate could reduce the load towards waste water treatment plant and produce biogas. The secondary condensate from semi-chemical pulp and board mill carries high load of fast degrading organic matter especially acetic acid, thus it could be suitable for biogas production. In the 10-day laboratory scale bat...

Lotti, Outi

2013-01-01

74

Electrochemistry of caffeic acid in acetate-ethanolic solutions  

Directory of Open Access Journals (Sweden)

Full Text Available The electrochemical behaviour of caffeic acid in acetate solutions with and without added ethanol was studied by cyclic voltammetry. Solutions of pH and ethanol content close to the wine values (3.5 and 12%, respectively were studied as a first model approach, pursuing work previously done. Studies at pH 7.4 and different ionic strengths were also done. It was found that cyclic voltammograms of caffeic acid acetate ethanolic solutions had oxidation peak potential values (? 470 mV at pH 3.5 irrespective of the previous excursions of potential with the same set of electrodes. However, the cathodic peaks potentials and currents strongly depended on the cyclic voltammogram of the corresponding solvent electrolyte which had previously been run. The separation of oxidation and reduction peak potentials evidenced the presence of dimmers of caffeic acid in solution, under the following conditions: 0.1 mol dm-3 acetate buffer pH 3.5 + 12% ethanol with the ionic strength increased by the addition of 0.05 mol dm-3 KCl; limits of the anodic potential: from -100 to + 700 mV and N2 bubbled through the solution for 10 minutes.

S.C. Mordido

2006-01-01

75

Fermentation of xylose into acetic acid by Clostridium thermoaceticum.  

Science.gov (United States)

For optimum fermentation, fermenting xylose into acetic acid by Clostridium thermoaceticum (ATCC 49707) requires adaptation of the strain to xylose medium. Exposed to a mixture of glucose and xylose, it preferentially consumes xylose over glucose. The initial concentration of xylose in the medium affects the final concentration and the yield of acetic acid. Batch fermentation of 20 g/L of xylose with 5 g/L of yeast extract as the nitrogen source results in a maximum acetate concentration of 15.2 g/L and yield of 0.76 g of acid/g of xylose. Corn steep liquor (CLS) is a good substitute for yeast extract and results in similar fermentation profiles. The organism consumes fructose, xylose, and glucose from a mixture of sugars in batch fermentation. Arabinose, mannose, and galactose are consumed only slightly. This organism loses viability on fed-batch operation, even with supplementation of all the required nutrients. In fed-batch fermentation with CSL supplementation, D-xylulose (an intermediate in the xylose metabolic pathway) accumulates in large quantities. PMID:11963866

Balasubramanian, N; Kim, J S; Lee, Y Y

2001-01-01

76

Electrochemistry of caffeic acid in acetate-ethanolic solutions  

Scientific Electronic Library Online (English)

Full Text Available SciELO Portugal | Language: English Abstract in english The electrochemical behaviour of caffeic acid in acetate solutions with and without added ethanol was studied by cyclic voltammetry. Solutions of pH and ethanol content close to the wine values (3.5 and 12%, respectively) were studied as a first model approach, pursuing work previously done. Studies [...] at pH 7.4 and different ionic strengths were also done. It was found that cyclic voltammograms of caffeic acid acetate ethanolic solutions had oxidation peak potential values (? 470 mV) at pH 3.5 irrespective of the previous excursions of potential with the same set of electrodes. However, the cathodic peaks potentials and currents strongly depended on the cyclic voltammogram of the corresponding solvent electrolyte which had previously been run. The separation of oxidation and reduction peak potentials evidenced the presence of dimmers of caffeic acid in solution, under the following conditions: 0.1 mol dm-3 acetate buffer pH 3.5 + 12% ethanol with the ionic strength increased by the addition of 0.05 mol dm-3 KCl; limits of the anodic potential: from -100 to + 700 mV and N2 bubbled through the solution for 10 minutes.

S.C., Mordido; M.J.F., Rebelo.

77

Indole-3-acetic acid in plant-microbe interactions.  

Science.gov (United States)

Indole-3-acetic acid (IAA) is an important phytohormone with the capacity to control plant development in both beneficial and deleterious ways. The ability to synthesize IAA is an attribute that many bacteria including both plant growth-promoters and phytopathogens possess. There are three main pathways through which IAA is synthesized; the indole-3-pyruvic acid, indole-3-acetamide and indole-3-acetonitrile pathways. This chapter reviews the factors that effect the production of this phytohormone, the role of IAA in bacterial physiology and in plant-microbe interactions including phytostimulation and phytopathogenesis. PMID:24445491

Duca, Daiana; Lorv, Janet; Patten, Cheryl L; Rose, David; Glick, Bernard R

2014-07-01

78

Simultaneous removal of sulfide, nitrate and acetate under denitrifying sulfide removal condition: Modeling and experimental validation  

Energy Technology Data Exchange (ETDEWEB)

Graphical abstract: Model evaluation applied to case study 1: (A-G) S{sup 2?}, NO{sub 3}{sup ?}-N, NO{sub 2}{sup ?}-N, and Ac{sup ?}-C profiles under initial sulfide concentrations of 156.2 (A), 539 (B), 964 (C), 1490 (D), 342.7 (E), 718 (F), and 1140.7 (G) mg L{sup ?1}. The solid line represents simulated result and scatter represents experimental result. -- Highlights: • This work developed a mathematical model for DSR process. • Kinetics of sulfur–nitrogen–carbon and interactions between denitrifiers were studied. • Kinetic parameters of the model were estimated via data fitting. • The model described kinetic behaviors of DSR processes over wide parametric range. -- Abstract: Simultaneous removal of sulfide (S{sup 2?}), nitrate (NO{sub 3}{sup ?}) and acetate (Ac{sup ?}) under denitrifying sulfide removal process (DSR) is a novel biological wastewater treatment process. This work developed a mathematical model to describe the kinetic behavior of sulfur–nitrogen–carbon and interactions between autotrophic denitrifiers and heterotrophic denitrifiers. The kinetic parameters of the model were estimated via data fitting considering the effects of initial S{sup 2?} concentration, S{sup 2?}/NO{sub 3}{sup ?}-N ratio and Ac{sup ?}-C/NO{sub 3}{sup ?}-N ratio. Simulation supported that the heterotrophic denitratation step (NO{sub 3}{sup ?} reduction to NO{sub 2}{sup ?}) was inhibited by S{sup 2?} compared with the denitritation step (NO{sub 2}{sup ?} reduction to N{sub 2}). Also, the S{sup 2?} oxidation by autotrophic denitrifiers was shown two times lower in rate with NO{sub 2}{sup ?} as electron acceptor than that with NO{sub 3}{sup ?} as electron acceptor. NO{sub 3}{sup ?} reduction by autotrophic denitrifiers occurs 3–10 times slower when S{sup 0} participates as final electron donor compared to the S{sup 2?}-driven pathway. Model simulation on continuous-flow DSR reactor suggested that the adjustment of hydraulic retention time is an efficient way to make the reactor tolerating high S{sup 2?} loadings. The proposed model properly described the kinetic behaviors of DSR processes over wide parametric ranges and which can offer engineers with basis to optimize bioreactor operation to improve the treatment capacity.

Xu, Xijun; Chen, Chuan; Wang, Aijie; Guo, Wanqian; Zhou, Xu [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Lee, Duu-Jong, E-mail: djlee@ntu.edu.tw [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan (China); Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); Ren, Nanqi, E-mail: rnq@hit.edu.cn [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Chang, Jo-Shu [Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan, Taiwan (China)

2014-01-15

79

Simultaneous removal of sulfide, nitrate and acetate under denitrifying sulfide removal condition: Modeling and experimental validation  

International Nuclear Information System (INIS)

Graphical abstract: Model evaluation applied to case study 1: (A-G) S2?, NO3?-N, NO2?-N, and Ac?-C profiles under initial sulfide concentrations of 156.2 (A), 539 (B), 964 (C), 1490 (D), 342.7 (E), 718 (F), and 1140.7 (G) mg L?1. The solid line represents simulated result and scatter represents experimental result. -- Highlights: • This work developed a mathematical model for DSR process. • Kinetics of sulfur–nitrogen–carbon and interactions between denitrifiers were studied. • Kinetic parameters of the model were estimated via data fitting. • The model described kinetic behaviors of DSR processes over wide parametric range. -- Abstract: Simultaneous removal of sulfide (S2?), nitrate (NO3?) and acetate (Ac?) under denitrifying sulfide removal process (DSR) is a novel biological wastewater treatment process. This work developed a mathematical model to describe the kinetic behavior of sulfur–nitrogen–carbon and interactions between autotrophic denitrifiers and heterotrophic denitrifiers. The kinetic parameters of the model were estimated via data fitting considering the effects of initial S2? concentration, S2?/NO3?-N ratio and Ac?-C/NO3?-N ratio. Simulation supported that the heterotrophic denitratation step (NO3? reduction to NO2?) was inhibited by S2? compared with the denitritation step (NO2? reduction to N2). Also, the S2? oxidation by autotrophic denitrifiers was shown two times lower in rate with NO2? as electron acceptor than that with NO3? as electron acceptor. NO3? reduction by autotrophic denitrifiers occurs 3–10 times slower when S0 participates as final electron donor compared to the S2?-driven pathway. Model simulation on continuous-flow DSR reactor suggested that the adjustment of hydraulic retention time is an efficient way to make the reactor tolerating high S2? loadings. The proposed model properly described the kinetic behaviors of DSR processes over wide parametric ranges and which can offer engineers with basis to optimize bioreactor operation to improve the treatment capacity

80

Remedial methods for intergranular attack of alloy 600 tubing. Volume 3. Boric acid and acetic acid remedial methods. Final report  

International Nuclear Information System (INIS)

An important cause of recent tube degradation in recirculating pressurized water reactor (PWR) steam generators with open tube/tubesheet crevices is intergranular attack (IGA) of alloy 600 tubing in the crevice region. The attack appears to occur on the hot leg tubing because of high concentrations of caustic species formed from remnants of past phosphate water treatment, combined with materials from inleakage from freshwater-cooled condensers. The concept of using neutralizers to modify the aggressiveness of the crevice environment was examined. It appears that this can be accomplished by neutralizing the caustic species with an acid. Two ways to apply the acid are by off-line flushing during plant shutdown and by on-line treatment during operation. The substance that appears to be most suitable for off-line flushing is acetic acid, with boric acid as a second choice. Concentrations should be in the range of from 1000 to 5000 ppM. The addition of 1000 to 5000 ppM of a non-ionic detergent in the flush solution should improve penetration of the crevice. Use of preflush lancing to remove sludge on the tubesheet will also help by reducing acid consumption. The requirements for materials to be used in on-line treatment are more stringent because of possible interaction with other components in the secondry system. Boric acid is the only substance that has operational experience. A series of tests are proposed to investigate the behavior of acetic acid and boric acid on tuhavior of acetic acid and boric acid on tubesheet sludge, on tubesheet/support plate material, and on alloy 600/tubesheet couples. Similarly, areas of uncertainty of on-line treatment with boric acid are its effect on tubesheet/support plate materials and on the rest of the secondary system. 23 refs

81

Brønsted Acid/Lewis Acid Cooperatively Catalyzed Addition of Diazoester to 2H-chromene Acetals.  

Science.gov (United States)

A novel Brønsted acid/Lewis acid dual catalyst system has been developed to promote an efficient C-C bond formation between a range of oxocarbenium precursors derived from chromene acetals and ethyl diazoacetate. The reaction proceeds under mild conditions and is tolerant of common functionalized 2H-chromene and isochromene acetals. In addition, an asymmetric variant of diazoacetate addition towards 2H-chromene acetal is described. Continued investigations include the further optimization of asymmetric induction towards the formation of diazo ester substituted 2H-chromene. PMID:25411552

Luan, Yi; Qi, Yue; Gao, Hongyi; Ma, Qianqian; Schaus, Scott E

2014-11-01

82

Production of acetic acid by Clostridium thermoaceticum in electrodialysis culture using a fermenter equipped with an electrodialyser.  

Science.gov (United States)

Electrodialysis culture of Clostridium thermoaceticum increased the yield of acetate by its continuous removal. In normal batch cultures without pH control the yield was 4.2 g acetic acid/800 ml, while in pH-controlled culture it was 16.8 g/800 ml. Although electrodialysis cultures gave almost the same yield (15.4 g/800 ml) as that in pH-controlled cultures, sparging CO2 into the broth in electrodialysis culture increased the amount of acetic acid to 22.3 g/800 ml. CO2 sparging into normal cultures with or without pH control did not significantly increase the amount of acetate produced but yields, in terms of amounts of glucose consumed, were higher than without sparging. The theoretical yield was almost obtained in pH-controlled, electrodialysis cultures with CO2 sparging. PMID:24421091

Nomura, Y; Iwahara, M; Hongo, M

1994-07-01

83

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

DEFF Research Database (Denmark)

The aerobic oxidation of aqueous ethanol to produce acetic acid and ethyl acetate was studied using heterogeneous gold catalysts. Comparing the performance of Au/MgAl2O4 and Au/TiO2 showed that these two catalysts exhibited similar performance in the reaction. By proper selection of the reaction conditions, yields of 90-95% of acetic acid could be achieved at moderate temperatures and pressures. Based on our findings, a reaction pathway for the catalytic oxidation of ethanol via acetaldehyde to acetic acid is proposed, and the rate-determining step (RDS) in the mechanism is found to be the (possibly oxygen-assisted) dehydrogenation of ethanol to produce acetaldehyde. It also is concluded that most of the CO2 formed as a byproduct in the reaction results from the absorbed intermediate in the dehydrogenation of ethanol to produce acetaldehyde. By varying the amount of water in the reaction mixture, the possibilities for producing ethyl acetate by the aerobic oxidation of ethanol is also studied. At low ethanol concentrations, the main product is acetic acid; at concentrations >60 wt%, it is ethyl acetate.

JØrgensen, Betina; Christiansen, Sofie Egholm

2007-01-01

84

Gas Cluster Ion Beam Etching under Acetic Acid Vapor for Etch-Resistant Material  

Science.gov (United States)

Gas cluster ion beam (GCIB) etching of etch-resistant materials under acetic acid vapor was studied for development of new manufacturing process of future nonvolatile memory. Etching depths of various etch-resistant materials (Pt, Ru, Ta, CoFe) with acetic acid vapor during O2-GCIB irradiations were 1.8-10.7 times higher than those without acetic acid. Also, etching depths of Ru, Ta, CoFe by Ar-GCIB with acetic acid vapor were 2.2-16.1 times higher than those without acetic acid. Even after etching of Pt, smoothing of Pt was realized using O2-GCIB under acetic acid. From XPS and angular distribution of sputtered Pt, it was shown that PtOx layer was formed on Pt after O2-GCIB irradiation. PtOx reacted with acetic acid by GCIB bombardments; as a result, increase of etching depth was observed.

Yamaguchi, Akira; Hinoura, Ryo; Toyoda, Noriaki; Hara, Ken-ichi; Yamada, Isao

2013-05-01

85

Tetra-n-propylammonium acetate–boric acid (1/1  

Directory of Open Access Journals (Sweden)

Full Text Available In the crystal structure of the ammonium carboxylate–boric acid cocrystal, (C3H74N+·CH3CO2?·H3BO3, the boric acid forms two O—H...O hydrogen bonds to the acetate anion. The acetate–boric acid species is hydrogen bonded to another acetate–boric acid species through the third OH unit of the boric acid about a twofold rotation axis.

Yun-Xia Yang

2009-11-01

86

Effects of Ethanol and Other Alkanols on Transport of Acetic Acid in Saccharomyces cerevisiae  

OpenAIRE

In glucose-grown cells of Saccharomyces cerevisiae IGC 4072, acetic acid enters only by simple diffusion of the undissociated acid. In these cells, ethanol and other alkanols enhanced the passive influx of labelled acetic acid. The influx of the acid followed first-order kinetics with a rate constant that increased exponentially with the alcohol concentration, and an exponential enhancement constant for each alkanol was estimated. The intracellular concentration of labelled acetic acid was al...

Casal, Margarida; Cardoso, Helena; Lea?o, Ceci?lia

1998-01-01

87

Probiotic and Acetic Acid Effect on Broiler Chickens Performance  

Directory of Open Access Journals (Sweden)

Full Text Available Probiotics and organic acids are widely accepted as an alternative to in-feed antibiotics in poultry production. We carried the experiment with broiler chickens. In experiment we research effect of probiotic and acetic acids on the performance of broiler chickens. A total number of 200 one day old broiler chickens were distributed to two dietary groups. Broiler chickens in control group were fed with standard feed mixture and experimental group 1% vinegar contained 5% acetic acid used in drinking water and probiotics mixed with feed mixture. Body weight, FCR and GIT pH were recorded. The performance showed no statistically significant increase in body weight (P>0.05 in the weeks 1, 2, 3 and 4 of age. The body weight of broiler chickens was significant increase (P?0.05 in weeks 5, and 6 of age. In different segments of the GIT was not statistically significant (P>0.05 difference of pH between the control and experimental groups.

Martin Král

2011-05-01

88

Simultaneous saccharification and fermentation of cellulosic biomass to acetic acid.  

Science.gov (United States)

A strain of Clostridium thermoaceticum (ATCC 49707) was evaluated for its homoacetate potential. This thermophilic anaerobe best produces acetate from glucose at pH 6.0 and 59 degrees C with a yield of 83% of theoretical. Enzyme hydrolysis of two substrates, a-cellulose and a pulp mill sludge, yielded 68% and 70% digestion, respectively. The optimum conditions for the simultaneous saccharification and fermentation (SSF) were substrate dependent: 55 degrees C, pH 6.0 for alpha-cellulose, and 55 degrees C, pH 5.5 for the pulp mill sludge. In the SSF with alpha-cellulose, the overall yield of acetate was strongly influenced by the enzyme loading. In a fed-batch operation of SSF with alpha-cellulose, an overall acetic acid yield of 60 wt% was obtained. Among the factors limiting the yields were incomplete digestion by the enzyme and the end-product inhibition. In the SSF of pulp mill sludge, inhibitors present in the sludge severely limited bacterial action. A large accumulation of glucose developed over the entire process, changing the intended SSF operation into a separate hydrolysis and fermentation operation. Despite a long lag phase of microbial growth, a terminal yield of 85% was obtained with this substrate. PMID:10849850

Borden, J R; Lee, Y Y; Yoon, H H

2000-01-01

89

Characteristics of chitosan-lithium acetate-palmitic acid complexes  

Energy Technology Data Exchange (ETDEWEB)

A new host polymer electrolyte with sufficiently high ionic conductivity was developed using chitosan, palmitic acid and lithium acetate, using the solution cast technique. The new electrolyte fits the requirements of lithium polymer batteries, and takes into account the need for a long cycle life for safe practical use and environmental friendliness. The room temperature ionic conductivity of the complexes was measured by the technique of impedance spectroscopy. The conductivity of the LiOAc-doped chitosan polymer was also studied as a function of temperature between 3003 degrees K and 363 degrees K. 28 refs., 1 tab., 7 figs.

Yahya, M. Z. A. [MARA Univ. of Technology, Selangor (Malaysia); Arof, A. K. [Malaya Univ. Physics Dept., Kuala Lumpur (Malaysia)

2002-04-01

90

Indole 3-acetic acid production by ectomycorrhizal fungi.  

Science.gov (United States)

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

Gopinathan, S; Raman, N

1992-02-01

91

Measurements of acetone, acetic acid, and formic acid in the northern midlatitude upper troposphere and lower stratosphere  

Science.gov (United States)

We have measured acetone, acetic acid, and formic acid concentrations in the upper troposphere and lower stratosphere over Germany. The measurements were performed by ion molecule reaction mass spectrometry using new kinetic data on ion molecule reactions of formic and acetic acids with negative ions obtained at our laboratory. Mean volume mixing ratios between 384 and 832 parts per trillion (pptv) for acetone, 110 and 357 pptv for acetic acid, and 59 and 215 pptv for formic acid were obtained. The correlation between formic acid and acetic acid was very poor (r2 = 0.14). A better correlation could be observed for acetone and acetic acid, with a correlation coefficient r2 = 0.46 and a slope (acetic acid/acetone) of 0.31. For acetic acid a maximum around 9 km was observed. A significant fraction of the acetic acid observed in the lower stratosphere may be due to in situ photochemical production by reactions of HO2 and CH3O2 with peroxy acetyl radicals produced by the photolysis of acetone. In the upper troposphere, vertical transport is much more efficient, and significant acetic acid production is only possible if HOx concentrations are elevated, making the production of acetic acid fast enough to compete with vertical transport.

Reiner, Thomas; MöHler, Ottmar; Arnold, Frank

1999-06-01

92

Acetic acid production from marine algae. Progress report No. 4, April 1-June 30, 1978  

Energy Technology Data Exchange (ETDEWEB)

To date fermentations of marine algal species run at a controlled pH of 5.5 to 6.0 have exhibited essentially complete conversion to organic acids in as little as 16 days. (By complete conversion is meant conversion of each hexose unit to three acetic acid molecules or higher organic acids on a reducing equivalent basis.) As a result of these rapid rates and high conversions economic calculations have shown that processing costs are sufficiently low to encourage commercial development of this process. In the course of this work a diffusion membrane extraction system has been developed for removing organic acids from the fermentation broth. In addition, a fixed packed bed fermenter with a capacity of approximately 300 liters has been constructed and operated for a six month period. Another significant result is that fermentation at thermophilic temperatures (55/sup 0/C) gives higher ratios of acetic acid to total acid product than at mesophilic temperatures (37/sup 0/C). Manuscripts of two technical presentations based on this work are attached.

Sanderson, J. E.; Wise, D. L.

1978-08-28

93

Acetic acid improves the sensitivity of theophylline analysis by gas chromatography-mass spectrometry.  

Science.gov (United States)

In the analysis of theophylline by gas chromatography-mass spectrometry (GC-MS), we found that the addition of acetic acid to the solvent (ethyl acetate) decreased the adsorption of theophylline to the glass wool packed into the inlet liner. The addition of acetic acid to ethyl acetate improved the sensitivity for theophylline (optimum concentration of 3%). This simple and sensitive method without derivatization can be applied to the quantification of theophylline in serum samples in clinical and toxicological practice. PMID:17011247

Saka, Kanju; Uemura, Koichi; Shintani-Ishida, Kaori; Yoshida, Ken-Ichi

2007-02-01

94

Removal of uranium(VI) from acetate medium using Lewatit TP 260 resin  

International Nuclear Information System (INIS)

Removal of uranium(VI) ions from acetate medium in aqueous solution was investigated using Lewatit TP260 (weakly acidic, macroporous-type ion exchange resin with chelating aminomethylphosphonic functional groups) in batch system. The parameters that affect the uranium(VI) sorption, such as contact time, solution pH, initial uranium(VI) concentration, adsorbent dose and temperature have been investigated. Results have been analyzed by Langmuir and Freundlich isotherm; the former was more suitable to describe the sorption process. The moving boundary particle diffusion model only fits the initial metal adsorption on the resin. The rate constant for the uranium sorption by Lewatit TP260 was 0.441 min-1 from the first order rate equation. The total sorption capacity was found to be 58.33 mg g-1 under optimum experimental conditions. Thermodynamic parameters (?H = 61.74 kJ/mol; ?S = 215.3 J/mol K; ?G = -2.856 kJ/mol) showed the adsorption of an endothermic process and spontaneous nature, respectively. (author)

95

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1999-03-01

96

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

OpenAIRE

Acetic acid bacteria are obligate aerobes able to oxidize ethanol, sugar alcohols, and sugars into their corresponding acids. Among them, Acetobacter and Gluconacetobacter species have very high ethanol oxidation capacity, leading to accumulation of vast amounts of acetic acid outside the cell. Since these bacteria are able to grow in media with high concentrations of acetic acid, they must possess a specific mechanism such as an efflux pump by which they can resist the toxic effects of aceti...

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

2005-01-01

97

Interaction effects of lactic acid and acetic acid at different temperatures on ethanol production by Saccharomyces cerevisiae in corn mash  

Energy Technology Data Exchange (ETDEWEB)

The combined effects of lactic acid and acetic acid on ethanol production by S. cerevisiae in corn mash, as influenced by temperature, were examined. Duplicate full factorial experiments (three lactic acid concentrations x three acetic acid concentrations) were performed to evaluate the interaction between lactic and acetic acids on the ethanol production of yeast at each of the three temperatures, 30, 34, and 37 C. Corn mash at 30% dry solids adjusted to pH 4 after lactic and acetic acid addition was used as the substrate. Ethanol production rates and final ethanol concentrations decreased (P<0.001) progressively as the concentration of combined lactic and acetic acids in the corn mash increased and the temperature was raised from 30 to 37 C. At 30 C, essentially no ethanol was produced after 96 h when 0.5% w/v acetic acid was present in the mash (with 0.5, 2, and 4% w/v lactic acid). At 34 and 37 C, the final concentrations of ethanol produced by the yeast were noticeably reduced by the presence of 0.3% w/v acetic acid and {>=}2% w/v lactic acid. It can be concluded that, as in previous studies with defined media, lactic acid and acetic acid act synergistically to reduce ethanol production by yeast in corn mash. In addition, the inhibitory effects of combined lactic and acetic acid in corn mash were more apparent at elevated temperatures. (orig.)

Graves, T.; Narendranath, N.V.; Dawson, K.; Power, R. [Alltech Biotechnology Center, Nicholasville, KY (United States)

2007-01-15

98

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

OpenAIRE

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

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

2008-01-01

99

Diffusion of electrolytes in hydrolyzable glassy polymers: Acetic acid in poly(vinyl acetate), poly(vinyl alcohol), and polyesters  

OpenAIRE

Engineering materials containing poly(vinyl acetate) (PVAc) as the key component undergo hydrolytic degradation, which must be minimized or, at least, controlled. To characterize PVAc hydrolysis quantitatively, the diffusion of acetic acid (HAc) in PVAc, poly(vinyl alcohol) (PVA), unsaturated polyester (UPE), and a UPE/PVAc blend was studied in detail. The permeability cell earlier developed by the authors was modified here to reduce experimental error. As the diffusion and solubility coeffic...

Polishchuk, A. Ya; Valente, A. J. M.; Camino, G.; Luda, M. P.; Madyuskin, N. N.; Lobo, V. M. M.; Zaikov, G. E.; Revellino, M.

2002-01-01

100

Metabolic analysis of the removal of formic acid by unacclimated activated sludge.  

Science.gov (United States)

This paper investigates the removal of formic acid by unacclimated biomass from a municipal activated sludge wastewater treatment plant. The biomass was initially able to remove formic acid, but its removal rate and Oxygen Uptake Rate (OUR) decreased with time, until formic acid removal stopped before the formic acid had been exhausted. Formaldehyde was removed in a similar way, whereas the same biomass was simultaneously able to grow and store PHAs when acetic acid was used as substrate. Batch tests with glycine and (13)C NMR analysis were performed, showing that unacclimated biomass was not able to synthesize all the metabolic intermediates from formic acid alone. At least glycine needed to be externally supplemented, in order to activate the serine synthesis pathway. A small amount of formic acid removal in the absence of growth was also possible through formaldehyde formation and its further conversion to formalin (1,2-formaldehyde dimer), whereas no PHAs were formed. PMID:20417951

Viggi, Carolina Cruz; Dionisi, Davide; Miccheli, Alfredo; Valerio, Mariacristina; Majone, Mauro

2010-06-01

101

The dynamics of acetic acid in the anaerobic treatment of abattoir sewage; Dinamica del acido acetico en la depuracion anaerobia de aguas residuales de mataderos  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this experiment was to examine the production and consumption of acetic acid during the anaerobic treatment of sewage from a municipal abattoir. The experiment studied a 20-litre UASB reactor under three hydraulic retention time (HRT) conditions-4 days, 2.5 days and 1.6 days-measuring the acetic acid concentration in the reactor in fluent and effluent. The results obtained during the experiment with the three different HRTs are reported. The highest percentages of acetic acid removed ( an average of 44%) were obtained with an HRT of 4 days. The amount of acetic acid removed with and HRT of 2.5 days was 27%. (Author) 18 refs.

Vazquez Borges, E.; Acosta Viana, K. [Universidad Autonoma de Yucatan. Mexico (Mexico)

1999-05-01

102

Radiation heterogeneous processes of 14C-acetic acid adsorbed in Na-montmorillonite  

International Nuclear Information System (INIS)

Oxidation processes over clay mineral surfaces have not been fully explored. This research addresses itself to the study of the mechanism of the acetic acid decarboxylation in Na-montmorillonite exposed to ionizing radiation. This reaction can be promoted by the loss of electrons from the carbonyl group and then could be accepted by the acid sites in the clay. One primary objective of this study, which belongs to the field of radiation heterogeneous catalysis, is to get an insight into the processes that are occurring during the irradiation of acetic acid adsorbed in the clay. It was felt that this objective could be attained through a careful study with radiotracer techniques. The excess of the acid was removed and the dry powder was irradiated at different doses. The irradiated samples was analyzed mainly by spectroscopic techniques, such as, IR, ESR and by liquid scintillation. The results of this study are discussed in terms of the yields of the products detected in combination with the clay-acid infrared spectra

103

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

Science.gov (United States)

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

104

Ethenzamide–gentisic acidacetic acid (2/1/1)  

OpenAIRE

In the title co-crystal solvate, 2-ethoxybenzamide–2,5-dihydroxybenzoic acid–ethanoic acid (2/1/1), 2C9H11NO2·C7H6O4·C2H4O2, two nonsteroidal anti-inflammatory drugs, ethenzamide (systematic name: 2-ethoxybenzamide) and gentisic acid (systematic name: 2,5-dihydroxybenzoic acid), together with acetic acid (systematic name: ethanoic acid) form a four-component molecular assembly held together by N—H...O and O—H...O hydrogen bonds. This a...

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

2010-01-01

105

Recent advances in nitrogen-fixing acetic acid bacteria.  

Science.gov (United States)

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

Pedraza, Raúl O

2008-06-30

106

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

Science.gov (United States)

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. PMID:16346034

Schwartz, R D; Keller, F A

1982-06-01

107

Radioimmunoassays for serotonin and 5-hydroxyindole acetic acid  

Energy Technology Data Exchange (ETDEWEB)

Radioimmunoassays for serotonin and 5-hydroxyindole acetic acid were developed. High titer antibodies, having a well-defined high specificity, have been raised by coupling the side-chain of both molecules to human serum albumin. Serotonin is first converted into N-hemisuccinate, and then treated like 5-HIAA, namely, conjugated with HSA for the immunogen. Synthesis of /sup 125/I iodinated analogues was performed by coupling 5-HIAA or N-succinyl serotonin to glycyltyrosine, without any contact between both molecules and the oxidizing reagents. Chemical conversions of biological samples (by succinylation for 5-HT and amidation for 5-HIAA) were carried out. This critical step makes the antigen molecules resemble the immunogen more closely, thus allowing an appreciable gain in specificity and sensitivity. These assays allow the rapid determination of 5-HT and 5-HIAA in small amounts of tissue, blood, cerebral spinal fluid or perfusate without any purification, with a sensitivity threshold of 50 pg.

Delaage, M.A. (Centre National de la Recherche Scientifique, 13 - Marseille (France)); Puizillout, J.J. (INSERM, 13 - Marseille (France))

1981-01-01

108

Radioimmunoassays for serotonin and 5-hydroxyindole acetic acid  

International Nuclear Information System (INIS)

Radioimmunoassays for serotonin and 5-hydroxyindole acetic acid were developed. High titer antibodies, having a well-defined high specificity, have been raised by coupling the side-chain of both molecules to human serum albumin. Serotonin is first converted into N-hemisuccinate, and then treated like 5-HIAA, namely, conjugated with HSA for the immunogen. Synthesis of 125I iodinated analogues was performed by coupling 5-HIAA or N-succinyl serotonin to glycyltyrosine, without any contact between both molecules and the oxidizing reagents. Chemical conversions of biological samples (by succinylation for 5-HT and amidation for 5-HIAA) were carried out. This critical step makes the antigen molecules resemble the immunogen more closely, thus allowing an appreciable gain in specificity and sensitivity. These assays allow the rapid determination of 5-HT and 5-HIAA in small amounts of tissue, blood, cerebral spinal fluid or perfusate without any purification, with a sensitivity threshold of 50 pg

109

Binding behavior of amino acid conjugates of indole-3-acetic acid to immobilized human serum albumin.  

Science.gov (United States)

The affinity of indole-3-acetic acid (IAA), indole-3-propionic acid, indole-3-butyric acid and 24 of their amino acid conjugates to immobilized human serum albumin, as expressed by the retention factor k (determined by HPLC), was dependent on (1) lipophilicity, (2) chirality and (3) functional groups in the amino acid moiety; in some cases conformation plays an additional role. Two lipophilicity-related parameters afforded quantitative correlations with k: retention on a C18 reversed-phase column (experimental approach) and the distance between the hydrophilic and hydrophobic poles of the molecules (in silico approach). Most compounds examined are possible metabolic precursors of IAA, an experimental tumor therapeutic. PMID:17459401

Tomasi?, Ana; Bertosa, Branimir; Tomi?, Sanja; Soski?, Milan; Magnus, Volker

2007-06-22

110

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

Directory of Open Access Journals (Sweden)

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

K Beheshti-Maal

2010-06-01

111

Kinetic stability of thulium(III) and samarium(III) with octaphenyltetraazaporphyrin in acetic acid base media  

International Nuclear Information System (INIS)

The state and kinetic stability of thulium(III) and samarium(III) acetylacetonate complexes with octaphenyltetraazaporphyrin in acetic acid, as well as in the systems acetic acid - benzene and acetic acid - sulfuric acid, were studied by the method of spectrophotometry. Solvoprotolytic dissociation of the complexes in the above-mentioned mixed solvents was considered. Stability constant of thulium complex acid form was estimated

112

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

OpenAIRE

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%, respe...

Schwartz, Robert D.; Keller, Frederick A.

1982-01-01

113

Atmospheric geochemistry of formic and acetic acids at a mid-latitude temperate site  

Science.gov (United States)

Tropospheric concentrations of formic and acetic acids in the gas, the aerosol, and the rainwater phases were determined in samples collected 1-2 m above ground level at an open field site in eastern Virginia. These acids were found to occur principally (98 percent or above) in the gas phase, with a marked annual seasonality, averaging 1890 ppt for formate and 1310 ppt for acetate during the growing season, as compared to 695 ppt and 700 ppt, respectively, over the nongrowing season. The data support the hypothesis that biogenic emissions from vegatation are important sources of atmospheric formic and acetic acid during the local growing season. The same time trends were observed for precipitation, although with less defined seasonality. The relative increase of the acetic acid/formic acid ratio during the nongrowing season points to the dominance of anthropogenic inputs of acetic acid from motor vehicles and biomass combustion in the wintertime.

Talbot, R. W.; Beecher, K. M.; Harriss, R. C.; Cofer, R. W., III

1988-01-01

114

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

Science.gov (United States)

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

115

Efficient sugar release by acetic Acid ethanol-based organosolv pretreatment and enzymatic saccharification.  

Science.gov (United States)

Acetic acid ethanol-based organosolv pretreatment of sugar cane bagasse was performed to enhance enzymatic hydrolysis. The effect of different parameters (including temperature, reaction time, solvent concentration, and acid catalyst dose) on pretreatment prehydrolyzate and subsequent enzymatic digestibility was determined. During the pretreatment process, 11.83 g of xylose based on 100 g of raw material could be obtained. After the ethanol-based pretreatment, the enzymatic hydrolysis was enhanced and the highest glucose yield of 40.99 g based on 100 g of raw material could be obtained, representing 93.8% of glucose in sugar cane bagasse. The maximum total sugar yields occurred at 190 °C, 45 min, 60:40 ethanol/water, and 5% dosage of acetic acid, reaching 58.36 g (including 17.69 g of xylose and 40.67 g of glucose) based on 100 g of raw material, representing 85.4% of total sugars in raw material. Furthermore, characterization of the pretreated sugar cane bagasse using X-ray diffraction and scanning electron microscopy analyses were also developed. The results suggested that ethanol-based organosolv pretreatment could enhance enzymatic digestibilities because of the delignification and removal of xylan. PMID:25393929

Zhang, Hongdan; Wu, Shubin

2014-12-01

116

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

Science.gov (United States)

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

117

Acetic acid enhanced purification of crude cellulose from sugarcane bagasse: Structural and morphological characterization  

Directory of Open Access Journals (Sweden)

Full Text Available Crude cellulose prepared from alkali-extracted sugarcane bagasse was subjected to a rapid purification treatment with a mixture of 80% acetic acid-68% nitric acid (10/1, v/v at 120 °C for 15 min. The yields of the preparations decreased slightly from 57.3%-58.6% in the crude cellulose preparations to 50.3%-51.9% in the purified cellulose samples. The purification treatment removed large amounts of resistant hemicelluloses strongly associated to the cellulose. XRD analysis revealed that the structure of both the crude and purified cellulose was cellulose I. Compared to the crude cellulose, a slight increase in the crystallinity index of the purified cellulose was observed by FTIR, XRD, and CP/MAS 13C NMR analyses. In addition, SEM showed that the macrofibril surface of the crude cellulose was almost free of trenches, but many terraces, steps, and kinks formed in the preparations after the purification.

Jing Bian

2012-11-01

118

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

Directory of Open Access Journals (Sweden)

Full Text Available Abstract 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.

Sá-Correia Isabel

2010-10-01

119

Development of xylose-fermenting yeasts for ethanol production at high acetic acid concentrations  

Energy Technology Data Exchange (ETDEWEB)

Mutants resistant to comparatively high levels of acetic acid were isolated from the xylose-fermenting yeasts Candida shehatae and Pichia Stipitis by adapting these cultures to increasing concentrations of acetic acid grown in shake-flask cultures. These mutants were tested for their ability to ferment xylose in presence of high acetic acid concentrations, in acid hydrolysates of wood, and in hardwood spent sulfite liquor, and compared with their wild-type counterparts and between themselves. The P. stipitis mutant exhibited faster fermentation times, better tolerance to acid hydrolysates, and tolerance to lower pH.

Mohandas, D.V.; Whelan, D.R.; Panchal, C.J. [Vetrogen Corporation, London, Ontario (Canada)

1995-12-31

120

Trehalose accumulation enhances tolerance of Saccharomyces cerevisiae to acetic acid.  

Science.gov (United States)

Trehalose confers protection against various environmental stresses on yeast cells. In this study, trehalase gene deletion mutants that accumulate trehalose at high levels showed significant stress tolerance to acetic acid. The enhancement of trehalose accumulation can thus be considered a target in the breeding of acetic acid-tolerant yeast strains. PMID:25060731

Yoshiyama, Yoko; Tanaka, Koichi; Yoshiyama, Kohei; Hibi, Makoto; Ogawa, Jun; Shima, Jun

2015-02-01

121

Efficacy of Acetic Acid against Listeria monocytogenes Attached to Poultry Skin during Refrigerated Storage  

Directory of Open Access Journals (Sweden)

Full Text Available This work evaluates the effect of acetic acid dipping on the growth of L. monocytogenes on poultry legs stored at 4 °C for eight days. Fresh inoculated chicken legs were dipped into either a 1% or 2% acetic acid solution (v/v or distilled water (control. Changes in mesophiles, psychrotrophs, Enterobacteriaceae counts and sensorial characteristics (odor, color, texture and overall appearance were also evaluated. The shelf life of the samples washed with acetic acid was extended by at least two days over the control samples washed with distilled water. L. monocytogenes counts before decontamination were 5.57 log UFC/g, and after treatment with 2% acetic acid (Day 0, L. monocytogenes counts were 4.47 log UFC/g. Legs washed with 2% acetic acid showed a significant (p < 0.05 inhibitory effect on L. monocytogenes compared to control legs, with a decrease of about 1.31 log units after eight days of storage. Sensory quality was not adversely affected by acetic acid. This study demonstrates that while acetic acid did reduce populations of L. monocytogenes on meat, it did not completely inactivate the pathogen. The application of acetic acid may be used as an additional hurdle contributing to extend the shelf life of raw poultry and reducing populations of L. monocytogenes.

Elena Gonzalez-Fandos

2014-09-01

122

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

Science.gov (United States)

...process in a wide range of foods. In plants and animals, it is generally produced biologically by bacteria from the genus Acetobacter. Acetic acid has a fundamental role in cellular metabolism, particularly in the tricarboxylic acid cycle, also...

2010-07-14

123

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

Science.gov (United States)

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

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

2015-01-28

124

Elucidation of Growth Inhibition and Acetic Acid Production by Clostridium thermoaceticum.  

Science.gov (United States)

The production of acetic acid by Clostridium thermoaceticum was studied by using batch fermentations. In a pH-controlled fermentation with sodium hydroxide (pH 6.9), this organism was able to produce 56 g of acetic acid per liter. On the other hand, when the pH was not controlled and was decreased during fermentation to 5.4, the maximum attainable acetic acid concentration was only 15.3 g/liter. To obtain a better understanding of the end product inhibition, various salts were tested to determine their effect on the growth rate of C. thermoaceticum. An inverse linear relationship between the growth rate and the final cell concentration to the sodium acetate concentration was found. By using different concentrations of externally added sodium salts, the relative growth inhibition caused by the anion was found to be in the order of acetate > chloride > sulfate. Various externally added cations of acetate were also examined with respect to their inhibitory effects on growth. The relative magnitude of inhibition on the growth rate was found to be ammonium > potassium > sodium. The combined results have shown that the undissociated acetic acid was much more inhibitory than the ionized acetate ion. Complete growth inhibition resulted when the undissociated acetic acid concentration was between 0.04 and 0.05 M and when the ionized acetate concentration was 0.8 M. Therefore, at low pH (below 6.0), undissociated acetic acid is responsible for growth inhibition, and at high pH (above 6.0), ionized acetate ion is responsible for growth inhibition. PMID:16346470

Wang, G; Wang, D I

1984-02-01

125

Kinetics of reaction between acetic acid and Ag2+ in nitric acid medium  

International Nuclear Information System (INIS)

The reaction kinetics between acetic acid and Ag2+ in nitric acid medium is studied by spectrophotometry. The effects of concentrations of acetic acid (HAc), H+, NO3- and temperature on the reaction are investigated. The rate equation has been determined to be -dc(Ag2+)/dt=kc(Ag2+)c(HAc)c-1(H+), where k = (610±15) (mol/L)-1·min-1 with an activation energy of about (48.8±3.5) kJ·mol-1 when the temperature is 25degC and the ionic strength is 4.0 mol/L. The reduction rate of Ag2+ increases with the increase of HAc concentration or temperature and the decrease of HNO3 concentration. However, the effect of NO3- concentrations on the reaction rate is negligible. (author)

126

Enzymatic hydrolysis and fermentability of corn stover pretreated by lactic acid and/or acetic acid  

DEFF Research Database (Denmark)

Four different pretreatments with and without addition of low concentration organic acids were carried out on corn stover at 195 °C for 15 min. The highest xylan recovery of 81.08% was obtained after pretreatment without acid catalyst and the lowest of 58.78% after pretreatment with both acetic and lactic acid. Glucan recovery was less sensitive to the pretreatment conditions than xylan recovery. The pretreatment with acetic and lactic acid yielded the highest glucan recovery of 95.66%. The glucan recoveries of the other three pretreatments varied between 83.92% and 94.28%. Fermentability tests were performed on liquors obtained from all pretreatments and there were no inhibition effect found in any of the liquors. Simultaneous saccharification and fermentation (SSF) of water-insoluble solids (WIS) showed that a high ethanol yield of 88.7% of the theoretical based on glucose in the raw material was obtained following pretreatment at 195 °C for 15 min with acetic acid employed. The estimated total ethanol production was 241.1 kg/ton raw material by assuming fermentation of both C-6 and C-5, and 0.51 g ethanol/g sugar.

Xu, Jian; Thomsen, Mette Hedegaard

2009-01-01

127

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

Science.gov (United States)

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

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

2006-11-01

128

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

Energy Technology Data Exchange (ETDEWEB)

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

129

Radioimmunoassay of 5-hydroxyindole acetic acid using an iodinated derivative  

International Nuclear Information System (INIS)

A radioimmunoassay for the main catabolite of serotonin, 5-hydroxyindole acetic acid (5-HIAA), was developed by using specific antibodies and iodinated derivative. The synthesis of a 125I-iodinated analog was performed by coupling 5-HIAA to [125I-]glycyl-tyrosine without any contact between 5-HIAA and iodine or chloramine T. It was purified on a G25 Sephadex column and diluted in citrate buffer up to 2.5 X 10(5) cpm/ml. Antibodies were obtained by coupling 5-HIAA to human serum albumin with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and tested by equilibrium dialysis. After the third immunogen injection, the four rabbits gave antisera capable of binding 50% of iodinated 5-HIIA-glycyl-tyrosine at 1/2000 final dilution. A chemical conversion of the biological samples gives to the antigen molecules a better resemblance to the immunogen, thus conferring a 100-fold gain in specificity and sensitivity. This assay allows 5-HIAA to be determined in small amounts of tissue, blood, cerebrospinal fluid or perfusate without purification with a sensitivity threshold below 0.1 ng. Some applications in cat and rat are presented

130

Acetic acid bacteria isolated from grapes of South Australian vineyards.  

Science.gov (United States)

Acetic acid bacteria (AAB) diversity from healthy, mould-infected and rot-affected grapes collected from three vineyards of Adelaide Hills (South Australia) was analyzed by molecular typing and identification methods. Nine different AAB species were identified from the 624 isolates recovered: Four species from Gluconobacter genus, two from Asaia and one from Acetobacter were identified by the analysis of 16S rRNA gene and 16S-23S rRNA gene internal transcribed spacer. However, the identification of other isolates that were assigned as Asaia sp. and Ameyamaea chiangmaiensis required more analysis for a correct species classification. The species of Gluconobacter cerinus was the main one identified; while one genotype of Asaia siamensis presented the highest number of isolates. The number of colonies recovered and genotypes identified was strongly affected by the infection status of the grapes; the rot-affected with the highest number. However, the species diversity was similar in all the cases. High AAB diversity was detected with a specific genotype distribution for each vineyard. PMID:24681711

Mateo, E; Torija, M J; Mas, A; Bartowsky, E J

2014-05-16

131

Mechanism of anodic dissolution of iron in acetic acid solution  

International Nuclear Information System (INIS)

The catalytic mechanism of the spontaneous dissolution of iron was proved by combined electro- and radiochemical (ER) methods and by the measurement of the amount of the absorbed O2. Acidic solution (20%) of sodium acetate (pH=3.7) and Fe59 isotope produced by neutron irradiation were used to measure the corrosion rate of iron containing 0.005% carbon. The iron dissolves electrochemically as Fe?Fe2++2e, measured by the ER methods. The Fe3++e?Fe2+ reaction and the autocatalytic dissolution of iron were proved as well. The elementary steps of the chemical reaction: 4Fe2++O2+4H+?4Fe3++2H2O were experimentally verified. It has been demonstrated by both methods that the reduction of Fe3+ ions at the electrode as well as the oxidation of Fe2+ ions by chemical reaction are processes of high speed so they may cause high corrosion rate. (Sz.J.)

132

Water interactions with acetic acid layers on ice and graphite.  

Science.gov (United States)

Adsorbed organic compounds modify the properties of environmental interfaces with potential implications for many Earth system processes. Here, we describe experimental studies of water interactions with acetic acid (AcOH) layers on ice and graphite surfaces at temperatures from 186 to 200 K. Hyperthermal D2O water molecules are efficiently trapped on all of the investigated surfaces, with only a minor fraction that scatters inelastically after an 80% loss of kinetic energy to surface modes. Trapped molecules desorb rapidly from both ?m-thick solid AcOH and AcOH monolayers on graphite, indicating that water has limited opportunities to form hydrogen bonds with these surfaces. In contrast, trapped water molecules bind efficiently to AcOH-covered ice and remain on the surface on the observational time scale of the experiments (60 ms). Thus, adsorbed AcOH is observed to have a significant impact on water-ice surface properties and to enhance the water accommodation coefficient compared to bare ice surfaces. The mechanism for increased water uptake and the implications for atmospheric cloud processes are discussed. PMID:24878257

Papagiannakopoulos, Panos; Kong, Xiangrui; Thomson, Erik S; Pettersson, Jan B C

2014-11-26

133

Radioimmunoassay of 5-hydroxyindole acetic acid using an iodinated derivative  

Energy Technology Data Exchange (ETDEWEB)

A radioimmunoassay for the main catabolite of serotonin, 5-hydroxyindole acetic acid (5-HIAA), was developed by using specific antibodies and iodinated derivative. The synthesis of a /sup 125/I-iodinated analog was performed by coupling 5-HIAA to (125I-)glycyl-tyrosine without any contact between 5-HIAA and iodine or chloramine T. It was purified on a G25 Sephadex column and diluted in citrate buffer up to 2.5 X 10(5) cpm/ml. Antibodies were obtained by coupling 5-HIAA to human serum albumin with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and tested by equilibrium dialysis. After the third immunogen injection, the four rabbits gave antisera capable of binding 50% of iodinated 5-HIIA-glycyl-tyrosine at 1/2000 final dilution. A chemical conversion of the biological samples gives to the antigen molecules a better resemblance to the immunogen, thus conferring a 100-fold gain in specificity and sensitivity. This assay allows 5-HIAA to be determined in small amounts of tissue, blood, cerebrospinal fluid or perfusate without purification with a sensitivity threshold below 0.1 ng. Some applications in cat and rat are presented.

Puizillout, J.J.; Delaage, M.A.

1981-06-01

134

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

Science.gov (United States)

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

135

Acid gas removal in synfuels production  

Energy Technology Data Exchange (ETDEWEB)

The CO/sub 2/, H/sub 2/S and COS contents of gas streams of some synfuel processes and the costs for removal of these gases are tabulated. Four different types of acid gas removal processes discussed are chemisorption, physical adsorption, hybrid or combination of the first two, and sulfur conversion processes. Results of an economic study of H/sub 2/S and CO/sub 2/ removal at pressures of 1379, 2758, and 4137 kPa for 13.8 million normal m/sup 3//day of gas containing 1% H/sub 2/S and 22% CO/sub 2/. The processes considered were selective removal of H/sub 2/S with a solvent process (CATASOL 3) followed by removal of CO/sub 2/ by either the CATASOL 4A physical solvent or the CATACARB process (catalyzed hot potassium). The main feature influencing the selection of acid gas removal process are the gas composition and pressure and availability of low-level waste heat. Capital investment, utilities, and chemical costs were considered for various processes. Since the cost of commercial size synfuel process plants runs into billions of dollars, the added cost of acid gas removal must be carefully considered. (BLM)

Eickmeyer, A.G.; Gangriwala, H.A.

1981-12-01

136

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

Energy Technology Data Exchange (ETDEWEB)

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

137

Measurements of the Temperature Dependence of the Rate Constant of the Reaction of Hydroxyl Radical and Acetic Acid and its Deuterated Isotopomers Between Temperatures 263-373K  

Science.gov (United States)

Acetic acid is ubiquitous in the earth's atmosphere where it has a global source strength of ~ 75 Tg yr-1 from secondary photochemical reactions and ~ 48 Tg yr-1 from direct emissions due to biomass burning. It contributes significantly to the acidity of natural waters and plays an important role in determining OH and HO2 radical budgets and ultimately affecting the oxidative capacity of troposphere. Acetic acid is removed from the atmosphere primarily by wet and dry deposition and by reaction with hydroxyl (OH) radical. However, current atmospheric chemistry models are not able to accurately reproduce acetic acid concentrations suggesting a gap in our understanding of its sources and sinks. We present low pressure (~ 5 Torr) measurements of the rate constant of the reaction of acetic acid with OH in the temperature range of 263-373K, using the discharge flow techniques coupled with resonance fluorescence detection of OH radicals. Our measured value of the rate constant of (7.37 ± 0.34) × 10-13cm3molecule-1s-1 at 298K is in good agreement with previous studies. At low pressure, the reaction displays a negative temperature dependence consistent with previous studies conducted at higher pressures. A primary kinetic isotope effect was observed while comparing the rate constants for reaction of OH with CD3COOH (acetic acid-d3) and CD3COOD (acetic acid-d4) confirming that the dominant reaction mechanism is H-abstraction from the carboxylic group.

Vimal, D.; Stevens, P. S.

2005-12-01

138

Removal of ovarian hormones affects the ageing process of acetate metabolism  

Directory of Open Access Journals (Sweden)

Full Text Available Background: Despite a close association between gastrointestinal motility and sex hormones, it has been unknown whether ovarian hormones affect absorption and metabolism of nutrients. The aim of this study is, therefore, to evaluate metabolism of acetate in rats with age and the influence of ovariectomy on its change. Methods: Fourteen female rats of the F344 strain were used, and 13C-acetate breath test was performed at 2, 7 and 13 months of age. Seven rats were ovariectomized at three weeks of age (ovariectomy group and the remaining seven rats were studied as control group. After 24-hr fasting, rats are orally administrated 1ml of water containing sodium 13C-acetate (100mg/kg and housed in an animal chamber. The expired air in the chamber is collected in a breath-sampling bag using a aspiration pump. The 13CO2 concentration is measured using an infrared spectrometer for 120 min and expressed as delta per mil. Results: The breath 13CO2 excretion increased with time and peaked 30 min in control rats. In ovariectomized rats, thee peak time of 13CO2 excretion was prolonged to 40 min at 7 and 13 months of age. Cmax was significantly higher at 2 months of age but lower at 4 months of age in ovariectomized rats than in control rats. Those of two groups became equal at 7 months of age. Conclusions: From the viewpoint of acetate metabolism, removal of ovarian hormones might make rats to be precocious ones and accelerate ageing.

Tsunehiko Imai

2009-07-01

139

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

Science.gov (United States)

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

Liu, Xiangyong; Zhang, Xiaohua; Zhang, Zhaojie

2014-10-10

140

Indole-3-acetic acid biosynthesis in colletotrichum gloeosporioides f. sp. aeschynomene  

Science.gov (United States)

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; Riov; Sharon

1998-12-01

141

An experimental study for efficacy of acetic acid as a sclerosing agent  

International Nuclear Information System (INIS)

To evaluate the efficacy of acetic acid as a sclerosing agent by observation of histologic change in urinary bladder epithelium after the instillation of acetic acid. Urinary bladder of the rabbit was catheterized with a Foley catheter, and acetic acid of 10%, 20%, 30%, 40% and 50% concentration was instilled for 5 minutes. After evacuation of the acid, the bladder was irrigated three times with normal saline. After two days, gross and histologic examinations of the bladder were performed. A bladder into which 10% acetic acid had been instilled revealed a nearly normal epithelium without denudation. In two cases, 20% acetic acid was instilled;one revealed partial denudation of the epithelium and the other revealed complete denudation. Mild to moderate interstitial edema and vascular congestion of the bladder wall were evident in all cases in which acid at a concentration of 30% or more had been instilled. In all cases in which the concentration of acid was greater than 30%, the epithelium was completely denuded. An acetic acid concentration of 40% or more is sufficient to completely destroy the epithelium of rabbit urinary bladder, and may be effective as a new sclerosing agent in cases of renal or hepatic cyst

142

Deprotection of Acetals and Ketals by Silica Sulfuric Acid and Wet SiO2  

Directory of Open Access Journals (Sweden)

Full Text Available Neat chlorosulfonic acid reacts with silica gel to give silica sulfuric acid in which sulfuric acid is immobilized on the surface of silica gel via covalent bonds. A combination of silica sulfuric acid and wet SiO2 was used as an effective deacetalizating agent for the conversion of acetals to their corresponding carbonyl derivatives under thermal conditions.

Abdolhamid Bamoniri

2002-10-01

143

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

International Nuclear Information System (INIS)

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

144

Acetic acid as a sclerosing agent for renal cysts: Comparison with ethanol in follow-up results  

International Nuclear Information System (INIS)

Purpose: To compare follow-up results of sclerotherapy for renal cyst using 50% acetic acid with those using 99% ethanol as sclerosing agents.Methods: Eighty-one patients underwent sclerotherapy and 58 patients, 23 males, 35 females, aged 6-76 years, having a total of 60 cysts, were included in this study; the others were lost to follow-up. The renal cysts were diagnosed by sonography, computed tomography (CT), or magnetic resonance imaging (MRI). Sclerotherapy was performed using 50% acetic acid for 32 cysts in 3 1 patients and 99% ethanol for 28 cysts in 27 patients. Under fluoroscopic guidance, cystic fluid was aspirated as completely as possible. After instillation of a sclerosing agent corresponding to 1 1.7%-25% (4-100 ml) of the aspirated volume, the patient changed position for 20 min and then the agent was removed. Patients were followed up by sonography for a period of 1-49 months. The volume of the renal cyst after sclerotherapy was compared with that of the renal cyst calculated before sclerotherapy. Medical records were reviewed to analyze complications.Results: The mean volume after sclerotherapy of the 17 cysts followed for 3-4 months in the acetic acid group was 5.1% of the initial volume, and for the 14 cysts in the ethanol group it was 10.2%. Complete regression during follow-up was shown in 21 cysts (66%) in the acetic acid group; the mean volume of these cysts before the procedure was 245 ml. The mean volume of the nine (32%) completely regressed ce of the nine (32%) completely regressed cysts in the ethanol group was 184 ml. Mild flank pain, which occurred in three patients in each group, was the only complication and resolved the next day.Conclusion: Acetic acid was an effective and safe sclerosing agent for renal cysts, tending to induce faster and more complete regression than ethanol.

145

Elucidation of Growth Inhibition and Acetic Acid Production by Clostridium thermoaceticum  

OpenAIRE

The production of acetic acid by Clostridium thermoaceticum was studied by using batch fermentations. In a pH-controlled fermentation with sodium hydroxide (pH 6.9), this organism was able to produce 56 g of acetic acid per liter. On the other hand, when the pH was not controlled and was decreased during fermentation to 5.4, the maximum attainable acetic acid concentration was only 15.3 g/liter. To obtain a better understanding of the end product inhibition, various salts were tested to deter...

Wang, George; Wang, Daniel I. C.

1984-01-01

146

Dissimilation of Carbon Monoxide to Acetic Acid by Glucose-Limited Cultures of Clostridium thermoaceticum  

OpenAIRE

Clostridium thermoaceticum was cultivated in glucose-limited media, and the dissimilation of CO to acetic acid was evaluated. We found that cultures catalyzed the rapid dissimilation of CO to acetic acid and CO2, with the stoichiometry obtained for conversion approximating that predicted from the following reaction: 4CO + 2H2O ? CH3CO2H + 2CO2. Growing cultures formed approximately 50 mmol (3 g) of CO-derived acetic acid per liter of culture, with the rate of maximal consumption approximati...

Martin, Douglas R.; Misra, Arun; Drake, Harold L.

1985-01-01

147

Removal of lactobionic acid by electrodialysis  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Lactobionic acid has a number of applications, such as in cosmetic formulations and detergents, as well as in the medical field, where it is used for the preservation of organs destined for transplantation. Previous studies have reported that a promising alternative procedure for the production of l [...] actobionic acid is the biotechnological route, using permeabilized cells of Zymomonas mobilis to produce sorbitol and lactobionic acid from fructose and lactose. However, the acid produced during the process accumulates in the reaction medium, causing enzyme deactivation. It was found that this problem can be avoided by coupling an electrodialysis unit to the reaction vessel, resulting in efficient removal of the acid from the reaction medium and improved the stability of the enzyme. These tests employed a synthetic mixture containing lactobionic acid, sorbitol, lactose, and fructose, and a factorial design was performed to identify the most influential variables. The NaCl concentration in the concentrate stream, together with the potential difference, exerted the greatest effects on the rate of removal of lactobionic acid. In all experiments, the removal efficiency exceeded 95%. The best conditions for the system investigated were a potential of 60 V, and NaCl concentrations of 3 and 25 g L-1 in the concentrate stream and the electrode compartment, respectively.

J. B., Severo Júnior; T. L. M., Alves; H. C., Ferraz.

1003-10-01

148

Actinide removal from nitric acid waste streams  

Energy Technology Data Exchange (ETDEWEB)

Actinide separations research at the Rocky Flats Plant (RFP) has found ways to significantly improve plutonium secondary recovery and americium removal from nitric acid waste streams generated by plutonium purification operations. Capacity and breakthrough studies show anion exchange with Dowex 1x4 (50 to 100 mesh) to be superior for secondary recovery of plutonium. Extraction chromatography with TOPO(tri-n-octyl-phosphine oxide) on XAD-4 removes the final traces of plutonium, including hydrolytic polymer. Partial neutralization and solid supported liquid membrane transfer removes americium for sorption on discardable inorganic ion exchangers, potentially allowing for non-TRU waste disposal.

Muscatello, A.C.; Navratil, J.D.

1986-01-01

149

Actinide removal from nitric acid waste streams  

International Nuclear Information System (INIS)

Actinide separations research at the Rocky Flats Plant (RFP) has found ways to significantly improve plutonium secondary recovery and americium removal from nitric acid waste streams generated by plutonium purification operations. Capacity and breakthrough studies show anion exchange with Dowex 1x4 (50 to 100 mesh) to be superior for secondary recovery of plutonium. Extraction chromatography with TOPO(tri-n-octyl-phosphine oxide) on XAD-4 removes the final traces of plutonium, including hydrolytic polymer. Partial neutralization and solid supported liquid membrane transfer removes americium for sorption on discardable inorganic ion exchangers, potentially allowing for non-TRU waste disposal

150

Actinide removal from nitric acid waste streams  

International Nuclear Information System (INIS)

Actinide separations research at the Rocky Flats Plant (RFP) has found ways to significantly improve plutonium secondary recovery and americium removal from nitric acid waste streams generated by plutonium purification operations. Capacity and breakthrough studies show anion exchange with Dowex 1 x 4 (50 to 100 mesh) to be superior for secondary recovery of plutonium. Extraction chromatography with TOPO (tri-n-octyl-phosphine oxide) on XAD-4 removes the final traces of plutonium, including hydrolytic polymer. Partial neutralization and solid supported liquid membrane transfer removes americium for sorption on discardable inorganic ion exchangers, potentially allowing for non-TRU waste disposal

151

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

Science.gov (United States)

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

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

2013-12-01

152

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1991-07-01

153

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

International Nuclear Information System (INIS)

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

154

Esterification of glycerol with acetic acid over dodecamolybdophosphoric acid encaged in USY zeolite  

OpenAIRE

The esterification of glycerol with acetic acid was carried out over dodecamolybdophosphoric acid (PMo) encaged in the USY zeolite. The products of glycerol acetylation were monoacetin, diacetin and triacetin. A series of PMo encaged in the NaUSY zeolite with different PMo loading from 0.6 to 5.4 wt.% were prepared. It was observed that the catalytic activity increases with the amount of PMo immobilized in the NaUSY zeolite, being the PMo3_NaUSY (with 1.9 wt.%) the most active sample...

Ferreira, P.; Fonseca, I.; Ramos, A.; Vital, J.; Castanheiro, Jose

2009-01-01

155

Effect of Exogenous Indole-3-acetic Acid and Naphthalene Acetic Acid on Regeneration of Damask Rose Cuttings in Three Growing Media  

Directory of Open Access Journals (Sweden)

Full Text Available 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.

Rahmat Ullah Khan

2007-01-01

156

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

Science.gov (United States)

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

157

THE EFFECTS OF ANIMAL AGE AND ACETIC ACID CONCENTRATION ON PIGSKIN GELATIN CHARACTERISTICS  

Directory of Open Access Journals (Sweden)

Full Text Available This research was aimed to study the influence of animal age and concentration of the acetic acid solution on physical and chemical properties of pigskin gelatin. The experiment used Completely Randomized Design (CRD with two factors. The first factor was animal age consisted of 3 levels (5, 7 and 9 months. The second factor was concentration of acetic acid solution consisted of 3 levels (2, 4 and 6 percents. The result showed that animal age had significant effect (P0.05 on the yields, gel strength, viscosity, protein content and pH value. It was concluded that pigskin gelatin from ages of 5, 7 and 9 months and acetic acid concentration of 2, 4 and 6% had similar characteristics to the commercial gelatin, but the optimum production of gelatin was combination of pigskin gelatin from 7 months and of 2% acetic acid.

Y. Pranoto

2012-09-01

158

Production and Optimization of Indole Acetic Acid by Indigenous Micro Flora using Agro Waste as Substrate  

Directory of Open Access Journals (Sweden)

Full Text Available 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 37C 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.

S. Yamuna Devi

2012-01-01

159

Metal chelate of uracil (4) methyl iminade acetic acid with different ? radioisotopes  

International Nuclear Information System (INIS)

The manufacture of metal chelates of the uracil (4) methyl iminade acetic acid on the laboratory scale is described. The uracil compounds with indium 113m and with technetium 99m were used for experiments on mice. (PW)

160

Bioproduction of usnic acid from acetate by kaolinite immobilized cells of Cladonia substellata Vain.  

Directory of Open Access Journals (Sweden)

Full Text Available Cells of the lichen Cladonia substellata, immobilized in kaolinite and supplied with acetate, produce at room temperature large amounts of usnic acid which can be recovered from the washing solution.

Eugenia C. Pereira

1995-06-01

161

Study of urinary excretion of acetic 5 hydroxyindole acid after irradiation  

International Nuclear Information System (INIS)

The set up for a reliable and relatively quick determination method to quantitatively follow urinary clearance changes of acetic 5 hydroxyindole acid, after whole-body irradiation by gamma rays of a cobalt 60 source, is described

162

Selective optimization in thermophilic acidogenesis of cheese-whey wastewater to acetic and butyric acids: partial acidification and methanation.  

Science.gov (United States)

For partial acidogenesis of cheese-whey wastewater, a set of experiments were carried out to produce short-chain volatile fatty acids (VFA) in laboratory-scale continuously stirred tank reactors (CSTR). The maximum rate of acetic and butyric acid production associated with simultaneous changes in hydraulic retention time (HRT), pH, and temperature was investigated, in which the degree of acidification of the whey to the short-chain VFAs was less than 20% of the influent chemical oxygen demand (COD) concentration. Response surface methodology was successfully applied to determine the optimum physiological conditions where the maximum rates of acetic and butyric acid production occurred. These were 0.40-day HRT, pH 6.0 at 54.1 degrees C and 0.22-day HRT, pH 6.5 at 51.9 degrees C, respectively. The optimum conditions for acetic acid production were selected for partial acidification of cheese-whey wastewater because of a higher rate in combined productions of acetic and butyric acids than that at optimum conditions for butyric acid production. A thermophilic two-phase process with the partial acidification followed by a methanation step was operated. Performance of the two-phase process was compared to the single-phase anaerobic system. The two-phase process clearly showed a better performance in management of cheese-whey wastewater over the single-phase system. Maximum rate of COD removal and the rate of methane production in the two-phase process were, respectively, 116% and 43% higher than those of the single-phase system. PMID:12727259

Yang, Keunyoung; Yu, Youngseob; Hwang, Seokhwan

2003-05-01

163

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

OpenAIRE

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 characterizati...

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

2012-01-01

164

Acetic Acid Bacteria and the Production and Quality of Wine Vinegar  

OpenAIRE

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 quali...

Albert Mas; Torija, Mar Xed A. Jes Xfa S.; Del Carmen Garc Xed A-parrilla, Mar Xed A.; Troncoso, Ana Mar Xed A.

2014-01-01

165

Evolution of Acetic Acid Bacteria During Fermentation and Storage of Wine  

OpenAIRE

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

Joyeux, A.; Lafon-lafourcade, S.; Ribe?reau-gayon, P.

1984-01-01

166

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

OpenAIRE

Some strains of Bradyrhizobium japonicum have the ability to catabolize indole-3-acetic acid (IAA). Examination of this catabolism in strain 110 by in vivo experiments has revealed an enzymatic activity catalyzing the degradation of IAA and 5-hydroxy-indole-3-acetic acid. The activity requires addition of the substrates for induction and is oxygen dependent. The highest activity is obtained when the concentration of inducer is 0.2 mM. Spectrophotometric data are consistent with the suggestion...

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

1991-01-01

167

Removal of radionuclides by reverse osmosis using a cellulose acetate membrane, (2)  

International Nuclear Information System (INIS)

Experiments were performed on the removal of radionuclides from radioactive liquid waste by reverse osmosis using asymmetric cellulose acetate membranes. In previous papers, we reported such removal properties as the dependence on solute concentration and the influence of co-existing material. In this paper we performed experiments on some separation properties, especially on the formation and the disappearance of concentration polarization layer of membrane surface. These experiments are necessary for the theoretical explanation of findings shown in previous papers. Concentration polarization layer is formed on the surface of the membrane, when pressurized feed solution is not stirred during reverse osmosis operation. This layer grows with elapsed time and reaches the equilibrium. The thickness of this concentration polarization layer and solute concentrations in this layer are calculated by a simple model. The formation and disappearance of this layer are experimented with intermittent stirring. The influence of intensity of stirring on the formation of concentration polarization layer is observed. These are important information on property of membrane for removing solute by reverse osmosis. (author)

168

Isolation of a strain of Clostridium thermoaceticum capable of growth and acetic acid production at pH 4. 5  

Energy Technology Data Exchange (ETDEWEB)

Using a series of pH controlled batch fermentations operated in a fed-batch mode and adaptation and selection techniques where pH and acetic acid provided the selective pressures, we isolated a culture of Clostridium thermoaceticum that can grow and produce acetic acid at pH 4.5. At pH 4.5 the fastest mass doubling time was 36 h, and the highest acetic acid concentration reached was 4.5 g/liter. Generally, as the pH was decreased from 6.0 and the initial acetic acid concentration increased, the mass doubling time increased, and the final acetic acid concentration decreased. These observations can be explained in terms of inhibition by the free acetic acid concentration at a given pH, relative to the total acetic acid concentration (free acid plus acetate ion). We have thus reached one of the criteria determined by us to be required for an economically viable fermentation acetic acid process, i.e., pH 4.5. A second requirement for a mass doubling time of about 7 h (0.1/h dilution rate) can probably be reached by selection in continuous culture. The final requirement for an acetic acid concentration of 50 g/liter will be the most difficult to achieve in view of the organism's sensitivity to low concentrations of free acetic acid. (Refs. 4).

Schwartz, R.D.; Keller, F.A. Jr.

1982-01-01

169

Recovery of arabinan in acetic acid-catalyzed hydrothermal pretreatment on corn stover  

DEFF Research Database (Denmark)

Acetic acid-catalyzed hydrothermal pretreatment was done on corn stover under 195 °C, 15 min with the acetic acid ranging from 5 × 10?3 to 0.2 g g?1 corn stover. After pretreatment, the water-insoluble solids (WISs) and liquors were collected respectively. Arabinan recoveries from both WIS and liquors were investigated. The results indicate that there was no detectable arabinan left in the WIS when the acetic acid of 0.1 and 0.2 g g?1 corn stover were used in the pretreatment. The arabinan contents in the other WISs were not more than 10%. However, the arabinan found in the liquors was not covering the amount of arabinan released from the raw corn stover. For the arabinan recovery from liquor fractions, the highest of 43.57% was obtained by the pretreatment of acetic acid of 0.01 g g?1 of corn stover and the lowest was only 26.77% when the acetic acid of 0.2 g g?1 corn stover was used. As far as the total arabinan recovery, the pretreatment with acetic acid at 0.01 g g?1 raw corn stover yielded the highest and it was 52.16%. This meant that almost half of the arabinose was degraded during the pretreatment process.

Xu, Jian; Hedegaard, Mette Christina

2009-01-01

170

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

Directory of Open Access Journals (Sweden)

Full Text Available 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.

Päivi Ylitervo

2014-07-01

171

Dissimilation of carbon monoxide to acetic acid by glucose-limited cultures of Clostridium thermoaceticum  

International Nuclear Information System (INIS)

Clostridium thermoaceticum was cultivated in glucose-limited media, and the dissimilation of CO to acetic acid was evaluated. The authors found that cultures catalyzed the rapid dissimilation of CO to acetic acid and CO2, with the stoichiometry obtained for conversion approximating that predicted from the following reaction: 4CO + 2H2O ? CH3CO2H + 2CO2. Growing cultures formed approximately 50 mmol (3 g) of CO-derived acetic acid per liter of culture, with the rate of maximal consumption approximating 9.1 mmol of CO consumed/h per liter of culture. In contrast, resting cells were found not to dissimilate CO to acetic acid. 14CO was incorporated, with equal distribution between the carboxyl and methyl carbons of acetic acid when the initial cultivation gas phase was 100% CO whereas 14CO2 preferentially entered the carboxyl carbon when the initial gas phase was 100% CO2. Significantly, in the presence of saturating levels of CO, 14CO2 preferentially entered the methyl carbon, whereas saturating levels of CO2 yielded 14CO-derived labeling predominantly in the carboxyl carbon. These findings are discussed in relation to the path of carbon flow to acetic acid

172

Dissimilation of carbon monoxide to acetic acid by glucose-limited cultures of Clostridium thermoaceticum  

Energy Technology Data Exchange (ETDEWEB)

Clostridium thermoaceticum was cultivated in glucose-limited media, and the dissimilation of CO to acetic acid was evaluated. The authors found that cultures catalyzed the rapid dissimilation of CO to acetic acid and CO/sub 2/, with the stoichiometry obtained for conversion approximating that predicted from the following reaction: 4CO + 2H/sub 2/O ..-->.. CH/sub 3/CO/sub 2/H + 2CO/sub 2/. Growing cultures formed approximately 50 mmol (3 g) of CO-derived acetic acid per liter of culture, with the rate of maximal consumption approximating 9.1 mmol of CO consumed/h per liter of culture. In contrast, resting cells were found not to dissimilate CO to acetic acid. /sup 14/CO was incorporated, with equal distribution between the carboxyl and methyl carbons of acetic acid when the initial cultivation gas phase was 100% CO whereas /sup 14/CO/sub 2/ preferentially entered the carboxyl carbon when the initial gas phase was 100% CO/sub 2/. Significantly, in the presence of saturating levels of CO, /sup 14/CO/sub 2/ preferentially entered the methyl carbon, whereas saturating levels of CO/sub 2/ yielded /sup 14/CO-derived labeling predominantly in the carboxyl carbon. These findings are discussed in relation to the path of carbon flow to acetic acid.

Martin, D.R.; Misra, A.; Drake, H.L.

1985-06-01

173

Removal of Organic Acids from Effluent via Freeze Crystallization.  

Directory of Open Access Journals (Sweden)

Full Text Available Freeze crystallization is an efficient separation process that can potentially be used in any application. Freeze crystallization is a high energy efficiency separation process that can be applied to a wide variety of industrial requirements. Although the vapor-liquid equilibrium is generally employed to separate the components of a solution, use of solid-liquid equilibrium should be considered – it may be cheaper. This paper describes a case study of recovery of acetic acid from effluent via freeze crystallization.Complete recovery of acetic acid from acetic acid-water solution by ordinary distillation is nearly impossible, because relative volatility of this mixture in the range of 1-30% of acetic acid in water is very close to one. Also, recovery of formic acid from its effluent stream by distillation is not economical viable as effluent stream of formic acid contains only 1-2% of formic acid. But the same separations are possible by freeze separation technique and it is found experimentally that large amount of acetic acid (about 70% and formic acid (about 90% can be recovered via freeze separation technique. Also it is found that the energy required for recovery of acetic acid is much lower (about 24 times than that of distillation.

Tarak C. Padhiyar

2013-05-01

174

Adsorptive removal of phenolic compounds using cellulose acetate phthalate–alumina nanoparticle mixed matrix membrane  

International Nuclear Information System (INIS)

Highlights: • Composite membrane of cellulose–acetate–phthalate and alumina nanoparticle is cast. • Surface charge of the membrane changes with nanoparticle concentration and pH. • Separation of phenolic compounds occurs due to adsorption. • The removal efficiency is maximum for 20% nanoparticle with 91% removal of catechol. • Transmembrane pressure drop has negligible effect on solute separation. -- Abstract: Mixed matrix membranes (MMMs) were prepared using alumina nanoparticles and cellulose acetate phthalate (CAP) by varying concentration of nanoparticles in the range of 10 to 25 wt%. The membranes were characterized by scanning electron micrograph, porosity, permeability, molecular weight cut off, contact angle, surface zeta potential, mechanical strength. Addition of nanoparticles increased the porosity, permeability of the membrane up to 20 wt% of alumina. pH at point of zero charge of the membrane was 5.4. Zeta potential of the membrane became more negative up to 20 wt% of nanoparticles. Adsorption of phenolic derivatives, catechol, paranitrophenol, phenol, orthochloro phenol, metanitrophenol, by MMMs were investigated. Variation of rejection and permeate flux profiles were studied for different solutes as a function of various operating conditions, namely, solution pH, solute concentration in feed and transmembrane pressure drop. Difference in rejection of phenolic derivatives is consequence of interplay of surface charge and adsorption by alumina. Adsorption isotherm was fitted for different solutes and effects of pH were investigated. Catechol showed the maximum rejection 91% at solution pH 9. Addition of electrolyte reduced the rejection of solutes. Transmembrane pressure drop has insignificant effects on solute rejection. Competitive adsorption reduced the rejection of individual solute

175

Effects of the use of acetic acid as the conservant in lucerne ensiling  

Directory of Open Access Journals (Sweden)

Full Text Available The influence of acetic acid as the chemical conservant in three doses (4, 6 8 g/kg green mass on the intensity of fermentation and proteolysis in lucerne silage was investigated. On the basis of chemical analysis, it was found that with the increase of conservant dose the pH value decreased aminogenesis and nitrogen solubility was limited. In silages treated the absolute and relative domination of acetic acid was found in total acid content. The increase of free and bonded acetic acid was discovered with the increase of conservant dose. Free butyric acid was not detected, while bonded butyric acid was present in negligible concentration, without effect on silage quality. Compared to control silage (III quality class according to DLG and Zelter method, a significant increase of acetic acid in silages resulted in the decline of their quality, and they were ranked as not useful (V quality class according to DLG method, or on the margin of usefulness (IV quality class according to Zelter method. In spite of some foreign references, domestic experiences show that acetic acid is not an effective conservant and it is not recommended for that use for lucerne that is not simple to ensile.

?or?evi? Nenad

2004-01-01

176

The fraction of cells that resume growth after acetic acid addition is a strain-dependent parameter of acetic acid tolerance in Saccharomyces cerevisiae.  

Science.gov (United States)

High acetic acid tolerance of Saccharomyces cerevisiae is a relevant phenotype in industrial biotechnology when using lignocellulosic hydrolysates as feedstock. A screening of 38 S. cerevisiae strains for tolerance to acetic acid revealed considerable differences, particularly with regard to the duration of the latency phase. To understand how this phenotype is quantitatively manifested, four strains exhibiting significant differences were studied in more detail. Our data show that the duration of the latency phase is primarily determined by the fraction of cells within the population that resume growth. Only this fraction contributed to the exponential growth observed after the latency phase, while all other cells persisted in a viable but non-proliferating state. A remarkable variation in the size of the fraction was observed among the tested strains differing by several orders of magnitude. In fact, only 11 out of 10(7)  cells of the industrial bioethanol production strain Ethanol Red resumed growth after exposure to 157 mM acetic acid at pH 4.5, while this fraction was 3.6 × 10(6) (out of 10(7)  cells) in the highly acetic acid tolerant isolate ATCC 96581. These strain-specific differences are genetically determined and represent a valuable starting point to identify genetic targets for future strain improvement. PMID:24645649

Swinnen, Steve; Fernández-Niño, Miguel; González-Ramos, Daniel; van Maris, Antonius J A; Nevoigt, Elke

2014-06-01

177

Putative ABC Transporter Responsible for Acetic Acid Resistance in Acetobacter aceti  

OpenAIRE

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. ...

Nakano, Shigeru; Fukaya, Masahiro; Horinouchi, Sueharu

2006-01-01

178

Americium removal from nitric acid waste streams  

International Nuclear Information System (INIS)

Separations research at the Rocky Flats Plant (RFP) has found ways to significantly improve americium removal from nitric acid (7M) waste streams generated by plutonium purification operations. Partial neutralization of the acid waste followed by solid supported liquid membranes (SLM) are useful in transferring and concentrating americium from nitrate solutions. Specifically, DHDECMP (dihexyl-N,N-diethylcarbamoylmethylphosphonate) supported on Accurel polypropylene hollow fibers assembled in modular form transfers >95% of the americium from high nitrate (6.9M), low acid (0.1M) feeds into 0.25M oxalic acid stripping solution. Maximum permeabilities were observed to be 0.001 cm/sec, consistent with typical values for other systems. The feed:strip volume ratio shows an inverse relationship to the fraction of metal ion transferred. Cation exchangers may be used to concentrate americium from the strip solution

179

Removal of fluoride from aqueous nitric acid  

International Nuclear Information System (INIS)

Several methods for removing fluoride from aqueous nitric acid were investigated and compared with the frequently used aluminum nitrate-calcium nitrate (Ca2+-Al3+) chemical trap-distillation system. Zirconium oxynitrate solutions were found to be superior in preventing volatilization of fluoride during distillation of the nitric acid, producing decontamination factors (DFs) on the order of 2 x 103 (vs approx. 500 for the Ca2+-Al3+ system). Several other metal nitrate systems were tested, but they were less effective. Alumina and zirconia columns proved highly effective in removing HF from HF-HNO3 vapors distilled through the columns; fluoride DFs on the order of 106 and 104, respectively, were obtained. A silica gel column was very effective in adsorbing HF from HF-HNO3 solutions, producing a fluoride DF of approx. 104

180

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

Science.gov (United States)

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

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

2012-06-01

181

Two-dimensional hydrogen-bonded polymers in the crystal structures of the ammonium salts of phen­oxy­acetic acid, (4-fluoro­phen­oxy)acetic acid and (4-chloro-2-methyl­phen­oxy)acetic acid  

Science.gov (United States)

The structures of the ammonium salts of phen­oxy­acetic acid, NH4 +·C8H6O3 ?, (I), (4-fluoro­phen­oxy)acetic acid, NH4 +·C8H5FO3 ?, (II), and the herbicidally active (4-chloro-2-methyl­phen­oxy)acetic acid (MCPA), NH4 +·C9H8ClO3 ?·0.5H2O, (III) have been determined. All have two-dimensional layered structures based on inter-species ammonium N—H?O hydrogen-bonding associations, which give core substructures consisting primarily of conjoined cyclic motifs. The crystals of (I) and (II) are isomorphous with the core comprising R 1 2(5), R 1 2(4) and centrosymmetric R 4 2(8) ring motifs, giving two-dimensional layers lying parallel to (100). In (III), the water mol­ecule of solvation lies on a crystallographic twofold rotation axis and bridges two carboxyl O atoms in an R 4 4(12) hydrogen-bonded motif, creating two R 4 3(10) rings, which together with a conjoined centrosymmetric R 4 2(8) ring incorporating both ammonium cations, generate two-dimensional layers lying parallel to (100). No ?–? ring associations are present in any of the structures. PMID:25552984

Smith, Graham

2014-01-01

182

Mixed metal zinc (II)-molybdenum (VI) peroxo complexes containing some amino acids and acetic acid  

International Nuclear Information System (INIS)

A facile synthesis of the title complexes which involve glycylglycine (Gg) glycine (Gly) and acetic acid (HAc) as ligands is reported. Reaction of equimolar mixtures of zinc and molybdic acid (MoO3.H2O) with Gg, or Gly or Ac, in excess hydrogen peroxide (H2O2) at ambient conditions, results in the formation of novel mixed metal complexes having the general formula, [Zn, Mo(O)2(O22-)(L)2(H2O)2], (L = Gg- or Gly- or Ac-). These new complexes have been characterised by elemental and thermogravimetric analyses, IR and electronic spectra. It is of interest to note that while heteronuclear peroxo complexes are quickly formed, the corresponding homonuclear Zn complexes could not be obtained. (author)

183

Production of acetic acid by Clostridium thermoaceticum in batch and continuous fermentations  

Energy Technology Data Exchange (ETDEWEB)

Batch and continuous fermentations with Clostridium thermoaceticum (ATCC 39073) using automatic pH control were conducted. The value of ..mu.. max obtained from batch fermentation was about 0.14/h, acetate yield, which was both growth and non-growth associated, was about 2 mole of acetic acid/mole of glucose, compared with a theoretical maxi..mu..m value of 3. This low yield, compared with literature data, may be explained by glucose loss through a combination of degradation routes. Continuous fermentation could be sustained for 1600 h or more without contamination problems. Continuous fermentation at high dilution rates indicates that mu max may be well above 0.17/h when fresh feed medium is used. Acetate yields in continuous fermentation were about 77% of theoretical or 2.3 mole of acetic acid/mole of glucose. 13 references.

Sugaya, K.; Tuse, D.; Jones, J.L.

1986-05-01

184

Production of acetic acid by Clostridium thermoaceticum in batch and continuous fermentations.  

Science.gov (United States)

Batch and continuous fermentations with Clostridium thermoaceticum (ATCC 39073) using automatic pH control were conducted. The value of mu(max) obtained from batch fermentation was about 0.14 h(-1); acetate yield, which was both growth and non-growth associated, was about 2 mole of acetic acid/mole of glucose, compared with a theoretical maximum value of 3. This low yield, compared with literature data, may be explained by glucose loss through a combination of degradation routes. Continuous fermentation could be sustained for 1600 h or more without contamination problems. Continuous fermentation at high dilution rates indicates that mu(max) may be well above 0.17 h(-1) when fresh feed medium is used. Acetate yields in continuous fermentation were about 77% of theoretical or 2.3 mole of acetic acid/mole of glucose. PMID:18555379

Sugaya, K; Tusé, D; Jones, J L

1986-05-01

185

A PreliminaryReport on the Mechanism of the Decomposition ofDiacetyl Peroxide in Acetic Acid  

Energy Technology Data Exchange (ETDEWEB)

The decomposition of diacetyl peroxide in acetic acid-2-C{sup 14} has been studied, The activity of the products in general confirmed the mechanism of the reaction as proposed by Kharasch and Gladstone, The presence and distribution of activity in the methyl acetate produced in this reaction is not explained by the previously proposed mechanism. There was no appreciable exchange of acetic acid and diacetyl peroxide under the conditions of the reaction. Essentially no exchange of methyl acetate and acetic acid was observed when those reagents mere heated at 100 for five hours.

Fry, A.J.; Tolbert, B.M.; Calvin, Melvin

1949-12-29

186

Selectivity of colour reactions between elements and organic reagents in organo-aqueous acetic acid media  

International Nuclear Information System (INIS)

Reasons, responsible for selectivity of photometric reactions in organo-aqueous acetic acid media, have been studied taking aluminium, gallium, and indium reactions as examples. Solution-and paper electrophoresis as well as distribution chromatography were used to examine the state of the elements in various media, including those for most selective determination of aluminium in the presence of gallium and indium. A high selectivity is due to the formation of an electrically neutral species of aluminium. And chloride complexes of gallium and indium in organo-aqueous acetic acid media. Coloured ternary complexes of aluminium with organic reagents and phosphoric acid are formed in the presence of the latter

187

Effect of fluorophenylalanine on indole-3-acetic acid levels in Aveaa coleoptiles  

Directory of Open Access Journals (Sweden)

Full Text Available The effect of the amino acid analogue D,L-p-fluorophenylalanine on indole-3-acetic acid levels in Avena has been examined. Previous studies have established that D,L-p-fluorophenylalanine promotes elongation, lowers phenolic levels and depresses auxin oxidase activity of etiolated Avena coleoptiles. This study employs an enzyme immunoassay to measure endogenous indole-3-acetic acid concentrations in coleoptile apices. These data demonstrate that treatment of Avena coleoptiles with D,L-p-fluorophenylalanine results in altered auxin levels and help clarify the mechanism of D,L-p-fluorophenylalanine action in Avena

Andrew B. Maksymowych

1988-12-01

188

Kinetic Resolution of Racemic Amino Alcohols through Intermolecular Acetalization Catalyzed by a Chiral Brønsted Acid.  

Science.gov (United States)

The kinetic resolution of racemic secondary alcohols is a fundamental method for obtaining enantiomerically enriched alcohols. Compared to esterification, which is a well-established method for this purpose, kinetic resolution through enantioselective intermolecular acetalization has not been reported to date despite the fact that the formation of acetals is widely adopted to protect hydroxy groups. By taking advantage of the thermodynamics of acetalization by the addition of alcohols to enol ethers, a highly efficient kinetic resolution of racemic amino alcohols was achieved for the first time and in a practical manner using a chiral phosphoric acid catalyst. PMID:25581575

Yamanaka, Takuto; Kondoh, Azusa; Terada, Masahiro

2015-01-28

189

Comparative analysis of acetic and citric acid on internal milieu of broiler chickens  

Directory of Open Access Journals (Sweden)

Full Text Available Normal 0 21 false false false CS JA X-NONE The aim of the present study was to analyse the effect of two organic acids (acetic and citric acid inclusion on serum parameters and the level of antioxidant status of broiler chickens. Some organic acidifiers reduce the growth of many intestinal bacteria, reduce intestinal colonisation and reduce infectious processes, decrease inflammatory processes at the intestinal mucosa, increase villus height and function of secretion, digestion and absorption of nutrients. Broiler chickens hybrid Ross 308 (n=180 were divided into 3 groups: one control (C and two experimental groups (E1, E2. Experimental animals received acetic and citric acid per os in water in single dose 0.25% for 42 days. After 42 days of feeding blood samples were collected (n=10 in each group. Significant decrease of serum triglycerides in citric acid group when compared with the control group was recorded. Acetic acid administration resulted in increased sodium level. Significant increase of albumin content in both experimental groups and increase of bilirubin content in citric group was recorded. Acids administration had no significant effect on other serum and antioxidant parameters. Acetic and citric acid had no harmful influenced on internal milieu of broiler chickens. The research on the field of organic acid will be worthy of further investigation.

Marcela Capcarova

2014-02-01

190

Silicotungstic Acid Modified Bentonite: An Efficient Catalyst for Synthesis of Acetal Derivatives of Aldehydes and Ketones  

OpenAIRE

Acetals and ketals are among the important materials of organic synthesis and as protecting agent of carbonyl functionality. A milder, efficient and green synthesis of acetals and ketals has been developed using Silicotungstic acid modified Bentonite (STA-Ben) as a catalyst. STA-Ben has been synthesized and characterized by various analytical techniques. It has been found to be an efficient and reusable catalyst for the synthesis ...

Reshu Chaudhary; Monika Datta

2013-01-01

191

Synthesis of 2-(6-Acetamidobenzothiazolethio)acetic Acid Esters as Photosynthesis Inhibitors  

OpenAIRE

The synthesis and photosynthesis-inhibiting activity of 13 new 2-(6-acetamidobenzothiazolethio)acetic acid esters are reported. The new compounds were prepared by acetylation of 2-(alkoxycarbonylmethylthio)-6-aminobenzothiazoles with acetic anhydride. The structure of the compounds was verified by 1H NMR spectra. The compounds inhibit photosynthetic electron transfer in spinach chloroplasts. The structure - activity relation was studied. Lipophilicity was found to influence substantially phot...

Dusan Loos; Katarina Kralova; Eva Sidoova

1998-01-01

192

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

DEFF Research Database (Denmark)

Feeding fermented liquid feed (FLF) to pigs has proven to benefit gastrointestinal health of the animals. However, growth performance data of piglets and growing pigs fed FLF are variable and often a lower feed intake compared to feeding non-FLF or dry feed has been observed. Accumulation of microbial metabolites, namely acetic acid, possibly in combination with low feed pH, has been suggested to be determinant in reducing feed intake by impairing palatability. However, this hypothesis has never been investigated. A study was carried out to determine the impact of increasing levels of acetic acid in FLF on feed intake of weaners. Three experimental FLF diets were prepared to contain varying levels of acetic acid (30, 60, and 120 mM). Twenty piglets per treatment, weaned at 4 weeks of age and housed individually, were fed the experimental diets during six weeks starting at weaning. Feed intake and body weight were registered weekly. The results showed that high acetic acid concentration in FLF, accompanied by a slight lower pH level, tended to decrease feed intake without affecting body weight gain. This discrepancy could partly be explained by the difficulty in measuring accurately feed intake on dry matter basis when feeding liquid feed to pigs. In conclusion, concentrations of acetic acid, at the levels normally measured in FLF, are not expected to affect markedly growth performance of piglets

Canibe, Nuria; Pedersen, Anni Øyan

2010-01-01

193

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

Science.gov (United States)

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

194

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

Directory of Open Access Journals (Sweden)

Full Text Available 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.

Miguel Macías Macías

2012-12-01

195

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

Science.gov (United States)

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

196

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

Science.gov (United States)

It was found for the first time that citric acid was decomposed to formic acid, acetic acid and lactic acid in the presence of coal ash particles at pH 3 at 20 degrees C, while it was not decomposed at more than pH 5. The yield of organic acid at stirring time of 60 min is in the order of formic acid>acetic acid>lactic acid. Since citric acid dissociates to citric anion at more than pH 5, it was suggested that citric anion and negatively charged coal ash particles repelled electrically each other at more than pH 5, resulting in that citric acid could not be adsorbed and not be decomposed on coal ash. Based on the obtained results, the decomposition of citric acid at pH 3 was suggested to be due to catalytic effects of coal ash. Since formic acid and acetic acid can be used as a material of hydrogen fermentation, coal ash could be used as a catalyst to synthesize the important material for hydrogen fermentation from wastewater of citric acid. PMID:19272701

Nakui, Hiroyuki; Okitsu, Kenji; Maeda, Yasuaki; Nishimura, Rokuro

2009-08-30

197

Effect of acetic acid on wet patterning of copper/molybdenum thin films in phosphoric acid solution  

Energy Technology Data Exchange (ETDEWEB)

Copper metallization is a key issue for high performance thin film transistor (TFT) technology. A phosphoric acid based copper etchant is a potentially attractive alternative to the conventional hydrogen peroxide based etchant due to its longer-life expectancy time and higher stability in use. In this paper, it is shown that amount of the acetic acid in the phosphoric based copper etchant plays an important role in controlling the galvanic reaction between the copper and the molybdenum. As the concentration of acetic acid in the phosphoric mixture solution increased from 0 M to 0.4 M, the measured galvanic current density dropped from 32 mA/cm{sup 2} to 26 mA/cm{sup 2}, indicating that the acetic acid induces the lower galvanic reaction between the copper and the molybdenum in the solution. From the XPS analysis, with the addition of the acetic acid, the thickness of the protective MoO{sub 2} passive film covering the molybdenum surface grew and the dissolution rate of the molybdenum thin film decreased. However, the dissolution rate of the copper thin film increased as the concentration of acetic acid in the mixture solution increased.

Seo, Bo.-Hyun; Lee, Sang-Hyuk; Park, In-Sun [Department of Materials Engineering, Korea Aerospace University, Hwajeon, Goyang, Gyonggi-do 412-791 (Korea, Republic of); Seo, Jong Hyun, E-mail: jhseo@kau.ac.kr [Department of Materials Engineering, Korea Aerospace University, Hwajeon, Goyang, Gyonggi-do 412-791 (Korea, Republic of); Choe, HeeHwan; Jeon, Jae-Hong [School of Electronics, Telecommunications and Computer Engineering, Korea Aerospace University, Hwajeon, Goyang, Gyonggi-do 412-791 (Korea, Republic of); Hong, Munpyo [Display and Semiconductor Physics, Korea University (Korea, Republic of); Lee, Yong Uk [PETEC (The Printable Electronics Technology Centre) (United Kingdom); Winkler, Joerg [PLANSEE Metal GmbH, Metallwerk-Plansee-Str. 71A-6600, Reutte (Austria)

2011-08-01

198

Pitting Corrosion of Tin by Acetate Anion in Acidic Media  

Directory of Open Access Journals (Sweden)

Full Text Available The corrosion behaviour of tin is studied in acetate buffer solutions (pH 4.5. The potentiodynamic anodic polarization curve in 0.1M acetate solution exhibits two anodic peaks A1 and A2 prior to the passive layer formation region which is followed by pitting corrosion. A1 and A2 are attributed to stannous and stannic species formation. The effect of scan rate on the potentiodynamic behaviour of tin in this solution was studied. It showed that the corrosion process in the potential range of peaks A1 and A2 is mass transport controlled. Pitting corrosion is confirmed by light microscope images. The negative going scans of the cyclic voltammograms show three cathodic peaks C1, C2 and C3. The potentiostatic current time transients, at different electrolyte concentrations and applied potentials (around the pitting potential involve three stages. The first stage, in which current decreases rapidly with time till reaching a minimum value im at the incubation time ti . The second and third stages, where current increases again linearly with time at two different slopes, are correlated to the pit nucleation and growth respectively. The nucleation rate (ti-1 was found to increase with increasing the electrolyte concentration and the anodic applied potential. The impedance spectra, at potentials of passive layer and pitting formations, exhibit a high frequency conductive semicircle and a low frequency inductive loop. The results showed a decrease in the electrode impedance as the applied potential approached the pitting potential.

Hamdy H. Hassan, Khalid Fahmy

2008-01-01

199

Synthesis and Antiradical/Antioxidant Activities of Caffeic Acid Phenethyl Ester and Its Related Propionic, Acetic, and Benzoic Acid Analoguesc  

OpenAIRE

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

Mohamed Touaibia; Surette, Marc E.; He?bert, Martin J. G.; Pare?, Aure?lie F.; Jacques Jean-François; Leblanc, Luc M.

2012-01-01

200

THIOGLYCOLIC ACID ESTERIFIED IN TO RICE STRAW FOR REMOVING LEAD FROM AQUEOUS SOLUTION  

Directory of Open Access Journals (Sweden)

Full Text Available Thiol rice straw (TRS was prepared by esterifying thioglycolic acid onto rice straw in the medium of acetic anhydride and acetic acid with sulfuric acid as catalyst. The sorption of lead (Pb on TRS from aqueous solution was subsequently investigated. The batch experiments showed that Pb removal was dependent on initial pH, sorbent dose, Pb concentration, contact time, and temperature. The maximum value of Pb removal appeared at pH 5. For 100 mg/L of Pb solution, a removal ratio of greater than 98% could be achieved with 2.0 g/L or more of TRS. The isothermal data of Pb sorption conformed well to the Langmuir model, and the maximum sorption capacity (Qm of TRS for Pb was 104.17 mg/g. The equilibrium of Pb removal was reached within 120 min. The Pb removal process could be described by the pseudo-first-order kinetic model. The thermodynamic study indicated that the Pb removal process was spontaneous and endothermic.

R. Gong

2011-09-01

201

The Effect of Curcumin (Active Substance of Turmeric)on the Acetic Acid-Induced Visceral Nociception in Rats  

OpenAIRE

In the present study, the effect of chronic oral administration of curcumin in the presence or absence of morphine and noloxone was investigated on the visceral nociception induced by acetic acid in rats. Intraperitoneal injection of acetic acid (1 mL, 2%) produced contractions in the abdominal musculature (writhes). The latency time to the beginning of the first writhe was measured and the total number of writhes in the 1 h after acetic acid injection was counted. The latency time to the ...

Hossein Tajik; Esmaeal Tamaddonfard; Nasrin Hamzeh-Gooshchi

2008-01-01

202

Cyclodextrin-grafted electrospun cellulose acetate nanofibers via “Click” reaction for removal of phenanthrene  

Science.gov (United States)

Beta-cyclodextrin (?-CD) functionalized cellulose acetate (CA) nanofibers have been successfully prepared by combining electrospinning and “click” reaction. Initially, ?-CD and electrospun CA nanofibers were modified so as to be azide-?-CD and propargyl-terminated CA nanofibers, respectively. Then, “click” reaction was performed between modified CD molecules and CA nanofibers to obtain permanent grafting of CDs onto nanofibers surface. It was observed from the SEM image that, while CA nanofibers have smooth surface, there were some irregularities and roughness at nanofibers morphology after the modification. Yet, the fibrous structure was still protected. ATR-FTIR and XPS revealed that, CD molecules were successfully grafted onto surface of CA nanofibers. The adsorption capacity of ?-CD-functionalized CA (CA-CD) nanofibers was also determined by removing phenanthrene (polycyclic aromatic hydrocarbons, PAH) from its aqueous solution. Our results indicate that CA-CD nanofibers have potential to be used as molecular filters for the purpose of water purification and waste water treatment by integrating the high surface area of nanofibers with inclusion complexation property of CD molecules.

Celebioglu, Asli; Demirci, Serkan; Uyar, Tamer

2014-06-01

203

Peroxidase activity may play a role in the cytotoxic effect of indole acetic acid.  

Science.gov (United States)

Peroxidase activity in neutrophils is higher than in thioglycollate macrophages, while in lymphocytes this enzyme activity is very low. Indole-3-acetic acid is oxidized by peroxidase and the role of this enzyme in the cytotoxic effect of the compound was evaluated by measuring oxygen consumption, light emission and cell death in neutrophils, macrophages and lymphocytes. The increase in light emission, oxygen consumption and rate of cell death in cells cultured in the presence of indole-3-acetic acid presented a direct correlation with the peroxidase activity of the cells as follows: neutrophils > thioglycollate macrophages > resident macrophages > lymphocytes. Indeed, in lymphocytes that possess very low peroxidase activity, indole-3-acetic acid did not result in an increase in light emission or oxygen consumption and it was not cytotoxic. PMID:9066308

de Melo, M P; Curi, T C; Curi, R; Di Mascio, P; Cilento, G

1997-02-01

204

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

International Nuclear Information System (INIS)

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

205

EFFECTS OF PH ON ACETIC ACID PRODUCTION FROM LACTOSE BY AN ANAEROBIC MIXED CULTURE FERMENTATION (MIXED CULTURE)  

OpenAIRE

Acetic acid was successfully produced from lactose or whey permeate by mixed culture fermentation of Clostridium formicoaceticum (ATCC 27076) and Streptococcus lactis (strain ML1) at pH 7.0 - 7.6, 35(DEGREES)C. The yield of acetic acid from lactose was about 95%. The final acetic acid concentration in the fermentation broth was higher than 30 g/L, although the fermentation rate was very slow at acetic acid concentration higher than 20 g/L (0.33 M).^ The pH range for C. formicoaceticum grow...

Tang, I-ching

1986-01-01

206

Determination of 4-Chloroindole-3-Acetic Acid Methyl Ester in Lathyrus Vicia and Pisum by Gas Chromatography - Mass Spectrometry  

DEFF Research Database (Denmark)

4-Chloroindole-3-acetic acid methyl ester was identified unequivocally in Lathyrus latifolius L., Vicia faba L. and Pisum sativum L. by thin layer chromatography, gas chromatography and mass spectrometry. The gas chromatographic system was able to separate underivatized chloroindole-3-acetic acid methyl ester isomers. The quantitative determination of 4-chloroindole-3-acetic acid methyl ester in immature seeds of these three species was performed by gas chromatography – mass spectrometry using deuterium labelled 4-chloro-indole-3-acetic acid methyl ester as an internal standard. P. sativum contained approximately 25 mg kg-1, V. faba 1–2 mg kg-1 and L. latifolius 2 mg kg-1 dry weight.

Engvild, Kjeld Christensen; Egsgaard, Helge

1980-01-01

207

Preventive activity of ascorbic acid on lead acetate induced cerebellar damaged in adult Wistar rats  

Directory of Open Access Journals (Sweden)

Full Text Available Among the environmental contaminants, lead is one of the most hazardous to living matter. In mammals, the main target is the central nervous system, particularly in the young. Ascorbic acid is an antioxidant which is a substance that may protect your cells against the effects of free radicals. This study investigated Experiment the protective effect of ascorbic acid on the cerebellum of adult Wistar rats following oral administration of different doses of Lead acetate. Thirty adult Wistar rats of average weight of 215g were used in this study. The animals were divided into five (5 groups of six animals per group and were administered different doses of lead acetate (60mg/kg bwt of 1/10th LD50 and 30mg/kg bwt of 1/20th of LD50 and ascorbic acid (4.3mg/kg bwt orally over a period of three (3 weeks.Group 1 (control was administered distilled water and Group 2 and 3 were administered 30mg/kg and 60mg/kg of Lead acetate respectively while Group 4 and 5 were given co-administration of 30mg/kg of Lead acetate 4.3mg/kg of ascorbic acid and 60gm/kg of Lead acetate 4.3mg/kg of ascorbic acid respectively. Histopathologically, Lead acetate induced cellular damage in the cerebellum of adult Wistar rats and it was also observed that ascorbic acid prevents or minimize lead-induced cellular damage in the cerebellum of adult Wistar rats.

Sunday Abraham Musa

2012-12-01

208

Effects of combined heat and acetic acid on natural microflora reduction on cantaloupe melons.  

Science.gov (United States)

Produce is an important source of nutrients and phytochemicals, which is important in a healthy diet. However, perishable fresh produce has caused recent outbreaks of foodborne diseases. High level of nutrients and water activity, direct contact with soil, and lack of thermal procedures during primary processing make fresh produce a potential food safety hazard. Fruits and vegetables with rough surfaces can harbor microorganisms and support their multiplication, increasing the risk of this hazard. This study evaluated the effects of extreme thermal processes combined with acetic acid on natural microflora reduction on cantaloupe melons. Melons from a local supermarket were assigned into five treatment groups: control, water at 25 degrees C, water at 95 degrees C, 5% acetic acid at 25 degrees C, and 5% acetic acid at 95 degrees C. Four skin samples were obtained from each melon, separately stomached for 2 min with 0.1% peptone water, and serially diluted. Aerobic plate counts (APC) of dilutions were determined. Statistical analysis (least significant difference-based analysis of variance) showed that there were no significant (P > 0.05) differences in APC among control, water at 25 degrees C, and 5% acetic acid at 25 degrees C. Thermal treatments with water at 95 degrees C, and 5% acetic acid at 95 degrees C, were both significantly (P < 0.05) more effective in APC reduction than were nonthermal treatments, but were not significantly different from each other. Results indicated that a thermal water immersion intervention in primary processing of fresh melons can result in a 3-log reduction of natural microflora surface contamination, but 5% acetic acid will not significantly augment this reduction. PMID:20501053

Fouladkhah, Aliyar; Avens, John S

2010-05-01

209

Performance of Granular Activated Carbon to 2,4-Dichlorophenoxy Acetic Acid Aemoval from Aqueous Environments  

Directory of Open Access Journals (Sweden)

Full Text Available Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 Background and Objectives: 2, 4-dichlorophenoxy acetic acid is a well-known herbicide which can be dangerous for  both human and animal health in different ways such as its presence in drinking water. This study aimed at Performance of granular activated carbon to 2-4-D removal from aqueous solution and assessing the relationship between COD and 2-4-D concentration Materials and Methods: This study is a lab-scale study. Firstly, different 2-4-D concentrations were prepared from Stock solution (1000 mg/L, and then their CODs were measured. Optimum pH for 2-4-D removal was determined and its absorption rate at different concentrations was measured. Results: Results showed a clear relationship between COD and 2-4-D concentration. On the other hand, COD removal increased as time elapsed, so that maximum removal 90% and 84% at initial 2-4-D concentrations of 50 and 100 mg/L were observed at contact time of 50 min respectively. Optimum pH for all concentrations was determined as 6. Conclusion: According to present study it can be concluded that activated carbon have be up to 90% of 2-4-D removal from water environment. In addition, a significant relationship was observed between COD and 2-4-D concentration, so that direct measurement of COD can be used instead of 2-4-D measurement. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;}

Meghdad Pirsaheb

2012-04-01

210

Extractive Distillation of Acetic Acid from its Dilute Solution using Lithium Bromide  

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Full Text Available Separation and purification are an integral part and a major cost factor in the chemical industry. Distillation is a very commonly used for solvent separation and purification process. It is neither cost effective nor process efficient when dealing with close-boiling and azeotropic solvent mixtures without modifying the relative volatility of the solvent components with an extraneous solvent or a non-volatile solute electrolyte or nonelectrolyte. The selection of a suitable modifier generally depends on the experimental determination of its effect on the Vapour–Liquid Equilibrium (VLE of the solvent mixture. Acetic acid is most widely used as aliphatic carbonic acid. It is frequently used as a solvent like in manufacture of cellulose acetate or in manufacture of many pharmaceutical products. Aqueous acetic acid is obtained during these processes and recovery of which is of great significance. Separation of pure water from dilute solution of Acetic acid –water mixture in the concentration range of 1 % to 30 % Acetic acid by simple rectification is almost impossible as relative volatility of the mixture in this range approaches unity.We would then require towers with large number of stages which would be operated with high reflux ratio and required high energy costs and operating costs. In practice extraction with suitable solvent is carried out before pure recovery occurs during the rectification of azeotropic mixture. An alternative separation process is the addition of Lithium Bromide(LiBr salt into acetic-acid water solution . Lithium bromide is largely soluble in water. Addition of salt will increase the boiling point of salt-water solution, there by separating comparatively pure acetic acid as overhead product. LiBr–water solution remains as residue from which LiBr can be readily separated by evaporation and reused. Experiments are carried out in laboratory with different concentrations of Acetic acid-water, in Othmer still which is vapor-liquid equilibrium apparatus. An Extractive distillation column will be designed based on experimental results. Cost analysis of this new separation technique will be carried out. The experimental data will be correlated to any model to calculate activity coefficients

R.P.Bhatt

2012-04-01

211

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

Science.gov (United States)

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

212

Effects of Pfaffia glomerata (Spreng) pedersen aqueous extract on healing acetic acid-induced ulcers  

OpenAIRE

The present study was carried out to evaluate the acute toxicity and the effect of the aqueous extract of the roots from Pfaffia glomerata (Spreng) Pedersen (Amaranthaceae) (AEP) on the prevention of acetic acid-induced ulcer and on the healing process of previously induced ulcers. The acute toxicity was evaluated in Swiss mice after oral administration of a single dose and the chronic gastric ulcer was induced with local application of acetic acid. The results showed that the LD50 of the ext...

Cristina Setim Freitas; Cristiane Hatsuko Baggio; Samanta Luiza Araújo; Maria Consuelo Andrade Marques

2008-01-01

213

THE EFFECTS OF ANIMAL AGE AND ACETIC ACID CONCENTRATION ON PIGSKIN GELATIN CHARACTERISTICS  

OpenAIRE

This research was aimed to study the influence of animal age and concentration of the acetic acid solution on physical and chemical properties of pigskin gelatin. The experiment used Completely Randomized Design (CRD) with two factors. The first factor was animal age consisted of 3 levels (5, 7 and 9 months). The second factor was concentration of acetic acid solution consisted of 3 levels (2, 4 and 6 percents). The result showed that animal age had significant effect (P<0.01) on the yields...

Pranoto, Y.; Pertiwiningrum, A.; Triatmojo, S.; Sompie, M.

2012-01-01

214

Polarographic study of Cd(2), Pb(2), Hg(1) in anhydrous acetic acid  

International Nuclear Information System (INIS)

Anhydrous acetic acid is a solvent which can be compared to water as far as its behaviour towards acid-base reactions is concerned. It is in fact, like water both a proton acceptor (basic) - and as such it can provoke the dissociation of acids - and a proton donor (acid). This amphoteric behaviour is characterized by the equilibrium: 2 H O Ac ? Ac OH2+ + Ac O- with Ki = |Ac O H2|+ |Ac O-| = 10-14.5 analogue to 2 H2O ? H3O+ + HO- with Ki = |H3O+| |HO-| = 10-14 The acid-base reactions can in principle be characterized by a pH scale based on a definition similar to that for the pH scale in aqueous solutions. The essential difference however between aqueous and acetic acid solutions is due to the fact that acetic acid has a low dielectric constant. ? = 6.1 (at 25 deg. C) The ions therefore remain associated, almost completely, in the form of ion-pairs produced as a result of the strong electrostatic interactions. This phenomenon requires us to modify the reasoning usually applied to aqueous solutions. The new general methods of reasoning have been established and discussed by G. CHARLOT and B. TREMILLON. We will make use of them for the particular case under consideration. In the first part, we have employed the polarographic method for the study of the acetic complexes of two elements: cadmium(II) and lead (II). In the second part we have tried to show that mercurous halides are formed in acetic acid; we have attempted to determine their stability. (author)

215

Anaerobic rotating disc batch reactor nutrient removal process enhanced by volatile fatty acid addition.  

Science.gov (United States)

RBC effluent needs further treatment because of water-quality standards requiring low nitrogen and phosphorus concentrations. It may be achieved by using reactors with biomass immobilized on the filling's surface as post-denitrification biofilm reactors. Due to the lack of organic matter in treated wastewater, the introduction of external carbon sources becomes necessary. The new attached growth bioreactor - anaerobic rotating disc batch reactor (ARDBR) - was examined as a post-denitrification reactor. The impact of selected volatile fatty acids on nutrient removal efficiency in an ARDBR was studied. The biofilm was developing on totally submerged discs mounted coaxially on a vertical shaft. Acetic, propionic, butyric and caproic acids were applied. Wastewaters were removed from the reactors after 24-h treatment, together with the excess solids. In the ARDBR tank, there was no biomass in the suspended form at the beginning of the treatment process. Acids with a higher number of carbon atoms (butyric and caproic) were the most efficient in denitrification process. The highest phosphorus removal efficiency was noted in the ARDBR with butyric and propionic acids. The lowest unitary consumption of the external source of carbon in denitrification was recorded for acetic acid, whereas the highest one for caproic acid. PMID:25252632

Rodziewicz, Joanna; Janczukowicz, Wojciech; Mielcarek, Artur; Filipkowska, Urszula; K?odowska, Izabella; Ostrowska, Kamila; Duchniewicz, Sylwia

2015-04-01

216

Monolaurin and acetic acid inactivation of Listeria monocytogenes attached to stainless steel.  

Science.gov (United States)

Individual and combined antimicrobial effects of monolaurin and acetic acid on Listeria monocytogenes planktonic cells or stainless-steel-adherent cells were determined in order to evaluate cell viability during a 25-min exposure period at 25 degrees C. A 10(7)-colony-forming units (CFU)/ml population of planktonic cells was completely inactivated by the synergistic combination of 1% acetic acid with 50 or 100 microg/ml of monolaurin within 25 or 20 min, respectively. Either compound alone caused partial but incomplete inactivation within the same time periods. A population of 10(5) CFU/cm2 of 1-day adherent cells on stainless steel was completely inactivated within 25 min, but with the highest concentrations of the combined chemicals, i.e., 1% acetic acid and 100 microg/ml of monolaurin. The combined chemical treatment again synergistically produced greater inhibition. A 10(6)-CFU/cm2 population of 7-day adherent cells was not completely inactivated within 25 min of exposure, although counts did decline. The results demonstrate increased resistance of attached L. monocytogenes to acetic acid and monolaurin and show that resistance increased with culture age. Combinations of organic acids and monolaurin might be considered as sanitizers of food contact surfaces, but activities of such combinations are likely to be less than other commonly used sanitizers. PMID:10463441

Oh, D H; Marshall, D L

1996-03-01

217

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

Science.gov (United States)

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

218

Formic and acetic acid: Valence threshold photoelectron and photoionisation total ion yield studies  

Energy Technology Data Exchange (ETDEWEB)

Highlights: Black-Right-Pointing-Pointer High-resolution threshold photoelectron spectrum of formic acid. Black-Right-Pointing-Pointer High-resolution total photo-ion yield spectrum of formic acid. Black-Right-Pointing-Pointer High-resolution threshold photoelectron spectrum of acetic acid. Black-Right-Pointing-Pointer High-resolution total photo-ion yield spectrum of acetic acid. -- Abstract: The carboxylic acids (formic and acetic) have been studied using threshold photoelectron (TPE) and total photoion yield (TPIY) spectroscopies; simultaneously obtained spectra of formic acid (HCOOH) were recorded over the entire valence ionisation region from 11-21 eV at a resolution of {approx}12 meV. Higher resolution spectra ({approx}6 meV) were also obtained in the energy region of the lowest two cationic states. Analysis of the TPE spectrum in this energy range agreed very favorably with the best available conventional photoelectron (PE) spectrum of formic acid. Autoionising Rydberg structure was observed in the TPIY spectrum of formic acid and is attributed primarily to the presence of the npa Prime Leftwards-Arrow 8a Prime Rydberg series converging on to the 3{sup 2}A Prime ionic state of formic acid. Preliminary results, at a resolution of {approx}8 meV, were obtained for acetic acid (CH{sub 3}COOH) over the onset of the ionisation energy region. The TPE spectrum was found to be very similar to the best published photoelectron spectrum, but no Rydberg structure was observed in the TPIY spectrum.

Siggel-King, Michele R.F., E-mail: michele.siggel-king@stfc.ac.uk [Cockcroft Institute, Daresbury Science and Innovation Campus, Daresbury, Warrington WA4 4AD (United Kingdom); Department of Physics, University of Liverpool, Liverpool L69 3BX,UK (United Kingdom); Yencha, Andrew J. [Department of Chemistry, State University of New York at Albany, Albany, NY 12222 (United States); King, George C. [Department of Physics and Astronomy and Photon Science Institute, Manchester University, Manchester M13 9PL (United Kingdom); Malins, Andrew E.R. [Cockcroft Institute, Daresbury Science and Innovation Campus, Daresbury, Warrington WA4 4AD (United Kingdom); Eypper, Marie [School of Chemistry, University of Southampton, Southampton SO17 1BJ (United Kingdom)

2012-09-15

219

Application of bipolar electrodialysis to E.coli fermentation for simultaneous acetate removal and pH control  

DEFF Research Database (Denmark)

The application of bipolar electrodialysis (BPED) for the simultaneous removal of inhibitory acetate and pH control during E. coli fermentation was investigated. A two cell pair electrodialysis module, consisting of cation exchange, anion exchange and bipolar membranes with working area of 100 cm2 each, was integrated with a standard 7 l stirred tank bioreactor. Results showed that BPED was beneficial in terms of in situ removal of inhibitory acetate and a reduction in the amount NH4OH used for pH control. In batch and fed-batch BPED fermentations, base additions were decreased by up to 50% in both cases compared to electrodialysis (ED) fermentations with pH controlled at 6.7 ± 0.1. Consequently, the final biomass (34.2 g DCW l?1) and recombinant protein (5.5 g l?1) concentrations obtained were increased by up to 37 and 20%, respectively.

Wong, M.; Woodley, John

2010-01-01

220

Combined sorption/transport of sodium dodecyl sulfate and hydrochloric acid in a blend of cellulose acetate butyrate with cellulose acetate hydrogen phthalate  

OpenAIRE

The transport of hydrochloric acid (0.001-0.1 M) and sodium dodecyl sulfate (0.001-0.1 M) has been measured through a membrane consisting of a blend of cellulose acetate butyrate and cellulose acetate hydrogen phthalate. The cellulose derivative blend is suggested to suffer an alteration in the degree of hydrophobicity when in equilibrium with sodium dodecyl sulfate (SDS) through hemimicelle formation. An increase in surface hydrophobicity of the blend when in equilibrium with SDS solution wa...

Valente, Artur J. M.; Burrows, Hugh D.; Polishchuk, Alexandre Ya; Miguel, Maria G.; Lobo, Victor M. M.

2004-01-01

221

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

Directory of Open Access Journals (Sweden)

Full Text Available 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.

K. B. Haase

2012-07-01

222

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

Science.gov (United States)

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

223

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

Directory of Open Access Journals (Sweden)

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

F. Paulot

2010-10-01

224

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

Directory of Open Access Journals (Sweden)

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

F. Paulot

2011-03-01

225

Protective Effect of Alpha-lipoic Acid Against Lead Acetate-Induced Oxidative Stress in the Bone Marrow of Rats  

OpenAIRE

The present study was designed to investigate the effects of alpha Lipoic Acid (LA) against lead acetate induced changes in free radical scavenging enzymes and lipid hydroperoxides in bone marrow of rats. Rats were exposed to lead acetate in their drinking water (500 ppm) for 14 days and alpha lipoic acid was given concurrently (25, 50 and 100 mg kg-1). Blood lead levels, lipid hydroperoxides, protein carbonyl contents and oxidative marker enzymes were estimated. Lead acetate in dr...

Srikumar Chakravarthi; Tan Jackie; Nagaraja Haleagrahara; Anupama Bangra Kulur

2011-01-01

226

Metabolism of indole-3-acetic acid in rice: identification and characterization of N-beta-D-glucopyranosyl indole-3-acetic acid and its conjugates.  

Science.gov (United States)

A search was made for conjugates of indole-3-acetic acid (IAA) in rice (Oryza sativa) using liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) in order to elucidate unknown metabolic pathways for IAA. N-beta-d-Glucopyranosyl indole-3-acetic acid (IAA-N-Glc) was found in an alkaline hydrolysate of rice extract. A quantitative analysis of 3-week-old rice demonstrated that the total amount of IAA-N-Glc was equal to that of IAA. A LC-ESI-MS/MS-based analysis established that the major part of IAA-N-Glc was present as bound forms with aspartate and glutamate. Their levels were in good agreement with the total amount of IAA-N-Glc during the vegetative growth of rice. Further detailed analysis showed that both conjugates highly accumulated in the root. The free form of IAA-N-Glc accounted for 60% of the total in seeds but could not be detected in the vegetative tissue. An incorporation study using deuterium-labeled compounds showed that the amino acid conjugates of IAA-N-Glc were biosynthesized from IAA-amino acids. IAA-N-Glc and/or its conjugates were also found in extracts of Arabidopsis, Lotus japonicus, and maize, suggesting that N-glucosylation of indole can be the common metabolic pathway of IAA in plants. PMID:17628621

Kai, Kenji; Wakasa, Kyo; Miyagawa, Hisashi

2007-10-01

227

Investigation of organic acids efficacy on rosa bourbonia waste biomass for Pb (II) removal from aqueous streams (abstract)  

International Nuclear Information System (INIS)

In the present study bio sorption technique, the accretion of metal by biomass was used for the removal of lead from aqueous streams. The adsorption characteristics of metal on Rosa bourbonia waste biomass after pretreatments with acetic acid, benzoic acid and citric acid were evaluated as a function of bio sorbent dosage, initial concentration of metal and time. The sorption capacity (mgg /sup -1/) increased with increase in initial Pb(II) ion concentration and maximum q at 400 (mg/L) was 119.92 with original biomass. The acidic pretreatments decreased the metal uptake capacity (mgg/sup -1/) in the order benzoic acid (82.58) > citric acid (70.23) > acetic acid (55.74). The kinetic data revealed that the equilibrium was established within 240 minutes for original as well as for acidically pretreated bio masses. The Langmuir isotherm model and pseudo second order kinetic model fitted well to the Pb (II) bio sorption data. (author)

228

Effect of relative humidity on copper corrosion by acetic and formic acid vapour  

Energy Technology Data Exchange (ETDEWEB)

A comparative study is made of the copper corrosion rate and corrosion products originated by acetic and formic acid vapours at 40%, 80% and 100% relative humidity (RH) using gravimetric, scanning electron microscopy, X-ray powder diffraction and X-ray photoelectron spectroscopy techniques. Five acetic and formic acid vapour concentration levels (10, 50, 100, 200 and 300 ppm) were tested for a period of 21 days at 30{sup o}C. The copper corrosion rate in the presence of acetic acid vapour was up to {approx}0.002 mg/cm{sup 2} day (mcd) for 40% RH, {approx}0.07 mcd for 80% RH and {approx}0.23 mcd for 100% RH. Formic acid vapours yielded a copper corrosion rate of up to {approx}0.005 mcd for 40% RH, {approx}0.03 mcd for 80% RH and {approx}0.13 mcd for 100% RH. The main compounds found were cuprite (Cu{sub 2}O), copper hydroxide (Cu(OH){sub 2}), copper acetate (Cu(CH{sub 3}COO){sub 2}) and copper formate (Cu(HCOO){sub 2}). (author)

Cano, E.; Bastidas, J.M. [CENIM-National Centre for Metallurgical Research (CSIC), Madrid (Spain)

2002-07-01

229

Phase behaviour of aqueous mixtures of acetic acid with isomers of xylene  

International Nuclear Information System (INIS)

Highlights: • The binodal curve and tie line data were obtained for four systems. • These systems are (water + acetic acid + o-xylene, m-xylene, p-xylene or xylenes). • Distribution coefficients and separation factors were measured. • Extraction of acetic acid by mixed xylenes is more suitable. • Experimental LLE data were correlated using NRTL model. -- Abstract: (Liquid–liquid) equilibrium (LLE) data of the solubility curves and tie-line compositions have been determined for mixtures of (water + acetic acid + organic solvent (o-xylene, m-xylene or p-xylene)) at T = 298.15 K and atmospheric pressure. The mixed isomers (xylenes) are also used as a mixed-solvent like the individual isomers and phase behaviour of (water + acetic acid + xylenes) is investigated. The experimental LLE data were correlated using the NRTL model, and the binary interaction parameters were obtained. Distribution coefficients and separation factors have been evaluated for the immiscibility region. The reliability of the experimental tie-lines has been confirmed by using Othmer–Tobias correlation

230

Hydrolysis of rice straw and rice husk to pentoses and the production of acetic acid  

Energy Technology Data Exchange (ETDEWEB)

The hemicellulose component of rice straw and rice hulls was quantatively hydrolyzed to pentoses with 1-2% H2SO4 at high temperature. This pentose solution consisted mainly of xylose, arabinose, and glucose. It was then fermented to produce acetic acid by an anaerobic, thermophilic strain of Clostridium thermoaceticum.

Yu, N.; Yin, F.S.; Hwang, A.L.; Hao, P.L.C.; Wang, S.D.; Yeh, Y.L.

1981-01-01

231

Acetic acid treatment for wrinkle-free oral mucosal epithelia in paraffin section preparation.  

Science.gov (United States)

For histopathological assessment of oral borderline malignancies, it is important to carefully detect subtle epithelial changes on fully stretched tissue sections. However, it is not generally easy to obtain wrinkle-free sections when using formalin-fixed paraffin-embedded oral mucosal samples. Since acetic acid treatment is already utilized for large brain tissue sections, we examined whether that treatment was also effective for oral mucosal tissues containing normal to malignant epithelial lesions. Paraffin sections were floated in various concentrations of acetic acid for 10 min after stretching in water for 1 min, then wrinkle formations were examined using hematoxylin and eosin staining, as well as for staining intensity with keratin immunohistochemistry. Wrinkles were formed in both epithelial and connective tissue zones of sections treated with less than a 40-mM (0.25%) concentration of acetic acid. In contrast, treatments with concentrations at 80 mM (0.5%) and higher resulted in cracking between the epithelial layer and lamina propria, as well as poor immunohistochemical results for keratins 13 and 17, even though the wrinkles completely disappeared. These results indicate that 40 mM is the optimal concentration of acetic acid solution to prevent wrinkles in the epithelial layer while maintaining the immunohistochemical qualities of oral mucosa tissue sections, especially those containing borderline malignant epithelial lesions. PMID:20623754

Ahsan, Md Shahidul; Maruyama, Satoshi; Cheng, Jun; Al-Eryani, Kamal; Yamazaki, Manabu; Hasegawa, Mayumi; Tsuneki, Masayuki; Saku, Takashi

2011-03-01

232

Karplus-type relationship for quadrupole coupling constants and asymmetry parameters for substituted acetic acids  

International Nuclear Information System (INIS)

The deuterium quadrupole coupling constant for the methyl group in acetic acid dimer was calculated as a function of the torsion angle about the carbon-carbon bond. The results show that when a deuteron approaches either of the negatively charged oxygen atoms, the quadrupole coupling constant for the deuteron is reduced by as much as 4.2 kHz. Both the calculated quadrupole coupling constant, e2q/sub zz/Q/h, and asymmetry parameter, eta, are fitted with a Karplus-type equation: e2q/sub zz/Q/h = A - 0.5491 cos theta - 1.7859 cos 2theta; eta = 0.0491 + 0.0058 cos theta - 0.0081 cos 2theta. Adiabatic demagnetization in the laboratory frame spectroscopy at 77 K for (4-chlorophenyl)[2,2-2H2]acetic acid showed two inequivalent deuteron sites that, on the basis of deuterium double transitions, are demonstrated to be due to two deuterium sites bound to the same carbon atom. The solid-state structure of (4-chlorophenyl)acetic acid was determined by single-crystal X-ray diffraction. The ADLF and structural data for (4-chlorophenyl)[2,2-2H2] acetic acid were used to obtain a preliminary value for the A parameter as 170.767 kHz

233

Effect of relative humidity on copper corrosion by acetic and formic acid vapour  

International Nuclear Information System (INIS)

A comparative study is made of the copper corrosion rate and corrosion products originated by acetic and formic acid vapours at 40%, 80% and 100% relative humidity (RH) using gravimetric, scanning electron microscopy, X-ray powder diffraction and X-ray photoelectron spectroscopy techniques. Five acetic and formic acid vapour concentration levels (10, 50, 100, 200 and 300 ppm) were tested for a period of 21 days at 30oC. The copper corrosion rate in the presence of acetic acid vapour was up to ?0.002 mg/cm2 day (mcd) for 40% RH, ?0.07 mcd for 80% RH and ?0.23 mcd for 100% RH. Formic acid vapours yielded a copper corrosion rate of up to ?0.005 mcd for 40% RH, ?0.03 mcd for 80% RH and ?0.13 mcd for 100% RH. The main compounds found were cuprite (Cu2O), copper hydroxide (Cu(OH)2), copper acetate (Cu(CH3COO)2) and copper formate (Cu(HCOO)2). (author)

234

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

Science.gov (United States)

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

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

2003-04-01

235

Preventive activity of ascorbic acid on lead acetate induced cerebellar damaged in adult Wistar rats  

OpenAIRE

Among the environmental contaminants, lead is one of the most hazardous to living matter. In mammals, the main target is the central nervous system, particularly in the young. Ascorbic acid is an antioxidant which is a substance that may protect your cells against the effects of free radicals. This study investigated Experiment the protective effect of ascorbic acid on the cerebellum of adult Wistar rats following oral administration of different doses of Lead acetate. Thirty adult Wistar rat...

Sunday Abraham Musa; Iliyasu Musa Omoniye; Wilson Oliver Hamman; Augustine Oseloka Ibegbu; Uduak Emmanuel Umana

2012-01-01

236

TGA-FTIR study of the vapors released by triethylamine-acetic acid mixtures  

OpenAIRE

Proprietary mixtures of amines and carboxylic acids are used as volatile corrosion inhibitors (VCIs) for the protection of iron and steel components against atmospheric corrosion. This study was focused on the nature of the vapors they release. VCI model compounds comprising mixtures of triethylamine and acetic acid were studied using thermogravimetric analysis coupled with Fourier-transform infrared spectroscopy (TGA–FTIR) at 50 ?C. As vaporization progressed, the composition...

Nhlapo, Nontete Susan; Focke, Walter Wilhelm; Vuorinen, Eino

2012-01-01

237

Supported Ionic Liquid Phase (SILP) Catalysis for the Production of Acetic acid by Methanol Carbonylation  

DEFF Research Database (Denmark)

The work presented here is focused on the development of a new reaction process. It applies Supported Ionic Liquid Phase (SILP) catalysis to a specific reaction. By reacting methanol and carbon monoxide over a rhodium catalyst, acetic acid can be formed. This reaction is important on a large scale industrially, with millions of tonnes of acetic acid being produced annually. Acetic acid is an important precursor for making adhesives, plastics and fabrics. By using the SILP concept we are able to carry out the reaction in a continuous system, allowing a steady production of acetic acid without having to stop and re-start the reaction. This sort of continuous flow reaction is a subject of great research effort in recent years as it is more sustainable (and in some cases financially viable) that the current method of carrying out chemical reactions in large size batch reactions The project started right at the beginning with the construction of a suitable test reactor, then followed by the synthesis and testing of all the catalysts reported. A variety of nitrogen based ionic liquids were initially tested, giving good results and stability in the system. Later a number of phosphonium based salts were tested (these were no longer classified as ionic liquids due to melting points above 100?C). The phosphonium salts showed even better activity in the system compared to the ionic liquids. Overall the work has shown that this process for the manufacture of acetic acid is viable industrially. This is backed up by the construction and operation of a pilot plant by Wacker Chemie AG in Munich.

Hanning, Christopher William

2012-01-01

238

Effect of acetic acid added to cooking water on the dissolution of proteins and activation of protease in rice.  

Science.gov (United States)

The effect of acetic acid on the dissolution of proteins in rice was studied to elucidate the mechanism for the textural change induced by the acid by chemical and SDS-PAGE analyses of the rice proteins in the soaking solution. More proteins were extracted with 0.2 M acetic acid (pH 2.7) than with water (pH 6.8). The effect of acetic acid on the protein dissolution increased with increasing temperature. Immunoblotting confirmed that, when rice was soaked in acetic acid, glutelin was dissolved into the soaking solution and degraded by aspartic proteinase. Aspartic proteinase degraded glutelin much more than it did albumin and globulin. It was found that the combined amount of albumin and globulin dissolved into the acetic acid solution was much larger than that of glutelin, despite the smaller amounts present of albumin and globulin than of glutelin. Metal ions were extracted more with acetic acid than with water. In addition, carboxypeptidase was activated under the acidic condition and resulted in an increase in the amount of free amino acids. The main effect of acetic acid on the dissolution of rice proteins was enhancement of the solubility of albumin, globulin, and glutelin, the effect of proteases being minor. PMID:12822946

Ohishi, Kyoko; Kasai, Midori; Shimada, Atsuko; Hatae, Keiko

2003-07-01

239

The Effect of Pre-chilling with Acetic and Lactic Acid on Shelf-life of Broiler Carcasses  

OpenAIRE

The effect of pre-chilling in acetic and lactic acid solutions on shelf-life of broiler carcass was investigated. Broiler carcasses were subjected to a 10-min pre-chill treatment with acetic acid, lactic acid and combination of them and examined for their sensorial properties, microbiological quality, pH values and ammonia levels. Treating with organic acids decreased initial microbial load of the carcasses, but not changed their colour, odour and appearance. Controls were spoiled on the 4

Kamil Bostan; Harun Aksu; Esra Ersoy; Ozge Ozgen; Muammer Ugur

2001-01-01

240

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

OpenAIRE

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

Tupper, J.; Stratford, MR; Hill, S.; Tozer, Gm; Dachs, Gu

2010-01-01

241

Flavone acetic acid (FAA) with recombinant interleukin-2 (rIL-2) in advanced malignant melanoma. IV: Pharmacokinetics and toxicity of flavone acetic acid and its metabolites.  

OpenAIRE

Flavone acetic acid (FAA) was administered at a dose of 4.8 g m-2 over 1 h to patients with advanced malignant disease in combination with Interleukin II. A new high performance liquid chromatography method is described to determine both the parent compound and eight drug-related products, and the conditions required to determine these components in plasma are discussed. The half-life over the first 8 h was 2.3 h, but the terminal clearance of the drug was extremely slow. Severe (WHO Grade 4)...

Stratford, M. R.; Rustin, G. J.; Dennis, M. F.; Watfa, R. R.; Howells, N.; O Reilly, S. M.

1993-01-01

242

The removal of dissolved humic acid during estuarine mixing  

Science.gov (United States)

A simple method for the determination of dissolved humic acid based on carbon analysis is presented. This method was used to measure the distribution of dissolved humic acids in seven coastal plain estuaries located in the middle-Atlantic United States. Results indicate that 100% of the dissolved humic acid was removed during estuarine mixing, although concurrent measurements of dissolved organic carbon showed either production or conservative behavior in regions of the estuary where humic acid removal was observed. It is apparent from these observations that removal of dissolved humic acid is a minor part of the estuarine transport of dissolved organic carbon. Laboratory experiments carried out by mixing river water with sea water demonstrated that salt-induced removal of dissolved humic acid was insignificant in two of three estuaries studied. These results suggest in situ removal of dissolved humic acid may not be universally caused by increasing estuarine salinity.

Fox, L. E.

1983-04-01

243

Clostridium stain which produces acetic acid from waste gases  

Science.gov (United States)

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

244

Acetic acid production from marine algae. Progress report No. 1, July 1--September 30, 1977  

Energy Technology Data Exchange (ETDEWEB)

Progress is reported in research designed to develop an economically competitive process for producing acetic acid from biomass for the purpose of sparing petroleum for other uses, to evaluate marine algae as a potential source of biomass, and to document the feasibility of running fermentations in fixed packed bed fermenters. It was demonstrated that marine algae can be fermented to acetic acid. Initial rates of up to 168 meq/1 day were observed. These rates are substantially in excess of the 47 meq/1 day used in the economic projections. Also, when using marine algae as a substrate, acid levels were generated equivalent to the highest reported with other substrates. It was also demonstrated that a 4-foot fixed packet bed fermenter may be operated with marine algae as a substrate at 20 percent solids or 200 meq/1.

Sanderson, J.E.; Augenstein, D.C.; Wise, D.L.

1977-10-14

245

An on-line potentiometric sequential injection titration process analyser for the determination of acetic acid.  

Science.gov (United States)

An on-line potentiometric sequential injection titration process analyser for the determination of acetic acid is proposed. A solution of 0.1 mol L(-1) sodium chloride is used as carrier. Titration is achieved by aspirating acetic acid samples between two strong base-zone volumes into a holding coil and by channelling the stack of well-defined zones with flow reversal through a reaction coil to a potentiometric sensor where the peak widths were measured. A linear relationship between peak width and logarithm of the acid concentration was obtained in the range 1-9 g/100 mL. Vinegar samples were analysed without any sample pre-treatment. The method has a relative standard deviation of 0.4% with a sample frequency of 28 samples per hour. The results revealed good agreement between the proposed sequential injection and an automated batch titration method. PMID:12207255

van Staden, J F; Mashamba, Mulalo G; Stefan, Raluca I

2002-09-01

246

Study on dissociation and solvation in water-acetic acid mixtures  

International Nuclear Information System (INIS)

The addition of acetic acid to water produces media of varying dielectric constant. The concepts of dissociation and solvation were defined in water-acetic acid mixtures containing from 5 per cent to 100 per cent water. The extent to which the activity of water and that of acetic acid participate in the solvation of molecules and of ions was demonstrated. The variation in the dissociation constants of HClO4, HCl and BH+ type acids and that of the ionic products can be interpreted by considering only the activity of the components of the mixture. These constants verify simple empirical relationships of the type pK = = Cte - p log (aH2O) - q log (aHOAc). By estimating the activity coefficients of ion and molecule solvation it was possible to determine their respective influences on the dissociation constants, of BH+ cationic acids. Thus the effect of medium on the constants appears as the sum of separate effects of medium of the chemical species B, H and BH+ taking part, in the reactions. Solvation of the B molecules and of the BH+ ions therefore depends to a large extent on the nature of the base. A study of the redox function R0 defined by Strehlow enabled the activity coefficients of solvation of the ions H+, Ag+, Cl-, Br- and I- to be determined. In the case of protons, the methods of Latimer and Izmailov lead to experimental results very similar to those obtained by the Strehlow's method. (author)

247

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

Science.gov (United States)

The concentrations of formic and acetic acids in the gas phase, atmospheric aerosol, and rainwater samples collected in Amazonia at ground level and in the atmosphere during the Amazon Boundary Layer Experiment in July/August 1985 were analyzed by ion exchange chromatography. The diurnal behavior of both acids at ground level and their vertical distribution in the forest canopy point to the existence of vegetative sources as well as to production by chemical reactions in the atmosphere. The concentrations of formic and acetic acids in the gas phase were about 2 orders of magnitude higher than the corresponding concentrations in the atmospheric aerosol. In rainwater, the total formate and acetate represented about one half of the anion equivalents, in contrast to less than 10 percent of the soluble anionic equivalents contributed by these acids in the atmospheric aerosol. The observed levels of these ions in rainwater are considered to be the result of a combination of chemical reactions in hydrometeors and the scavenging of the gaseous acids by cloud droplets.

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

1988-01-01

248

An Improved Ion Chromatography Methods for Analysis of Acetic and Formic Acid Vapours  

Directory of Open Access Journals (Sweden)

Full Text Available Air quality monitoring for acetic and formic acid vapours inmuseum galleries and storage environments is commonlyconducted using passive sampling and ion chromatography(IC. We report development of a rapid IC method with 2 to60-fold improvement in detection limits for acetate and formate. Baseline resolution is achieved in 4.5 min using anAS11-HC anion exchange column with 4 mM NaOH eluent at1.5 mL/min flow rate. The detection limits are 12 µg/mL(0.24 ng for acetate and 11 µg/mL (0.21 ng for formate.The method was successfully used for air quality monitoring in a Los Angeles museum warehouse.

Robyn E. Hodgkins

2011-01-01

249

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

OpenAIRE

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

Zimin, Sergey P.; Gorlachev, Egor S.; Naumov, Viktor V.; Skok, Fedor O.

2012-01-01

250

Azospirillum brasilense Produces the Auxin-Like Phenylacetic Acid by Using the Key Enzyme for Indole-3-Acetic Acid Biosynthesis  

OpenAIRE

An antimicrobial compound was isolated from Azospirillum brasilense culture extracts by high-performance liquid chromatography and further identified by gas chromatography-mass spectrometry as the auxin-like molecule, phenylacetic acid (PAA). PAA synthesis was found to be mediated by the indole-3-pyruvate decarboxylase, previously identified as a key enzyme in indole-3-acetic acid (IAA) production in A. brasilense. In minimal growth medium, PAA biosynthesis by A. brasilense was only observed ...

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

2005-01-01

251

Possibility of formic and acetic acids as active substrates for methanogenesis in the groundwater in Horonobe, Hokkaido  

International Nuclear Information System (INIS)

Groundwater samples in Horonobe district, Hokkaido, were analyzed to evaluate the possibility that formic and acetic acids are active substrates for methanogens in Quaternary and Neogene (Koetoi formation) formations. ?Gr corresponding to CH4-producing reactions indicates that both acids could be active substrates in almost all sampling locations. However, acetic acid was recognized to be an active substrate only in the Koetoi formation on the basis of the principle of competitive exclusion (CE) of microorganisms. The limited possibility by the CE principle suggests that dynamic equilibrium between substrate production rates and consumption rates is established only in the Koetoi formation for acetic acid. (author)

252

Synthesis and Antiradical/Antioxidant Activities of Caffeic Acid Phenethyl Ester and Its Related Propionic, Acetic, and Benzoic Acid Analoguesc  

Directory of Open Access Journals (Sweden)

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

Mohamed Touaibia

2012-12-01

253

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

Science.gov (United States)

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

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

2012-01-01

254

Solubilities of {?-D-glucose in water + (acetic acid or propionic acid)} mixtures at atmospheric pressure and different temperatures  

International Nuclear Information System (INIS)

Highlights: • The solubility of ?-D-glucose in binary mixtures has been obtained in this work. • The solubility decreases with the increase of volume fraction of water in the solvents. • The solubility of ?-D-glucose increases with the increase of temperature. • The results show that the three models agree well with the experimental data. • The Apelblat equation was more accurate than the ?h model and ideal model. -- Abstract: Using dynamic method and the laser monitoring observation technique, the solubility of ?-D-glucose in {water + (acetic acid or propionic acid)} was measured over the temperature range (297.55 to 331.45) K at atmospheric pressure. Its corresponding (solid + liquid) equilibrium data will provide essential support for industrial design and further theoretical studies. The solubility of ?-D-glucose in the mixtures of (water + acetic acid), and (water + propionic acid) was found to increase with increasing temperature and decrease with increasing volume fractions of acetic acid, and propionic acid in aqueous solution. The experimental data were correlated by using the Apelblat equation, the ?h equation and the ideal solution equation. The results showed that these three models agreed well with the experimental values, and the Apelblat equation was found to regress the solubility data better than the other two models

255

Fatty acid synthesis in human testis incubated with [1-14C] acetate  

International Nuclear Information System (INIS)

Slices of human testes were incubated for 3 h with [1-14C]-acetate, and the lipids extracted and analysed. The total incorporation of 14C into the total fatty acids of 23 samples was 3.7 +- 0.22% (S.E.M.) of the substrate per g tissue. There was no consistent detectable variation with age or with the spermatogenic rating of the tissue. The distribution of radioactivity in individual fatty acids of the incubated testes, in hydrogenated derivatives and in various classes of lipids showed that the tissue could both synthesize fatty acids and incorporate them into complex lipids. (U.K.)

256

Lactobacillus acidophilus NCFM affects vitamin E acetate metabolism and intestinal bile acid signature in monocolonized mice.  

Science.gov (United States)

Monocolonization of germ-free (GF) mice enables the study of specific bacterial species in vivo. Lactobacillus acidophilus NCFM(TM) (NCFM) is a probiotic strain; however, many of the mechanisms behind its health-promoting effect remain unknown. Here, we studied the effects of NCFM on the metabolome of jejunum, cecum, and colon of NCFM monocolonized (MC) and GF mice using liquid chromatography coupled to mass-spectrometry (LC-MS). The study adds to existing evidence that NCFM in vivo affects the bile acid signature of mice, in particular by deconjugation. Furthermore, we confirmed that carbohydrate metabolism is affected by NCFM in the mouse intestine as especially the digestion of oligosaccharides (penta- and tetrasaccharides) was increased in MC mice. Additionally, levels of ?-tocopherol acetate (vitamin E acetate) were higher in the intestine of GF mice than in MC mice, suggesting that NCFM affects the vitamin E acetate metabolism. NCFM did not digest vitamin E acetate in vitro, suggesting that direct bacterial metabolism was not the cause of the altered metabolome in vivo. Taken together, our results suggest that NCFM affects intestinal carbohydrate metabolism, bile acid metabolism and vitamin E metabolism, although it remains to be investigated whether this effect is unique to NCFM. PMID:24717228

Roager, Henrik M; Sulek, Karolina; Skov, Kasper; Frandsen, Henrik L; Smedsgaard, Jørn; Wilcks, Andrea; Skov, Thomas H; Villas-Boas, Silas G; Licht, Tine R

2014-01-01

257

Regulation of acetate kinase isozymes and its importance for mixed-acid fermentation in Lactococcus lactis.  

Science.gov (United States)

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; Poolman, Bert

2014-04-01

258

Electron spin resonance studies of barriers to hindered rotation in acetic acid, acetamide, and peptide radicals  

International Nuclear Information System (INIS)

Activation energies for methyl group rotation in the radicals of type H3C-C2O) as well as in 8 M NaOD glasses have produced the acetic acid anion, the acetate dianion, and the acetamide anion. ESR spectra of these have revealed a doublet (ca. 32G) at 90 K reversibly interconverting to a 1:3:3:1 quartet, of ca. 15-G hyperfine splitting, at higher temperatures (170 K). This interconversion has been attributed to the hindered internal rotation of the methyl group about the H3C-C< bond. The ESR spectra are analyzed using modified Bloch equations for the three-jump process. The mean lifetime (tau) at each temperature (T) has been estimated by a comparison of experimental and simulated ESR spectra. The activation energy (E/sub a/) for the sixfold barrier to the rotation is found to be 5.0 +- 0.5 kcal/mol in the acetate dianion and is about 3.0 kcal/mol for the acetate and acetamide as well as N-acetylamino acids. ESR spectra characteristic of the tunneling methyl group were observed at low temperature (20 K< T<100K) for the radicals produced in ?-irradiated polycrystalline samples of glycyl-L-alanine and L-alanyl-L-alanine. 3 figures, 1 table

259

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

Science.gov (United States)

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 (Pirrigation 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

260

Effects of acetic acid on the kinetics of xylose fermentation by an engineered, xylose-isomerase-based Saccharomyces cerevisiae strain.  

Science.gov (United States)

Acetic acid, an inhibitor released during hydrolysis of lignocellulosic feedstocks, has previously been shown to negatively affect the kinetics and stoichiometry of sugar fermentation by (engineered) Saccharomyces cerevisiae strains. This study investigates the effects of acetic acid on S. cerevisiae RWB 218, an engineered xylose-fermenting strain based on the Piromyces XylA (xylose isomerase) gene. Anaerobic batch cultures on synthetic medium supplemented with glucose-xylose mixtures were grown at pH 5 and 3.5, with and without addition of 3 g L(-1) acetic acid. In these cultures, consumption of the sugar mixtures followed a diauxic pattern. At pH 5, acetic acid addition caused increased glucose consumption rates, whereas specific xylose consumption rates were not significantly affected. In contrast, at pH 3.5 acetic acid had a strong and specific negative impact on xylose consumption rates, which, after glucose depletion, slowed down dramatically, leaving 50% of the xylose unused after 48 h of fermentation. Xylitol production was absent (<0.10 g L(-1)) in all cultures. Xylose fermentation in acetic -acid-stressed cultures at pH 3.5 could be restored by applying a continuous, limiting glucose feed, consistent with a key role of ATP regeneration in acetic acid tolerance. PMID:19416101

Bellissimi, Eleonora; van Dijken, Johannes P; Pronk, Jack T; van Maris, Antonius J A

2009-05-01

261

Analysis of Indole-3-Acetic Acid and Related Indoles in Culture Medium from Azospirillum lipoferum and Azospirillum brasilense  

OpenAIRE

Analysis of neutral and acidic ethyl acetate extracts from culture medium of Azospirillum brasilense 703Ebc by high-performance liquid chromatography (HPLC) and combined gas chromatography-mass spectrometry demonstrated the presence of indole-3-acetic acid (IAA), indole-3-ethanol, indole-3-methanol, and indole-3-lactic acid. IAA in media of 20 strains of A. brasilense and Azospirillum lipoferum was analyzed quantitatively by both the colorimetric Salkowski assay and HPLC-based isotopic diluti...

Crozier, Alan; Arruda, Paulo; Jasmim, Janie M.; Monteiro, Ana Maria; Sandberg, Go?ran

1988-01-01

262

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

OpenAIRE

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-...

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

2012-01-01

263

Measuring acetic and formic acid by proton transfer reaction-mass spectrometry: sensitivity, humidity dependence, and quantifying interferences  

OpenAIRE

We present a detailed investigation of the factors governing the quantification of formic acid (FA), acetic acid (AA) and their relevant mass analogues by proton transfer reaction-mass spectrometry (PTR-MS), assess the underlying fragmentation pathways and humidity dependencies, and present a new method for separating FA and AA from their main isobaric interferences. PTR-MS sensitivities towards glycolaldehyde, ethyl acetate and peroxyacetic acid at m/z 61...

Baasandorj, M.; Millet, D. B.; Hu, L.; Mitroo, D.; Williams, B. J.

2014-01-01

264

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

Science.gov (United States)

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

265

The effect of volatile fatty acids (VFAs) on nutrient removal in SBR with biomass adapted to dairy wastewater.  

Science.gov (United States)

This study aims to determine the effect of volatile fatty acids on nitrates and orthophosphate removal in a sequencing batch reactor (SBR) with activated sludge biomass adapted to process dairy wastewater. The research also determine whether it is the type of fatty acid applied that is responsible for the effectiveness of denitrification and dephosphatation at varying nitrate:orthophosphate ratios, or whether these processes are additionally affected by the presence of microorganisms that have adapted to the specific carbon composition of the wastewater being treated. At the beginning of an operating cycle SBRs were dosed with VFAs to provide a source of carbon. A comparative analysis was performed of nitrate and orthophosphate removal at initial nitrate concentrations of 1.22, 7.3 and 15.2 mgN(NO3)L?¹. Doses of fatty acids were approximately 10.5 mg?¹COD·mgP(PO4). They consisted of acetic, propionic, butyric, isobutyric, valeric, isovaleric and caproic acids. Increases of nitrate concentration from 1.22 to 15.2 mg N(NO3)L?¹ were observed to reduce the quantity of removed orthophosphate depending on the fatty acid applied, from 7.2-9.2 mgP(PO4)L to 4.5 - 6.7 mgP(PO4)L. Every increase in the removed nitrates by 5.0 mgN(NO3)L?¹ was accompanied by a decrease in the removed orthophosphate of around 1 mgP(PO4)L?¹. The reactor containing acetic acid was found to remove the highest amount of orthophosphate irrespective of the nitrates concentration. Acids present in significant amount in dairy wastewaters (i.e. acetic, propionic and butyric) were more effective source of carbon in the denitrification process compared to low concentration acids. PMID:23445424

Janczukowicz, Wojciech; Rodziewicz, Joanna; Czaplicka, Kamila; K?odowska, Izabella; Mielcarek, Artur

2013-01-01

266

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

International Nuclear Information System (INIS)

Conditions for electrochemical generation of cerium(IV) at glassy carbon in acetic acid in the presence of alkali-metal acetates and sodium perchlorate, respectively, were investigated. A high current efficiency was achieved in anodic oxidation of cerium(III) in acetate supporting electrolytes. Coulometric titration methods for the determination of reducing substances with the generated oxidant were also developed. The end-points were determined by the biamperometric and bipotentiometric methods. The error of the determinations was less than ± 2%

267

Removal of benzylidene acetal and benzyl ether in carbohydrate derivatives using triethylsilane and Pd/C  

OpenAIRE

Clean deprotection of carbohydrate derivatives containing benzylidene acetals and benzyl ethers was achieved under catalytic transfer hydrogenation conditions by using a combination of triethylsilane and 10% Pd/C in CH3OH at room temperature. A variety of carbohydrate diol derivatives were prepared from their benzylidene derivatives in excellent yield.

Abhishek Santra; Tamashree Ghosh; Anup Kumar Misra

2013-01-01

268

Anticoccidial effects of acetic acid on performance and pathogenic parameters in broiler chickens challenged with Eimeria tenella  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The objective of the present study was to evaluate the anticoccidial effect of the different concentrations of the acetic acid in the broiler chickens in comparison with the amprolium anticoccidial. A total of 198 chicks were placed 11 per pen with three pens per treatment. The different concentrati [...] ons (1%, 2% and 3%) of acetic acid and amproilum (at the dose rate of 125ppm) were given to the experimental groups in drinking water from 10-19th days of age. One group was kept as infected non medicated control and one as non infected non medicated control. All the groups were inoculated orally with 75,000 sporulated oocysts at the 12th day of age except non infected non medicated control. Anticoccidial effect was evaluated on the basis of performance (weight gain, feed conversion ratio) and pathogenic (oocyst score, lesion score and mortality %age) parameters. Among acetic acid medicated groups, the maximum anticoccidial effect was seen in the group medicated with 3% acetic acid followed by 2% and 1% acetic acid medicated groups. Amprolium and 3% acetic acid were almost equivalent in suppressing the negative performance and pathogenic effects associated with coccidiosis (Eimeria tenella) challenge. In summary, acetic acid has the potential to be used as alternative to chemotherapeutic drugs for Eimeria tenella control. Concentration-dependent anticoccidial effect of acetic acid suggests that further studies should be carried out to determine the possible maximum safe levels of acetic acid with least toxic effects to be used as anticoccidial.

Rao Z., Abbas; Shokat H., Munawar; Zahid, Manzoor; Zafar, Iqbal; Muhammad N., Khan; Muhammad K., Saleemi; Muhammad A., Zia; Arfan, Yousaf.

2011-02-01

269

Uncoupling by Acetic Acid Limits Growth of and Acetogenesis by Clostridium thermoaceticum.  

Science.gov (United States)

When cells of the anaerobic thermophile Clostridium thermoaceticum grow in batch culture and homoferment glucose to acetic acid, the pH of the medium decreases until growth and then acid production cease, at about pH 5. We postulated that the end product of fermentation limits growth by acting as an uncoupling agent. Thus, when the pH of the medium is low, the cytoplasm of the cells becomes acidified below a tolerable pH. We have therefore measured the internal pH of growing cells and compared these values with those of nongrowing cells incubated in the absence of acetic acid. Growing cells maintained an interior about 0.6 pH units more alkaline than the exterior throughout most of batch growth (i.e., DeltapH = 0.6). We also measured the transmembrane electrical potential (DeltaPsi), which decreased from 140 mV at pH 7 at the beginning of growth to 80 mV when the medium had reached pH 5. The proton motive force, therefore, was 155 mV at pH 7, decreasing to 120 mV at pH 5. When further fermentation acidified the medium below pH 5, both the DeltapH and the DeltaPsi collapsed, indicating that these cells require an internal pH of at least 5.5 to 5.7. Cells harvested from stationary phase and suspended in citrate-phosphate buffer maintained a DeltapH of 1.5 at external pH 5.0. This DeltapH was dissipated by acetic acid (at the concentrations found in the growth medium) and other weak organic acids, as well as by ionophores and inhibitors of glycolysis and of the H-ATPase. Nongrowing cells had a DeltaPsi which ranged from about 116 mV at external pH 7 to about 55 mV at external pH 5 and which also was sensitive to ionophores. Since acetic acid, in its un-ionized form, diffuses passively across the cytoplasmic membrane, it effectively renders the membrane permeable to protons. It therefore seems unlikely that mutations at one or a few loci would result in C. thermoaceticum cells significantly more acetic acid tolerant than their parental type. PMID:16346677

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

1984-12-01

270

Synthesis and in vitro anticancer activity of 2,4-azolidinedione-acetic acids derivatives.  

Science.gov (United States)

The synthesis and evaluation of anticancer activity of 2,4-thia(imida)zolidinedione-3- and 5-acetic acids amides were described. The structures of compounds were determined by IR, (1)H NMR, and MS analysis. In vitro anticancer activity of these compounds has been tested in National Cancer Institute (NCI) and the relationships between structure and anticancer activity are discussed. Among 2,4-azolidinedione-acetic acids derivatives 2-[5-(4-chlorobenzylidene)-2,4-dioxo-imidazolidin-3-yl]-N-(2-trifluoromethyl-phenyl)-acetamide (Ic) was superior to other related compounds in terms of high selectivity for the leukemia CCRF-CEM (logGI(50)=-6.06), HL-60(TB) (logGI(50)=-6.53), MOLT-4 (logGI(50)=-6.52) and SR (logGI(50)=-6.51) cell lines. PMID:19299038

Kaminskyy, Danylo; Zimenkovsky, Borys; Lesyk, Roman

2009-09-01

271

Acetic Acid Formation by Selective Aerobic Oxidation of Aqueous Ethanol over Heterogeneous Ruthenium Catalysts  

DEFF Research Database (Denmark)

Heterogeneous catalyst systems comprising ruthenium hydroxide supported on different carrier materials, titania, alumina, ceria, and spinel (MgAl2O4), were applied in selective aerobic oxidation ethanol to form acetic acid, an important bulk chemical and food ingredient. The catalysts were characterized by X-ray powder diffraction (XRPD), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), and nitrogen physisorption and utilized in the oxidation of 2.5–50 wt % aqueous ethanol solutions at elevated temperatures and pressures. The effects of Ru metal loading, pretreatment of catalysts, oxidant pressure, reaction temperature, and substrate concentration were investigated. Quantitative yield of acetic acid was obtained with 1.2 wt % Ru(OH)x/CeO2 under optimized conditions (150 °C, 10 bar O2, 12 h of reaction time, 0.23 mol % Ru to substrate).

Gorbanev, Yury; Kegnæs, SØren

2012-01-01

272

PRODUCTION OF CAROTENOIDS (ANTIOXIDANTS/ COLOURANT IN SPIRULINA PLATENSIS IN RESPONSE TO INDOLE ACETIC ACID (IAA  

Directory of Open Access Journals (Sweden)

Full Text Available The Carotenoid compounds (antioxidants synthesis in spirulina platennsis was studied in vitro under the influence of the Indole Acetic Acid (IAA. Spirulina platensis is grown in Zarrouks medium supplemented with different concentration of Indole Acetic Acid ( 1?g/ml–10?g/ml . The gradual increase in the total Carotenoidscontent was recorded from 1- 6 ?g/ml of IAA. Inhibition in the synthesis of Carotenoids compounds was noticed in 7?g/ml-10?g/ml the similar trend was also observed with synthesis of chlorophyll a .Growth of Spirulina was also inhibited at higher level of IAA .Maximum production of Carotenoid compounds noticed at 6?g/ml IAA.

Munawer Khan Mohammed,

2011-06-01

273

Conclusion on the peer review of the pesticide risk assessment of the active substance acetic acid  

Directory of Open Access Journals (Sweden)

Full Text Available The conclusions of the European Food Safety Authority (EFSA following the peer review of the initial risk assessments carried out by the competent authority of the rapporteur Member State, Germany, for the pesticide active substance acetic acid are reported. The context of the peer review was that required by Commission Regulation (EC No 2229/2004, as amended by Commission Regulation (EC No 1095/2007 and Commission Regulation (EU No. 114/2010. The conclusions were reached on the basis of the evaluation of the representative uses of acetic acid as a herbicide in pome fruit, stone fruit, paths and roads, ornamental trees and shrubs, turf, and lawns. The reliable endpoints concluded as being appropriate for use in regulatory risk assessment, derived from the available studies and literature in the dossier peer reviewed, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are identified.

European Food Safety Authority

2013-01-01

274

Synthesis of 2, 4-- dichloro phenoxy acetic acid [ Carboxy- 14 C] as herbicide  

International Nuclear Information System (INIS)

One of the important herbicide, that can be used for the practical mechanism investigations and studies of metabolism functions of different plants is 2,4 dichlorophenoxy acetic acid compound. In this article, the production method for labeling the titled compound is explained. At the first stage of this research work, barium[14C] carbonate is converted into potassium [14C] by using potassium azid at a reasonable temperature. Then, after a few synthesis reaction, the compound 2,4 dichlorophenoxy methyl iodide is produced via 2,4 dichlorophenoxy as a starting material. At the next stage, the real material as a herbicide: 2,4 dichlorophenoxy acetic acid [carboxy- 14C] is prepared and produced, by the coupling reaction between 2,4 dichlorophenoxy methyl iodide and potassium [14C] cyanide, and then the resulting nitrile has been hydrolyzed

275

Extraction of Lead, Cadmium and Nickel from Contaminated Soil Using Acetic Acid  

OpenAIRE

The accumulation of heavy metals in soil is a serious environmental problem. It is well known that heavy metals have an affinity for different compartments of soil. The risk associated with the presence of metals in soil is the ability of their transfer in water or plants. In the present research, batch extraction experiments were conducted using acetic acid (AA) as an extractant solution at various concentrations and contact times to determine the best conditions of...

Hatem Asal Gzar; Abdul-hameed, Awatif S.; Asmaa Younus Yahya

2014-01-01

276

Halogenated indole-3-acetic acids as oxidatively activated prodrugs with potential for targeted cancer therapy.  

OpenAIRE

Substituted indole-3-acetic acid (IAA) derivatives, plant auxins with potential for use as prodrugs in enzyme-prodrug directed cancer therapies, were oxidised with horseradish peroxidase (HRP) and toxicity against V79 Chinese hamster lung fibroblasts was determined. Rate constants for oxidation by HRP compound I were also measured. Halogenated IAAs were found to be the most cytotoxic, with typical surviving fractions of <10(-3) after incubation for 2h with 100 microM prodrug and HRP.

Rossiter, S.; Folkes, Lk; Wardman, P.

2002-01-01

277

Flavone acetic acid induces a G2/M cell cycle arrest in mammary carcinoma cells  

OpenAIRE

Flavone acetic acid (FAA) is a synthetic flavonoid that demonstrated extraordinary anti-tumour properties in murine models but was not effective in clinical trials. In an effort to better understand the molecular mechanisms by which FAA asserts its tumouricidal activities, we have examined the effect of FAA on the cell cycle. We observed FAA-mediated G2/M cell cycle arrest in mammary carcinoma cells at a concentration previously demonstrated to have anti-tumour effects in rodent models. The c...

Panaro, N. J.; Popescu, N. C.; Harris, S. R.; Thorgeirsson, U. P.

1999-01-01

278

Application of molecular techniques for identification and ennumeration of acetic acid bacteria  

OpenAIRE

Application of molecular techniques for identification and enumeration of acetic acid bacteria:Los principales objetivos de la tesis son el desarrollo de técnicas de biología molecular rápidas y fiables para caracterizar bacterias acéticas.Las bacterias acéticas son las principales responsables del picado de los vinos y de la producción de vinagre. Sin embargo, existe un desconocimiento importante sobre su comportamiento y evolución. Las técnicas de enumeración y de identificación b...

Gonza?lez Benito, Angel

2005-01-01

279

Acetic and Acrylic Acid Molecular Imprinted Model Silicone Hydrogel Materials for Ciprofloxacin-HCl Delivery  

OpenAIRE

Contact lenses, as an alternative drug delivery vehicle for the eye compared to eye drops, are desirable due to potential advantages in dosing regimen, bioavailability and patient tolerance/compliance. The challenge has been to engineer and develop these materials to sustain drug delivery to the eye for a long period of time. In this study, model silicone hydrogel materials were created using a molecular imprinting strategy to deliver the antibiotic ciprofloxacin. Acetic and acrylic acid were...

Lyndon Jones; Alex Hui; Heather Sheardown

2012-01-01

280

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

OpenAIRE

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 and it was shown that the lower the surface porosity the higher the selectivity of the composite memb...

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

1993-01-01

281

Production of acetic acid by immobilized whole cells of Clostridium thermoaceticum.  

Science.gov (United States)

Immobilized cells of Clostridium thermoaceticum for acetic acid production has been investigated. Using kappa-carrageenan gel as the immobilization-matrix, high cell concentration within the gel could be achieved and thus lead to high volumetric acetic acid productivity. Batch experiments using 3% gel showed that cell concentration up to 65 g (dry cell weight)/L gel could be achieved. These dry weight cell concentrations in the gel through immobilization are typically 10-15 times greater than what can be obtained in free-cell fermentations. The specific growth rate and acetic acid formation rate were similar to those observed for the free cells. Continuous culture experiments using a feed medium containing 20 g/L of glucose were performed where the reactor contained 50% by volume of the carrageenan gel and the pH was controlled at 6.9. Different steady states were acheived at dilution rates ranging from 0.061 to 0.399 h-1. Cells grew mainly near the surface of the gel and reached maximum concentration within the matrix of approximately 35 g/L. Dilution rates much greater than the maximum specific growth rate were obtained, which resulted in volumetric productivity up to 4.9 g/L-h. This value was significantly greater than that for the conventional continuous culture with free cells. Using a 40 g/L feed glucose concentration, steady states could be achieved between dilution rates of 0.12-0.4 h-1. The maximum productivity further increased to 6.9 g/L-h at a dilution rate of 0.37 h-1 and at an acetic acid concentration of 19 g/L. The cell concentration was 60 g (dry weight)/L gel at steady state. PMID:6679712

Wang, G; Wang, D I

1983-12-01

282

N-(7-Methyl-1,8-naphthyridin-2-ylacetamide–acetic acid (1/1  

Directory of Open Access Journals (Sweden)

Full Text Available In the title adduct, C11H11N3O·C2H4O2, all non-H atoms of the acetamide molecule are roughly coplanar, with an r.m.s. deviation of 0.0720?Å. The dihedral angle between the ring plane and the acetamide group is 8.5?(2°. In the crystal, O—H...N and N—H...O hydrogen bonds link the acetamide and acetic acid molecules.

Gao-Zhang Gou

2013-04-01

283

Visual inspection with acetic acid as a cervical cancer test: accuracy validated using latent class analysis  

OpenAIRE

Abstract Background The purpose of this study was to validate the accuracy of an alternative cervical cancer test – visual inspection with acetic acid (VIA) – by addressing possible imperfections in the gold standard through latent class analysis (LCA). The data were originally collected at peri-urban health clinics in Zimbabwe. Methods Conventional accuracy (sensitivity/specificity) estimates for VIA and two other screening tests using colposcopy/biopsy as ...

McGrath John A; Gaffikin Lynne; Arbyn Marc; Blumenthal Paul D

2007-01-01

284

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

OpenAIRE

Numerous plant pathogens, rhizosphere symbionts, and endophytic bacteria and yeasts produce the important phytohormone indole-3-acetic acid (IAA), often with profound effects on host plants. However, to date IAA production has not been documented among foliar endophytes -- the diverse guild of primarily filamentous Ascomycota that live within healthy, above-ground tissues of all plant species studied thus far. Recently bacteria that live within hyphae of endophytes (endohyphal bacteria) have ...

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

2013-01-01

285

Trifluoroacetic anhydride promoted tandem conjugate addition of boronic acids/acetal ring opening.  

Science.gov (United States)

A new stereoselective tandem reaction consisting of the metal-free conjugate addition of boronic acids followed by an intramolecular ring opening of a cyclic acetal has been disclosed. Optically pure polysubstituted tetrahydropyrans have been synthesized diastereoselectively by this new reaction. Two new C-C bonds and up to three stereocenters are formed in a single step, allowing the generation of quaternary stereocenters. PMID:22339156

Roscales, Silvia; Csáky, Aurelio G

2012-03-01

286

Monoclinic polymorph of 2-(pyrimidin-2-ylsulfan­yl)acetic acid  

OpenAIRE

The title compound, C6H6N2O2S, is a new polymorphic form of 2-(pyrimidin-2-ylsulfanyl)acetic acid. Unlike the previous orthorhombic polymorph [Pan & Chen (2009) Acta Cryst. E65, o652], the molecules are not planar: the aromatic ring makes an angle of 80.67?(17)° with the carboxyl plane. In the crystal, molecules are linked by O—H...N hydrogen bonds into chains along [overline{1}02].

Manuela Ramos Silva; Pereira Silva, Pedro S.; Consuelo Yuste; José A. Paixão

2011-01-01

287

Radiation heterogeneous processes of 14C-acetic acid adsorbed in Na-Montmorillonite  

International Nuclear Information System (INIS)

This research addresses itself to the study of the mechanism of the acetic acid decarboxylation in Na-Montmorillonite exposed to ionizing radiation. The results obtained indicated that the decarboxylation reaction is enhanced several times by the irradiation. This behavior is probably due to an oxidation reaction at the edges of the clay. Also it is by energy transfer from the clay to adsorbed molecules by an interaction of non-equilibrium charge carriers with the adsorbed molecules. (author) 9 refs.; 1 tab

288

Investigation on Ethylenediaminetetra-Acetic Acid as Corrosion Inhibitor for Mild Steel in 1.0M Hydrochloric Acid  

Directory of Open Access Journals (Sweden)

Full Text Available The influence of ethylenediaminetetra-acetic acid (EDTA on the corrosion of mild steel in 1.0 M hydrochloric acid solution was investigated by means of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS. The efficiency of EDTA was compared with thiourea. Primary results obtained revealed that EDTA performed as good corrosion inhibitor for mild steel in 1.0 M hydrochloric acid media comparing with thiourea. Polarization curves show that the behavior of EDTA and thiourea are mixed-type inhibitors. EIS shows that the control step for corrosion process is a charge transfer mechanism.

Ahmed Y. Musa

2009-03-01

289

Analysis of phenolic and indole acetic acids in Meloidogyne graminicola infected rice plants (Oryza sativa L.  

Directory of Open Access Journals (Sweden)

Full Text Available Meloidogyne spp. incite root-knot disease in the roots of Solanaceous and Cereal crop plants inflicting heavy damage to the crops. M. graminicola, a root-knot nematode is ubiquitous as a rice pathogen wherever rice is grown. High Performance Liquid Chromatographic (HPLC analysis of phenolic acids in healthy and root-knot infected plant parts of rice indicated that phenolic acid contents were highly variable in both the cases. Upper leaves of healthy plants had seven phenolic acids in which gallic acid was maximum (140.3 ?g/g fresh wt followed by ferulic, tannic and vanillic acids. However, in root knot-infected plants, upper leaves had six phenolic acids in which gallic acid was maximum (190.68 ?g followed by caffeic, ferulic, o-coumeric, cinnamic and salicylic acids. In healthy leaf sheath gallic acid was the maximum (8.6 ?g followed by tannic, ferulic, vanillic, caffeic acid but o-coumeric, cinnamic and Indole Acetic Acid (IAA were detected in traces. Root knot-infected leaf sheath had nine phenolic acids, where gallic was the maximum (26.84 ?g followed by vanillic, ferulic, o-coumeric and tannic acids but other phenolic acids, viz., cinnamic, salicylic and IAA were present in traces. Roots of healthy rice plants had seven phenolic acids while infected roots had nine phenolic acids. Moreover, in infected roots without root-knot had eight phenolic acids, in which gallic was the maximum (29.30 ?g followed by ferulic, caffeic, vanillic, tannic and o-coumeric acids but salicylic and IAA were present in traces.

Amitabh Singh

2013-08-01

290

Kinetics of acetic acid synthesis from ethanol over a Cu/SiO2 catalyst  

DEFF Research Database (Denmark)

The dehydrogenation of ethanol via acetaldehyde for the synthesis of acetic acid over a Cu based catalyst in a new process is reported. Specifically, we have studied a Cu on SiO2 catalyst which has shown very high selectivity to acetic acid via acetaldehyde compared to competing condensation routes. The dehydrogenation experiments were carried out in a flow through lab scale tubular reactor. Based on 71 data sets a power law kinetic expression has been derived for the description of the dehydrogenation of acetaldehyde to acetic acid. The apparent reaction order was 0.89 with respect to water and 0.45 with respect to acetaldehyde, and the apparent activation energy was 33.8kJ/mol. The proposed oxidation of acetaldehyde with hydroxyl in the elementary rate determining step is consistent with these both. Density Functional Theory (DFT) calculations show the preference of water cleavage at the Cu step sites. In light of this, an observed intrinsic activity difference between whole catalyst pellets and crushed pellets may be explained by the Cu crystal size and growth rate being functions of the catalyst particle size and time.

Voss, Bodil; SchjØdt, Niels Christian

2011-01-01

291

Pulse radiolysis of aqueous solutions of acetic acid 2-hydroxyethyl ester  

International Nuclear Information System (INIS)

The reaction of OH radicals with acetic acid 2-hydroxyethyl ester, in aqueous solutions has been studied. A rate constant of ksub(OH + 1) = 8.5 x 108 M-1 s-1 was obtained. The transients a few ?s after pulse consist of approximately 83% formylmethyl radicals, CH2CHO, the remainder being mainly CH3C(O)OCHCH2OH radicals. ?-radiolysis of 1 in N2O saturated aqueous solutions led to G(acetic acid) = 5.0 without contribution of a chain reaction. A lower limit of the rate constant of this reaction, at 200C, k >= 5 x 105 s-1, was derived from pulse radiolysis and an upper limit of k 6 s-1 was estimated from scavenging experiments with oxygen under Co60-?-irradiation. At higher concentrations of 1, and/or higher temperatures CH2CHO attacks 1, leading to a chain decomposition of 1 yielding acetic acid and acetaldehyde. Succinic aldehyde was identified as a product of the dimerization of CH2CHO. (orig./HK)

292

Mechanical behavior of alumina and alumina-feldspar based ceramics in an acetic acid (4%) environment  

International Nuclear Information System (INIS)

This study investigates the mechanical properties of alumina-feldspar based ceramics when exposed to an aggressive environment (acetic acid 4%). Alumina ceramics containing different concentrations of feldspar (0%, 1%, 5%, 10%, or 40%) were sintered at either 1300, 1600, or 1700 oC. Flaws (of width 0%, 30%, or 50%) were introduced into the specimens using a saw. Half of these ceramic bodies were exposed to acetic acid. Their flexural strength, KIC, and porosity were measured and the fractured samples were evaluated using scanning electronic- and optical microscopy. It was found that in the ceramic bodies sintered at 1600 oC, feldspar content up to 10% improved flexural strength and KIC, and reduced porosities. Generally, it was found that acetic acid had a weakening effect on the flexural strength of samples sintered at 1700 oC but a beneficial effect on KIC of ceramics sintered at 1600 oC. It was concluded that alumina-based ceramics with feldspar content up to 10% and sintered at higher temperatures would perform better in an aggressive environment similar to oral cavity.

293

Investigation of acetic acid-catalyzed hydrothermal pretreatment on corn stover  

DEFF Research Database (Denmark)

Acetic acid (AA)-catalyzed liquid hot water (LHW) pretreatments on raw corn stover (RCS) were carried out at 195 °C at 15 min with the acetic acid concentrations between 0 and 400 g/kg RCS. After pretreatment, the liquor fractions and water-insoluble solids (WIS) were collected separately and tested in terms of the recoveries of glucan and xylan from both the liquor fractions and the WIS, toxicity level of the liquors, and the convertibility of WIS to ethanol. The highest glucan recoveries was found to be 97.42% and 97.94% when 15 and 30 g AA/kg RCS were employed, respectively. The highest xylan recovery of 81.82% was observed by the pretreatment with 10 g AA/kg RCS. The toxic test on liquors showed that the inhibition effect happened to Baker's yeast when the acetic acid used in the pretreatment was higher than 100 g/kg RCS. The WIS obtained from the pretreatment with 15 g and 30 g/kg RCS were subjected to enzymatic hydrolysis and more easily converted to ethanol by Baker's yeast, which gave the ethanol concentration of 33.72 g/L and 32.06 g/L, respectively, higher than 22.04 g/L which was from the non-catalyzed LHW pretreatment (195 °C, 15 min). The ethanol concentration from the RCS was only 8.02 g/L.

Xu, Jian; Thomsen, Mette Hedegaard

2010-01-01

294

Antireflectance coating on shielding window glasses using glacial acetic acid at ambient temperature  

International Nuclear Information System (INIS)

High density lead glasses having thickness of several centimeters and large dimensions are used as shielding windows in hot cells. To improve visibility, the reflection of light from its optically polished surfaces needs to be minimized to improve transmission as absorption of light in the thick glasses can not be avoided. Antireflectance coating of a material having low refractive index is required for this purpose. Selective leaching of lead at ambient temperature in glacial acetic acid develops a silica rich leached layer on glass surface. Since silica has low refractive index, the leached layer serves as antireflectance coating. Two optically polished discs of shielding window glasses were leached in glacial acetic acid at ambient temperature for 2, 5 and 10 days and their reflectance and transmittance spectra were taken to find effect of leaching. For transparent glass transmittance could be improved from 78.76% to 85.31% after 10 days leaching. Reflectance from the glass could be decreased from 12.48 to 11.67%. For coloured glass transmittance improved from 87.77% to 88.24% after 5 days leaching while reflectance decreased from 12.28% to 5.6% during same period. Based on data generated, 10 days leaching time is recommended for developing anti reflectance coating on transparent shielding window glass and 5 days for coloured shielding window glass. The procedure can be used for shielding windows of any dimensions by fabrication a PVC tank of slightly high dimensions and filling with acetic acid (author)

295

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

Science.gov (United States)

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

296

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

Science.gov (United States)

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

Kisan, Hemanta K; Sunoj, Raghavan B

2014-12-01

297

Adaptive response to acetic acid in the highly resistant yeast species Zygosaccharomyces bailii revealed by quantitative proteomics.  

Science.gov (United States)

Zygosaccharomyces bailii is the most tolerant yeast species to acetic acid-induced toxicity, being able to grow in the presence of concentrations of this food preservative close to the legal limits. For this reason, Z. bailii is the most important microbial contaminant of acidic food products but the mechanisms behind this intrinsic resistance to acetic acid are very poorly characterized. To gain insights into the adaptive response and tolerance to acetic acid in Z. bailii, we explored an expression proteomics approach, based on quantitative 2DE, to identify alterations occurring in the protein content in response to sudden exposure or balanced growth in the presence of an inhibitory but nonlethal concentration of this weak acid. A coordinate increase in the content of proteins involved in cellular metabolism, in particular, in carbohydrate metabolism (Mdh1p, Aco1p, Cit1p, Idh2p, and Lpd1p) and energy generation (Atp1p and Atp2p), as well as in general and oxidative stress response (Sod2p, Dak2p, Omp2p) was registered. Results reinforce the concept that glucose and acetic acid are coconsumed in Z. bailii, with acetate being channeled into the tricarboxylic acid cycle. When acetic acid is the sole carbon source, results suggest the activation of gluconeogenic and pentose phosphate pathways, based on the increased content of several proteins of these pathways after glucose exhaustion. PMID:22685079

Guerreiro, Joana F; Mira, Nuno P; Sá-Correia, Isabel

2012-08-01

298

Sol-gel sulphated silica as a catalyst for glycerol acetylation with acetic acid  

Directory of Open Access Journals (Sweden)

Full Text Available 800x600 This paper reports on the impact of sol-gel sulphated silica (SS, used as a solid acid catalyst in the esterification of glycerol with acetic acid. The effects of time, temperature, and molar ratio of acetic acid to glycerol were evaluated in order to optimize the reaction conditions for achieving a high monoacetin yield. A series of catalysts were prepared, with different loading percentages from 5 to 20 wt.%. The obtained sulphated silica had high specific surface area, in the range of 330-720 m2g-1. The results indicated that, the catalytic activity (acidic properties increased with the amount of sulphuric acid loaded into the silica. In fact, the SS20 showed the highest catalytic activity, when using a reaction temperature of 50°C, and a glycerol to acetic acid mole ratio of 6 in 6h. Meanwhile all the catalysts showed a favorable selectivity to monoacetin. Normal 0 false false false EN-US X-NONE AR-SA /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-bidi-font-family:Arial;}

khadijeh beigom Ghoreishi

2013-07-01

299

Uncoupling by Acetic Acid Limits Growth of and Acetogenesis by Clostridium thermoaceticum  

OpenAIRE

When cells of the anaerobic thermophile Clostridium thermoaceticum grow in batch culture and homoferment glucose to acetic acid, the pH of the medium decreases until growth and then acid production cease, at about pH 5. We postulated that the end product of fermentation limits growth by acting as an uncoupling agent. Thus, when the pH of the medium is low, the cytoplasm of the cells becomes acidified below a tolerable pH. We have therefore measured the internal pH of growing cells and compare...

Baronofsky, Jerald J.; Schreurs, Wilhelmus J. A.; Kashket, Eva R.

1984-01-01

300

Charge transfer interaction in the acetic acid-benzene cation complex  

Science.gov (United States)

Geometrical and electronic structures of the acetic acid-benzene cation complex, (CH3COOH)?(C6H6)+, are studied experimentally and theoretically. Experimentally, a vibrational spectrum of (CH3COOH)?(C6H6)+ in the supersonic jet is measured in the 3000-3680 cm-1 region using an ion-trap photodissociation spectrometer. An electronic spectrum is also observed with this spectrometer in the 12 000-29 600 cm-1 region. Theoretically, ab initio molecular orbital calculations are performed for geometry optimization and evaluation of vibrational frequencies and electronic transition energies. The vibrational spectrum shows two distinct bands in the O-H stretching vibrational region. The frequency of the strong band (3577 cm-1) is close to that of the O-H stretching vibration of acetic acid and the weak one is located at 3617 cm-1. On the basis of geometry optimizations and frequency calculations, the strong band is assigned to the O-H stretching vibration of the cis-isomer of acetic acid in the hydrogen-bonded complex (horizontal cis-isomer). The weak one is assigned to the vertical trans-isomer where the trans-isomer of acetic acid interacts with the ?-electron system of the benzene cation. The weakness of the high frequency band in the photodissociation spectrum is attributed to the binding energy larger than the photon energy injected. Only hot vertical trans-isomers can be dissociated by the IR excitation. The electronic spectrum exhibits two bands with intensity maxima at 17 500 cm-1 and 24 500 cm-1. The calculations of electronic excitation energies and oscillator strengths suggest that charge transfer bands of the vertical trans-isomer can be observed in this region in addition to a local excitation band of the horizontal cis-isomer. We assign the 17 500 cm-1 band to the charge transfer transition of the vertical trans-isomer and the 24 500 cm-1 band to the ?-? transition of the horizontal cis-isomer. The calculations also suggest that the charge transfer is induced through the intermolecular C⋯O=C bond formed between a carbon atom of benzene and the carbonyl oxygen atom of acetic acid.

Kosugi, Kentaroh; Inokuchi, Yoshiya; Nishi, Nobuyuki

2001-03-01

301

Bioethanol production from lignocellulosics with hot-compressed water treatment followed by acetic acid fermentation and hydrogenolysis  

Energy Technology Data Exchange (ETDEWEB)

This presentation described a newly developed ethanol production system which involves hot-compressed water treatment combined with acetic acid fermentation and catalytic hydrogenation. The hot-compressed water treatment was optimized by using a semi-flow treatment on Japanese beech wood at 230 degrees C/10 MPa for 15 min, and then at 270 degrees C/10 MPa for 15 min. Under these conditions, 54 per cent of the hemicelluloses and 71 wt per cent of the cellulose were hydrolyzed, respectively. However, approximately 12 wt per cent of the wood decomposed into dehydrated and fragmented products. Approximately 88 per cent of the lignin also decomposed. The fermentability of these various compounds to acetic acid was then examined. Monosaccharides as well as some decomposed compounds and lignin-derived compounds were all found to be fermentable to acetic acid with Clostridium thermoaceticum. In particular, glucose, xylose and fructose could be effectively converted to acetic acid with a 70 to 80 per cent yield. Oligosaccharides and polysaccharides were converted with C. thermocellum to glucose and organic acids. Almost all compounds obtained by the hot-compressed water treatment were converted to acetic acid in co-culture fermentation. A flow-type laboratory reactor was used to evaluate ethanol production from acetic acid using a one-step hydrogenation method to ethanol. A very dilute aqueous solution of acetic acid was effectively hydrogenated to ethanol. It was concluded that compared to conventional yeast fermentation, ethanol can be produced more efficiently from lignocellulosics by combining the 3 steps of hot-compressed water treatment followed by acetic acid fermentation and hydrogenation.

Saka, S.; Phaiboonsilpa, N.; Nakamura, Y.; Masuda, S.; Lu, X.; Yamauchi, K.; Miyafuji, H.; Kawamoto, H. [Kyoto Univ., Kyoto (Japan)

2009-07-01

302

Modeling and optimization in anaerobic bioconversion of complex substrates to acetic and butyric acids.  

Science.gov (United States)

Cheese-processing wastewater was biologically treated to produce short-chain organic acids in laboratory scale continuously stirred tank reactors. A constant inoculum system was used to mimimize the experimental error due to the use of inconsistent inoculum. The inoculum system was operated with dilute cheese-processing wastewater with 5000 mg soluble chemical oxygen demand/L at pH 6.5 and 35 degrees C at 0.5 days hydraulic retention time. Response surface methodology was successfully applied to determine the optimum physiological conditions where the maximum rates of acetic and butyric acid production occurred. These were pH 7.01 at 36.2 degrees C and pH 7.26 at 36.2 degrees C, respectively. The lack of overall predictability for butyric acid production meant that the response surface was much more complicated than that of acetic acid; therefore, a small change in pH or temperature could cause large variations in the response of butyric acid production. PMID:18634137

Hwang, S; Hansen, C L

1997-06-01

303

Flavone acetic acid (FAA) with recombinant interleukin-2 (rIL-2) in advanced malignant melanoma. IV: Pharmacokinetics and toxicity of flavone acetic acid and its metabolites.  

Science.gov (United States)

Flavone acetic acid (FAA) was administered at a dose of 4.8 g m-2 over 1 h to patients with advanced malignant disease in combination with Interleukin II. A new high performance liquid chromatography method is described to determine both the parent compound and eight drug-related products, and the conditions required to determine these components in plasma are discussed. The half-life over the first 8 h was 2.3 h, but the terminal clearance of the drug was extremely slow. Severe (WHO Grade 4) hypotension was observed in some patients. However, incidence of this did not appear to be associated with any differences in FAA plasma concentrations, nor were there differences in FAA clearance between those patients whose tumour responded to the drug combination and those who did not. PMID:8512820

Stratford, M R; Rustin, G J; Dennis, M F; Watfa, R R; Howells, N; O'Reilly, S M

1993-06-01

304

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

Science.gov (United States)

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

305

Isolation and characterization of indole acetic acid (IAA) producing bacteria from rhizospheric soil and its effect on plant growth  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english Indole acetic acid (IAA) production is a major property of rhizosphere bacteria that stimulate and facilitate plant growth. The present work deals with isolation, characterization and identification of indole acetic acid producing bacteria from the rhizospheric soil. Out of ten Indole acetic acid pr [...] oducing isolates, five were selected as efficient producers. Optimization of indole acetic acid production was carried out at different cultural conditions of pH and temperature with varying media components such as carbon and nitrogen source, tryptophan concentration. Partial purification of IAA was done and purity was confirmed with Thin layer chromatography. Subsequently, effect on plant growth was tested by pot assay. In conclusion the study suggests the IAA producing bacteria as efficient biofertilizer inoculants to promote plant growth.

B, Mohite.

2013-09-01

306

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

Science.gov (United States)

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

307

Restoration of reproductive potential following expiration or removal of melengestrol acetate contraceptive implants in golden lion tamarins (Leontopithecus rosalia).  

Science.gov (United States)

Although reversible contraception is important to successful management of small populations, there are concerns about the reversibility of melengestrol acetate (MGA), the most commonly used implant in captive animals. Female golden lion tamarins (Leontopithecus rosalia) placed in potential breeding situations after surgical MGA implant removal showed a 75% return to reproduction within 2 yr, unlike golden-headed tamarins (Leontopithecus chrysomelas), which have had a 29% return to reproduction following implant removal. This rate was indistinguishable from the breeding probability for newly formed pairs involving nonimplanted females. Litter size, stillbirth rate, and infant survival rate were not significantly different between nonimplanted and implant-removed female golden lion tamarins. However, females with implants left in (and assumed to have expired) showed higher stillbirth and infant mortality rates than did females with implants removed. For seven female golden lion tamarins for which reproductive histories before and after MGA implantation were available, litter size was unaffected by MGA implantation and subsequent removal. Infant survival rate for these females appeared to be lower after removal but was indistinguishable from rates in the nonimplanted females. Prior reproductive experience, length of time with an implant, and age of the females did not affect the probability of breeding for females after removal of the implants. Overall, breeding probability of nonimplanted females declined with age. Although the results of this study confirm the reversibility of MGA implants in golden lion tamarins, there appear to be some effects on viability of offspring, particularly offspring born to females with implants left in and presumed expired. PMID:12785695

Wood, C; Ballou, J D; Houle, C S

2001-12-01

308

Reactivity toward thiols and cytotoxicity of 3-methylene-2-oxindoles, cytotoxins from indole-3-acetic acids, on activation by peroxidases.  

OpenAIRE

Oxidation of indole-3-acetic acid and its derivatives by peroxidases such as that from horseradish produces many products, including 3-methylene-2-oxindoles. These have long been associated with biological activity, but their reactivity has not been characterized. We have previously demonstrated the potential value of substituted indole acetic acids and horseradish peroxidase as the basis for targeted cancer therapy, since the compounds are of low cytotoxicity until oxidized, when high cytoto...

Folkes, Lk; Rossiter, S.; Wardman, P.

2002-01-01

309

Oxovanadium(IV) complexes of imidazole-4-acetic, imidazole-4,5-dicarboxylic and pyrazole-3,5-dicarboxylic acids  

OpenAIRE

Complex formation between oxovanadium(IV) and several diazole derivatives (imidazole-4-acetic, imidazole-4,5-dicarboxylic and pyrazole-3,5-dicarboxylic acid) was studied in aqueous solution by pH-potentiometric and spectroscopic (electron paramagnetic resonance and electronic absorption) techniques. The results show that the imidazole-4-acetate ligand, being suitable for bidentate coordination, forms monomeric or mixed hydroxo-bridged species. In the case of the dicarboxylic acids both having...

Sanna, Daniele; Micera, Giovanni; Buglyo?, Pe?ter; Kiss, Tama?s; Gajda, Tama?s; Surdy, Pe?ter

1998-01-01

310

Mutants of the pentose-fermenting yeast Pachysolen tannophilus tolerant to hardwood spent sulfite liquor and acetic acid.  

Science.gov (United States)

A strain development program was initiated to improve the tolerance of the pentose-fermenting yeast Pachysolen tannophilus to inhibitors in lignocellulosic hydrolysates. Several rounds of UV mutagenesis followed by screening were used to select for mutants of P. tannophilus NRRL Y2460 with improved tolerance to hardwood spent sulfite liquor (HW SSL) and acetic acid in separate selection lines. The wild type (WT) strain grew in 50 % (v/v) HW SSL while third round HW SSL mutants (designated UHW301, UHW302 and UHW303) grew in 60 % (v/v) HW SSL, with two of these isolates (UHW302 and UHW303) being viable and growing, respectively, in 70 % (v/v) HW SSL. In defined liquid media containing acetic acid, the WT strain grew in 0.70 % (w/v) acetic acid, while third round acetic acid mutants (designated UAA301, UAA302 and UAA303) grew in 0.80 % (w/v) acetic acid, with one isolate (UAA302) growing in 0.90 % (w/v) acetic acid. Cross-tolerance of HW SSL-tolerant mutants to acetic acid and vice versa was observed with UHW303 able to grow in 0.90 % (w/v) acetic acid and UAA302 growing in 60 % (v/v) HW SSL. The UV-induced mutants retained the ability to ferment glucose and xylose to ethanol in defined media. These mutants of P. tannophilus are of considerable interest for bioconversion of the sugars in lignocellulosic hydrolysates to ethanol. PMID:24122119

Harner, Nicole K; Bajwa, Paramjit K; Habash, Marc B; Trevors, Jack T; Austin, Glen D; Lee, Hung

2014-01-01

311

Removal of fluoride in aqueous solution by adsorption on acid activated water treatment sludge  

Science.gov (United States)

This paper reports the use of a pellet of adsorbent made from water treatment sludge (S) and acid activated water treatment sludge (SH) for removal of fluoride in the batch equilibration technique. The influence of pH, adsorbent dosage, temperature and effect of other ions were employed to find out the feasibility of acid activated adsorbent to remove fluoride to the permissible concentration of 0.7 mg/L. The results from the adsorption isotherm followed both Langmuir and Freundlich models and the highest fluoride removal was found for adsorbent activated with acetic acid at 2.0 mol/L. The optimum adsorbent dosage was found at 40 g/L, 0.01 mol/L acid activated adsorbent which was able to adsorb fluoride from 10 down to 0.11 mg/L. The adsorption capacity was decreased when the temperature increased. This revealed that the adsorption of fluoride on SH was exothermic. In the presence of nitrate and carbonate ions in the aqueous solution, fluoride removal efficiency of SH decreased from 94.4% to 86.6% and 90.8%, respectively. However, there is no significant effect in the presence of sulfate and chloride ions.

Vinitnantharat, Soydoa; Kositchaiyong, Sriwilai; Chiarakorn, Siriluk

2010-06-01

312

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

Science.gov (United States)

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

Zimin, Sergey P.; Gorlachev, Egor S.; Naumov, Viktor V.; Skok, Fedor O.

2012-06-01

313

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

Science.gov (United States)

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 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

314

Acetic Acid Bacterial Biota of the Pink Sugar Cane Mealybug, Saccharococcus sacchari, and Its Environs.  

Science.gov (United States)

Saccharococcus sacchari is the primary colonizer of the developing "sterile" tissue between the leaf sheath and stem of sugar cane. The honeydew secreted by the mealybugs is acidic (about pH 3) and supports an atypical epiphytic microbiota dominated by acetobacter-like bacteria and acidophilic yeast species. However, Erwinia and Leuconostoc species predominate within the leaf sheath pocket region when the mealybugs die out. The unidentified acetobacters were readily isolated from S. sacchari throughout its life cycle and from other genera of mealybugs on sugar cane and various other plants, both above and below ground. No other insect present on sugar cane was a significant vector of acetic acid bacteria. The major factors restricting microbial diversity within the environs of mealybugs were considered to be yeast activity along with bacterial production of acetic acid, ketogluconic acids, and gamma-pyrones, in association with their lowering of pH. The microbial products may aid in suppressing the attack by the parasitic mold Aspergillus parasiticus on mealybugs but could act as attractants for the predatory fruit fly Cacoxenus perspicax. PMID:16348144

Ashbolt, N J; Inkerman, P A

1990-03-01

315

A mutation affecting the synthesis of 4-chloroindole-3-acetic acid.  

Science.gov (United States)

Traditionally, schemes depicting auxin biosynthesis in plants have been notoriously complex. They have involved up to four possible pathways by which the amino acid tryptophan might be converted to the main active auxin, indole-3-acetic acid (IAA), while another pathway was suggested to bypass tryptophan altogether. It was also postulated that different plants use different pathways, further adding to the complexity. In 2011, however, it was suggested that one of the four tryptophan-dependent pathways, via indole-3-pyruvic acid (IPyA), is the main pathway in Arabidopsis thaliana, although concurrent operation of one or more other pathways has not been excluded. We recently showed that, for seeds of Pisum sativum (pea), it is possible to go one step further. Our new evidence indicates that the IPyA pathway is the only tryptophan-dependent IAA synthesis pathway operating in pea seeds. We also demonstrated that the main auxin in developing pea seeds, 4-chloroindole-3-acetic acid (4-Cl-IAA), which accumulates to levels far exceeding those of IAA, is synthesized via a chlorinated version of the IPyA pathway. PMID:23073010

Ross, John J; Tivendale, Nathan D; Davidson, Sandra E; Reid, James B; Davies, Noel W; Quittenden, Laura J; Smith, Jason A

2012-12-01

316

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

Directory of Open Access Journals (Sweden)

Full Text Available Jamal A Jilani,1 Maha Shomaf,2 Karem H Alzoubi3 1Department of Medicinal Chemistry and Pharmacognosy, Jordan University of Science and Technology, Irbid, Jordan; 2Department of Pathology, Jordan University, Amman, Jordan; 3Department of Clinical Pharmacy, Jordan University of Science and Technology, Irbid, Jordan Abstract: In this study, the syntheses of 4-aminophenylbenzoxazol-2-yl-5-acetic acid, (an analogue of a known nonsteroidal anti-inflammatory drug [NSAID] and 5-[4-(benzoxazol-2-yl-5-acetic acidphenylazo]-2-hydroxybenzoic acid (a novel mutual azo prodrug of 5-aminosalicylic acid [5-ASA] are reported. The structures of the synthesized compounds were confirmed using infrared (IR, hydrogen-1 nuclear magnetic resonance (1H NMR, and mass spectrometry (MS spectroscopy. Incubation of the azo compound with rat cecal contents demonstrated the susceptibility of the prepared azo prodrug to bacterial azoreductase enzyme. The azo compound and the 4-aminophenylbenzoxazol-2-yl-5-acetic acid were evaluated for inflammatory bowel diseases, in trinitrobenzenesulfonic acid (TNB-induced colitis in rats. The synthesized diazo compound and the 4-aminophenylbenzoxazol-2-yl-5-acetic acid were found to be as effective as 5-aminosalicylic acid for ulcerative colitis. The results of this work suggest that the 4-aminophenylbenzoxazol-2-yl-5-acetic acid may represent a new lead for treatment of ulcerative colitis. Keywords: benzoxazole acetic acid, azo prodrug, colon drug delivery

Jilani JA

2013-07-01

317

Bimodal electricity generation and aromatic compounds removal from purified terephthalic acid plant wastewater in a microbial fuel cell.  

Science.gov (United States)

Wastewater of purified terephthalic acid (PTA) from a petrochemical plant was examined in a membrane-less single chamber microbial fuel cell for the first time. Time course of voltage during the cell operation cycle had two steady phases, which refers to the fact that metabolism of microorganisms was shifted from highly to less biodegradable carbon sources. The produced power density was 31.8 mW m(-2) (normalized per cathode area) and the calculated coulombic efficiency was 2.05 % for a COD removal of 74 % during 21 days. The total removal rate of different pollutants in the PTA wastewater was observed in the following order: (acetic acid) > (benzoic acid) > (phthalic acid) > (terephthalic acid) > (p-toluic acid). The cyclic voltammetry results revealed that the electron transfer mechanism was dominated by mediators which were produced by bacteria. PMID:23076363

Marashi, Seyed Kamran Foad; Kariminia, Hamid-Reza; Savizi, Iman Shahidi Pour

2013-02-01

318

Biosynthesis of indole-3-acetic acid in Azospirillum brasilense. Insights from quantum chemistry.  

Science.gov (United States)

Quantum chemical methods AM1 and PM3 and chromatographic methods were used to qualitatively characterize pathways of bacterial production of indole-3-acetic acid (IAA). The standard free energy changes (delta G(o)'sum) for the synthesis of tryptophan (Trp) from chorismic acid via anthranilic acid and indole were calculated, as were those for several possible pathways for the synthesis of IAA from Trp, namely via indole-3-acetamide (IAM), indole-3-pyruvic acid (IPyA), and indole-3-acetonitrile (IAN). The delta G(o)'sum for Trp synthesis from chorismic acid was -402 (-434) kJ.mol-1 (values in parentheses were calculated by PM3). The delta G(o)'sum for IAA synthesis from Trp were -565 (-548) kJ.mol-1 for the IAN pathway, -481 (-506) kJ.mol-1 for the IAM pathway, and -289 (-306) kJ.mol-1 for the IPyA pathway. By HPLC analysis, the possibility was assessed that indole, anthranilic acid, and Trp might be utilized as precursors for IAA synthesis by Azospirillum brasilense strain Sp 245. The results indicate that there is a high motive force for Trp synthesis from chorismic acid and for IAA synthesis from Trp, and make it unlikely that anthranilic acid and indole act as the precursors to IAA in a Trp-independent pathway. PMID:10092839

Zakharova, E A; Shcherbakov, A A; Brudnik, V V; Skripko, N G; Bulkhin, N Sh; Ignatov, V V

1999-02-01

319

Removal of radium from sand filters by inorganic acids  

International Nuclear Information System (INIS)

Sand filters are used in water treatment stations to remove particulate matter from underground water, where iron and manganese are collected forming thin oxide films. These oxides of iron and manganese adsorb radium from underground water. Radium concentration increases in time on the filters, and consequently the level of radioactivity increases in the station. The removal of adsorbed radium on sand using inorganic acids was studied. Good efficiency of radium removal was obtained by controlling different parameters like temperature, time, pH, addition of competitive cations and anions. It was found that hydrochloric acid is the best for radium removal from sand filters. Maximum removal obtained was about 60% at 5M BaCl2 and 2M HCl at 50 deg C for 180-minute contact time. Kinetic parameters of the removal process were studied and compared with literature data. (author)

320

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

Science.gov (United States)

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

321

Removal of Organic Acids from Effluent via Freeze Crystallization.  

OpenAIRE

Freeze crystallization is an efficient separation process that can potentially be used in any application. Freeze crystallization is a high energy efficiency separation process that can be applied to a wide variety of industrial requirements. Although the vapor-liquid equilibrium is generally employed to separate the components of a solution, use of solid-liquid equilibrium should be considered – it may be cheaper. This paper describes a case study of recovery of acetic acid from effluent v...

Padhiyar, Tarak C.; Thakore, Prof Suchen B.

2013-01-01

322

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

Science.gov (United States)

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

323

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

Science.gov (United States)

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

324

Acetalization of hexanal with 2-ethyl hexanol catalyzed by solid acids  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese A atividade catalítica de sólidos ácidos como o fosfato de nióbio e a Amberlyst 35, uma resina trocadora de íons, foi avaliada na acetalização do hexanal com 2-etil-hexanol. Foram avaliadas a concentração do catalisador e a temperatura de reação na conversão do hexanal. A possibilidade de re-utiliza [...] ção do fosfato de nióbio também foi estudada e evidenciou ser possível re-utilizar este catalisador sem perda da atividade. O rendimento em acetal foi acima de 90% em condições brandas de reação. Abstract in english The catalyst activity of solid acids such as niobium phosphate and Amberlyst 35, an ion exchange resin, was evaluated in the acetalization of hexanal with 2-ethyl-hexanol. The catalyst loading and the reaction temperature were evaluated in the hexanal conversions. The possibility of recycling niobiu [...] m phosphate was also studied, showing that it was possible to reuse this catalyst without significant loss in its catalytic activity. The yield in acetal was above 90% under mild conditions.

Alessandro O, Barros; Aline T, Faísca; Elizabeth R, Lachter; Regina S. V, Nascimento; Rosane A. S, San Gil.

2011-02-01

325

Liquid phase equilibria of (water + phosphoric acid + 1-butanol or butyl acetate) ternary systems at T = 308.2 K  

Energy Technology Data Exchange (ETDEWEB)

(Liquid + liquid) equilibria and tie lines for the ternary systems of (water + phosphoric acid + 1-butanol) and (water + phosphoric acid + butyl acetate) were measured at T = 308.2 K. The experimental ternary (liquid + liquid) equilibrium data were correlated with the UNIQUAC model. The reliability of the experimental tie lines was confirmed using Othmer-Tobias correlation. The average root-mean-square deviation (RMSD) values of (water + phosphoric acid + 1-butanol) and (water + phosphoric acid + butyl acetate) systems were 2.17% and 2.16%, respectively. Distribution coefficients and separation factors were measured to evaluate the extracting capability of the solvents. The results show that butyl acetate may be considered as a reliable organic solvent for the extraction of phosphoric acid from aqueous solutions.

Ghanadzadeh, H. [Department of Chemistry, Faculty of Science, University of Guilan, Rasht (Iran, Islamic Republic of); Department of Chemical Engineering, University of Guilan, Rasht (Iran, Islamic Republic of); Ghanadzadeh, A. [Department of Chemistry, Faculty of Science, University of Guilan, Rasht (Iran, Islamic Republic of)], E-mail: aggilani@guilan.ac.ir; Bahrpaima, Kh. [Department of Chemistry, Faculty of Science, University of Guilan, Rasht (Iran, Islamic Republic of)

2008-12-15

326

[Hydroxylation of indolyl-3-acetic acid by the fungus aspergillus niger IBFM-F-12].  

Science.gov (United States)

Physiological and biochemical properties of the culture of Aspergillus niger IBPM F 12 carrying out hydroxylation IAA in the 4-, 5-, 6-positions of the indole nucleus were studied. The optimal composition of the medium for the cultivation was established. The transformation was performed by the washed fungal mycelium taken in the middle of the growth log-phase at a substrate concentration of I g/l. The correlation between the hydroxylase activity and pH, temperaure and biomass quantity was shown. The method of isolating 4-, 5- and 6-hydroxyindolyl-3-acetic acids in preparative amounts was developed. PMID:866301

Koshcheenko, K A; Baklashova, T G; Kozlovski?, A G; Arinbasarov, M U; Skriabin, G K

1977-01-01

327

In planta production of indole-3-acetic acid by Colletotrichum gloeosporioides f. sp. aeschynomene.  

Science.gov (United States)

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

2004-03-01

328

Response to flavone acetic acid (NSC 347512) of primary and metastatic human colorectal carcinoma xenografts.  

OpenAIRE

The antitumour activity of flavone acetic acid (FAA) was evaluated against two human colorectal carcinoma (HCC) lines, HCC-P2988 and HCC-M1410, transplanted into nude mice. On repeated i.v. injection of 200 mg kg-1 every 4 days FAA was moderately active against the s.c. growing HCC-P2988. HCC-M1410 transplanted s.c. was almost unresponsive in the same experimental conditions. In contrast, FAA (200 mg kg-1 i.v. every 4 days, repeated three times) significantly reduced liver tumour colonies pro...

Giavazzi, R.; Garofalo, A.; Damia, G.; Garattini, S.; D Incalci, M.

1988-01-01

329

Ion exchange and separation of actinide elements in mixed solutions of acetic and nitric acid  

International Nuclear Information System (INIS)

Behaviour of actinide elements in mixed HNO3-CH3COOH solutions as a function of composition and concentration of components and nature of ion exchangers is investigated. Conditions for concentration and separation of some elements on anionites using HNO3-CH3COOH solutions as elutriators are determined. It is shown that solutions with HNO3 concentration ?1 mol/l containing ?90 % of CH3COOH can be used for actinide elements concentrating on anionites as well as on cationites. Superiorities of acetic acid solutions of HNO3 for leaching of actinides from nature objects with their following radiochemical separation in uninterrupted regime were discussed

330

2-[2-(1,3-Dioxoisoindolin-2-yl)acetamido]­acetic acid  

Science.gov (United States)

The title mol­ecule, C12H10N2O5, is non-planar with dihedral angles of 89.08?(7) and 83.21?(7)° between the phthalimide and acetamide mean planes, and the acetamide and acetic acid mean planes, respectively. In the crystal, symmetry-related mol­ecules are linked via N—H?O and O—H?O hydrogen bonds, forming an undulating two-dimensional network. There are also a number of weak C—H?O inter­actions, leading to the formation of a three-dimensional arrangement. PMID:21589136

Bhatti, Moazzam H.; Yunus, Uzma; Imtiaz-ud-Din; Shams-ul-Islam, S.; Wong, Wai-Yeung

2010-01-01

331

Hexa-?2-acetato-triaqua-?3-oxido-triiron(III nitrate acetic acid solvate  

Directory of Open Access Journals (Sweden)

Full Text Available The asymmetric unit of the title compound, [Fe3(CH3COO6O(H2O3]NO3·CH3COOH, consists of a hexa-?2-acetato-triaqua-?3-oxo-triiron(III macrocation, a nitrate ion and an acetic acid solvent molecule. In the cation, each Fe3+ ion is coordinated by four carboxylate O atoms, one central bridged O atom and one water molecule, resulting in distorted FeO6 octahedra. A network of O—H...O hydrogen bonds helps to establish the packing.

Sumei Yao

2008-08-01

332

Hexa-?2-acetato-triaqua-?3-oxido-triiron(III) nitrate acetic acid solvate  

Science.gov (United States)

The asymmetric unit of the title compound, [Fe3(CH3COO)6O(H2O)3]NO3·CH3COOH, consists of a hexa-?2-acetato-triaqua-?3-oxo-triiron(III) macrocation, a nitrate ion and an acetic acid solvent mol­ecule. In the cation, each Fe3+ ion is coordinated by four carboxyl­ate O atoms, one central bridged O atom and one water mol­ecule, resulting in distorted FeO6 octa­hedra. A network of O—H?O hydrogen bonds helps to establish the packing. PMID:21203085

Yao, Sumei; Liu, Jianhua; Han, Qiuxia

2008-01-01

333

Hexa-?(2)-acetato-triaqua-?(3)-oxido-triiron(III) nitrate acetic acid solvate.  

Science.gov (United States)

The asymmetric unit of the title compound, [Fe(3)(CH(3)COO)(6)O(H(2)O)(3)]NO(3)·CH(3)COOH, consists of a hexa-?(2)-acetato-triaqua-?(3)-oxo-triiron(III) macrocation, a nitrate ion and an acetic acid solvent mol-ecule. In the cation, each Fe(3+) ion is coordinated by four carboxyl-ate O atoms, one central bridged O atom and one water mol-ecule, resulting in distorted FeO(6) octa-hedra. A network of O-H?O hydrogen bonds helps to establish the packing. PMID:21203085

Yao, Sumei; Liu, Jianhua; Han, Qiuxia

2008-01-01

334

1-[3-(4-Nitro­phen­yl)propano­yl]urea acetic acid monosolvate  

Science.gov (United States)

The title compound, C10H11N3O4·C2H4O2, was prepared by an electrochemical technique. In the crystal, acetic acid mol­ecules are involved in hydrogen bonding to two separate propano­ylurea mol­ecules, acting as a donor in an O—H?O inter­action and as an acceptor in two N—H?O inter­actions. The propano­ylurea mol­ecules inter­act with each other via N—H?O hydrogen bonds. C—H?O inter­actions also stabilize the crystal structure. PMID:22219927

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

2011-01-01

335

2-[2-(1,3-Dioxoisoindolin-2-ylacetamido]acetic acid  

Directory of Open Access Journals (Sweden)

Full Text Available The title molecule, C12H10N2O5, is non-planar with dihedral angles of 89.08?(7 and 83.21?(7° between the phthalimide and acetamide mean planes, and the acetamide and acetic acid mean planes, respectively. In the crystal, symmetry-related molecules are linked via N—H...O and O—H...O hydrogen bonds, forming an undulating two-dimensional network. There are also a number of weak C—H...O interactions, leading to the formation of a three-dimensional arrangement.

Moazzam H. Bhatti

2010-11-01

336

Polyacrylonitrile/manganese acetate composite nanofibers and their catalysis performance on chromium (VI) reduction by oxalic acid  

Energy Technology Data Exchange (ETDEWEB)

Highlights: Black-Right-Pointing-Pointer We have successfully prepared PAN/Mn(CH{sub 3}COO){sub 2} composite nanofibers. Black-Right-Pointing-Pointer The nanofibers exhibit excellent catalysis performance for Cr(VI) reduction. Black-Right-Pointing-Pointer The nanofibers are effective and environment-friendly materials to remove Cr(VI). - Abstract: Polyacrylonitrile(PAN)/manganese acetate(Mn(CH{sub 3}COO){sub 2}) composite nanofibers have been fabricated by electrospinning, a simple and effective technology. The obtained composite nanofibers were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectrometer (FT-IR). The composite nanofibers are amorphous in structure, continuous, even and smooth. At the same time, the reduction performance of Cr(VI) by oxalic acid in the presence of the composite nanofibers is also investigated. The results indicate that the composite nanofibers have exhibited excellent catalysis performance for Cr(VI) reduction from a Cr{sub 2}O{sub 7}{sup 2-}-containing solution by oxalic acid. And the critical parameters, such as the catalyst dosage, oxalic acid content, chromium concentration, the pH value of the reaction solution and light have important impact on the reduction process. Under the simulated solar light irradiation, after only 60 min, 1.2 mM initial Cr(VI) solution was reduced absolutely in the presence of PAN/Mn(CH{sub 3}COO){sub 2} composite nanofibers containing 17.5 wt.% Mn(CH{sub 3}COO){sub 2} by 0.3 mL 0.5 M oxalic acid. In light, the reduction of Cr(VI) by oxalic acid is markedly accelerated.

Zhang, Chengcheng [Jilin University Alan G MacDiarmid Institute, Changchun 130012 (China); Li, Xiang, E-mail: xiangli@jlu.edu.cn [Jilin University Alan G MacDiarmid Institute, Changchun 130012 (China); Bian, Xiujie; Zheng, Tian [Jilin University Alan G MacDiarmid Institute, Changchun 130012 (China); Wang, Ce, E-mail: cwang@jlu.edu.cn [Jilin University Alan G MacDiarmid Institute, Changchun 130012 (China)

2012-08-30

337

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

Energy Technology Data Exchange (ETDEWEB)

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

Zhu, Yunhua; Jones, Susanne B.

2009-04-01

338

PCL-gelatin composite nanofibers electrospun using diluted acetic acid-ethyl acetate solvent system for stem cell-based bone tissue engineering.  

Science.gov (United States)

Composite nanofibrous scaffolds with various poly(?-caprolactone) (PCL)/gelatin ratios (90:10, 80:20, 70:30, 60:40, 50:50 wt.%) were successfully electrospun using diluted acetic and ethyl acetate mixture. The effects of this solvent system on the solution properties of the composites and its electrospinning properties were investigated. Viscosity and conductivity of the solutions, with the addition of gelatin, allowed for the electrospinning of uniform nanofibers with increasing hydrophilicity and degradation. Composite nanofibers containing 30 and 40 wt.% gelatin showed an optimum combination of hydrophilicity and degradability and also maintained the structural integrity of the scaffold. Human mesenchymal stem cells (hMSCs) showed favorable interaction with and proliferation on, the composite scaffolds. hMSC proliferation was highest in the 30 and 40 wt.% gelatin containing composites. Our experimental data suggested that PCL-gelatin composite nanofibers containing 30-40 wt.% of gelatin and electrospun in diluted acetic acid-ethyl acetate mixture produced nanofiber scaffolds with optimum hydrophilicity, degradability, and bio-functionality for stem cell-based bone tissue engineering. PMID:24274102

Binulal, N S; Natarajan, Amrita; Menon, Deepthy; Bhaskaran, V K; Mony, Ullas; Nair, Shantikumar V

2014-01-01

339

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

Science.gov (United States)

The growth of acetic acid bacteria on grapes or throughout the winemaking process influences the quality of wine, mainly because it increases the volatile acidity. The objective of this study was to analyse how the acetic acid bacteria population evolves in the changing environment of the grape surface and during wine fermentation. We have analysed the influence of yeast inoculation and SO2 addition on acetic acid bacteria populations. These bacteria were analysed at both the species and the strain level by molecular methods such as Restriction Fragment Length Polimorfism (RFLP) of amplified 16S rDNA, and amplification by polymerase chain reaction of Enterobacterial Repetitive Intergenic Consensus (ERIC-PCR) and Repetitive Extragenic Palindromic (REP-PCR). Our results show that the increases in population size are normally accompanied by a proliferation of Acetobacter aceti, which is the main species during fermentation. The diversity of strains is considerable in natural environments such as the grape surface. Changes in the environment during alcoholic fermentation substantially reduce the survival and the diversity of acetic acid bacteria. Few strains are able to survive these conditions and they seem to originate from both the grapes and the winery. To the best of our knowledge this is the first time that acetic acid bacteria are analysed at the strain level in grape surfaces and during winemaking. PMID:16014297

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

2005-07-25

340

Suspended biofilm carrier and activated sludge removal of acidic pharmaceuticals  

DEFF Research Database (Denmark)

Removal of seven active pharmaceutical substances (ibuprofen, ketoprofen, naproxen, diclofenac, clofibric acid, mefenamic acid, and gemfibrozil) was assessed by batch experiments, with suspended biofilm carriers and activated sludge from several full-scale wastewater treatment plants. A distinct difference between nitrifying activated sludge and suspended biofilm carrier removal of several pharmaceuticals was demonstrated. Biofilm carriers from full-scale nitrifying wastewater treatment plants, demonstrated considerably higher removal rates per unit biomass (i.e. suspended solids for the sludges and attached solids for the carriers) of diclofenac, ketoprofen, gemfibrozil, clofibric acid and mefenamic acid compared to the sludges. Among the target pharmaceuticals, only ibuprofen and naproxen showed similar removal rates per unit biomass for the sludges and biofilm carriers. In contrast to pharmaceutical removal, the nitrification capacity per unit biomass was lower for the carriers than the sludges, which suggests that neither the nitrite nor the ammonia oxidizing bacteria are primarily responsible for the observed differences in pharmaceutical removal. The low ability of ammonia oxidizing bacteria to degrade or transform the target pharmaceuticals was further demonstrated by the limited pharmaceutical removal in an experiment with continuous nitritation and biofilm carriers from a partial nitritation/anammox sludge liquor treatment process.

Falås, Per; Baillon-Dhumez, Aude

2012-01-01

341

Deuterium isotope effects and solvolysis of tosylates of cis- and trans-2-phenylcyclopentanol in formic acid, acetic acid and ethanol  

International Nuclear Information System (INIS)

The solvolysis of the tosylates of cis and trans 2-phenylcyclopentanol has been studied in formic acid, acetic acid and ethanol by kinetic measurements and secondary isotopes effects. In the case of the cis isomer, hydrogen migration (93 to 97%) from C-2 occurs after rapid ionisation of the tosylate to form an ion-pair which subsequently gives a bridged intermediate in a slow step. With the trans isomer the migration of the hydrogen atom (15 to 47%) and that of the phenyl group (38% in formic acid solution; less than 10% in the two other solvents) would occur in a slow step after ionisation of the tosylate to an intimate ion-pair which dissociates to a loose solvent-separated ion-pair

342

Heterogeneity in human acid beta-glucosidase revealed by cellulose-acetate electrophoresis.  

Science.gov (United States)

Cellulose-acetate gel electrophoresis, a technique commonly used for the separation of human acid hydrolases, was applied to study heterogeneity in acid beta-glucosidase (EC 3.2.1.45). With this technique, three forms of beta-glucosidase were distinguishable in extracts of several tissues. The most anodic beta-glucosidase activity (band 3) represents the broad-specificity beta-glucosidase that is not deficient in Gaucher disease and is not inhibited by conduritol B-epoxide (CBE). The beta-glucosidase activity was deficient in Gaucher disease. A third beta-glucosidase activity with an intermediate mobility (band 2) was also inhibited by CBE and deficient in Gaucher disease. Band 1 and band 2 beta-glucosidase thus represent different forms of glucocerebrosidase. By adding phosphatidylserine and sphingolipid activator protein (SAP-2), monomeric glucocerebrosidase could be completely converted into a form that comigrated with band 2 beta-glucosidase of tissue extracts. The addition of phosphatidylserine only also resulted in a changed mobility of the monomeric enzyme, but the migration in this case differed from that of band 2 beta-glucosidase of tissue extracts. The electrophoretic profile of beta-glucosidase activity of tissue extracts changed upon ethanol/chloroform extraction: the two glucocerebrosidase forms were converted into a band with a mobility identical to that of band 1 beta-glucosidase. Our findings indicate that the interaction of glucocerebrosidase with phospholipid and SAP-2 has major effects on the mobility of the enzyme in the cellulose-acetate gel electrophoresis system. The findings with the cellulose-acetate gel electrophoretic system are discussed in relation to the heterogeneity in glucocerebrosidase observed with sucrose density gradient analysis, immunochemical methods and isoelectric focussing studies. PMID:3130106

Sa Miranda, M C; Aerts, J M; Pinto, R A; Magalhaes, J A; Barranger, J A; Tager, J M; Schram, A W

1988-05-12

343

Temperature dependence of the dielectric permittivity of acetic acid, propionic acid and their methyl esters: a molecular dynamics simulation study.  

Science.gov (United States)

For most liquids, the static relative dielectric permittivity is a decreasing function of temperature, because enhanced thermal motion reduces the ability of the molecular dipoles to orient under the effect of an external electric field. Monocarboxylic fatty acids ranging from acetic to octanoic acid represent an exception to this general rule. Close to room temperature, their dielectric permittivity increases slightly with increasing temperature. Herein, the causes for this anomaly are investigated based on molecular dynamics simulations of acetic and propionic acids at different temperatures in the interval 283-363 K, using the GROMOS 53A6(OXY) force field. The corresponding methyl esters are also considered for comparison. The dielectric permittivity is calculated using either the box-dipole fluctuation (BDF) or the external electric field (EEF) methods. The normal and anomalous temperature dependences of the permittivity for the esters and acids, respectively, are reproduced. Furthermore, in the EEF approach, the response of the acids to an applied field of increasing strength is found to present two successive linear regimes before reaching saturation. The low-field permittivity ?, comparable to that obtained using the BDF approach, increases with increasing temperature. The higher-field permittivity ?' is slightly larger, and decreases with increasing temperature. Further analyses of the simulations in terms of radial distribution functions, hydrogen-bonded structures, and diffusion properties suggest that increasing the temperature or the applied field strength both promote a relative population shift from cyclic (mainly dimeric) to extended (chain-like) hydrogen-bonded structures. The lower effective dipole moment associated with the former structures compared to the latter ones provides an explanation for the peculiar dielectric properties of the two acids compared to their methyl esters. PMID:22383366

Riniker, Sereina; Horta, Bruno A C; Thijssen, Bram; Gupta, Saumya; van Gunsteren, Wilfred F; Hünenberger, Philippe H

2012-04-10

344

Rhodanineacetic Acid Derivatives as Potential Drugs: Preparation, Hydrophobic Properties and Antifungal Activity of (5-Arylalkylidene-4-oxo-2-thioxo-1,3-thiazolidin-3-yl)acetic Acids  

OpenAIRE

Some [(5Z)-(5-arylalkylidene-4-oxo-2-thioxo-1,3-thiazolidin-3-yl)]acetic acids were prepared as potential antifungal compounds. The general synthetic approach to all synthesized compounds is presented. Lipophilicity of all the discussed rhodanine-3-acetic acid derivatives was analyzed using a reversed phase high performance liquid chromatography (RP-HPLC) method. The procedure was performed under isocratic conditions with methanol as an organic modifier in the mobile phase using an end-capped...

Josef Jampilek; Jiri Kunes; Vejsova Marcela; Petra Hirsova; Jiri Dohnal; Veronika Opletalova; Jan Dolezel

2009-01-01

345

Phosphoric acid purification. Removal of thorium and other chemical species  

International Nuclear Information System (INIS)

Separation techniques like solvent extraction, ion exchange resin retention, precipitation and inorganic adsorption showed very low efficiency in removing thorium from the phosphoric acid. Then the process was directed to the extraction of phosphoric acid with tri-n-butyl phosphate (TBP) for its purification which consequently removed the thorium isotopes. This phosphoric acid purification was established to use the mixer-settler cells in countercurrent system. The operational conditions were defined first in discontinuous tests at the laboratory scale and thereafter consolidated in a continuous unit. (orig.)

346

Transgenically enhanced expression of indole-3-acetic Acid confers hypervirulence to plant pathogens.  

Science.gov (United States)

ABSTRACT Fusarium oxysporum and F. arthrosporioides, pathogenic on Orobanche aegyptiaca, were transformed with two genes of the indole-3-acetamide (IAM) pathway leading to indole-3-acetic acid (IAA) to attempt to enhance virulence. Transgenic F. oxysporum lines containing both the tryptophan-2-monooxyngenase (iaaM) and indole-3-acetamide hydrolase (iaaH) genes produced significantly more IAA than the wild type. IAM accumulated in culture extracts of F. oxysporum containing iaaM alone. F. arthrosporioides containing only iaaM accumulated IAM and an unidentified indole. Some transformants of F. oxysporum expressing only the iaaM gene also produced more IAA than the wild type. Sub-threshold levels (that barely infect Orobanche) of transgenic F. oxysporum expressing both genes and of F. arthrosporioides expressing iaaM were more effective in suppressing the number and size of Orobanche shoots than the wild type on tomato plants grown in soil mixed with Orobanche seed. Stimulating an auxin imbalance enhanced pathogen virulence by affecting the host in a manner similar to low doses of auxin herbicides such as 2,4-dichlorophenoxy acetic acid. PMID:18944254

Cohen, Barry A; Amsellem, Ziva; Maor, Rudy; Sharon, Amir; Gressel, Jonathan

2002-06-01

347

Synthesis and anticancer activities of 3-arylflavone-8-acetic acid derivatives.  

Science.gov (United States)

This paper describes the synthesis and the antiproliferative activities of compounds 9a-r, 3-aryl analogs of flavone-8-acetic acid that bear diverse substituents on the benzene rings at the 2- and 3-positions of the flavone nucleus. Their direct and indirect cytotoxicities were evaluated against HT-29 human colon adenocarcinoma cell lines, A549 lung adenocarcinoma cell lines and Human Peripheral Blood Mononuclear Cells (HPBMCs). The results indicate that most of the compounds bearing electron-withdrawing substituents (9b-m) exhibited moderate direct cytotoxicities. And compounds 9e and 9i showed comparable indirect cytotoxicities with 5, 6-dimethylxanthenone-4-acetic acid (DMXAA), and low direct cytotoxicities toward HPBMCs. Interestingly, the compounds 9n-r bearing methoxy groups at the 2- or 3-position of the flavone nucleus exhibited higher indirect cytotoxicities against A549 cell lines than DMXAA, and lower cytotoxicities against HPBMCs. In addition, compounds 9p-r were found to be able to induce tumor necrosis factor ? (TNF-?) production in HPBMCs. PMID:25461325

Yan, Guang-Hua; Li, Xiao-Fang; Ge, Bing-Chen; Shi, Xiu-Dong; Chen, Yu-Fang; Yang, Xue-Mei; Xu, Jiang-Ping; Liu, Shu-Wen; Zhao, Pei-Liang; Zhou, Zhong-Zhen; Zhou, Chun-Qiong; Chen, Wen-Hua

2015-01-27

348

Toward targeted 'oxidation therapy' of cancer: peroxidase-catalysed cytotoxicity of indole-3-acetic acids  

International Nuclear Information System (INIS)

Purpose: The study aimed to identify suitable prodrugs that could be used to test the hypothesis that peroxidase activity in cells, either endogenous or enhanced by immunological targeting, can activate prodrugs to cytotoxins. We hypothesized that prototype prodrugs based on derivatives of indole-3-acetic acid (IAA), when activated by peroxidase enzymes (e.g., from horseradish, HRP) should produce peroxyl radicals, with deleterious biological consequences. Methods and Materials: V79 hamster cells were incubated with IAA or derivatives ± HRP and cytotoxicity assessed by a clonogenic assay. To assess the toxicity of stable oxidation products, prodrugs were also oxidized by HRP without cells, and the products then added to cells. Results: The combination of prodrug and enzyme resulted in cytotoxicity, but neither indole nor enzyme in isolation was toxic under the conditions used. Although lipid peroxidation was stimulated in liposomes by the prodrug/enzyme treatment, it could not be measured in mammalian cells. Adding oxidized prodrugs to cells resulted in cytotoxicity. Conclusions: Although the hypothesis that prodrugs of this type could enhance oxidative stress via lipid peroxidation was not established, the results nonetheless demonstrated oxidatively-activated cytotoxicity via indole acetic acid prodrugs, and suggested these as a new type of substrate for antibody-directed enzyme-prodrug therapy (ADEPT). The hypothesized free-radical fragmentation intermediates were-radical fragmentation intermediates were demonstrated, but lipid peroxidation associated with peroxyl radical formation was unlikely to be the major route to cytotoxicity

349

Agreement Between Visual Inspection with Acetic Acid and Papanicolaous Smear as Screening Methods for Cervical Cancer  

International Nuclear Information System (INIS)

Objective: To determine degree of agreement between visual inspection with acetic acid (VIA) and Papanicolaous (Pap) smear as screening methods for cervical cancer. Study Design: A cross-sectional study. Place and Duration of Study: Department of Obstetrics and Gynaecology, Sir Ganga Ram Hospital, Lahore, from July to December 2012. Methodology: Two hundred and fifty women in reproductive age group presenting with various gynaecological complaints were included in the study. A Papanicolaous smear was taken and visual inspection with 5% acetic acid was done. VIA was reported as positive or negative according to acetowhite changes and cytology result was graded as CIN 1, 2, 3 and squamous carcinoma. Those women who showed positive result with either VIA or Pap smear or both were further subjected to colposcopic directed biopsy which was taken as gold standard. Results were computed using Statistical Package for Social Sciences (SPSS) version 16 and statistical test used was kappa. Results: Out of 250 women, VIA was positive in 55 (22%) patients and Pap smear was abnormal in 27 (10.8%). Histological diagnosis of CIN/cancer was made in 36 out of a total 62 patients who underwent biopsy. Conclusion: There was a fair agreement between VIA and Pap smear, with VIA detecting more abnormalities than cytology. In the absence of Pap smear availability, VIA may be a reasonable cervical cancer screening method, especially in low resource settings. (author)

350

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

Science.gov (United States)

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

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

2012-03-22

351

Fermentative Conversion of Cellulose to Acetic Acid and Cellulolytic Enzyme Production by a Bacterial Mixed Culture Obtained from Sewage Sludge †  

OpenAIRE

A simple procedure that uses a cellulose-enriched culture started from sewage sludge was developed for producing cellulolytic enzymes and converting cellulose to acetic acid rather than CH4 and CO2. In this procedure, the culture which converts cellulose to CH4 and CO2 was mixed with a synthetic medium and cellulose and heated to 80°C for 15 min before incubation. The end products formed were acetic acid, propionic acid, CO2, and traces of ethanol and H2. Supernatants from 6- to 10-day-old c...

Khan, A. W.; Wall, Duncan; Den Berg, L.

1981-01-01

352

PREPARATION AND CHARACTERIZATION OF ACETIC ACID LIGNIN-BASED EPOXY BLENDS  

Directory of Open Access Journals (Sweden)

Full Text Available Lignin-based epoxy resin (LER was prepared from phenolated lignin (PL and epichlorohydrin (ECH in the presence of sodium hydroxide. The eucalyptus acetic acid lignin (AAL was first reacted with phenol in the presence of sulfuric acid to obtain PL. Then, PL was reacted with ECH in aqueous sodium hydroxide to obtain LER. LER was mixed with diglycidyl ether of bisphenol A (E-44 and then cured with triethylenetetramine (TETA. The initial thermal degradation temperature (Td of the cured epoxy blends decreased with the increase in LER content. The residue ratio at 500 °C of the cured epoxy blends (R500, however, increased with the LER content. The maximum adhesive shear strength of the cured epoxy blends was obtained at 20 wt% of LER. The water absorption of epoxy blends increased with increasing the content of LER. SEM photos showed that increasing the content of LER increased inhomogeneity and porosity of epoxy blends.

Fangeng Chen

2012-05-01

353

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

Science.gov (United States)

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

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

2014-01-01

354

Rapid identification of acetic acid bacteria using MALDI-TOF mass spectrometry fingerprinting.  

Science.gov (United States)

Acetic acid bacteria (AAB) are widespread microorganisms characterized by their ability to transform alcohols and sugar-alcohols into their corresponding organic acids. The suitability of matrix-assisted laser desorption-time of flight mass spectrometry (MALDI-TOF MS) for the identification of cultured AAB involved in the industrial production of vinegar was evaluated on 64 reference strains from the genera Acetobacter, Gluconacetobacter and Gluconobacter. Analysis of MS spectra obtained from single colonies of these strains confirmed their basic classification based on comparative 16S rRNA gene sequence analysis. MALDI-TOF analyses of isolates from vinegar cross-checked by comparative sequence analysis of 16S rRNA gene fragments allowed AAB to be identified, and it was possible to differentiate them from mixed cultures and non-AAB. The results showed that MALDI-TOF MS analysis was a rapid and reliable method for the clustering and identification of AAB species. PMID:23182036

Andrés-Barrao, Cristina; Benagli, Cinzia; Chappuis, Malou; Ortega Pérez, Ruben; Tonolla, Mauro; Barja, François

2013-03-01

355

SYNTHESIS OF 2-METHYL4QUINOLONE-3-ACETIC ACIDS WITH POTENTIAL ANTIBACTERIAL ACTIVITY  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english A number of quinolone-3-acetic acids were synthesized by cyclocondensation of substituted anilines with diethyl acetylsuccinate in the presence of phosphorous pentoxide and followed by base hydrolysis of the resultant esters to form respective acids. All synthesized compounds were found to exhibit a [...] ntibacterial activities against a range of gram-positive (Bacillus subtilis, Staphylococcus aureus) and gram-negative bacteria (Shigella sonnei, Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi) by broth dilution method. All the compounds exhibited antibacterial activities comparable to fluoroquinolones and in some cases even better activity was found. These findings suggest a great potential of these compounds for screening and use as antibacterial compounds for further studies with a battery of bacteria.

Fauzia Anjum, Chattha; Munawar Ali, Munawar; Muhammad, Ashraf; Saeed Ahmad, Nagra; , Mehr-Un-Nisa; Ismat, Fatima.

1237-12-01

356

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

Science.gov (United States)

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

357

Allergic Contact Dermatitis Syndrome Due to Tocopherol Acetate, in Addition to Glycyrrhetinic Acid  

Directory of Open Access Journals (Sweden)

Full Text Available Natural vitamin E is suggested to have an antioxidant function. However, the synthetic form of vitamin E, DL-tocopherol, which has been widely used in topical ointments, may cause allergic contact dermatitis. Here, we report a case of allergic contact dermatitis with erythema multiforme-like eruption caused by a topical ointment. Patch testing indicated a positive allergic reaction to an anti-inflammatory ointment the patient had been using and its ingredient, DL-alpha-tocopheryl acetate (vitamin E. In addition, a positive reaction to glycyrrhetinic acid was observed. Both vitamin E and glycyrrhetinic acid are useful ingredients of topical applications. However, the possibility that both can cause contact dermatitis, albeit rarely, should be considered.

Masaaki Ito

2012-03-01

358

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

CERN Document Server

Fragments from organic molecule dissociation (such as reactive ions and radicals) can form interstellar complex molecules like amino acids. The goal of this work is to experimentally study photoionization and photodissociation processes of acetic acid (CH$_3$COOH), a glycine (NH$_2$CH$_2$COOH) precursor molecule, by soft X-ray photons. The measurements were taken at the Brazilian Synchrotron Light Laboratory (LNLS), employing soft X-ray photons from a toroidal grating monochromator (TGM) beamline (100 - 310 eV). Mass spectra were obtained using the photoelectron photoion coincidence (PEPICO) method. Kinetic energy distribution and abundances for each ionic fragment have been obtained from the analysis of the corresponding peak shapes in the mass spectra. Absolute photoionization and photodissociation cross sections were also determined. We have found, among the channels leading to ionization, that only 4-6% of CH$_3$COOH survive the strong ionization field. CH$_3$CO$^+$, COOH$^+$ and CH$_3^+$ ions are the mai...

Pilling, S; Boechat-Roberty, H M

2006-01-01

359

An intercomparison of measurement systems for vapor and particulate phase concentrations of formic and acetic acids  

Science.gov (United States)

During June 1986, eight systems for measuring vapor phase and four for measuring particulate phase concentrations of formic acid (HCOOH) and acetic acid (CH3COOH) were intercompared in central Virginia. HCOOH and CH3COOH vapors were sampled by condensate, mist, Chromosorb 103 GC resin, NaOH-coated annular denuders, NaOH-impregnated quartz filters, K2CO3 and NaCO3-impregnated cellulose filters, and Nylasorb membranes. Atmospheric aerosol was collected on Teflon and Nuclepore filters using both hi-vol and lo-vol systems to measure particulate phase concentrations. Performances of the mist chamber and K2CO3-impregnated filter techniques were evaluated using zero air and ambient air spiked with HCOOH(g) and CH3COOH(g), and formaldehyde from permeation sources. The advantages and drawbacks of these methods are reported and discussed.

Keene, William C.; Talbot, Robert W.; Andreae, Meinrat O.; Beecher, Kristene; Berresheim, Harold

1989-01-01

360

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

Science.gov (United States)

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...

361

PHOTOLYSIS RATES OF (2,4,5-TRICHLOROPHENOXY)ACETIC ACID AND 4-AMINO-3,5,6-TRICHLOROPICOLINIC ACID IN NATURAL WATERS  

Science.gov (United States)

Photoreactions of (2,45-trichlorophenoxy) acetic acid (2,4,5-T) and 4-amino-3,5,6-trichloropicolinic acid (picloram) were studied in distilled water, natural water samples, fulvic acid solutions, and solutions containing iron (III) and/or hydrogen peroxide to determine the effect...

362

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

Science.gov (United States)

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

363

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

Science.gov (United States)

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 astilbes or as "Commensalibacter intestini", except for two isolates (R-52486 and LMG 28161T) that showed an identical profile. A nearly complete 16S rRNA gene sequence of LMG 28161T was determined and showed the highest pairwise similarity to Saccharibacter floricola (96.5 %), which corresponded with genus level divergence in the Acetobacteraceae family. Isolate LMG 28161T 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 data obtained confirmed that this isolate is best classified into a novel genus in the family Acetobacteraceae. Its DNA G+C content was 54.9 mol%. The fatty acid compositions of R-52486 and LMG 28161T were similar to those of established AAB species [with C18:1?7c (43.3 %) as 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 lack of ability 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-gluconic acid, but not 5-keto-D-gluconic acid from D-glucose. Therefore, the name Bombella intestini is proposed for this new taxon, with LMG 28161T (= DSM 28636T) as the type strain. PMID:25336723

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

2014-10-21

364

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

Science.gov (United States)

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

365

Studies on the complexes of uranium(IV), thorium(IV) and lanthanum(III) acetates with p-aminobenzoic acid, m-aminobenzoic acid, benzilic acid and phthalic acid  

International Nuclear Information System (INIS)

Complexes of acetates of U(IV), Th(IV) and La(III) with the ligands p-aminobenzoic acid, m-aminobenzoic acid, benzilic acid and phthalic acid have been prepared. Colour and chemical analytical data are recorded. They are characterised on the basis of IR and reflectance spectra and magnetic susceptibility data. (M.G.B.)

366

Sol-gel process for preparing YBa2Cu4O8 precursors from Y, Ba, and Cu acidic acetates/ammonia/ascorbic acid systems  

International Nuclear Information System (INIS)

Sols were prepared by addition of ammonia to acidic acetate solutions of Y3+, Ba2+, and Cu2+. Ascorbic acid was added to a part of the sol. The resultant sols were gelled to a shard, a film, or microspheres by evaporation at 60 C or by extraction of water from drops of emulsion suspended in 2-ethylhexanol-1. Addition of ethanol to the sols facilitated the formation of gel films, fabricated by a dipping technique, on glass or silver substrates. At 100 C, gels that were formed in the presence of ascorbic acid were perfectly amorphous, in contrast to the crystalline acetate gels. Conversion of the amorphous ascorbate gels to final products was easier than for the acetate gels. The quality of coatings prepared from ascorbate gels was superior to that of acetate gel coatings

367

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

Science.gov (United States)

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

368

Application of systems biology tools to understand the effect of acetic acid on ethanol production by Saccharomyces cerevisiae 424A(LNH-ST)  

OpenAIRE

A significant challenge facing the cellulosic ethanol industry is the availability of robust industrial microbes that are capable of mixed sugar fermentation with tolerance to inhibitors. One such inhibitor is acetic acid, a compound released from the cellulosic biomass during pretreatment. Engineering an organism for improved inhibitor tolerance requires a fundamental understanding of the effect of acetic acid at a cellular level. ^ This dissertation evaluated the effect of acetic acid on...

Casey, Elizabeth

2012-01-01

369

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

Science.gov (United States)

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

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

2012-10-01

370

Hydrogen production from steam reforming of acetic acid over Cu-Zn supported calcium aluminate.  

Science.gov (United States)

Hydrogen can be produced by catalytic steam reforming (CSR) of biomass-derived oil. Typically bio oil contains 12-14% acetic acid; therefore, this acid was chosen as model compound for reforming of biooil with the help of a Cu-Zn/Ca-Al catalyst for high yield of H(2) with low CH(4) and CO content. Calcium aluminate support was prepared by solid-solid reaction at 1350°C. X-ray diffraction indicates 12CaO·7Al(2)O(3) as major, CaA(l4)O(7) and Ca(5)A(l6)O(14) as minor phases. Cu and Zn were loaded onto the support by wet-impregnation at 10 and 1wt.%, respectively. The catalysts were characterized by Brunauer-Emmett-Teller (BET), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy TEM and the surface area for both support and Cu-Zn were 10.5 and 5.8m(2)/g, respectively. CSR was carried out in a tubular fixed bed reactor (I.D.=19mm) at temperatures between 600 and 800°C with 3-g loadings and (H(2)O/acetic acid) wt. ratio of 9:1. Significantly high (80%) yield of hydrogen was obtained over Cu-Zn/Ca-Al catalyst, as incorporation of Zn enhanced the H(2) yield by reducing deactivation of the catalyst. The coke formation on the support (Ca-12/Al-7) surface was negligible due to the presence of excess oxygen in the 12CaO·7Al(2)O(3) phase. PMID:22944490

Mohanty, Pravakar; Patel, Madhumita; Pant, Kamal K

2012-11-01

371

Changes in Growth, Auxin- and Ribonucleic Acid Metabolism in Wheat Coleoptile Sections Following Pulse Treatment with Indole-3-Acetic Acid  

DEFF Research Database (Denmark)

Growth reactions of wbeat coleoptile sections following a brief pretreament in indole-3-acetic acid (LAA) were studied. The growth versus concentration curves 24 hours after the treatment showed a minimum value surrounded by bigber values. The minimum was never at concentrations lower than 10-5M lAA but it could be found at higher concentrations after short pretreatment periods. The growth versus time curves reveated that the hormone treatment cansed the growth rate initially to increase but later on to decrease. The decrease was followed by a second increase for some treatments. Analysis of IAA content after the pretreatment showed that the attered growth patterns could be ascribed to declining auxin content with time, but not to thc actual concentration in the sections. The results indicate that the metabolic activation brought about by IAA leads to its own disappearance. Such a phenomenon was mirroretl in effects of IAA on hte net synthesis of ribonucleic acid.

Truelsen, T.A.; Galston, A.W.

1966-01-01

372

An investigation of liquid acetic acid and its mixtures with CCl4 and cyclohexane by the nuclear magnetic relaxation method  

International Nuclear Information System (INIS)

The systems CH3COOH-CCl4 and CH3COOH-C6D12 were studied by measuring the magnetic relaxation times T1 of the various protons in these mixtures. From these data, intermolecular relaxation rates arising from interactions among the protons of OH- and CH3-groups were determined. By means of the association parameter A association between various groups of acetic acid in mixtures with CCL4 and C6D12 has been investigated. Closest distances of approach between various protons of acetic acid and configurations of maximum probability are reported for the pure liquid and the mixtures. For pure acetic acid a comparison with X-ray and neutron scattering results is given. (orig.)

373

Protective Effect of Alpha-lipoic Acid Against Lead Acetate-Induced Oxidative Stress in the Bone Marrow of Rats  

Directory of Open Access Journals (Sweden)

Full Text Available The present study was designed to investigate the effects of alpha Lipoic Acid (LA against lead acetate induced changes in free radical scavenging enzymes and lipid hydroperoxides in bone marrow of rats. Rats were exposed to lead acetate in their drinking water (500 ppm for 14 days and alpha lipoic acid was given concurrently (25, 50 and 100 mg kg-1. Blood lead levels, lipid hydroperoxides, protein carbonyl contents and oxidative marker enzymes were estimated. Lead acetate in drinking water had elicited a significant (p-1 b.wt. LA. The potency of alpha lipoic acid on the reversal of lead induced changes in oxidative biomarkers in bone marrow confirms the importance of lead induced oxidative stress in bone and suggests a therapeutic approach.

Srikumar Chakravarthi

2011-01-01

374

Growth inhibitory effect of grape phenolics against wine spoilage yeasts and acetic acid bacteria.  

Science.gov (United States)

This paper investigates the in vitro antimicrobial potential of 15 grape phenolic compounds of various chemical classes (phenolic acids, stilbenes and flavonoids) using the broth microdilution method against yeasts and acetic acid bacteria frequently occurring in deteriorated wine. Pterostilbene (MICs=32-128 ?g/mL), resveratrol (MICs=256-512 ?g/mL) and luteolin (MICs=256-512 ?g/mL) are among six active compounds that possessed the strongest inhibitory effects against all microorganisms tested. In the case of phenolic acids, myricetin, p-coumaric and ferulic acids exhibited selective antimicrobial activity (MICs=256-512 ?g/mL), depending upon yeasts and bacteria tested. In comparison with potassium metabisulphite, all microorganisms tested were more susceptible to the phenolics. The results revealed the antibacterial and antiyeast effects against wine spoilage microorganisms of several highly potent phenolics naturally occurring in grapes. These findings also provide arguments for further investigation of stilbenes as prospective compounds reducing the need for the use of sulphites in winemaking. PMID:23334100

Pastorkova, E; Zakova, T; Landa, P; Novakova, J; Vadlejch, J; Kokoska, L

2013-02-15

375

Spectrophotometric determination of beryllium with sulfochlorophenol S in organo-aqueous acetic-acid media  

International Nuclear Information System (INIS)

The possibility has been shown of photometric determination of beryllium with sulphochlorophenol S using an acetic acid-propanol mixture (1:1), containing 0.5-1.5 vol% of water, as the reaction medium. Under such conditions, the reaction between beryllium and sulphochlorophenol S is sensitive and selective with respect to some easily hydrolized elements (Sn, Bi, Sb, Hg) as well as to Ga, In, Tl, Zn in the presence of HCl. The following excess amounts do not interfere with the determination of 0.45 ?g Be: Hg-1.2x104, Sb-6.2x103, In-2.5x103, Tl-2.0x103, Zn-1.4x103, Ga-1.2x103. The reaction between beryllium and sulphochlorophenol S is selective with respect to a number of complexing agents. Beryllium can be determined in the presence of 150000-200000 times its weight amounts of tartaric, citric and boric acids, 5000-sulphosalycilic acid, 6000-oxalic acid, 6000-dimethyl glyoxime, 150-8-hydroxyquinoline

376

Synthesis Of Some New Benzimidazole Acetic Acid Derivatives And Evaluation For Their Antimicrobial And Antitubercular Activities  

Directory of Open Access Journals (Sweden)

Full Text Available  Substituted benzimidazole  have received considerable attention during last few decades as they are endowed with variety of biological activities and have wide range of therapeutic properties. A literature survey indicates that benzimidazole derivatives possess different biological activities such as anti-microbial activity, anti-ulcer ,antiparasitic, antiprotozoal , antiviral and antitubercular.         Physical properties shown that, Benzimidazoles have high melting points, Benzimidazoles are usually soluble in polar solvents and sparingly soluble in non polar solvent,Benzimidazoles are weakly basic, being some what less basic than imidazole, Benzimidazoles are also sufficiently acidic to be generally soluble in aqueous alkali . The acidic properties of benzimidazoles, like those of imidazole, seem to be due to stabilization of the ion by resonance. The pKa value of benzimidazoles (pKa=5.30A new series of benzimidazoles acetic acid derivatives were synthesized by reacting 2(2-substituted phenyl ethenyl 1H benzimidazole with chloroacetic acid under reflux. The structures of these compounds were established by means of IR, 1H-NMR, 13C-NMR and elemental analysis. All compounds were evaluated for antibacterial, antifungal and antitubercular activities.       Most of the compounds have shown significant antibacterial, antifungal and antitubercular activity when compared with the standard drug Stryptomycin.

Sachin Kale

2013-05-01

377

Effects of Pfaffia glomerata (Spreng pedersen aqueous extract on healing acetic acid-induced ulcers  

Directory of Open Access Journals (Sweden)

Full Text Available The present study was carried out to evaluate the acute toxicity and the effect of the aqueous extract of the roots from Pfaffia glomerata (Spreng Pedersen (Amaranthaceae (AEP on the prevention of acetic acid-induced ulcer and on the healing process of previously induced ulcers. The acute toxicity was evaluated in Swiss mice after oral administration of a single dose and the chronic gastric ulcer was induced with local application of acetic acid. The results showed that the LD50 of the extract was 684.6 mg.kg-1 for the intraperitoneal administration and higher than 10 mg.kg-1by the oral route. The administration of the AEP did not prevent ulcers formation. However, the AEP increased of the healing process of previously induced ulcers. The results suggest that AEP chronically administered promote an increase of tissue healing, after the damage induced by acetic acid and the extract seemed to be destituted of toxic effects in the mice by the oral route.Pfaffia glomerata (Spreng Pedersen (Amaranthaceae, uma planta conhecida popularmente como "Ginseng Brasileiro" e "paratudo", é utilizada para tratar distúrbios gástricos e como cicatrizante. Em estudos anteriores, foi demonstrado que o extrato aquoso bruto da P. glomerata (AEP protegeu a mucosa gástrica contra úlceras induzidas por etanol e estresse e reduziu a secreção ácida gástrica basal e estimulada em ratos com ligadura de piloro. Além disso, a secreção gástrica de animais tratados com AEP apresentou níveis de nitrato e nitrito aumentados. O objetivo deste estudo foi avaliar se o AEP previne o desenvolvimento de úlceras induzidas por ácido acético e o efeito desse extrato no processo de cicatrização em úlceras previamente formadas. A administração do AEP em diferentes doses produziu efeitos tóxicos baixos e não preveniu a formação de úlceras, porém aumentou o processo de cicatrização em úlceras já existentes, como evidenciado no estudo histopatológico. Em conclusão, o AEP administrado cronicamente promove o aumento da cicatrização do tecido após a lesão induzida com o ácido acético.

Cristina Setim Freitas

2008-08-01

378

Effects of Pfaffia glomerata (Spreng) pedersen aqueous extract on healing acetic acid-induced ulcers  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Pfaffia glomerata (Spreng) Pedersen (Amaranthaceae), uma planta conhecida popularmente como "Ginseng Brasileiro" e "paratudo", é utilizada para tratar distúrbios gástricos e como cicatrizante. Em estudos anteriores, foi demonstrado que o extrato aquoso bruto da P. glomerata (AEP) protegeu a mucosa g [...] ástrica contra úlceras induzidas por etanol e estresse e reduziu a secreção ácida gástrica basal e estimulada em ratos com ligadura de piloro. Além disso, a secreção gástrica de animais tratados com AEP apresentou níveis de nitrato e nitrito aumentados. O objetivo deste estudo foi avaliar se o AEP previne o desenvolvimento de úlceras induzidas por ácido acético e o efeito desse extrato no processo de cicatrização em úlceras previamente formadas. A administração do AEP em diferentes doses produziu efeitos tóxicos baixos e não preveniu a formação de úlceras, porém aumentou o processo de cicatrização em úlceras já existentes, como evidenciado no estudo histopatológico. Em conclusão, o AEP administrado cronicamente promove o aumento da cicatrização do tecido após a lesão induzida com o ácido acético. Abstract in english The present study was carried out to evaluate the acute toxicity and the effect of the aqueous extract of the roots from Pfaffia glomerata (Spreng) Pedersen (Amaranthaceae) (AEP) on the prevention of acetic acid-induced ulcer and on the healing process of previously induced ulcers. The acute toxicit [...] y was evaluated in Swiss mice after oral administration of a single dose and the chronic gastric ulcer was induced with local application of acetic acid. The results showed that the LD50 of the extract was 684.6 mg.kg-1 for the intraperitoneal administration and higher than 10 mg.kg-1by the oral route. The administration of the AEP did not prevent ulcers formation. However, the AEP increased of the healing process of previously induced ulcers. The results suggest that AEP chronically administered promote an increase of tissue healing, after the damage induced by acetic acid and the extract seemed to be destituted of toxic effects in the mice by the oral route.

Cristina Setim, Freitas; Cristiane Hatsuko, Baggio; Samanta Luiza, Araújo; Maria Consuelo Andrade, Marques.

2008-08-01

379

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1988-01-01

380

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

International Nuclear Information System (INIS)

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

381

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

Science.gov (United States)

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

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

1988-01-01

382

Isolation of a Strain of Clostridium thermoaceticum Capable of Growth and Acetic Acid Production at pH 4.5  

OpenAIRE

Using a series of pH controlled batch fermentations operated in a fed-batch mode and adaptation and selection techniques where pH and acetic acid provided the selective pressures, we isolated a culture of Clostridium thermoaceticum that can grow and produce acetic acid at pH 4.5. At pH 4.5 the fastest mass doubling time was 36 h, and the highest acetic acid concentration reached was 4.5 g/liter. Generally, as the pH was decreased from 6.0 and the initial acetic acid concentration increased, t...

1982-01-01

383

Cloning and characterization of a locus encoding an indolepyruvate decarboxylase involved in indole-3-acetic acid synthesis in Erwinia herbicola.  

OpenAIRE

Erwinia herbicola 299R synthesizes indole-3-acetic acid (IAA) primarily by the indole-3-pyruvic acid pathway. A gene involved in the biosynthesis of IAA was cloned from strain 299R. This gene (ipdC) conferred the synthesis of indole-3-acetaldehyde and tryptophol upon Escherichia coli DH5 alpha in cultures supplemented with L-tryptophan. The deduced amino acid sequence of the gene product has high similarity to that of the indolepyruvate decarboxylase of Enterobacter cloacae. Regions within py...

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

1996-01-01

384

Acid-gas removal systems in coal gasification  

Energy Technology Data Exchange (ETDEWEB)

A large number of acid-gas removal systems exist or are under development for the removal of H/sub 2/S and CO/sub 2/ from process gas streams. A few systems have been applied to coal conversion processes; others will require extrapolation of presently-proved commercial operation. The feed to the acid-gas removal system for the generic coal-to-ammonia facility is not well-defined; particularly for minor and trace constituents. This is particularly true in the case of newer gasification processes that may have significant economic advantages in the overall process when evaluated on a total systems analysis approach. A number of species that could be present in the gas fed to the acid-gas removal system are discussed; the design of that subprocess should consider the fate of these species from both an environmental and an economic standpoint. In an overall evaluation, it appears that acid-gas removal systems can be successfully applied in coal conversion; no technical obstacle has yet been discovered to restrict their application.

Fleming, D.K.

1979-01-01

385

Production of acetic acid from ethanol solution by acetobactor acetigenum and effect of gamma-ray irradiation on the bacteria  

International Nuclear Information System (INIS)

A preliminary study on fermentation of acetic acid by S. cerevisiae and A. acetigenum was carried out to obtain information to develop the effective utilization technology of agricultural liquid wastes. Aqueous solutions of glucose and/or ethanol were used as a model of agricultural liquid waste. The effect of gamma-ray irradiation on A. acetigenum for enhancement of the fermentation was also examined. In this study, irradiated A. acetigenum had activity to produce acetic acid even after loss the activity to grow. (author)

386

Removal of acidic pharmaceuticals within a nitrifying recirculating biofilter.  

Science.gov (United States)

The fate of pharmaceutically active compounds (PhACs) in wastewater treatment systems is an area of increasing concern. Little research has been done to understand this issue in rural or decentralized communities. The objective of this research was to examine the ability of a bench scale nitrifying recirculating biofilter (RBF) to remove four acidic PhACs: gemfibrozil, naproxen, ibuprofen and diclofenac from secondary treated municipal wastewater at concentrations of 20 and 200?g/L. The average removals in this study were between 92 and 99% for ibuprofen, 89 and 99% for naproxen, 62 and 92% for gemfibrozil and 40 and 76% for diclofenac, which is consistent with literature. Ibuprofen and naproxen were largely removed through biological transformation; whereas gemfibrozil and diclofenac showed more variable removal, likely due to both biological transformation and sorption processes. PhAC removal in the RBFs was repeatable between trials, robust and responsive to system upsets, and the presence of PhACs as a single compound versus mixtures had no impact on PhAC removal efficiency. In summary, this study indicates that RBFs as a nitrifying stage of a multi-stage filtration process could be a viable technology for removal of some acidic pharmaceuticals in small onsite wastewater treatment facilities. PMID:24727009

Krkošek, W H; Payne, S J; Gagnon, G A

2014-05-30

387

Utilization of Vinegar for Isolation of Cellulose Producing Acetic Acid Bacteria  

Science.gov (United States)

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

388

(Liquid + liquid) equilibria of (water + butyric acid + cyclohexyl acetate) ternary system  

International Nuclear Information System (INIS)

(Liquid + liquid) equilibrium (LLE) data for the ternary system (water + butyric acid + cyclohexyl acetate) have been determined experimentally at T (298.15, 308.15 and 318.15) K. Complete phase diagrams were obtained by determining solubility and the tie-line data. Tie-line compositions were correlated by the Othmer-Tobias method. The UNIFAC method was used to predict the phase equilibrium in the system using the interaction parameters determined from experimental data between CH, CH2, CH3, COOH, CH3COO and H2O groups. It is found that UNIFAC group interaction parameters used for LLE could not provide a good prediction. Distribution coefficients and separation factors were evaluated for the immiscibility region

389

(Liquid + liquid) equilibria of (water + butyric acid + cyclohexyl acetate) ternary system  

Energy Technology Data Exchange (ETDEWEB)

(Liquid + liquid) equilibrium (LLE) data for the ternary system (water + butyric acid + cyclohexyl acetate) have been determined experimentally at T (298.15, 308.15 and 318.15) K. Complete phase diagrams were obtained by determining solubility and the tie-line data. Tie-line compositions were correlated by the Othmer-Tobias method. The UNIFAC method was used to predict the phase equilibrium in the system using the interaction parameters determined from experimental data between CH, CH{sub 2}, CH{sub 3}, COOH, CH{sub 3}COO and H{sub 2}O groups. It is found that UNIFAC group interaction parameters used for LLE could not provide a good prediction. Distribution coefficients and separation factors were evaluated for the immiscibility region.

Ismail Kirbaslar, S. [Chemical Engineering Department, Engineering Faculty, Istanbul University, Avcilar-Campus, 34320 Avcilar, Istanbul (Turkey)]. E-mail: krbaslar@istanbul.edu.tr; Bilgin, Mehmet [Chemical Engineering Department, Engineering Faculty, Istanbul University, Avcilar-Campus, 34320 Avcilar, Istanbul (Turkey); Batr, Deniz [Chemical Engineering Department, Engineering Faculty, Istanbul University, Avcilar-Campus, 34320 Avcilar, Istanbul (Turkey)

2005-02-01

390

Growth inhibitory indole acetic acid polyacetylenic ester from Japanese ivy (Hedera rhombea Bean).  

Science.gov (United States)

Polyacetylenes 1 and 2 were isolated from extracts of Japanese ivy (Hedera rhombea Bean) flower buds, with their chemical structures established on the basis of extensive 1D and 2D NMR and MS analyses. The absolute configurations of compounds 1 and 2 were determined by both chemical means, and by using the modified Mosher's method. Compound 1 is the first polyacetylene having an ester linkage between falcarindiol (3) and indole-3-acetic acid (IAA) moieties and 2 also had an unique substructure containing a conjugated diene adjacent to a hydroxy group. Polyacetylenes 1, 2, and 3 were also subjected to assessment of growth inhibition against the shoot and root growth of the monocotyledon plants, rice and perennial ryegrass, as well as the dicotyledons, cockscomb, lettuce, cress, and fenugreek. The most bioactive compound appeared to be compound 1, while 2 showed no activity. Compound 1 selectively showed growth inhibitory activity against dicotyledons. PMID:17532018

Yamazoe, Sayumi; Hasegawa, Koji; Shigemori, Hideyuki

2007-06-01

391

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

Science.gov (United States)

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

392

A comparative study on the chitosan membranes prepared from glycine hydrochloride and acetic acid.  

Science.gov (United States)

In this study, glycine hydrochloride (Gly·HCl) is confirmed to be a promising solvent for dissolving native chitosan and preparing regenerated chitosan membrane. As compared with the chitosan membrane prepared from traditional acetic acid, the membrane prepared from Gly·HCl by dry technique shows excellent tensile strength and initial modulus, i.e. 103.8MPa and 3.2GPa, respectively, which is superior to any chitosan membrane and most chitosan blend membranes reported in literatures. Besides, scanning electron microscopy (SEM), wide-angle X-ray diffraction (WAXD) and Fourier transform infrared spectroscopy (FT-IR) were used to visualize the difference between the two kind of regenerated chitosan membranes. The SEM results show that the membrane prepared from Gly·HCl by dry technique presents a novel structure, which ensures its high tenacity. Furthermore, the chitosan microporous membranes were also prepared using PEG as porogen. PMID:23121935

Ma, Bomou; Li, Xiang; Qin, Aiwen; He, Chunju

2013-01-16

393

2-[(1R*,4R*-1,4-Dihydroxycyclohexyl]acetic acid  

Directory of Open Access Journals (Sweden)

Full Text Available The title compound, C8H14O4, is an isolation product of the aerial parts of Senecio desfontanei. The acetic acid group is oriented at a dihedral angle of 48.03?(9° with respect to the basal plane of the cyclohexane-1,4-diol chair. An intramolecular O—H...O hydrogen bond generates an S(6 ring with an envelope conformation. In the crystal, molecules are linked by O—H...O hydrogen bonds, resulting in R33(20 ring motifs and C(2 O—H...O—H...O—H... chains. Overall, a three-dimensional polymeric network arises. A C—H...O contact is also present.

Mohammad Arfan

2011-04-01

394

Utilization of Vinegar for Isolation of Cellulose Producing Acetic Acid Bacteria  

International Nuclear Information System (INIS)

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.

395

Exponential decay activities of radiocesium In mushrooms by the help of acetic acid  

International Nuclear Information System (INIS)

Gross activity of radiocesium in food from environmental ecosystems is decreasing slower than it was supposed and therefore it is subject for public repeatedly. Belong there mushrooms, game and wood fruits. Interest in this problems is and substantial improvement tighten up admissible levels of radioactive contamination of food (137Cs and 134Cs) for irradiation after Chernobyl in public notice for Czech republic is 600 Bq/kg. It is in unity with European Union. We can search possibilities to decrease content of radiocesium in food. Mainly mushrooms cumulate considerable quantity of radiocesium. Were examined samples Boletus badius of three other condition. Samples come from two other localities. Activity of radiocesium was detected by gamma-spectrometry (f.Canberra). For decrease content of radiocesium was using elution in 2% solution of acetate acid. Curve of graphic analysis have exponential nature. (authors)

396

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

Science.gov (United States)

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

397

Ultrastructure of sheep primordial follicles cultured in the presence of indol acetic acid, EGF, and FSH  

DEFF Research Database (Denmark)

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

Andrade, Evelyn Rabelo; Hyttel, Poul

2011-01-01

398

Ruthenium recovery from acetic acid waste water through sorption with bacterial biosorbent fibers.  

Science.gov (United States)

A fibrous bacterial biosorbent was developed to bind precious metal-organic complexes in batch and column processes. Polyethylenimine (PEI)-modified bacterial biosorbent fiber (PBBF) was prepared by spinning Corynebacterium glutamicum biomass-chitosan blends, coating them with PEI and cross-linking with glutaraldehyde. When an acetic acid waste solution containing 1822.9mg/L Ru was used as a model waste solution, Ru uptake by the PBBF was 16.5 times higher than that of the commercial ion exchange resin, Lewatit MonoPlus M600. The maximum amounts of Ru uptake were 110.5, 16.0 and 6.7mg/g for PBBF, raw biomass, and Lewatit MonoPlus M600, respectively. In a flow-through packed bed, PBBF exhibited the breakthrough time of 42.32h. Therefore, PBBF can be considered as an alternative sorbent for recovery of anionic metal-organic complexes from waste solutions. PMID:23196218

Kwak, In Seob; Won, Sung Wook; Chung, Yong Sik; Yun, Yeoung-Sang

2013-01-01

399

Role of Visual Inspection of Cervix with Acetic Acid (VIA in Detecting Precancerous Lesions of Cervix  

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Full Text Available Background: Carcinoma of cervix is the most common malignancy in female and a major public health problem worldwide. It is the leading cause of death from cancer among women in low resource settings. In Bangladesh, mortality rate is high as most of the cases with cervical cancer are diagnosed in advanced stage. World Health Organization considers cervical cancer as a preventable disease as it can be identified in preinvasive stage. Considerable efforts have been given in detection and treatment of the condition all over the world. A number of cervical cancer screening tests are available. Among them, visual inspection of cervix with acetic acid is rational and can be competently performed by physicians with proper training. Objective: To find out the feasibility of the visual inspection of cervix with acetic acid for the detection of the precancerous lesions of the cervix in our country. Materials and Methods: This cross sectional, analytical study was carried out among the patients attending the outpatient department of Bangabandhu Sheikh Mujib Medical University (BSMMU who were VIA positive and sent for colposcopy in the colposcopy clinic in the department of Obstetrics and Gynecology in BSMMU from June to December 2004. Two hundred samples were considered for this study. Results: Out of 200 cases, colposcopically 85% had CIN and invasive lesions, 4% had inflammatory lesions while 11% had normal findings. Colposcopy directed punch biopsy revealed positive lesions in 81%, 4% had inflammatory lesions while 15% had normal findings. Conclusion: The study concluded that VIA and colposcopy are the important methods in the evaluation of cervical premalignancy. VIA may be an important tool for screening of cervical cancer in low resource settings as it is simple, easy to perform and cost-effective. After screening, VIA positive cases must be referred for colposcopic evaluation. We can screen cervical cancer by VIA all over the country and thus reduce morbidity and mortality rate.

Kamrun Nessa

2014-01-01

400

Synthesis of silica xerogels with high surface area using acetic acid as catalyst  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Nesse trabalho foi estudada a influência do ácido acético na estrutura de poros e na área superficial de sílicas preparadas pelo método sol-gel. Condições experimentais de síntese, tais como temperatura de policondensação e solventes, também foram estudadas. Isotermas de adsorção de N2 das amostras [...] foram classificadas como do tipo 1, típicas de materiais microporosos, o que explica os altos valores de área superficial obtidos. A adição simultânea dos ácidos acético e clorídrico como catalisadores e de acetona como solvente, bem como o emprego de uma temperatura de policondensação de 20 ºC, possibilitaram a preparação de sílicas amorfas com valores de área superficial de até 850 m² g-1. O alto valor de área superficial dessas amostras pode ser explicado principalmente pela microporosidade e também pelo tamanho nanométrico das partículas. Abstract in english The influence of acetic acid on the pore structure and surface area of silica prepared by the sol-gel method was investigated. Experimental conditions of synthesis, such as gelation temperature and solvents, were also studied. N2 adsorption isotherms of the samples were type 1, typical of microporou [...] s materials, explaining the high surface area values (BET) observed. The simultaneous addition of acetic and hydrochloric acids as catalysts and of acetone as solvent, together with the use of a gelation temperature of 20 ºC, made it possible to prepare amorphous silica materials with surface area values up to 850 m² g-1. The high surface area value of these samples could be explained by the microporosity and the nanometric size of the particles.

Leliz T., Arenas; Carolina W., Simm; Yoshitaka, Gushikem; Silvio L. P., Dias; Celso C., Moro; Tania M. H., Costa; Edilson V., Benvenutti.

401

Highly dispersed supported ruthenium oxide as an aerobic catalyst for acetic acid synthesis  

DEFF Research Database (Denmark)

The increasing need for shifting to renewable feedstocks in the chemical industry has driven research toward using green aerobic, selective oxidation reactions to produce bulk chemicals. Here, we report the use of a ruthenium mixed oxide/hydroxide (RuOx) on different support materials for the selective aerobic oxidation of ethanol to acetic acid. The RuOx was deposited onto different oxide supports using a new gas-phase reaction, which in all cases resulted in homogeneous nanoparticulate films. The RuOx particle size ranged from 0.3 to 1.5nm. The catalytic activity was evaluated on TiO2, Mg6Al2(CO3)(OH)16·4(H2O), MgAl2O4, Na2Ti6O13 nanotubes, ZnO, ?-Al2O3, WO3, CeO2, and Ce0.5Zr0.5O2 supports. The CeO2 supported RuOx had the highest activity, and selectivity toward acetic acid, of all the materials when normalized with respect to Ru-loading. This high activity was independent of the surface area of the support and the loading of RuOx under the tested conditions. This was attributed to the highly uniform size of the RuOx deposits, demonstrating that the deposition is suitable for producing small nanoparticles at high loadings. To elucidate the reason for the promotional effect of CeO2, Ce0.5Zr0.5O2 was investigated as a high oxygen storage capacity support, however, this did not result in higher catalytic activity. The high activity of CeO2 supports compared to the low activity ZnO appear correlated to the presence of high valence Ru(VI) species analogous to that observed in literature.

Laursen, Anders Bo; Gorbanev, Yury

2012-01-01

402

Seasonality Influence in the Distribution of Formic and Acetic Acids in the Urban Atmosphere of São Paulo City, Brazil  

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Full Text Available Ambient levels and diurnal profiles of formic and acetic acids were measured in the atmosphere of São Paulo City in winter and spring 1996. A comparison between two different urban sites was done. Results demonstrate that carboxylic acid levels were affected by seasonality in the site with high vehicular emission density, while no seasonal influence was observed for the other site studied. Ranges of mixing ratios from 0.64 to 11.8 ppbv for formic acid and 0.51 to 10.7 ppbv for acetic acid were recorded. The results concerning the carboxylic acid concentrations were discussed with respect to direct emission and in situ photochemical production.

Souza Silvia R.

2001-01-01

403

Variability of Acid-Base Status in Acetate-Free Biofiltration 84% versus Bicarbonate Dialysis  

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Full Text Available 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 paCO2 level was not significant. A comparison of these parameters between the two techniques showed statistically significant difference in pH, HCO3 - and paCO2 levels, but not for paO2 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.

Harzallah Kais

2008-01-01

404

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

Science.gov (United States)

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

405

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

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Full Text Available 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.

Ohgi Takahashi

2015-01-01

406

Primary and secondary kinetic isotope effects in the acid-catalyzed dehydration of 1,1'-diadamantylmethylcarbinol in aqueous acetic acid  

International Nuclear Information System (INIS)

The sulfuric acid catalyzed dehydration of 1,1'-diadamantyl-methylcarbinol in anhydrous acetic acid proceeds exclusively to 1,1'-bis(1-adamantyl)ethylene. The secondary deuterium isotope effect of 1.32 found for this reaction shows that carbonium ion formation from the protonated alcohol is rate determining. In the presence of water, however, capture of the carbonium ion competes with deprotonation, introducing a primary isotope effect. Consequently, the overall KIE rises, reaching 3.18 for 80% aqueous acetic acid. Analysis of the KIE for 80 to 100% aqueous acetic acid is consistent with a simple classical mechanism involving reversible formation of the intermediate carbonium ion. The primary isotope effect upon deprotonation is at the most 2.98, indicative of an asymmetric transition state close to the carbonium ion

407

Oxidation of fatty acid may be enhanced by a combination of pomegranate fruit phytochemicals and acetic acid in HepG2 cells  

OpenAIRE

We investigated whether the combination of phytochemicals and acetic acid in the form of fruit vinegar provides an additive effect on changes of mRNA levels related to fatty acid oxidation in human hepatocyte (HepG2). Among the seven fruit vinegars (Rubuscoreanus, Opuntia, blueberry, cherry, red ginseng, mulberry, and pomegranate) studied, treatment of HepG2 with pomegranate vinegar (PV) at concentrations containing 1 mM acetic acid showed the highest in vitro potentiating effect on the mRNA ...

Kim, Ji Yeon; Ok, Elly; Kim, You Jin; Choi, Kyoung-sook; Kwon, Oran

2013-01-01

408

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  

Science.gov (United States)

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 ...

409

Degree of sulfate-reducing activities on COD removal in various reactor configurations in anaerobic glucose and acetate-fed reactors  

Energy Technology Data Exchange (ETDEWEB)

Sulfate-reduction data from various anaerobic reactor configurations, e. g., upflow anaerobic sludge blanket reactor (UASBR), completely stirred tank reactor (CSTR), and batch reactor (BR) with synthetic wastewaters, having glucose and acetate as the substrates and different levels of sulfate, were evaluated to determine the level of sulfate-reducing activity by sulfate-reducing bacteria coupled to organic matter removal. Anaerobic reactors were observed for the degree of competition between sulfate-reducing sulfidogens and methane producing bacteria during the degradation of glucose and acetate. Low sulfate-reducing activity was obtained with a maximum of 20% of organic matter degradation with glucose-fed upflow anaerobic sludge bed reactors (UASBRs), while a minimum of 2% was observed with acetate-fed batch reactors. The highest sulfate removal performance (72-89%) was obtained from glucose fed-UASB reactors, with the best results observed with increasing COD/SO{sub 4} ratios. UASB reactors produced the highest level of sulfidogenic activity, with the highest sulfate removal and without a performance loss. Hence, this was shown to be the optimum reactor configuration. Dissolved sulfide produced as a result of sulfate reduction reached 325 mg/L and 390 mg/L in CST and UASB reactors, respectively, and these levels were tolerated. The sulfate removal rate was higher at lower COD/SO{sub 4} ratios, but the degree of sulfate removal improved with increasing COD/SO{sub 4} ratios. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

Erdirencelebi, Dilek [Environmental Engineering Department, Selcuk University (Turkey); Ozturk, Izzet; Ubay Cokgor, Emine [Environmental Engineering Department, Istanbul Technical University, Istanbul (Turkey); Ubay Tonuk, Gulseren [City and Regional Planing, Gazi University, Ankara (Turkey)

2007-04-15

410

Removal of coagulant aluminum from water treatment residuals by acid.  

Science.gov (United States)

Sediment sludge during coagulation and sedimentation in drinking water treatment is called "water treatment residuals (WTR)". Polyaluminum chloride (PAC) is mainly used as a coagulant in Japan. The recycling of WTR has been desired; one method for its reuse is as plowed soil. However, WTR reuse in this way is inhibited by the aluminum from the added PAC, because of its high adsorption capacity for phosphate and other fertilizer components. The removal of such aluminum from WTR would therefore be advantageous for its reuse as plowed soil; this research clarified the effect of acid washing on aluminum removal from WTR and on plant growth in the treated soil. The percentage of aluminum removal from raw WTR by sulphuric acid solution was around 90% at pH 3, the percentage decreasing to 40% in the case of a sun-dried sample. The maximum phosphate adsorption capacity was decreased and the available phosphorus was increased by acid washing, with 90% of aluminum removal. The enhancement of Japanese mustard spinach growth and the increased in plant uptake of phosphates following acid washing were observed. PMID:24835954

Okuda, Tetsuji; Nishijima, Wataru; Sugimoto, Mayo; Saka, Naoyuki; Nakai, Satoshi; Tanabe, Kazuyasu; Ito, Junki; Takenaka, Kenji; Okada, Mitsumasa

2014-09-01

411

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

Science.gov (United States)

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

412

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

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Full Text Available Acetic acid is one of the most abundant organic acids in the ambient atmosphere, with maximum mixing ratios reaching into the tens of parts per billion by volume (ppbv range. The identities and associated magnitudes of the major sources and sinks for acetic acid are poorly characterized, due in part to the limitations of available measurement techniques. This paper demonstrates that, when properly calibrated, proton-transfer-reaction mass spectrometry (PTR-MS can be a valuable technique for fast response, accurate quantification of acetic acid in ambient air. Three different PTR-MS configurations were calibrated at low ppbv mixing ratios using permeation tubes, which yielded calibration factors between 7.0 and 10.9 normalized counts per second per ppbv (ncps ppbv?1 at a drift tube field strength of 132 Townsend (Td. Detection limits ranged from 0.06 to 0.32 ppbv with dwell times of 5 s. These calibration factors showed negligible humidity dependence. Acetic acid was measured with PTR-MS on Appledore B Island, ME, during the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT campaign and validated based on acetic acid measured in parallel using tandem mist chambers coupled with ion chromatography (MC/IC. Mixing ratios ranged from a minimum of 0.075 ± 0.004 ppbv to 3.555 ± 0.171 ppbv, with a median mixing ratio of 0.530 ± 0.025 ppbv. An orthogonal least squares linear regression of paired data yielded a slope of 1.14 ± 0.06 (2?, an intercept of 0.049 ± 0.020 (2? ppbv, and an R2 of 0.78.

K. B. Haase

2012-11-01

413

Removal of iodine species with concentrated nitric acid, (3)  

International Nuclear Information System (INIS)

In the reprocessing of FBR spent fuel, the removal of radioactive iodine by the Iodox process (the absorption by highly concentrated nitric acid) has been studied, but also the steps to concentrate and solidify the iodine for storage must be examined. The behavior of iodine in these steps must be made clear for the evaluation of iodine removal. The results of the fundamental experiments in this connection using 131I as a tracer are described. The effects of parameters on iodine removal, i.e. nitric acid concentration and iodine concentration, were examined, and a method to minimize the quantity of released iodine was studied. (1) Higher concentration of nitric acid is better for iodine concentration. (2) It is desirable that the quantity of NOx in nitric acid is as low as possible. (3) It is not necessary to consider the release of iodine during solidification at the temperature lower than 190 deg C. Since (1) and (2) above contradict, some new special treatment of nitric acid has to be developed. When the solution is solidified at temperature higher than 190 deg C, the thermal decomposition of I2O5 must be considered. (J.P.N.)

414

Effect of Post-Harvest Acetic Acid and Plant Essential Oils on Shelf-Life Extension of Tomato Fruits  

International Nuclear Information System (INIS)

In vitro effect of different concentrations of acetic acid on linear growth of Alternaria alternate was studied. The causal agent of tomato black rots in contact and fumigation showed that acetic acid inhibit A. alternata growth at 2 ml/L and on 0.8 ml/L in contact and fumigation, respectively. In vivo effect showed that acetic acid at 6 ml/L reduced severity of infection of tomato fruits from 53.5% to 4.8% after 3 weeks of storage in dipping method but at the strongest fumigation methods, acetic acid inhibit tomato fruits rot at 0.4 ml/L after 3 weeks of storage. In vitro effect of camphore (Eucalyptus globulus Labill), caraway (Carium carvum L.) and peppermint oil (Mentha piperita L.) at different concentrations were tested against Alternaria alternata, since caraway oil is the strongest oil effect on fungal growth followed by peppermint and camphore respectively. Similarly in in vivo caraway oil inhibit tomato fruits rots at 6 ml/L followed by peppermint that inhibited tomato rots at 8 ml / L but camphore reduced tomato rots at 8 ml/L from 40% to 8.1%. Accepted April 2013

415

5-MERCAPTOTETRAZOLE-1-ACETIC Acid as a Novel Capping Ligand for Stabilization of Metal Nanoparticles in Water  

Science.gov (United States)

The novel stabilizing ligand, 5-mercaptotetrazole-1-acetic acid, has been applied for synthesis of silver and palladium nanoparticles in aqueous media. The morphology of the synthesized particles and some properties were determined by TEM, FTIR and UV-visible spectroscopy, thermogravimetric analysis and quantum-chemical calculations.

Nichick, M. N.; Voitekhovich, S. V.; Matulis, V. E.; Komsa, D. N.; Lesnikovich, A. I.; Ivashkevich, O. A.

2013-05-01

416

7-Amino-4-methyl-6-sulfocoumarin-3-acetic acid: a novel blue fluorescent dye for protein labeling.  

Science.gov (United States)

7-Amino-4-methyl-6-sulfocoumarin-3-acetic acid (AMCA-S, also called Alexa 350) 2 was synthesized as a new water-soluble blue fluorescent dye for protein labeling. Compared with its nonsulfonated counterpart (AMCA) 1 the new dye gave significantly higher fluorescence quantum yields on proteins. PMID:10465551

Leung, W Y; Trobridge, P A; Haugland, R P; Haugland, R P; Mao, F

1999-08-01

417

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

International Nuclear Information System (INIS)

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.

418

Isolasi Dan Uji Kemampuan Bakteri Endofit Penghasil Hormon Iaa (Indole Acetic Acid) Dari Akar Tanaman Padi (Oryza sativa L.)  

OpenAIRE

Penelitian Isolasi dan Uji Kemampuan Bakteri Endofit Penghasil IAA (Indole Acetic Acid) dari Akar Tanaman Padi (Oryza sativa L.) dilakukan di Laboratorium Mikrobiologi, Fakultas Matematika dan Ilmu Pengetahuan Alam dan Laboratorium Kimia Kuantitatif, Fakultas Farmasi, Universitas Sumatera Utara. Penelitian ini bertujuan untuk mendapatkan bakteri endofit penghasil hormon IAA dari akar padi dan untuk mengetahui kemampuannya dalam perkecambahan padi. Isolat telah dikarakterisasi morfologi, bioki...

Siregar, Mustika Wildasari

2010-01-01

419